WO2015014603A2 - Benefit delivery particle - Google Patents

Benefit delivery particle Download PDF

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Publication number
WO2015014603A2
WO2015014603A2 PCT/EP2014/065101 EP2014065101W WO2015014603A2 WO 2015014603 A2 WO2015014603 A2 WO 2015014603A2 EP 2014065101 W EP2014065101 W EP 2014065101W WO 2015014603 A2 WO2015014603 A2 WO 2015014603A2
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WO
WIPO (PCT)
Prior art keywords
chain
particle
meth
agents
composition
Prior art date
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PCT/EP2014/065101
Other languages
French (fr)
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WO2015014603A3 (en
Inventor
Sarah Jayne Clare
Martin Peter Cropper
Craig Warren Jones
Hailey Kelso
Adam John Limer
James Merrington
Original Assignee
Unilever Plc
Unilever N.V.
Conopco, Inc., D/B/A Unilever
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Application filed by Unilever Plc, Unilever N.V., Conopco, Inc., D/B/A Unilever filed Critical Unilever Plc
Publication of WO2015014603A2 publication Critical patent/WO2015014603A2/en
Publication of WO2015014603A3 publication Critical patent/WO2015014603A3/en

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61QSPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
    • A61Q15/00Anti-perspirants or body deodorants
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00Cosmetics or similar toiletry preparations
    • A61K8/02Cosmetics or similar toiletry preparations characterised by special physical form
    • A61K8/0241Containing particulates characterized by their shape and/or structure
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00Cosmetics or similar toiletry preparations
    • A61K8/18Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/72Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
    • A61K8/81Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
    • A61K8/8141Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
    • A61K8/8152Homopolymers or copolymers of esters, e.g. (meth)acrylic acid esters; Compositions of derivatives of such polymers
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K2800/00Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
    • A61K2800/40Chemical, physico-chemical or functional or structural properties of particular ingredients
    • A61K2800/56Compounds, absorbed onto or entrapped into a solid carrier, e.g. encapsulated perfumes, inclusion compounds, sustained release forms
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K2800/00Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
    • A61K2800/40Chemical, physico-chemical or functional or structural properties of particular ingredients
    • A61K2800/60Particulates further characterized by their structure or composition
    • A61K2800/61Surface treated
    • A61K2800/62Coated
    • A61K2800/624Coated by macromolecular compounds
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K2800/00Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
    • A61K2800/40Chemical, physico-chemical or functional or structural properties of particular ingredients
    • A61K2800/60Particulates further characterized by their structure or composition
    • A61K2800/65Characterized by the composition of the particulate/core
    • A61K2800/654The particulate/core comprising macromolecular material

Definitions

  • the present invention is concerned with the delivery of particles, comprising a benefit agent, to skin, from a composition comprising said particles. Processes for the manufacture of said compositions and a method of treating skin are also described. The particles have application in antiperspirant compositions.
  • These particles may comprise polymers and many different types of
  • a chain-growth polymer is a polymer which is formed by a reaction in which monomers bond together via
  • Chain-growth polymers grow in a single direction from one end of the chain only and an initiator is typically used. In chain-growth polymerisation it is commonplace that once a growth at a chain end is terminated the end becomes unreactive.
  • chain-growth polymerisation is the free-radical polymerisation reaction, for example the well-known polymerization of styrene (vinyl benzene) in the presence of benzoyl peroxide (as radical initiator) to produce polystyrene.
  • styrene vinyl benzene
  • benzoyl peroxide as radical initiator
  • aluminum chloride may be used to initiate the polymerisation of isobutylene to form synthetic rubber.
  • Other examples include the polymerization reactions of acrylates or methacryates.
  • WO 2012/044929 and WO 2012/006402 disclose personal care, home care, or health care compositions having two visually distinct phases, where one comprises acrylic-based mixed linear and crosslinked core- shell polymers.
  • the compositions may contain adjuncts including antiperspirant or deodorant actives.
  • WO 2012/007438 discloses a particle less than 50 ⁇ comprising a shell formed by step-growth polymerization and a core formed by chain-growth polymerization which does not involve an isocyanate. An optional benefit agent and deposition aid may be included.
  • the particle can be used in a variety of product formats. US 2003/0053976, US 2003/0044440 and US 2003/0039671 (all L'Oreal,
  • JP 2000/143483 discloses a cosmetic composition that contains a water-insoluble core-shell polymer particle and a cosmetic component.
  • WO 2005/107684 and WO 2005/107683 relate to adhesive film-forming particles that may be produced by chain-growth (free-radical) polymerization. The particles are held in a fatty phase.
  • improved particles comprise a shell and a core, each of which comprise a chain-growth polymer (for example a
  • the shell and the core may be formed by radical
  • the present invention provides a composition comprising a composition comprising: a) a particle, wherein the particle comprises, i) a core comprising a solid polymer formed by chain-growth
  • the chain-growth polymerisation reaction is a radical polymerisation reaction, preferably of at least one ethylenically unsaturated monomer, and wherein the ethylenically unsaturated, monomer is selected from C-i-C 2 o linear or branched, alkyl acrylates and methacrylates, and wherein the particle has an average diameter of less than 1 micron, and wherein the particle further comprises a shell comprising a polymer formed by chain growth polymerisation of non-crossl inked monomers.
  • a further aspect of the invention provides a process for the manufacture of the composition according to the invention wherein the particles and the benefit agent are added separately to the formulation.
  • a further aspect of the present invention provides a method of treatment of skin, which includes the step of treating the substrate with a composition according to the present invention.
  • the particle comprises i) a core comprising a solid polymer formed by chain- growth polymerisation, and a skin benefit agent, which is liquid at room
  • a shell comprising a polymer formed by chain growth polymerisation of non-crosslinked monomers.
  • solid solid at ambient temperature, preferably from 20 to 50 °C, most preferably from 20 to 40 °C.
  • the core provides a sink for the benefit agent and the "shell” protects the benefit agent and regulates the flow of benefit agent into and out of the core.
  • the particle has a volume average diameter of less than 1 micron, preferably from 50 to 500 nm, more preferably an average diameter of from 100 to 400 nm, most preferably from 200 to 300 nm.
  • One benefit of small particles is that they are less visible in products.
  • the diameter of the particles may be measured by dynamic light scattering (DLS), such as described in “Introduction to Colloids and Surface Chemistry", by Duncan J Shaw, fourth edition, published 1992 by Butterworth-Heinemann (page 61 ).
  • DLS dynamic light scattering
  • the particle comprises a hydrophobic benefit agent, preferably a fragrance.
  • hydrophobic preferably means a material having a ClogP above 3.
  • ClogP means the logarithm to base 10 of the octanol/water partition coefficient (P).
  • the octanol/water partition coefficient of a PRM is the ratio between its equilibrium concentrations in octanol and water.
  • ClogP is also a measure of the hydrophobicity of a material-the higher the ClogP value, the more hydrophobic the material. Suitable methods of measuring ClogP will be known to one skilled in the art.
  • the core and the shell are formed by chain-growth polymerisation.
  • the core materials enables compatibility between the core and the benefit agent.
  • solubility parameters of the benefit agent and the chain-growth polymer comprising the core may be matched to achieve improved absorption and/or delivery.
  • the chain-growth polymerisation reaction used to form the core and shell is a radical polymerisation reaction.
  • the monomer capable of chain-growth polymerisation is preferably ethylenically unsaturated, more preferably vinyllic.
  • a ring-opening mechanism may be used.
  • the monomer is selected from acrylate or methacryate. At least one ethylenically unsaturated monomer is used, preferably from 1 to 5, more preferably from 1 to 3, most preferably 1 or 2 monomers.
  • Especially preferred "core" monomers for chain growth polymerisation are C1-C20 linear or branched, alkyl acrylates and methacrylates, preferably C 2 -C 2 o linear or branched, alkyl acrylates and methacrylates.
  • Preferred "shell" monomers for chain growth polymerisation are those that form a glassy polymer at 20 °C, preferably Ci to C 2 o alkyl acrylates and methacrylates, most preferably Ci or C 2 alkyl acrylates and methacrylates.
  • Free-radical polymerisation (FRP) is a suitable method of chain-growth
  • FRP FRP a mono-functional monomer is polymerised in the presence of free-radical initiator and, optionally, a chain transfer agent. Chain transfer agents can act to reduce the average molecular weight of the final polymer.
  • the free-radical initiator can be any molecule known to initiate free-radical polymerisation such as azo-containing molecules, persulfates, redox initiators, peroxides, benzyl ketones. These initiators may be activated via thermal, photolytic or chemical means. In the method of the present invention, thermal activation is preferred.
  • suitable initiators include but are not limited to 2,2'- azobisisobutyronitrile (AIBN), azobis(4-cyanovaleric acid), , benzoyl peroxide, cumylperoxide, 1 -hydroxy-cyclohexyl phenyl ketone, hydrogen peroxide/ascorbic acid. So-called 'iniferters' such as benzyl-N,N-diethyldithio-carbamate can also be used.
  • the residue of the initiator in a free-radical polymerisation comprises 0 to 5% w/w, preferably 0.01 to 5% w/w and especially 0.01 to 3% w/w, of the resulting copolymer based on the total weight of the monomers.
  • the chain transfer agent is preferably a thiol-containing molecule and can be either mono-functional or multi-functional.
  • the agent may be hydrophilic, hydrophobic, amphiphilic, anionic, cationic, neutral or zwitterionic.
  • the molecule can also be an oligomer containing a thiol moiety.
  • Suitable thiols include but are not limited to C 2 -Ci 8 alkyl thiols such as dodecane thiol, thioglycolic acid, thioglycerol, cysteine and cysteamine.
  • Thiol-containing oligomers may also be used such as oligo(cysteine) or an oligomer which has been post-functionalised to give a thiol group(s), such as oligoethylene glycolyl (di)thio glycollate.
  • Xanthates, dithioesters, and dithiocarbonates may also be used, such as cumyl phenyldithioacetate.
  • Chain transfer agents may be any species known to limit the molecular weight in a free-radical addition polymerisation.
  • the chain-transfer agent may also be a hindered alcohol, halocarbon, alkyl halide or a transition metal salt or complex, or similar free-radical stabiliser.
  • Catalytic chain transfer agents such as those based on transition metal complexes such as cobalt bis(borondi- fluorodimethyl-glyoximate) may also be used.
  • More than one chain transfer agent may be used in combination.
  • the residue of the chain transfer agent may comprise 0 to 20 mole%, preferably 0 to 10 mole% and especially 0 to 3 mole%, of the copolymer (based on the number of moles of mono-functional monomer).
  • a chain transfer agent is not required.
  • Monomers for the chain-growth polymerisation may comprise any carbon-carbon unsaturated (or cyclic) compound which can form an addition polymer, e.g. vinyl and allyl compounds.
  • the mono-functional monomer may be hydrophilic, hydrophobic, amphiphilic, anionic, cationic, neutral or zwitterionic in nature.
  • the mono-functional monomer may be selected from but not limited to monomers such as vinyl acids, vinyl acid esters, vinyl aryl compounds, vinyl acid anhydrides, vinyl amides, vinyl ethers, vinyl amines, vinyl aryl amines, vinyl nitriles, vinyl ketones, and derivatives of the aforementioned compounds as well as
  • Suitable mono-functional monomers for the chain-growth polymer include hydroxyl-containing monomers and monomers which can be post-reacted to form hydroxyl groups, acid-containing or acid functional monomers, zwitterionic monomers and quaternised amino monomers.
  • Oligomeric or oligo-functionalised monomers may also be used, especially oligomeric (meth)acrylic acid esters such as mono(alk/aryl) (meth)acrylic acid esters of oligo[alkyleneglycol] or oligo[dimethylsiloxane] or any other mono-vinyl or allyl adduct of a low molecular weight oligomer. Mixtures of more than one monomer may also be used.
  • Preferred vinyl acids and derivatives thereof include (meth)acrylic acid and acid halides thereof such as (meth)acryloyl chloride.
  • Preferred vinyl acid esters and derivatives thereof include C1 -20
  • alkyl(meth)acrylates linear & branched
  • alkyl(meth)acrylates linear & branched
  • aryl(meth)acrylates such as benzyl (meth)acrylate
  • tri(alkyloxy)silylalkyl (meth)acrylates such as
  • Vinyl aryl compounds and derivatives thereof include styrene, acetoxystyrene, styrene sulfonic acid, vinyl pyridine, vinylbenzyl chloride and vinyl benzoic acid.
  • Vinyl acid anhydrides and derivatives thereof include maleic anhydride.
  • Vinyl amides and derivatives thereof include (meth)acrylamide, N-vinyl pyrrolidone, N-vinyl formamide, (meth)acrylamidopropyl trimethyl ammonium chloride, [3-((meth)acrylamido)propyl]dimethyl ammonium chloride, 3-[N-(3-(meth) acrylamidopropyl)-N,N-dimethyl]aminopropane sulfonate, methyl (meth) acrylamidoglycolate methyl ether and N-isopropyl(meth)acrylamide.
  • Vinyl ethers and derivatives thereof include methyl vinyl ether.
  • Vinyl amines and derivatives thereof include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, diisopropylaminoethyl (meth)acrylate, mono-t-butylaminoethyl (meth)acrylate, morpholinoethyl(nneth)acrylate and monomers which can be post- reacted to form amine groups, such as vinyl formamide.
  • Vinyl aryl amines and derivatives thereof include vinyl aniline, vinyl pyridine, N-vinyl carbazole and vinyl imidazole.
  • Vinyl nitriles and derivatives thereof include (meth)acrylonitrile.
  • Vinyl ketones and derivatives thereof include acreolin.
  • Hydroxyl-containing monomers include vinyl hydroxyl monomers such as hydroxyethyl (meth)acrylate, hydroxy propyl (meth)acrylate, glycerol
  • sugar mono(meth)acrylates such as glucose
  • Monomers which can be post-reacted to form hydroxyl groups include vinyl acetate, acetoxystyrene and glycidyl (meth)acrylate.
  • Acid- containing or acid functional monomers include (meth)acrylic acid, styrene sulfonic acid, vinyl phosphonic acid, vinyl benzoic acid, maleic acid, fumaric acid, itaconic acid, 2-(meth)acrylamido 2-ethyl propanesulfonic acid, mono-2- ((meth)acryloyloxy)ethyl succinate and ammonium sulfatoethyl (meth)acrylate.
  • Zwitterionic monomers include (meth)acryloyl oxyethylphosphoryl choline and betaines, such as [2-((meth)acryloyloxy)ethyl] dimethyl-(3-sulfopropyl)ammonium hydroxide.
  • Quaternised amino monomers include (meth)acryloyloxyethyltri- (alk/aryl)ammonium halides such as (meth)acryloyloxyethyltrimethyl ammonium chloride.
  • Oligomeric (or polymeric) monomers include oligomeric (meth)acrylic acid esters such as mono(alk/aryl)oxyoligo-alkyleneoxide(meth)acrylates and mono(alk/aryl)o xyoligo-dimethyl-siloxane(meth)acrylates. These esters include monomethoxy oligo(ethyleneglycol) mono(meth)acrylate, monomethoxy oligo(propyleneglycol) mono(meth)acrylate, monohydroxy oligo(ethyleneglycol) mono(meth)acrylate and monohydroxy oligo(propyleneglycol) mono(meth)acrylate.
  • oligomers examples include vinyl or allyl esters, amides or ethers of pre-formed oligomers formed via ring-opening polymerisation such as oligo(caprolactam) or oligo-(caprolactone), or oligomers formed via a living polymerisation technique such as oligo(1 ,4-butadiene).
  • the polymeric monomers are the same, save that the oligomers are polymers.
  • Macromonomers are generally formed by linking a polymerisable moiety, such as a vinyl or allyl group, to a pre-formed monofunctional polymer via a suitable linking unit such as an ester, an amide or an ether.
  • suitable polymers include mono functional poly(akylene oxide) such as
  • Preferred macromonomers include monomethoxy[poly-(ethyleneglycol)] mono (methacrylate), monomethoxy[poly-(propyleneglycol)] mono(methacrylate), poly (dimethylsiloxane) monomethacrylate.
  • the corresponding allyl monomers to those listed above can also be used where appropriate.
  • More preferred monomers include: amide-containing monomers such as
  • (meth)acrylic acid derivatives such as (meth)acrylic acid, (meth)acryoloyl chloride (or any halide), (alkyl/aryl) (meth)acrylate, oligo-functionalised monomers such as monomethoxy poly(ethyleneglycol) monomethacrylate or monomethoxy poly(propyleneglycol) mono(meth)acrylate, glycerol mono(meth)acrylate, glycidyl (meth)acrylate and sugar mono(meth)acrylates such as glucose
  • vinyl amines such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, t-butylamino (meth)acrylate,
  • vinyl aryl amines such as vinyl aniline, vinyl pyridine, N-vinyl carbazole, vinyl imidazole; vinyl aryl monomers such as styrene, vinyl benzyl chloride, vinyl toluene, a-methyl styrene, styrene sulfonic acid and vinyl benzoic acid; vinyl hydroxyl monomers such as hydroxyethyl (meth)acrylate, hydroxy propyl (meth)acrylate, glyceryl (meth)acrylate or monomers which can be post-functionalised into hydroxyl groups such as vinyl acetate or acetoxy styrene can also be used; acid-containing monomers such as (meth)acrylic acid, styrene sulfonic acid, vinyl phosphonic, maleic acid, fumaric acid, itaconic acid, 2- acrylamido 2-ethyl propanesulfonic acid and mono
  • (meth)acryloyloxyethyl-phosphoryl choline quaternised amino monomers such as methacryloyl-oxyethyltrimethyl ammonium chloride.
  • Hydrophobic monomers include: vinyl aryl compounds such as styrene and vinylbenzyl chloride; (meth)acrylic acid esters such as mono-t-butylaminoethyl (meth)acrylate, C1 -20 alkyl(meth)acrylates (linear & branched), aryl(meth) acrylates such as benzyl methacrylate; oligomeric (meth)acrylic acid esters such as mono(alk/aryl)oxyoligo-[dimethylsiloxane (meth)acrylate] and tri(alkyloxy)- silylalkyl (meth)acrylates such as trimethoxysilylpropyl-(meth)acrylate.
  • (meth)acrylic acid esters such as mono-t-butylaminoethyl (meth)acrylate, C1 -20 alkyl(meth)acrylates (linear & branched), aryl(meth) acrylates such as
  • Functional monomers i.e. monomers with reactive pendant groups which can be post or pre-modified with another moiety can also be used such as glycidyl (meth)acrylate, trimethoxysilylpropyl(meth)acrylate, (meth)acryloyl chloride, maleic anhydride, hydroxyalkyl (meth)acrylates, (meth)acrylic acid, vinylbenzyl chloride, activated esters of (meth)acrylic acid such as N-hydroxysuccinamido
  • the copolymer may contain unreacted polymerisable groups from the
  • the core may further comprise a cross-linking agent, derived from a more than di- or multi-functional species, for example an ethylenically unsaturated monomer, a vinyllic monomer, acrylate or methacryate. Tri- and tetra- functional materials are preferred.
  • the benefit of cross-linking agents is to increase robustness of the core, and or decrease permeability.
  • Cross linking agents in the core can modify interaction of the "core" with the benefit agent, e.g. by
  • the shell does not contain a crosslinking agent.
  • Cross-linking agents can be used to modify the properties of the chain-growth polymer of the core.
  • Suitable materials comprise a molecule containing at least two vinyl groups that may be polymerised.
  • the molecule may be hydrophilic, hydrophobic, amphiphilic, neutral, cationic, zwitterionic or oligomeric. Examples include di- or multivinyl esters, di- or multivinyl amides, di- or multivinyl aryl compounds and di- or multivinyl alk/aryl ethers.
  • a linking reaction is used to attach a polymerisable moiety to a di- or multifunctional oligomer or a di- or multifunctional group.
  • the brancher may itself have more than one branching point, such as T-shaped divinylic oligomers. In some cases, more than one multifunctional monomer may be used.
  • Macro cross-linkers or macro branchers are generally formed by linking a polymerisable moiety, such as a vinyl or aryl group, to a pre-formed multifunctional polymer via a suitable linking unit such as an ester, an amide or an ether.
  • suitable polymers include di-functional poly(alkylene oxides) such as poly(ethyleneglycol) or poly(propylene glycol), silicones such as poly(dimethyl-siloxane)s, polymers formed by ring-opening polymerisation such as poly(caprolactone) or poly(caprolactam) or poly-functional polymers formed via living polymerisation such as poly(1 ,4-butadiene).
  • di-functional poly(alkylene oxides) such as poly(ethyleneglycol) or poly(propylene glycol)
  • silicones such as poly(dimethyl-siloxane)s
  • polymers formed by ring-opening polymerisation such as poly(caprolactone) or poly(caprolactam)
  • poly-functional polymers formed via living polymerisation such as poly(1 ,4-butadiene).
  • Preferred macro branchers include poly(ethyleneglycol) di(meth)acrylate, poly(propyleneglycol) di(meth)acrylate, (meth)acryloxypropyl-terminated poly (dimethylsiloxane), poly(caprolactone) di(meth)acrylate and poly(caprolactam) di(meth)acrylamide.
  • the corresponding allyl monomers to those listed above can also be used where appropriate.
  • Preferred multifunctional monomers include but are not limited to divinyl aryl monomers such as divinyl benzene; (meth)acrylate diesters such as glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, propyleneglycol
  • di(meth)acrylates such as tetra ethyleneglycol di(meth)acrylate
  • oligo(ethyleneglycol) di(meth)acrylate and oligo(propyleneglycol) di(meth)- acrylate divinyl acrylamides such as methylene bis-acrylamide; silicone- containing divinyl esters or amides such as (meth)acryloxypropyl-terminated oligo (dimethyl-siloxane); divinyl ethers such as oligo (ethyleneglycol)-divinyl ether; and tetra- or tri-(meth)acrylate esters such as pentaerythritol tetra-(meth)acrylate, trimethylolpropane tri(meth)acrylate or glucose di- to penta(meth)acrylate.
  • divinyl acrylamides such as methylene bis-acrylamide
  • silicone- containing divinyl esters or amides such as (meth)acryloxypropyl-terminated oligo (dimethyl-siloxane)
  • oligomers examples include vinyl or allyl esters, amides or ethers of pre-formed oligomers formed via ring-opening polymerisation such as oligo(caprolactam) or oligo- (caprolactone), or oligomers formed via a living polymerisation technique such as oligo(1 ,4-butadiene).
  • oligo(caprolactam) or oligo- (caprolactone) or oligomers formed via a living polymerisation technique such as oligo(1 ,4-butadiene).
  • cross-linkers are divinyl benzene, ethylene glycol
  • Levels of cross-linker are typically 0-75, preferably 0.0001 to 50, more preferably 0.0001 to 25 mol %.
  • the benefit agent is a hydrophobic material, which is suitable for application to the skin.
  • Suitable benefit agents include perfume raw materials (also referred to herein as fragrance), silicone oils, waxes, hydrocarbons, higher fatty acids, essential oils, lipids, skin coolants, vitamins, sunscreens, antioxidants, malodour reducing agents, odour controlling materials, skin softening agents, insect and moth repelling agents, colourants, chelants, sanitization agents, germ control agents , skin care agents, natural actives, antibacterial actives, preservatives,
  • chemosensates for example menthol
  • sunless-tanning agents for example dihydroxyacetone
  • emollients for example sunflower oil and pertrolatum
  • antiaging agents anti-inflammatory agents
  • skin conditioning agents skin lightening agents and mixtures thereof.
  • Preferred benefit agents are fragrance, anti-aging agents, anti oxidants, vitamins, antimicrobial agents, anti-bacterial agents, anti-inflammatory actives, skin lightening agents, skin conditioning agents , for example 12-hydroxy stearic acid, oils, insect repellents and sunscreens.
  • Preferred antimicrobial agents include quaternary ammonium compounds, biguanides (polyhexamethylene biguanide), phenols (e.g. triclosan, thymol), essential oils (such as Tea Tree Oil and Thyme Oil) and antifungals (preferably Octapyrox, Climbazole, ketoconazole and zinc pyrithione).
  • biguanides polyhexamethylene biguanide
  • phenols e.g. triclosan, thymol
  • essential oils such as Tea Tree Oil and Thyme Oil
  • antifungals preferably Octapyrox, Climbazole, ketoconazole and zinc pyrithione
  • UV-B filters such as 2-ethylhexyl-4- methoxycinnamate (sold commercially under the trade name Parsol MCX by DSM), and UV-A filters such as benzophenone or 4-tert-butyl-4'- methoxydibenzoylmethane (Avobenzone, sold commercially under the trade name Parsol 1789 by DSM).
  • Preferred sunscreens and/or skin lightening agents are vitamin B3 compounds. Suitable vitamin B3 compounds are selected from niacin, niacinamide, nicotinyl alcohol, or derivatives or salts thereof.
  • vitamins which act as skin lightening agents can be advantageously included in the skin lightening composition to provide for additional skin lightening effects.
  • vitamins include vitamin B6, vitamin C, vitamin A or their precursors. Mixtures of the vitamins can also be employed in the composition of the invention.
  • An especially preferred additional vitamin is vitamin B6.
  • skin lightening agents useful herein include adapalene, aloe extract, ammonium lactate, arbutin, azelaic acid, butyl hydroxy anisole, butyl hydroxy toluene, citrate esters, deoxyarbutin, 1 ,3 diphenyl propane derivatives, 2, 5 di-hydroxyl benzoic acid and its derivatives, 2-(4- acetoxyphenyl)-1 ,3-dithane, 2-(4- hydroxylphenyl)-1 ,3 diethane, ellagic acid, gluc- pyranosyl-1 -ascorbate, gluconic acid, glycolic acid, green tea extract, 4-Hydroxy- 5-methyl-3[2H]-furanone, hydroquinone, 4-hydroxyanisole and its derivatives, 4- hydroxy benzoic acid derivatives, hydroxycaprylic acid, inositol ascorbate, kojic acid, lactic acid, lemon extract,
  • Preferred sunscreens useful in the present invention are 2-ethylhexyl-p-methoxycinnamate, butyl methoxy dibenzoylmethane, 2-hydroxy-4- methoxybenzophenone, octyl dimethyl-p-aminobenzoic acid and mixtures thereof.
  • Particularly preferred sunscreen is chosen from 2-ethyl hexyl-p-methoxycinnamate, 4,- t-butyl-4'- methoxydibenzoyl-methane or mixtures thereof.
  • Antioxidants, anti-ageing actives and anti-inflammatory actives are antioxidants, anti-ageing actives and anti-inflammatory actives
  • Suitable actives include Retinol (Vitamin A), ascorbyl palmitate (Vitamin C palmitate), Cholecalciferol (Vitamin D3), tocopheryl (Vitamin E) acetate, Vitamin E palmitate, linoleic acid (Vitamin F), carotenoids such as beta-carotene and curcumin, phenols and polyphenols (e.g. resveratrol).
  • Preferred anti-oxidants include vitamin E, retinol, antioxiants based on
  • hydroxytoluene such as IrganoxTM or commercially available antioxidants such as the TrolloxTM series.
  • Perfume and fragrance materials are a particularly preferred benefit agent.
  • the pro-fragrance can, for example, be a food lipid.
  • Food lipids typically contain structural units with pronounced hydrophobicity. The majority of lipids are derived from fatty acids. In these 'acyl' lipids the fatty acids are predominantly present as esters and include mono-, di-, triacyl glycerols, phospholipids, glycolipids, diol lipids, waxes, sterol esters and tocopherols.
  • plant lipids comprise antioxidants to prevent their oxidation. While these may be at least in part removed during the isolation of oils from plants some antioxidants may remain. These antioxidants can be pro-fragrances.
  • the carotenoids and related compounds including vitamin A, retinol, retinal, retinoic acid and provitamin A are capable of being converted into fragrant species including the ionones, damascones and damscenones.
  • Preferred pro-fragrance food lipids include olive oil, palm oil, canola oil, squalene, sunflower seed oil, wheat germ oil, almond oil, coconut oil, grape seed oil, rapeseed oil, castor oil, corn oil, cottonseed oil, safflower oil, groundnut oil, poppy seed oil, palm kernel oil, rice bran oil, sesame oil, soybean oil, pumpkin seed oil, jojoba oil and mustard seed oil.
  • the perfume is typically present in an amount of from 10-85% by total weight of the particle, preferably from 15 to 75% by total weight of the particle.
  • the perfume suitably has a molecular weight of from 50 to 500Dalton. Pro-fragrances can be of higher molecular weight, being typically 1 -10 kD.
  • Useful components of the perfume include materials of both natural and synthetic origin. They include single compounds and mixtures. Specific examples of such components may be found in the current literature, e.g., in Fenaroli's Handbook of Flavour Ingredients, 1975, CRC Press; Synthetic Food Adjuncts, 1947 by
  • perfume in this context is not only meant a fully formulated product fragrance, but also selected components of that fragrance, particularly those which are prone to loss, such as the so-called 'top notes'.
  • Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80 [1955]). Examples of well known top-notes include citrus oils, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol. Top notes typically comprise 15-25%wt of a perfume composition and in those embodiments of the invention which contain an increased level of top-notes it is envisaged at that least 20%wt would be present within the particle.
  • embodiments of the present invention include those with a relatively low boiling point, preferably those with a boiling point of less than 300, preferably 100-250 Celsius.
  • perfume components which have a low LogP (i.e. those which will be partitioned into water), preferably with a LogP of less than 3.0.
  • materials, of relatively low boiling point and relatively low LogP have been called the "delayed blooming" perfume ingredients and include the following materials:
  • Methyl Eugenol Methyl Heptenone, Methyl Heptine Carbonate, Methyl Heptyl Ketone, Methyl Hexyl Ketone, Methyl Phenyl Carbinyl Acetate, Methyl Salicylate, Methyl-N-Methyl Anthranilate, Nerol, Octalactone, Octyl Alcohol, p- Cresol, p-Cresol Methyl Ether, p-Methoxy Acetophenone, p-Methyl
  • Aromatherapy benefit agents it is envisaged that there will be four or more, preferably five or more, more preferably six or more or even seven or more different perfume components from the list given of delayed blooming perfumes given above present in the particles.
  • perfumes with which the present invention can be applied are the so-called 'aromatherapy' materials. These include many components also used in perfumery, including components of essential oils such as Clary Sage, Eucalyptus, Geranium, Lavender, Mace Extract, Neroli, Nutmeg, Spearmint, Sweet Violet Leaf and Valerian.
  • the benefit agent may also be an insect repellent material (where insect should be read broadly to include other pests which are arthropods but not strictly hexapods - for example ticks). Many of these materials overlap with the class of perfume components and some are odourless to humans or have a non-perfume odour.
  • repellents include: DEET (N,N-diethyl-m-toluamide), essential oil of the lemon eucalyptus (Corymbia citriodora) and its active compound p-menthane-3,8-diol (PMD), lcaridin, also known as Picaridin, D- Limonene, Bayrepel, and KBR 3023, Nepetalactone, also known as "catnip oil”, Citronella oil, Permethrin, Neem oil and Bog Myrtle.
  • Known insect repellents derived from natural sources include: Achillea alpina, alpha-terpinene, Basil oil (Ocimum basilicum), Callicarpa americana (Beautyberry), Camphor, Carvacrol, Castor oil (Ricinus communis), Catnip oil (Nepeta species), Cedar oil (Cedrus atlantica), Celery extract (Apium graveolens), Cinnamon (Cinnamomum
  • cinerariifolium and C. coccineum Rosemary oil (Rosmarinus officinalis), Spanish Flag Lantana camara (Helopeltis theivora), Solanum villosum berry juice, Tea tree oil (Melaleuca alternifolia) and Thyme (Thymus species) and mixtures thereof.
  • the encapsulate optionally comprises a carrier oil (also referred to herein as a diluent).
  • a carrier oil also referred to herein as a diluent.
  • the carrier oils are hydrophobic materials that are miscible in the benefit agent materials used in the present invention.
  • Suitable oils are those having reasonable affinity for the benefit agent.
  • Suitable materials include, but are not limited to triglyceride oil, mono and diglycerides, mineral oil, silicone oil, diethyl phthalate, polyalpha olefins, castor oil and isopropyl myristate.
  • the oil is a triglyceride oil, most preferably a capric/caprylic triglyceride oil.
  • Polymerisation occurs in at least two phases. In an earlier of these phases a core is formed by a chain-growth polymerisation. A shell is subsequently formed by another chain-growth polymerisation.
  • Temporal separation of these phases is accomplished by control of the reagents present and the reaction conditions.
  • a preferred embodiment of the present invention provides a particle obtainable by a method comprising: Forming a core by:
  • a) fornning an emulsion preferably having a volume mean dispersed particle size diameter of less than 1000nm, more preferably less than 500nm and having a dispersed non-aqueous phase comprising: i) a hydrophobic benefit agent, ii) at least one monomer, preferably acrylate or methacrylate, capable of chain-growth polymerisation, and, a continuous aqueous phase comprising: i) water, and ii) an emulsifying agent, b) adding an initiator, and c) maintaining the emulsion at a temperature at which the chain-growth
  • polymerisation proceeds to form the core; and forming a shell around the core by: adding to the core i) at least one monomer, preferably acrylate or methacrylate, capable of chain-growth polymerisation, and ii) an initiator; and b) maintaining the mixture at a temperature at which the chain-growth polymerisation proceeds.
  • the above described method provides a potentially “one-pot” reaction which has the advantages of simplicity and reduced losses: i.e. the core is first formed by chain-growth polymerisation and the shell is subsequently formed around the shell by another chain-growth polymerisation.
  • preformed core particles may first be obtained and the shell applied at a later time.
  • the benefit agent may be present in the reaction mixture, at a level to give the benefit agent levels in the resulting particles at the levels disclosed above, although it is also possible to form "empty" particles and subsequently expose them to a benefit agent which can be adsorbed into the core.
  • the particles and the benefit agent may be added separately such that the particles take up the benefit agent in the composition.
  • compositions of the invention are preferably prepared by a method comprising the following:-
  • Carrier preferably water
  • antiperspirant active preferably aluminium
  • the first and second phases are mixed,
  • a fragrance may be added.
  • the mixture may be milled if desired.
  • emulsifying agents are known for use in emulsion polymerisation.
  • Suitable emulsifying agents for use in the polymerisation process may comprise, but are not limited to, non-ionic surfactants such as polyvinylpyrrolidone (PVP), polyethylene glycol sorbitan monolaurate (Tween 20), polyethylene glycol sorbitan monopalmitate (Tween 40), polyethylene glycol sorbitan monooleate (Tween 80), polyvinyl alcohol (PVA), and poly(ethoxy)nonyl phenol, ethylene maleic anhydride (EMA) copolymer, Easy-SperseTM (from ISP Technologies Inc.), ionic surfactants such as partially neutralized salts of polyacrylic acids such as sodium or potassium polyacrylate or sodium or potassium polymethacrylate. BrijTM-35, HypermerTM A 60, or sodium lignosulphate, and mixtures thereof.
  • PVP polyvinylpyrrolidone
  • Tween 20
  • Emulsifiers may also include, but are not limited to, acrylic acid-alkyl acrylate copolymer, poly(acrylic acid), polyoxyalkylene sorbitan fatty esters, polyalkylene co-carboxy anhydrides, polyalkylene co-maleic anhydrides, poly(methyl vinyl ether-co-maleic anhydride), poly(propylene-co-maleic anhydride), poly(butadiene co-maleic anhydride), and polyvinyl acetate-co-maleic anhydride), polyvinyl alcohols, polyalkylene glycols, polyoxyalkylene glycols, and mixtures thereof.
  • Preferred emulsifying agents are fatty alcohol ethoxylates (particularly of the BrijTM class), salts of ether sulphates (including SLES), alkyl and alkaryl sulphonates and sulphates (including LAS and SDS) and cationic quaternary salts (including CTAC and CTAB).
  • the emulsifying agent comprises a non-ionic surfactant. This is believed to produce a particle which deposits better on cloth than one produced solely with an anionic surfactant emulsifier, as cloth become anionic during a wash. It is also preferred that the non-ionic surfactant is hydrophilic, so as to promote the formation of a stable mini-emulsion.
  • the ratio of non-ionic to anionic emulsifier should be greater than 1 :1 (i.e. non-ionic is present in excess) and the total surfactant level should be >3%wt of the polymerisation mixture.
  • co-surfactant typically a co-surfactant will be present in the dispersed phase and in the resulting particle.
  • Suitable co-surfactants for use in the present invention include hexadecane, cetyl alcohol, lauroyl peroxide, n-dodecyl mercaptan, dodecyl methacrylate, stearyl methacrylate, polystyrene, polydecene, mineral oils, isopropyl myristate, C12-C15 alkyl benzoate and polymethyl methacrylate.
  • the preferred cosurfactants comprise hexadecane, polydecene and isopropyl myristate.
  • the co-surfactant is typically 0-20%, preferably 1 - 15%, more preferably 2-12.5%.
  • polymerisation typically occurs in at least two phases (where a shell is present).
  • the core is formed by a reaction which, in preferred embodiments occurs at less than about 95 Celsius, typically 55-90 Celsius.
  • the shell monomer is added and polymerised at a preferred temperature of 55-90 Celcius.
  • the core excluding benefit agent is less than or equal to 90%wt of mass, and the shell generally 10%wt or greater of the mass of the particle.
  • the active ingredient is an antiperspirant active.
  • the antiperspirant active is typically one containing aluminium and/or zirconium. Such actives are water-soluble and are may be fully dissolved in an aqueous continuous phase of the composition.
  • the antiperspirant active is typically selected from astringent salts, including both inorganic salts, salts with organic anions, and complexes. Preferred
  • Zirconium salts are usually defined by the general formula ZrO(OH) 2- xQx.wH 2 O in which Q represents chlorine, bromine or iodine; x is from about 1 to 2; w is from about 1 to 7; and x and w may both have non-integer values.
  • Particular zirconium salts are zirconyl oxyhalides, zirconiun hydroxyhalides, and combinations thereof.
  • Antiperspirant actives as used in the invention may be present as mixtures or complexes.
  • Suitable aluminium-zirconium complexes often comprise a compound with a carboxylate group, for example an amino acid.
  • suitable amino acids include tryptophan, ⁇ -phenylalanine, valine, methionine, ⁇ -alanine and, most preferably, glycine.
  • ZAG actives generally contain aluminium, zirconium and chloride with an Al/Zr ratio in a range from 2 to 10, especially 2 to 6, an AI/CI ratio from 2.1 to 0.9 and a variable amount of glycine.
  • activated aluminium chlorohydrate or enhanced activity aluminium chlorohydrate sometimes abbreviated to AACH, in which the proportion of the more active species is higher by virtue of its method of manufacture.
  • activated given in EP 6739, the material has greater than 20% Band III.
  • Other methods of making AACH are given in EP 191628 and EP 451395.
  • Antiperspirant actives when employed, are preferably incorporated in an amount of from 0.5 to 60%, particularly from 5 to 30% or 40% and especially from 10% to 30% of the total composition.
  • compositions for use in the invention may contain one or more other ingredients.
  • Formulated compositions comprising the particles of the invention may contain a surface-active compound (surfactant) which may be chosen from soap and non soap anionic, cationic, non-ionic, amphoteric and zwitterionic surface active compounds and mixtures thereof.
  • surfactant may be chosen from soap and non soap anionic, cationic, non-ionic, amphoteric and zwitterionic surface active compounds and mixtures thereof.
  • surface active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch.
  • the preferred surface-active compounds that can be used are soaps and synthetic non soap anionic, and non-ionic compounds.
  • Preferred deodorant actives that are not antiperspirant actives that may be employed include antimicrobial actives such as polyhexamethylene biguanides, e.g. those available under the trade name CosmocilTM or chlorinated aromatics, e.g. triclosan available under the trade name IrgasanTM, non-microbiocidal deodorant actives such as triethylcitrate, bactericides and bacteriostats. Yet other deodorant actives can include zinc salts such as zinc ricinoleate.
  • antimicrobial actives such as polyhexamethylene biguanides, e.g. those available under the trade name CosmocilTM or chlorinated aromatics, e.g. triclosan available under the trade name IrgasanTM
  • non-microbiocidal deodorant actives such as triethylcitrate, bactericides and bacteriostats.
  • zinc salts such as zinc ricinoleate.
  • compositions can additionally or alternatively contain, as a deodorant, an iron chelator such as pentenoic acid which hinders bacterial growth/reproduction.
  • an iron chelator such as pentenoic acid which hinders bacterial growth/reproduction.
  • the proportion of the deodorant active in the formulation is often selected in the range of from about 0.05 to 2% and especially from 0.1 to 0.5% by weight.
  • Such ingredients include further preservatives (e.g. bactericides), pH buffering agents, perfume carriers, anti-redeposition agents, soil-release agents,
  • polyelectrolytes polyelectrolytes, anti-shrinking agents, anti-wrinkle agents, anti-oxidants, sunscreens, anti-corrosion agents, drape imparting agents, anti-static agents, pearlisers and/or opacifiers, natural oils/extracts, processing aids, eg electrolytes, hygiene agents, eg anti-bacterials and antifungals, thickeners, skin benefit agents, colourants, whiteners, optical brighteners, soil suspending agents, detersive enzymes, compatible bleaching agents (particularly peroxide compounds and active chlorine releasing compounds), gel-control agents, freeze-thaw stabilisers, bactericides, preservatives (for example 1 ,2-benzisothiazolin-3-one), hydrotropes, perfumes and mixtures thereof.
  • processing aids eg electrolytes, hygiene agents, eg anti-bacterials and antifungals, thickeners, skin benefit agents, colourants, whiteners, optical brighteners, soil suspending agents, detersive enzyme
  • compositions for use in the invention may also contain pH modifiers such as hydrochloric acid or lactic acid.
  • compositions of the invention may be in any suitable physical form e.g. a solid such as a solid bar, a paste; or a liquid or gel, preferably, an aqueous-based liquid.
  • a solid such as a solid bar, a paste
  • a liquid or gel preferably, an aqueous-based liquid.
  • the composition is in the form of an aqueous based liquid, it is advantageously in the form of a cream, a roll-on or a lotion.
  • the particles are typically included in said compositions at levels of from 0.01 % to 10%, preferably from 0.5% to 7%, most preferably from 0.5% to 5% by weight of the total composition.
  • Example 1 Preparation of particle P1 A particle, P1 , having a poly acrylate core and a poly acrylate shell was synthesised by miniemulation polymerisation as follows:-
  • a surfactant stock solution was prepared by dissolving 0.75 g SLES- 1 EO (Texapon N701 - Clariant) in 50 ml demineralised water. 1 g of hexadecane (a skin benefit agent) and 20 g of butyl methacrylate monomer were weighed into a 125 ml glass jar. To this 8 g of surfactant stock solution and 66.6g water was added and the mixture gently shaken to form a crude emulsion.
  • SLES- 1 EO Texapon N701 - Clariant
  • the crude emulsion was sonicated at 60 % amplitude for 1 .5 min, the jar resealed, shaken and sonicated at 60% amplitude for a further 1 .5 min.
  • the miniemulsion was charged to a 250 mL 2-neck round bottom flask fitted with a condenser and an overhead stirrer and heated to 85 °C. Once the miniemulsion had reached the desired temperature the initiation system (0.2 g Sodium bicarbonate in 2 mL water plus 0.2 g ammonium persulphate in 2 mL water) was added over a two minute period and the reaction left to polymerise for 3 hours. Subsequently, the reaction was cooled and filtered through
  • antiperspirant composition DP1 Particles P1 , of example 1 , were incorporated into a antiperspirant composition, to form antiperspirant composition DP1 .
  • Table 1 Composition of antiperspirant composition DP1 , comprising P1
  • Example 3 Fragrance uptake by particles P1 in antiperspirant composition DP1
  • antiperspirant composition DP1 5g was transferred to a 20ml_ glass solid-phase microextraction (SPME) vial and the vial was sealed. Each test antiperspirant formulation was tested in triplicate. The vials were left for 7 days at ambient conditions, before fragrance headspace
  • fragrance components were identified using a Total Ion Count (TIC) method, and Selected Ion monitoring (SIM) method was used for the quantification of analytes.
  • TIC Total Ion Count
  • SIM Selected Ion monitoring
  • SPME fibre for extraction of analytes SPME fibre assembly of 23-Gauge, 50/30 microns, DVB/CAR/PDMS was used for the extraction of the analytes from the sample headspace
  • Table 2 Uptake of fragrance components into particle P1 in composition DP1 , after 7 days storage.
  • Example 4 Fragrance release by particles P1 in antiperspirant composition DP1
  • Antiperspirant formulation, DP1 was applied to 70x70mm 2 squares of
  • polyester fabric for assessment. 12 fabric squares were prepared and
  • Example 5 Preparation of particle P2 in accordance with the invention, and comparative particle PA.
  • Table 4 Composition of particle P2 in accordance with the invention and comparative particle PA.
  • the particles shown in Table 4 above were prepared as follows:- A 2.5 % (wt/wt) stock solution of sodium dodecyl sulfate and Synperonic A7 was prepared; this consisted of 2.5 g sodium dodecyl sulfate and 10 g A7 in 500 ml of deionised water. The aqueous phase was prepared using this stock solution and a further portion of deionised water. An organic phase containing 30 g of monomer (as shown in Table 4 above) and 1 .5 g hexadecane was measured out. These phases were mixed and then homogenised for 2 x 2.5 minutes with the ultrasonic probe at 50 % amplitude (Branson Digital Sonfier 450D). The resulting
  • Example 6 Fragrance uptake by particle P2 and comparative particle PA.
  • Particles P2 and PA, of example 5 were incorporated into a antiperspirant composition, to form antiperspirant compositions DP2 and DPA.
  • Table 5 Composition of antiperspirant composition DP2, comprising P2
  • each antiperspirant composition was transferred to a 20ml_ glass solid-phase microextraction (SPME) vials and the vials were sealed.
  • SPME solid-phase microextraction
  • fragrance components were identified using a Total Ion Count (TIC) method, and Selected Ion monitoring (SIM) method was used for the quantification of analytes.
  • TIC Total Ion Count
  • SIM Selected Ion monitoring
  • SPME fibre for extraction of analytes SPME fibre assembly of 23-Gauge, 50/30 microns, DVB/CAR/PDMS was used for the extraction of the analytes from the sample headspace

Abstract

The invention provides a composition comprising: a) a particle, wherein the particle comprises, i) a core comprising a solid polymer formed by chain-growth polymerisation reaction, and a hydrophobic skin benefit agent, which is liquid at room temperature; and b) an active material, which is an antiperspirant active; wherein the chain-growth polymerisation reaction is a radical polymerisation reaction, preferably of at least one ethylenically unsaturated monomer,and wherein the ethylenically unsaturated, monomer is selected from C1-C20 linear or branched, alkyl acrylates and methacrylates, and wherein the particle has a volume average diameter of less than 1 micron, and wherein the particle further comprises a shell comprising a polymer formed by chain growth polymerisation of non-crosslinked monomers.

Description

BENEFIT DELIVERY PARTICLE
Technical Field
The present invention is concerned with the delivery of particles, comprising a benefit agent, to skin, from a composition comprising said particles. Processes for the manufacture of said compositions and a method of treating skin are also described. The particles have application in antiperspirant compositions.
Background
Many personal care formulations seek to deliver so-called benefit agents to substrates such as hair and skin. Encapsulation of the benefit agent in particles has been proposed as a means of enhancing delivery, which is advantageous because of the expense of some benefit agents. Delivery of particles per se can also be useful where the particles, even in the absence of specific benefit agents, confer a benefit.
These particles may comprise polymers and many different types of
polymerisation are known, most notably step-growth and chain-growth
polymerisation. The well-established reaction mechanisms have been
documented by Paul Flory in 1953 (see Paul J. Flory, "Principles of Polymer Chemistry", Cornell University Press, 1953, p.39. ISBN 0801401348). For the purposes of the present specification a chain-growth polymer is a polymer which is formed by a reaction in which monomers bond together via
rearrangement (for example, of unsaturated and typically vinyllic bonds, or by a ring-opening reaction) without the loss of any atom or molecule. Chain-growth polymers grow in a single direction from one end of the chain only and an initiator is typically used. In chain-growth polymerisation it is commonplace that once a growth at a chain end is terminated the end becomes unreactive.
An example of one type of chain-growth polymerisation is the free-radical polymerisation reaction, for example the well-known polymerization of styrene (vinyl benzene) in the presence of benzoyl peroxide (as radical initiator) to produce polystyrene. Similarly, aluminum chloride may be used to initiate the polymerisation of isobutylene to form synthetic rubber. Other examples include the polymerization reactions of acrylates or methacryates.
Both chain-growth and step-growth have been used to prepare particles by polymerisation in which some of the components are present in the dispersed phase of an emulsion. WO 2012/044929 and WO 2012/006402 (Lubrizol Advanced Materials, Inc) disclose personal care, home care, or health care compositions having two visually distinct phases, where one comprises acrylic-based mixed linear and crosslinked core- shell polymers. The compositions may contain adjuncts including antiperspirant or deodorant actives.
WO 2012/007438 (Hindustan Unilever Ltd) discloses a particle less than 50 μηη comprising a shell formed by step-growth polymerization and a core formed by chain-growth polymerization which does not involve an isocyanate. An optional benefit agent and deposition aid may be included. The particle can be used in a variety of product formats. US 2003/0053976, US 2003/0044440 and US 2003/0039671 (all L'Oreal,
20/03/2003) concern nano-particle dispersion with different core and shell material for use in cosmetic makeup compositions, in order to improve the comfort and staying power of cosmetic compositions.
JP 2000/143483 (Kao Coporation) discloses a cosmetic composition that contains a water-insoluble core-shell polymer particle and a cosmetic component.
WO 2005/107684 and WO 2005/107683 relate to adhesive film-forming particles that may be produced by chain-growth (free-radical) polymerization. The particles are held in a fatty phase.
We have now determined that improved particles comprise a shell and a core, each of which comprise a chain-growth polymer (for example a
poly(meth)acrylate). The shell and the core may be formed by radical
polymerisation.
Definition of the Invention In a first aspect, the present invention provides a composition comprising a composition comprising: a) a particle, wherein the particle comprises, i) a core comprising a solid polymer formed by chain-growth
polymerisation reaction, and a hydrophobic skin benefit agent, which is liquid at room temperature; and b) an active material, which is an antiperspirant active;
wherein the chain-growth polymerisation reaction is a radical polymerisation reaction, preferably of at least one ethylenically unsaturated monomer, and wherein the ethylenically unsaturated, monomer is selected from C-i-C2o linear or branched, alkyl acrylates and methacrylates, and wherein the particle has an average diameter of less than 1 micron, and wherein the particle further comprises a shell comprising a polymer formed by chain growth polymerisation of non-crossl inked monomers.
A further aspect of the invention provides a process for the manufacture of the composition according to the invention wherein the particles and the benefit agent are added separately to the formulation.
A further aspect of the present invention provides a method of treatment of skin, which includes the step of treating the substrate with a composition according to the present invention. Detailed Description of the Invention
In order that the present invention may be further and better understood it will be further described below with reference to specific embodiments of the invention and further preferred and/or optional features. All amounts quoted are wt.% of total composition unless otherwise stated.
The particle
The particle comprises i) a core comprising a solid polymer formed by chain- growth polymerisation, and a skin benefit agent, which is liquid at room
temperature; and ii) a shell comprising a polymer formed by chain growth polymerisation of non-crosslinked monomers.
By solid is meant solid at ambient temperature, preferably from 20 to 50 °C, most preferably from 20 to 40 °C. The core provides a sink for the benefit agent and the "shell" protects the benefit agent and regulates the flow of benefit agent into and out of the core.
The particle has a volume average diameter of less than 1 micron, preferably from 50 to 500 nm, more preferably an average diameter of from 100 to 400 nm, most preferably from 200 to 300 nm. One benefit of small particles is that they are less visible in products.
The diameter of the particles may be measured by dynamic light scattering (DLS), such as described in "Introduction to Colloids and Surface Chemistry", by Duncan J Shaw, fourth edition, published 1992 by Butterworth-Heinemann (page 61 ).
The particle comprises a hydrophobic benefit agent, preferably a fragrance. In the context of this invention, hydrophobic preferably means a material having a ClogP above 3. As used herein, the term "ClogP" means the logarithm to base 10 of the octanol/water partition coefficient (P). The octanol/water partition coefficient of a PRM is the ratio between its equilibrium concentrations in octanol and water. Given that this measure is a ratio of the equilibrium concentration of a PRM in a non-polar solvent (octanol) with its concentration in a polar solvent (water), ClogP is also a measure of the hydrophobicity of a material-the higher the ClogP value, the more hydrophobic the material. Suitable methods of measuring ClogP will be known to one skilled in the art. The Chain Growth Polymers
The core and the shell are formed by chain-growth polymerisation.
Careful selection of the core materials enables compatibility between the core and the benefit agent. In particular the solubility parameters of the benefit agent and the chain-growth polymer comprising the core may be matched to achieve improved absorption and/or delivery.
Preferably, the chain-growth polymerisation reaction used to form the core and shell is a radical polymerisation reaction. The monomer capable of chain-growth polymerisation is preferably ethylenically unsaturated, more preferably vinyllic. In the alternative, a ring-opening mechanism may be used. Most preferably the monomer is selected from acrylate or methacryate. At least one ethylenically unsaturated monomer is used, preferably from 1 to 5, more preferably from 1 to 3, most preferably 1 or 2 monomers.
Especially preferred "core" monomers for chain growth polymerisation are C1-C20 linear or branched, alkyl acrylates and methacrylates, preferably C2-C2o linear or branched, alkyl acrylates and methacrylates.
Preferred "shell" monomers for chain growth polymerisation are those that form a glassy polymer at 20 °C, preferably Ci to C2o alkyl acrylates and methacrylates, most preferably Ci or C2 alkyl acrylates and methacrylates. Free-radical polymerisation (FRP) is a suitable method of chain-growth
polymerisation. In FRP a mono-functional monomer is polymerised in the presence of free-radical initiator and, optionally, a chain transfer agent. Chain transfer agents can act to reduce the average molecular weight of the final polymer.
The use of a separate chain transfer agent and an initiator is preferred. However, some molecules can perform both these functions.
The free-radical initiator can be any molecule known to initiate free-radical polymerisation such as azo-containing molecules, persulfates, redox initiators, peroxides, benzyl ketones. These initiators may be activated via thermal, photolytic or chemical means. In the method of the present invention, thermal activation is preferred. Examples of suitable initiators include but are not limited to 2,2'- azobisisobutyronitrile (AIBN), azobis(4-cyanovaleric acid), , benzoyl peroxide, cumylperoxide, 1 -hydroxy-cyclohexyl phenyl ketone, hydrogen peroxide/ascorbic acid. So-called 'iniferters' such as benzyl-N,N-diethyldithio-carbamate can also be used.
In some cases, more than one initiator may be used. The preferred initiators are: 2,2'-Azobis(2-methylbutyro-nitrile), 2,2'-Azobis(2.4- dimethyl valeronitrile), 1 ,1 '-Azobis(cyclohexane -1 -carbonitrile), t-butyl hydro- peroxide/ascorbic acid and mixtures thereof as these minimise the production of unwanted by products. Preferably, the residue of the initiator in a free-radical polymerisation comprises 0 to 5% w/w, preferably 0.01 to 5% w/w and especially 0.01 to 3% w/w, of the resulting copolymer based on the total weight of the monomers.
The chain transfer agent is preferably a thiol-containing molecule and can be either mono-functional or multi-functional. The agent may be hydrophilic, hydrophobic, amphiphilic, anionic, cationic, neutral or zwitterionic. The molecule can also be an oligomer containing a thiol moiety.
Suitable thiols include but are not limited to C2-Ci8 alkyl thiols such as dodecane thiol, thioglycolic acid, thioglycerol, cysteine and cysteamine. Thiol-containing oligomers may also be used such as oligo(cysteine) or an oligomer which has been post-functionalised to give a thiol group(s), such as oligoethylene glycolyl (di)thio glycollate. Xanthates, dithioesters, and dithiocarbonates may also be used, such as cumyl phenyldithioacetate.
Alternative chain transfer agents may be any species known to limit the molecular weight in a free-radical addition polymerisation. Thus the chain-transfer agent may also be a hindered alcohol, halocarbon, alkyl halide or a transition metal salt or complex, or similar free-radical stabiliser. Catalytic chain transfer agents such as those based on transition metal complexes such as cobalt bis(borondi- fluorodimethyl-glyoximate) may also be used.
More than one chain transfer agent may be used in combination. The residue of the chain transfer agent may comprise 0 to 20 mole%, preferably 0 to 10 mole% and especially 0 to 3 mole%, of the copolymer (based on the number of moles of mono-functional monomer). In some cases, for example in the case of some so-called living polymerisation methods, a chain transfer agent is not required.
Monomers for the chain-growth polymerisation may comprise any carbon-carbon unsaturated (or cyclic) compound which can form an addition polymer, e.g. vinyl and allyl compounds. The mono-functional monomer may be hydrophilic, hydrophobic, amphiphilic, anionic, cationic, neutral or zwitterionic in nature. Thus, the mono-functional monomer may be selected from but not limited to monomers such as vinyl acids, vinyl acid esters, vinyl aryl compounds, vinyl acid anhydrides, vinyl amides, vinyl ethers, vinyl amines, vinyl aryl amines, vinyl nitriles, vinyl ketones, and derivatives of the aforementioned compounds as well as
corresponding allyl variants thereof. Other suitable mono-functional monomers for the chain-growth polymer include hydroxyl-containing monomers and monomers which can be post-reacted to form hydroxyl groups, acid-containing or acid functional monomers, zwitterionic monomers and quaternised amino monomers.
Oligomeric or oligo-functionalised monomers may also be used, especially oligomeric (meth)acrylic acid esters such as mono(alk/aryl) (meth)acrylic acid esters of oligo[alkyleneglycol] or oligo[dimethylsiloxane] or any other mono-vinyl or allyl adduct of a low molecular weight oligomer. Mixtures of more than one monomer may also be used.
Preferred vinyl acids and derivatives thereof include (meth)acrylic acid and acid halides thereof such as (meth)acryloyl chloride. Preferred vinyl acid esters and derivatives thereof include C1 -20
alkyl(meth)acrylates (linear & branched) such as methyl (meth)acrylate, stearyl (meth)acrylate and 2-ethyl hexyl (meth)acrylate, aryl(meth)acrylates such as benzyl (meth)acrylate, tri(alkyloxy)silylalkyl (meth)acrylates such as
trimethoxysilylpropyl(meth)acrylate and activated esters of (meth)acrylic acid such as N-hydroxysuccinamido (meth)acrylate. Vinyl aryl compounds and derivatives thereof include styrene, acetoxystyrene, styrene sulfonic acid, vinyl pyridine, vinylbenzyl chloride and vinyl benzoic acid. Vinyl acid anhydrides and derivatives thereof include maleic anhydride. Vinyl amides and derivatives thereof include (meth)acrylamide, N-vinyl pyrrolidone, N-vinyl formamide, (meth)acrylamidopropyl trimethyl ammonium chloride, [3-((meth)acrylamido)propyl]dimethyl ammonium chloride, 3-[N-(3-(meth) acrylamidopropyl)-N,N-dimethyl]aminopropane sulfonate, methyl (meth) acrylamidoglycolate methyl ether and N-isopropyl(meth)acrylamide.
Vinyl ethers and derivatives thereof include methyl vinyl ether. Vinyl amines and derivatives thereof include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, diisopropylaminoethyl (meth)acrylate, mono-t-butylaminoethyl (meth)acrylate, morpholinoethyl(nneth)acrylate and monomers which can be post- reacted to form amine groups, such as vinyl formamide. Vinyl aryl amines and derivatives thereof include vinyl aniline, vinyl pyridine, N-vinyl carbazole and vinyl imidazole. Vinyl nitriles and derivatives thereof include (meth)acrylonitrile. Vinyl ketones and derivatives thereof include acreolin.
Hydroxyl-containing monomers include vinyl hydroxyl monomers such as hydroxyethyl (meth)acrylate, hydroxy propyl (meth)acrylate, glycerol
mono(meth)acrylate and sugar mono(meth)acrylates such as glucose
mono(meth)acrylate. Monomers which can be post-reacted to form hydroxyl groups include vinyl acetate, acetoxystyrene and glycidyl (meth)acrylate. Acid- containing or acid functional monomers include (meth)acrylic acid, styrene sulfonic acid, vinyl phosphonic acid, vinyl benzoic acid, maleic acid, fumaric acid, itaconic acid, 2-(meth)acrylamido 2-ethyl propanesulfonic acid, mono-2- ((meth)acryloyloxy)ethyl succinate and ammonium sulfatoethyl (meth)acrylate. Zwitterionic monomers include (meth)acryloyl oxyethylphosphoryl choline and betaines, such as [2-((meth)acryloyloxy)ethyl] dimethyl-(3-sulfopropyl)ammonium hydroxide. Quaternised amino monomers include (meth)acryloyloxyethyltri- (alk/aryl)ammonium halides such as (meth)acryloyloxyethyltrimethyl ammonium chloride.
Oligomeric (or polymeric) monomers include oligomeric (meth)acrylic acid esters such as mono(alk/aryl)oxyoligo-alkyleneoxide(meth)acrylates and mono(alk/aryl)o xyoligo-dimethyl-siloxane(meth)acrylates. These esters include monomethoxy oligo(ethyleneglycol) mono(meth)acrylate, monomethoxy oligo(propyleneglycol) mono(meth)acrylate, monohydroxy oligo(ethyleneglycol) mono(meth)acrylate and monohydroxy oligo(propyleneglycol) mono(meth)acrylate. Further examples include vinyl or allyl esters, amides or ethers of pre-formed oligomers formed via ring-opening polymerisation such as oligo(caprolactam) or oligo-(caprolactone), or oligomers formed via a living polymerisation technique such as oligo(1 ,4-butadiene). The polymeric monomers are the same, save that the oligomers are polymers.
Macromonomers are generally formed by linking a polymerisable moiety, such as a vinyl or allyl group, to a pre-formed monofunctional polymer via a suitable linking unit such as an ester, an amide or an ether. Examples of suitable polymers include mono functional poly(akylene oxide) such as
monomethoxy[poly(ethyleneoxide) or monomethoxy [poly-(propyleneoxide), silicones such as poly(dimethylsiloxane), polymers formed by ring-opening polymerisation such as poly(caprolactone) or poly(caprolactam) or mono- functional polymers formed via living polymerisation such as poly(1 ,4-butadiene).
Preferred macromonomers include monomethoxy[poly-(ethyleneglycol)] mono (methacrylate), monomethoxy[poly-(propyleneglycol)] mono(methacrylate), poly (dimethylsiloxane) monomethacrylate. The corresponding allyl monomers to those listed above can also be used where appropriate.
More preferred monomers include: amide-containing monomers such as
(meth)acrylamide, N,N'-dimethyl(meth)acrylamide, N and or N'-di(alkyl or aryl) (meth)acrylamide, N-vinyl pyrollidone, (meth)acrylamidopropyl trimethyl ammonium chloride, [3-(methacroylamino) propyl]dimethyl ammonium chloride, 3- [N-(3-methacrylamido-propyl)-N,N-dimethyl]-aminopropane sulfonate, 4-(2- acrylamido-2-methylpropyl-dimethylammonio) butanoate, methyl
acrylamidoglycolate methyl ether and N-isopropyl-(meth)acrylamide; (meth)acrylic acid derivatives such as (meth)acrylic acid, (meth)acryoloyl chloride (or any halide), (alkyl/aryl) (meth)acrylate, oligo-functionalised monomers such as monomethoxy poly(ethyleneglycol) monomethacrylate or monomethoxy poly(propyleneglycol) mono(meth)acrylate, glycerol mono(meth)acrylate, glycidyl (meth)acrylate and sugar mono(meth)acrylates such as glucose
mono(meth)acrylate; vinyl amines such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, t-butylamino (meth)acrylate,
morpholinoethylmethacrylate, or vinyl aryl amines such as vinyl aniline, vinyl pyridine, N-vinyl carbazole, vinyl imidazole; vinyl aryl monomers such as styrene, vinyl benzyl chloride, vinyl toluene, a-methyl styrene, styrene sulfonic acid and vinyl benzoic acid; vinyl hydroxyl monomers such as hydroxyethyl (meth)acrylate, hydroxy propyl (meth)acrylate, glyceryl (meth)acrylate or monomers which can be post-functionalised into hydroxyl groups such as vinyl acetate or acetoxy styrene can also be used; acid-containing monomers such as (meth)acrylic acid, styrene sulfonic acid, vinyl phosphonic, maleic acid, fumaric acid, itaconic acid, 2- acrylamido 2-ethyl propanesulfonic acid and mono-2-(methacryloyloxy)ethyll succinate. Or aryl/alkyl esters thereof. Or carboxylic anhydride containing monomers such as maleic anhydride; zwitterionic monomers such as
(meth)acryloyloxyethyl-phosphoryl choline, quaternised amino monomers such as methacryloyl-oxyethyltrimethyl ammonium chloride.
The corresponding allyl monomer, where applicable, can also be use in each case.
Hydrophobic monomers include: vinyl aryl compounds such as styrene and vinylbenzyl chloride; (meth)acrylic acid esters such as mono-t-butylaminoethyl (meth)acrylate, C1 -20 alkyl(meth)acrylates (linear & branched), aryl(meth) acrylates such as benzyl methacrylate; oligomeric (meth)acrylic acid esters such as mono(alk/aryl)oxyoligo-[dimethylsiloxane (meth)acrylate] and tri(alkyloxy)- silylalkyl (meth)acrylates such as trimethoxysilylpropyl-(meth)acrylate. Functional monomers, i.e. monomers with reactive pendant groups which can be post or pre-modified with another moiety can also be used such as glycidyl (meth)acrylate, trimethoxysilylpropyl(meth)acrylate, (meth)acryloyl chloride, maleic anhydride, hydroxyalkyl (meth)acrylates, (meth)acrylic acid, vinylbenzyl chloride, activated esters of (meth)acrylic acid such as N-hydroxysuccinamido
(meth)acrylate and acetoxystyrene.
The copolymer may contain unreacted polymerisable groups from the
multifunctional monomer.
Cross-linking Agents for Chain-Growth Polymerisation:
Optionally, the core may further comprise a cross-linking agent, derived from a more than di- or multi-functional species, for example an ethylenically unsaturated monomer, a vinyllic monomer, acrylate or methacryate. Tri- and tetra- functional materials are preferred. The benefit of cross-linking agents is to increase robustness of the core, and or decrease permeability. Cross linking agents in the core can modify interaction of the "core" with the benefit agent, e.g. by
modification of the solubility parameters.
The shell does not contain a crosslinking agent.
Cross-linking agents can be used to modify the properties of the chain-growth polymer of the core. Suitable materials comprise a molecule containing at least two vinyl groups that may be polymerised. The molecule may be hydrophilic, hydrophobic, amphiphilic, neutral, cationic, zwitterionic or oligomeric. Examples include di- or multivinyl esters, di- or multivinyl amides, di- or multivinyl aryl compounds and di- or multivinyl alk/aryl ethers. Typically, in the case of oligomeric or multifunctional branching agents, a linking reaction is used to attach a polymerisable moiety to a di- or multifunctional oligomer or a di- or multifunctional group. The brancher may itself have more than one branching point, such as T-shaped divinylic oligomers. In some cases, more than one multifunctional monomer may be used. Macro cross-linkers or macro branchers (multifunctional monomers typically having a molecular weight of at least 1000 Daltons) are generally formed by linking a polymerisable moiety, such as a vinyl or aryl group, to a pre-formed multifunctional polymer via a suitable linking unit such as an ester, an amide or an ether. Examples of suitable polymers include di-functional poly(alkylene oxides) such as poly(ethyleneglycol) or poly(propylene glycol), silicones such as poly(dimethyl-siloxane)s, polymers formed by ring-opening polymerisation such as poly(caprolactone) or poly(caprolactam) or poly-functional polymers formed via living polymerisation such as poly(1 ,4-butadiene). Preferred macro branchers include poly(ethyleneglycol) di(meth)acrylate, poly(propyleneglycol) di(meth)acrylate, (meth)acryloxypropyl-terminated poly (dimethylsiloxane), poly(caprolactone) di(meth)acrylate and poly(caprolactam) di(meth)acrylamide. The corresponding allyl monomers to those listed above can also be used where appropriate.
Preferred multifunctional monomers include but are not limited to divinyl aryl monomers such as divinyl benzene; (meth)acrylate diesters such as glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, propyleneglycol
di(meth)acrylate and 1 ,3-butylenedi(meth)acrylate; oligoalkylene oxide
di(meth)acrylates such as tetra ethyleneglycol di(meth)acrylate,
oligo(ethyleneglycol) di(meth)acrylate and oligo(propyleneglycol) di(meth)- acrylate; divinyl acrylamides such as methylene bis-acrylamide; silicone- containing divinyl esters or amides such as (meth)acryloxypropyl-terminated oligo (dimethyl-siloxane); divinyl ethers such as oligo (ethyleneglycol)-divinyl ether; and tetra- or tri-(meth)acrylate esters such as pentaerythritol tetra-(meth)acrylate, trimethylolpropane tri(meth)acrylate or glucose di- to penta(meth)acrylate. Further examples include vinyl or allyl esters, amides or ethers of pre-formed oligomers formed via ring-opening polymerisation such as oligo(caprolactam) or oligo- (caprolactone), or oligomers formed via a living polymerisation technique such as oligo(1 ,4-butadiene). Especially preferred cross-linkers are divinyl benzene, ethylene glycol
di(meth)acrylate and trimethylolpropane tri(meth)acrylate.
Levels of cross-linker are typically 0-75, preferably 0.0001 to 50, more preferably 0.0001 to 25 mol %.
The Benefit Agent
The benefit agent is a hydrophobic material, which is suitable for application to the skin.
Suitable benefit agents include perfume raw materials (also referred to herein as fragrance), silicone oils, waxes, hydrocarbons, higher fatty acids, essential oils, lipids, skin coolants, vitamins, sunscreens, antioxidants, malodour reducing agents, odour controlling materials, skin softening agents, insect and moth repelling agents, colourants, chelants, sanitization agents, germ control agents , skin care agents, natural actives, antibacterial actives, preservatives,
chemosensates, (for example menthol), sunless-tanning agents (for example dihydroxyacetone), emollients (for example sunflower oil and pertrolatum), antiaging agents, anti-inflammatory agents, skin conditioning agents, skin lightening agents and mixtures thereof. Preferred benefit agents are fragrance, anti-aging agents, anti oxidants, vitamins, antimicrobial agents, anti-bacterial agents, anti-inflammatory actives, skin lightening agents, skin conditioning agents , for example 12-hydroxy stearic acid, oils, insect repellents and sunscreens.
Antimicrobial agents
Preferred antimicrobial agents include quaternary ammonium compounds, biguanides (polyhexamethylene biguanide), phenols (e.g. triclosan, thymol), essential oils (such as Tea Tree Oil and Thyme Oil) and antifungals (preferably Octapyrox, Climbazole, ketoconazole and zinc pyrithione).
Suncreens and skin lightening agents
Examples of sunscreen payloads: UV-B filters such as 2-ethylhexyl-4- methoxycinnamate (sold commercially under the trade name Parsol MCX by DSM), and UV-A filters such as benzophenone or 4-tert-butyl-4'- methoxydibenzoylmethane (Avobenzone, sold commercially under the trade name Parsol 1789 by DSM). Preferred sunscreens and/or skin lightening agents are vitamin B3 compounds. Suitable vitamin B3 compounds are selected from niacin, niacinamide, nicotinyl alcohol, or derivatives or salts thereof. Other vitamins which act as skin lightening agents can be advantageously included in the skin lightening composition to provide for additional skin lightening effects. These include vitamin B6, vitamin C, vitamin A or their precursors. Mixtures of the vitamins can also be employed in the composition of the invention. An especially preferred additional vitamin is vitamin B6. Other non-limiting examples of skin lightening agents useful herein include adapalene, aloe extract, ammonium lactate, arbutin, azelaic acid, butyl hydroxy anisole, butyl hydroxy toluene, citrate esters, deoxyarbutin, 1 ,3 diphenyl propane derivatives, 2, 5 di-hydroxyl benzoic acid and its derivatives, 2-(4- acetoxyphenyl)-1 ,3-dithane, 2-(4- hydroxylphenyl)-1 ,3 diethane, ellagic acid, gluc- pyranosyl-1 -ascorbate, gluconic acid, glycolic acid, green tea extract, 4-Hydroxy- 5-methyl-3[2H]-furanone, hydroquinone, 4-hydroxyanisole and its derivatives, 4- hydroxy benzoic acid derivatives, hydroxycaprylic acid, inositol ascorbate, kojic acid, lactic acid, lemon extract, linoleic acid, magnesium ascorbyl phosphate, 5- octanoyl salicylic acid, 2,4 resorcinol derivatives, 3,5 resorcinol derivatives, salicylic acid, 3,4,5 trihydroxybenzyl derivatives, and mixtures thereof. Preferred sunscreens useful in the present invention are 2-ethylhexyl-p-methoxycinnamate, butyl methoxy dibenzoylmethane, 2-hydroxy-4- methoxybenzophenone, octyl dimethyl-p-aminobenzoic acid and mixtures thereof. Particularly preferred sunscreen is chosen from 2-ethyl hexyl-p-methoxycinnamate, 4,- t-butyl-4'- methoxydibenzoyl-methane or mixtures thereof. Other conventional sunscreen agents that are suitable for use in the skin lightening composition of the invention include 2-hydroxy-4-methoxybenzophenone, octyldimethyl- p-aminobenzoic acid, digalloyltrioleate, 2,2-dihydroxy-4- methoxybenzophenone, ethyl-4-
(bis(hydroxypropyl)) aminobenzoate, 2- ethylhexyl-2- cyano-3,3-diphenylacrylate, 2-ethylhexylsalicylate, glyceryl- p-aminobenzoate, 3,3,5- trimethylcyclohexyl- salicylate, methylanthranilate, p-dimethyl-aminobenzoic acid or aminobenzoate, 2- ethylhexyl-p-dimethyl- amino-benzoate, 2-phenylbenzimidazole-5- sulfonic acid, 2- (p- dimethylaminophenyl)-5-sulfonic benzoxazoic acid and mixtures of these compounds.
Antioxidants, anti-ageing actives and anti-inflammatory actives
Suitable actives include Retinol (Vitamin A), ascorbyl palmitate (Vitamin C palmitate), Cholecalciferol (Vitamin D3), tocopheryl (Vitamin E) acetate, Vitamin E palmitate, linoleic acid (Vitamin F), carotenoids such as beta-carotene and curcumin, phenols and polyphenols (e.g. resveratrol). Preferred anti-oxidants include vitamin E, retinol, antioxiants based on
hydroxytoluene such as Irganox™ or commercially available antioxidants such as the Trollox™ series. Perfumes
Perfume and fragrance materials (which include pro-fragrances) are a particularly preferred benefit agent.
The pro-fragrance can, for example, be a food lipid. Food lipids typically contain structural units with pronounced hydrophobicity. The majority of lipids are derived from fatty acids. In these 'acyl' lipids the fatty acids are predominantly present as esters and include mono-, di-, triacyl glycerols, phospholipids, glycolipids, diol lipids, waxes, sterol esters and tocopherols. In their natural state, plant lipids comprise antioxidants to prevent their oxidation. While these may be at least in part removed during the isolation of oils from plants some antioxidants may remain. These antioxidants can be pro-fragrances. In particular, the carotenoids and related compounds including vitamin A, retinol, retinal, retinoic acid and provitamin A are capable of being converted into fragrant species including the ionones, damascones and damscenones. Preferred pro-fragrance food lipids include olive oil, palm oil, canola oil, squalene, sunflower seed oil, wheat germ oil, almond oil, coconut oil, grape seed oil, rapeseed oil, castor oil, corn oil, cottonseed oil, safflower oil, groundnut oil, poppy seed oil, palm kernel oil, rice bran oil, sesame oil, soybean oil, pumpkin seed oil, jojoba oil and mustard seed oil.
The perfume is typically present in an amount of from 10-85% by total weight of the particle, preferably from 15 to 75% by total weight of the particle. The perfume suitably has a molecular weight of from 50 to 500Dalton. Pro-fragrances can be of higher molecular weight, being typically 1 -10 kD. Useful components of the perfume include materials of both natural and synthetic origin. They include single compounds and mixtures. Specific examples of such components may be found in the current literature, e.g., in Fenaroli's Handbook of Flavour Ingredients, 1975, CRC Press; Synthetic Food Adjuncts, 1947 by
M. B. Jacobs, edited by Van Nostrand; or Perfume and Flavour Chemicals by S. Arctander 1969, Montclair, N.J. (USA). These substances are well known to the person skilled in the art of perfuming, flavouring, and/or aromatizing consumer products, i.e., of imparting an odour and/or a flavour or taste to a consumer product traditionally perfumed or flavoured, or of modifying the odour and/or taste of said consumer product.
By perfume in this context is not only meant a fully formulated product fragrance, but also selected components of that fragrance, particularly those which are prone to loss, such as the so-called 'top notes'.
Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80 [1955]). Examples of well known top-notes include citrus oils, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol. Top notes typically comprise 15-25%wt of a perfume composition and in those embodiments of the invention which contain an increased level of top-notes it is envisaged at that least 20%wt would be present within the particle.
Typical perfume components which it is advantageous to employ in the
embodiments of the present invention include those with a relatively low boiling point, preferably those with a boiling point of less than 300, preferably 100-250 Celsius.
It is also advantageous to encapsulate perfume components which have a low LogP (i.e. those which will be partitioned into water), preferably with a LogP of less than 3.0. These materials, of relatively low boiling point and relatively low LogP have been called the "delayed blooming" perfume ingredients and include the following materials:
Allyl Caproate, Amyl Acetate, Amyl Propionate, Anisic Aldehyde, Anisole,
Benzaldehyde, Benzyl Acetate, Benzyl Acetone, Benzyl Alcohol, Benzyl Formate, Benzyl Iso Valerate, Benzyl Propionate, Beta Gamma Hexenol, Camphor Gum, Laevo-Carvone, d-Carvone, Cinnamic Alcohol, Cinamyl Formate, Cis-Jasmone, cis-3-Hexenyl Acetate, Cuminic Alcohol, Cyclal C, Dimethyl Benzyl Carbinol, Dimethyl Benzyl Carbinol Acetate, Ethyl Acetate, Ethyl Aceto Acetate, Ethyl Amyl Ketone, Ethyl Benzoate, Ethyl Butyrate, Ethyl Hexyl Ketone, Ethyl Phenyl Acetate, Eucalyptol, Eugenol, Fenchyl Acetate, Flor Acetate (tricyclo Decenyl Acetate), Frutene (tricyclco Decenyl Propionate), Geraniol, Hexenol, Hexenyl Acetate, Hexyl Acetate, Hexyl Formate, Hydratropic Alcohol, Hydroxycitronellal, Indone, Isoamyl Alcohol, Iso Menthone, Isopulegyl Acetate, Isoquinolone, Ligustral, Linalool, Linalool Oxide, Linalyl Formate, Menthone, Menthyl Acetphenone, Methyl Amyl Ketone, Methyl Anthranilate, Methyl Benzoate, Methyl Benyl
Acetate, Methyl Eugenol, Methyl Heptenone, Methyl Heptine Carbonate, Methyl Heptyl Ketone, Methyl Hexyl Ketone, Methyl Phenyl Carbinyl Acetate, Methyl Salicylate, Methyl-N-Methyl Anthranilate, Nerol, Octalactone, Octyl Alcohol, p- Cresol, p-Cresol Methyl Ether, p-Methoxy Acetophenone, p-Methyl
Acetophenone, Phenoxy Ethanol, Phenyl Acetaldehyde, Phenyl Ethyl Acetate, Phenyl Ethyl Alcohol, Phenyl Ethyl Dimethyl Carbinol, Prenyl Acetate, Propyl Bornate, Pulegone, Rose Oxide, Safrole, 4-Terpinenol, Alpha-Terpinenol, and/or Viridine
It is commonplace for a plurality of perfume components to be present in a formulation. In the encapsulates of the present invention it is envisaged that there will be four or more, preferably five or more, more preferably six or more or even seven or more different perfume components from the list given of delayed blooming perfumes given above present in the particles. Aromatherapy benefit agents
Another group of perfumes with which the present invention can be applied are the so-called 'aromatherapy' materials. These include many components also used in perfumery, including components of essential oils such as Clary Sage, Eucalyptus, Geranium, Lavender, Mace Extract, Neroli, Nutmeg, Spearmint, Sweet Violet Leaf and Valerian.
Insect repellents
The benefit agent may also be an insect repellent material (where insect should be read broadly to include other pests which are arthropods but not strictly hexapods - for example ticks). Many of these materials overlap with the class of perfume components and some are odourless to humans or have a non-perfume odour. Commonly used repellents include: DEET (N,N-diethyl-m-toluamide), essential oil of the lemon eucalyptus (Corymbia citriodora) and its active compound p-menthane-3,8-diol (PMD), lcaridin, also known as Picaridin, D- Limonene, Bayrepel, and KBR 3023, Nepetalactone, also known as "catnip oil", Citronella oil, Permethrin, Neem oil and Bog Myrtle. Known insect repellents derived from natural sources include: Achillea alpina, alpha-terpinene, Basil oil (Ocimum basilicum), Callicarpa americana (Beautyberry), Camphor, Carvacrol, Castor oil (Ricinus communis), Catnip oil (Nepeta species), Cedar oil (Cedrus atlantica), Celery extract (Apium graveolens), Cinnamon (Cinnamomum
Zeylanicum, leaf oil), Citronella oil (Cymbopogon fleusus), Clove oil (Eugenic caryophyllata), Eucalyptus oil (70%+ eucalyptol, also known as cineol), Fennel oil (Foeniculum vulgare), Garlic Oil (Allium sativum), Geranium oil (also known as Pelargonium graveolens), Lavender oil (Lavandula officinalis), Lemon eucalyptus (Corymbia citriodora) essential oil and its active ingredient p-menthane-3,8-diol (PMD), Lemongrass oil (Cymbopogon flexuosus), Marigolds (Tagetes species), Marjoram (Tetranychus urticae and Eutetranychus orientalis), Neem oil (Azadirachta indica), Oleic acid, Peppermint (Mentha x piperita), Pennyroyal (Mentha pulegium), Pyrethrum (from Chrysanthemum species, particularly C. cinerariifolium and C. coccineum), Rosemary oil (Rosmarinus officinalis), Spanish Flag Lantana camara (Helopeltis theivora), Solanum villosum berry juice, Tea tree oil (Melaleuca alternifolia) and Thyme (Thymus species) and mixtures thereof.
The encapsulate optionally comprises a carrier oil (also referred to herein as a diluent). It will be clear to a skilled person which oils are suitable for use with a certain benefit composition. The carrier oils are hydrophobic materials that are miscible in the benefit agent materials used in the present invention.
Suitable oils are those having reasonable affinity for the benefit agent.
Suitable materials include, but are not limited to triglyceride oil, mono and diglycerides, mineral oil, silicone oil, diethyl phthalate, polyalpha olefins, castor oil and isopropyl myristate. Preferably, the oil is a triglyceride oil, most preferably a capric/caprylic triglyceride oil.
Method of Manufacture
Polymerisation occurs in at least two phases. In an earlier of these phases a core is formed by a chain-growth polymerisation. A shell is subsequently formed by another chain-growth polymerisation.
Temporal separation of these phases is accomplished by control of the reagents present and the reaction conditions.
A preferred embodiment of the present invention provides a particle obtainable by a method comprising: Forming a core by:
a) fornning an emulsion, preferably having a volume mean dispersed particle size diameter of less than 1000nm, more preferably less than 500nm and having a dispersed non-aqueous phase comprising: i) a hydrophobic benefit agent, ii) at least one monomer, preferably acrylate or methacrylate, capable of chain-growth polymerisation, and, a continuous aqueous phase comprising: i) water, and ii) an emulsifying agent, b) adding an initiator, and c) maintaining the emulsion at a temperature at which the chain-growth
polymerisation proceeds to form the core; and forming a shell around the core by: adding to the core i) at least one monomer, preferably acrylate or methacrylate, capable of chain-growth polymerisation, and ii) an initiator; and b) maintaining the mixture at a temperature at which the chain-growth polymerisation proceeds.
Advantageously, the above described method provides a potentially "one-pot" reaction which has the advantages of simplicity and reduced losses: i.e. the core is first formed by chain-growth polymerisation and the shell is subsequently formed around the shell by another chain-growth polymerisation.
Alternatively, preformed core particles may first be obtained and the shell applied at a later time.
The benefit agent may be present in the reaction mixture, at a level to give the benefit agent levels in the resulting particles at the levels disclosed above, although it is also possible to form "empty" particles and subsequently expose them to a benefit agent which can be adsorbed into the core. Thus, the particles and the benefit agent may be added separately such that the particles take up the benefit agent in the composition.
The compositions of the invention are preferably prepared by a method comprising the following:-
Carrier (preferably water), antiperspirant active (preferably aluminium
chlorhydrate), and optional further active materials are mixed with
heating to the desired processing temperature (typically 50 °C), to form
a first phase.
Hydrophobic skin benefit agent and a surfactant are melted together
with stirring, to form a second phase, before being cooled to the
processing temperature. The first and second phases are mixed,
followed by the addition of the particles (which are prepared as
described above) and cooling to a lower temperature, typically 40 °C or below, whereupon a fragrance may be added. The mixture may be milled if desired.
Emulsifying Agents
Many emulsifying agents are known for use in emulsion polymerisation. Suitable emulsifying agents for use in the polymerisation process may comprise, but are not limited to, non-ionic surfactants such as polyvinylpyrrolidone (PVP), polyethylene glycol sorbitan monolaurate (Tween 20), polyethylene glycol sorbitan monopalmitate (Tween 40), polyethylene glycol sorbitan monooleate (Tween 80), polyvinyl alcohol (PVA), and poly(ethoxy)nonyl phenol, ethylene maleic anhydride (EMA) copolymer, Easy-Sperse™ (from ISP Technologies Inc.), ionic surfactants such as partially neutralized salts of polyacrylic acids such as sodium or potassium polyacrylate or sodium or potassium polymethacrylate. Brij™-35, Hypermer™ A 60, or sodium lignosulphate, and mixtures thereof.
Emulsifiers may also include, but are not limited to, acrylic acid-alkyl acrylate copolymer, poly(acrylic acid), polyoxyalkylene sorbitan fatty esters, polyalkylene co-carboxy anhydrides, polyalkylene co-maleic anhydrides, poly(methyl vinyl ether-co-maleic anhydride), poly(propylene-co-maleic anhydride), poly(butadiene co-maleic anhydride), and polyvinyl acetate-co-maleic anhydride), polyvinyl alcohols, polyalkylene glycols, polyoxyalkylene glycols, and mixtures thereof.
Preferred emulsifying agents are fatty alcohol ethoxylates (particularly of the Brij™ class), salts of ether sulphates (including SLES), alkyl and alkaryl sulphonates and sulphates (including LAS and SDS) and cationic quaternary salts (including CTAC and CTAB).
It is particularly preferred that the emulsifying agent comprises a non-ionic surfactant. This is believed to produce a particle which deposits better on cloth than one produced solely with an anionic surfactant emulsifier, as cloth become anionic during a wash. It is also preferred that the non-ionic surfactant is hydrophilic, so as to promote the formation of a stable mini-emulsion. The alcohol ethoxylates with more than ten moles of ethoxylation, for example Synperonic A20 (C1320EO), yield good results. DLS data for samples shows that as the level of surfactant increases the particle size becomes smaller, which is also
advantageous. Preferably, the ratio of non-ionic to anionic emulsifier should be greater than 1 :1 (i.e. non-ionic is present in excess) and the total surfactant level should be >3%wt of the polymerisation mixture.
Co-surfactant:
Typically a co-surfactant will be present in the dispersed phase and in the resulting particle. Suitable co-surfactants for use in the present invention include hexadecane, cetyl alcohol, lauroyl peroxide, n-dodecyl mercaptan, dodecyl methacrylate, stearyl methacrylate, polystyrene, polydecene, mineral oils, isopropyl myristate, C12-C15 alkyl benzoate and polymethyl methacrylate.
The preferred cosurfactants comprise hexadecane, polydecene and isopropyl myristate.
As a wt% of oil phase as a total, the co-surfactant is typically 0-20%, preferably 1 - 15%, more preferably 2-12.5%. Polymerisation Conditions
As noted above, polymerisation typically occurs in at least two phases (where a shell is present). In the earlier phase the core is formed by a reaction which, in preferred embodiments occurs at less than about 95 Celsius, typically 55-90 Celsius. In the optional later phase the shell monomer is added and polymerised at a preferred temperature of 55-90 Celcius.
Both reactions are allowed to proceed for sufficiently long for polymerisation to be essentially complete, 1 -3 hours being typical for each stage.
For simple core-shell particles, the core excluding benefit agent is less than or equal to 90%wt of mass, and the shell generally 10%wt or greater of the mass of the particle.
The Active Ingredient
The active ingredient is an antiperspirant active.
When employed, the antiperspirant active is typically one containing aluminium and/or zirconium. Such actives are water-soluble and are may be fully dissolved in an aqueous continuous phase of the composition.
The antiperspirant active is typically selected from astringent salts, including both inorganic salts, salts with organic anions, and complexes. Preferred
antiperspirant actives are aluminium, zirconium, and aluminium-zirconium chlorides, oxychlorides, and chlorohyd rates salts. Particularly preferred antiperspirant actives are polynuclear in nature, meaning that the cations of the salt are associated into groups comprising more than one metal ion. Aluminium halohydrates are especially preferred antiperspirant actives and may be defined by the general formula AI2(OH)xQy.wH20, in which Q represents chlorine, bromine or iodine, x is variable from 2 to 5 and x + y = 6 while wH2O represents a variable amount of hydration. Aluminium chlorohydrate (ACH) is the most preferred active. Zirconium salts are usually defined by the general formula ZrO(OH)2-xQx.wH2O in which Q represents chlorine, bromine or iodine; x is from about 1 to 2; w is from about 1 to 7; and x and w may both have non-integer values. Particular zirconium salts are zirconyl oxyhalides, zirconiun hydroxyhalides, and combinations thereof.
Antiperspirant actives as used in the invention may be present as mixtures or complexes. Suitable aluminium-zirconium complexes often comprise a compound with a carboxylate group, for example an amino acid. Examples of suitable amino acids include tryptophan, β-phenylalanine, valine, methionine, β-alanine and, most preferably, glycine.
In some embodiments, it is desirable to employ complexes of a combination of aluminium halohydrates and zirconium chlorohyd rates with amino acids such as glycine, which are disclosed in US 3,792,068 (Procter and Gamble Co.). Certain of these Al/Zr complexes are commonly called ZAG in the literature. ZAG actives generally contain aluminium, zirconium and chloride with an Al/Zr ratio in a range from 2 to 10, especially 2 to 6, an AI/CI ratio from 2.1 to 0.9 and a variable amount of glycine. Particularly in anhydrous formulations, it is especially desirable to employ what is commonly called activated aluminium chlorohydrate or enhanced activity aluminium chlorohydrate, sometimes abbreviated to AACH, in which the proportion of the more active species is higher by virtue of its method of manufacture. In one definition of activated, given in EP 6739, the material has greater than 20% Band III. Other methods of making AACH are given in EP 191628 and EP 451395.
Antiperspirant actives, when employed, are preferably incorporated in an amount of from 0.5 to 60%, particularly from 5 to 30% or 40% and especially from 10% to 30% of the total composition. Further Optional Ingredients
The compositions for use in the invention may contain one or more other ingredients. Formulated compositions comprising the particles of the invention may contain a surface-active compound (surfactant) which may be chosen from soap and non soap anionic, cationic, non-ionic, amphoteric and zwitterionic surface active compounds and mixtures thereof. Many suitable surface active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch. The preferred surface-active compounds that can be used are soaps and synthetic non soap anionic, and non-ionic compounds.
Preferred deodorant actives that are not antiperspirant actives that may be employed include antimicrobial actives such as polyhexamethylene biguanides, e.g. those available under the trade name Cosmocil™ or chlorinated aromatics, e.g. triclosan available under the trade name Irgasan™, non-microbiocidal deodorant actives such as triethylcitrate, bactericides and bacteriostats. Yet other deodorant actives can include zinc salts such as zinc ricinoleate. The
compositions can additionally or alternatively contain, as a deodorant, an iron chelator such as pentenoic acid which hinders bacterial growth/reproduction. The proportion of the deodorant active in the formulation is often selected in the range of from about 0.05 to 2% and especially from 0.1 to 0.5% by weight. Such ingredients include further preservatives (e.g. bactericides), pH buffering agents, perfume carriers, anti-redeposition agents, soil-release agents,
polyelectrolytes, anti-shrinking agents, anti-wrinkle agents, anti-oxidants, sunscreens, anti-corrosion agents, drape imparting agents, anti-static agents, pearlisers and/or opacifiers, natural oils/extracts, processing aids, eg electrolytes, hygiene agents, eg anti-bacterials and antifungals, thickeners, skin benefit agents, colourants, whiteners, optical brighteners, soil suspending agents, detersive enzymes, compatible bleaching agents (particularly peroxide compounds and active chlorine releasing compounds), gel-control agents, freeze-thaw stabilisers, bactericides, preservatives (for example 1 ,2-benzisothiazolin-3-one), hydrotropes, perfumes and mixtures thereof.
The compositions for use in the invention may also contain pH modifiers such as hydrochloric acid or lactic acid.
Use in Products
The end-product compositions of the invention may be in any suitable physical form e.g. a solid such as a solid bar, a paste; or a liquid or gel, preferably, an aqueous-based liquid. Where the composition is in the form of an aqueous based liquid, it is advantageously in the form of a cream, a roll-on or a lotion.
The particles are typically included in said compositions at levels of from 0.01 % to 10%, preferably from 0.5% to 7%, most preferably from 0.5% to 5% by weight of the total composition.
In order that the present invention may be still further understood and carried forth into practice it will be further described with reference to the following examples:
EXAMPLES
Example 1 - Preparation of particle P1 A particle, P1 , having a poly acrylate core and a poly acrylate shell was synthesised by miniemulation polymerisation as follows:-
A) Synthesis of Core by Miniemulsion Polymerisation. A surfactant stock solution was prepared by dissolving 0.75 g SLES- 1 EO (Texapon N701 - Clariant) in 50 ml demineralised water. 1 g of hexadecane (a skin benefit agent) and 20 g of butyl methacrylate monomer were weighed into a 125 ml glass jar. To this 8 g of surfactant stock solution and 66.6g water was added and the mixture gently shaken to form a crude emulsion. Using a sonic probe (Branson Digital Sonfier 450D), the crude emulsion was sonicated at 60 % amplitude for 1 .5 min, the jar resealed, shaken and sonicated at 60% amplitude for a further 1 .5 min. The miniemulsion was charged to a 250 mL 2-neck round bottom flask fitted with a condenser and an overhead stirrer and heated to 85 °C. Once the miniemulsion had reached the desired temperature the initiation system (0.2 g Sodium bicarbonate in 2 mL water plus 0.2 g ammonium persulphate in 2 mL water) was added over a two minute period and the reaction left to polymerise for 3 hours. Subsequently, the reaction was cooled and filtered through
BioPrepNylon synthetic cheesecloth (50 μιτι). The reaction vessel and stirrer were checked for signs of coagulation and grit formation. Final solids content was determined by gravimetric analysis and the particle size determined by dynamic light scattering. (20.2 % solids and 166 nm particle size.) B) Addition of Methyl methacrylate Shell.
100 g miniemulsion prepared via the above example was transferred to a 250m L 3-neck reaction flask fitted with an overhead stirrer and condenser. The emulsion was heated to 80°C with stirring at 2300 rpm. Initiator solutions were prepared by dissolving 0.05 g ammonium persulfate in 1 ml water and 0.05 g sodium bicarbonate in 2 ml water and added via pipette. The shell monomer, 3 g methyl methacrylate, was added dropwise via syringe pump over the course of 60 minutes. After complete monomer addition, the reaction was stirred for a further 1 .5 hours. 0.015 g ascorbic acid in mL water and 0.015 g t-butyl hydroperoxide were added subsequently, and the reaction allowed to stir for a further 30 minutes after which, the reaction was cooled to room temperature and filtered through BioPrepNylon synthetic cheesecloth (50 microns).
Final solids content was determined by gravimetric analysis and the particle size determined by dynamic light scattering. (P1 : 21 .6 % solids and 195 nm particle size.)
Example 2: Preparation of antiperspirant composition DP1
Particles P1 , of example 1 , were incorporated into a antiperspirant composition, to form antiperspirant composition DP1 . Table 1 : Composition of antiperspirant composition DP1 , comprising P1
Figure imgf000034_0001
Water, aluminium chlorohydrate, steareth-20 were mixed and heated to 50°C with overhead stirring at 250rpm. The sunflower oil, steareth-2 were melted at 70°C and mixed, before being cooled to 50°C. The oil- phase mixture was added to aqueous-phase mixture over 5 minutes. The particle, P1 , was added, followed by cooling to 40°C. Fragrance was added and mixed for 2 minutes. The mixture was milled using a Silverson high shear mixer at 6500rpm for 2 minutes.
Example 3: Fragrance uptake by particles P1 in antiperspirant composition DP1
5g of antiperspirant composition DP1 was transferred to a 20ml_ glass solid-phase microextraction (SPME) vial and the vial was sealed. Each test antiperspirant formulation was tested in triplicate. The vials were left for 7 days at ambient conditions, before fragrance headspace
assessment using gas chromatography/mass spectroscopy (GCMS), using the following conditions: Gas chromatographic conditions:
• Column: Agilent HP5 column (30 m length, 0.32 mm diameter, 0.25 micron film thickness)
• Injector Temperature: 270 °C
• Initial Oven Temperature: 60 °C
• Temperature programme: Initial temperature 60 °C, Hold for 1 minute
Ramp at rate of 5 °C per minute up to 280 °C
• Column flow: 1 .69 mL/min
• Total run time: 45 minutes
Mass spectrometric conditions:
• Ion source temperature : 200 °C
• Interface temperature : 290 °C
• Solvent delay: 6 minutes
• The fragrance components were identified using a Total Ion Count (TIC) method, and Selected Ion monitoring (SIM) method was used for the quantification of analytes.
Sampling (SPME) conditions:
• SPME fibre for extraction of analytes: SPME fibre assembly of 23-Gauge, 50/30 microns, DVB/CAR/PDMS was used for the extraction of the analytes from the sample headspace
• Sample pre-incubation time : 20 minutes at 35°C
• SPME-fibre absorption time: 10 seconds at 35 °C
• SPME-fibre desorption time: 2 minutes at 270°C
The following table shows uptake of fragrance components into the particle. Table 2: Uptake of fragrance components into particle P1 in composition DP1 , after 7 days storage.
Figure imgf000036_0001
* % uptake = 00-((average MS peak area for particle-containing base/ average MS peak area for control base)*100)
It can be seen that fragrance components were absorbed into the particle in the composition of the invention. Example 4: Fragrance release by particles P1 in antiperspirant composition DP1
Antiperspirant formulation, DP1 , was applied to 70x70mm2 squares of
polyester fabric for assessment. 12 fabric squares were prepared and
placed in a chamber at 35°C and 80%RH. Three fabric squares were
removed after the following time intervals: 30 minutes, 1 hour, 4 hours
and 16 hours. A set of three fresh fabric squares was also prepared. Each fabric square was placed in a 20ml_ SPME vial, along with 10g of
GC-grade tetrahydrofuran (THF). The vial was agitated using a bottle- roller for 6 hours. 2 mL of tetrahydrofuran solution was removed from the vial, filtered and analysed by liquid-injection GCMS, using the following
conditions:
Gas chromatographic conditions:
• Column: Agilent HP5 column (30 m length, 0.32 mm diameter, 0.25 micron film thickness)
• Injector Temperature: 270 °C
· Initial Oven Temperature: 60 °C
• Temperature programme: Initial temperature 60 °C, hold for 1 minute
Ramp at rate of 5 °C per minute up to 280 °C
• Column flow: 1 .69 mL/min
• Total run time: 45 minutes
Mass spectrometric conditions
• Ion source temperature: 200 °C
• Interface temperature: 290 °C
• Solvent delay: 6 minutes • The fragrance components were identified using a Total Ion Count (TIC) method, and Selected Ion monitoring (SIM) method was used for the quantification of analytes. Sampling (Liquid Injection) Conditions:
• Liquid Injection volume: 1 microlitre.
DP1 , containing particle P1 , was assessed using the release test described above. The results are shown in Table 3 below.
Table 3: Release of fragrance components from composition DP1 at 0,
4 and 16 h storage.
Figure imgf000038_0001
It was seen that the presence of the particle inhibited the loss of fragrance during ageing. Example 5: Preparation of particle P2 in accordance with the invention, and comparative particle PA.
Table 4: Composition of particle P2 in accordance with the invention and comparative particle PA.
Figure imgf000039_0001
The particles shown in Table 4 above were prepared as follows:- A 2.5 % (wt/wt) stock solution of sodium dodecyl sulfate and Synperonic A7 was prepared; this consisted of 2.5 g sodium dodecyl sulfate and 10 g A7 in 500 ml of deionised water. The aqueous phase was prepared using this stock solution and a further portion of deionised water. An organic phase containing 30 g of monomer (as shown in Table 4 above) and 1 .5 g hexadecane was measured out. These phases were mixed and then homogenised for 2 x 2.5 minutes with the ultrasonic probe at 50 % amplitude (Branson Digital Sonfier 450D). The resulting
miniemulsion was then charged into a 250 ml tornado flask. The temperature was set to 85 °C and stirring speed to 200 rpm. 0.45g of ascorbic acid was dissolved in 4.05 ml_ of water and added to the tornado flask. 0.45 g of t-butyl hydroperoxide were dissolved in 4.05 ml_ of water and added to the tornado flask at the rate of 0.5ml_ every 5 minutes. The reaction was then left to proceed for 2 hours to yield the particles. Example 6: Fragrance uptake by particle P2 and comparative particle PA.
Particles P2 and PA, of example 5, were incorporated into a antiperspirant composition, to form antiperspirant compositions DP2 and DPA.
Table 5: Composition of antiperspirant composition DP2, comprising P2
Figure imgf000040_0001
Water, aluminium chlorohydrate, steareth-20 were mixed and heated to 50°C with overhead stirring at 250rpm. The sunflower oil, steareth-2 were melted at 70°C and mixed, before being cooled to 50°C. The oil- phase mixture was added to aqueous-phase mixture over 5 minutes. The particle, P2, was added, followed by cooling to 40°C. Fragrance was added and mixed for 2 minutes. The mixture was milled using a Silverson high shear mixer at 6500rpm for 2 minutes. Fragrance uptake by particle P2 and comparative particle PA.
5g of each antiperspirant composition was transferred to a 20ml_ glass solid-phase microextraction (SPME) vials and the vials were sealed. Each test antiperspirant formulation was tested in triplicate. The vials were left for 7 days at ambient conditions, before fragrance SPME
headspace assessment using gas chromatography/mass spectroscopy
(GCMS), using the following conditions:
Gas chromatographic conditions:
• Column: Agilent DB-624 column (60 m length, 0.25 mm diameter, 1 .4 micron film thickness)
• Injector Temperature: 250 °C
· Initial Oven Temperature: 45 °C
• Temperature programme: Initial temperature 45 °C, Hold for 1 minute
Ramp at rate of 5 °C per minute up to 240 °C
Mass spectrometric conditions
· Ion source temperature : 200 °C
• Interface temperature : 250 °C
• Solvent delay: 6 minutes
• The fragrance components were identified using a Total Ion Count (TIC) method, and Selected Ion monitoring (SIM) method was used for the quantification of analytes.
Sampling (SPME) conditions:
• SPME fibre for extraction of analytes: SPME fibre assembly of 23-Gauge, 50/30 microns, DVB/CAR/PDMS was used for the extraction of the analytes from the sample headspace
• Sample pre-incubation time : 20 minutes at 35°C
• SPME-fibre absorption time: 10 seconds at 35 °C
• SPME-fibre desorption time: 2 minutes at 250°C

Claims

Claims
1 . A composition comprising: a) a particle, wherein the particle comprises, i) a core comprising a solid polymer formed by chain-growth
polymerisation reaction, and a hydrophobic skin benefit agent, which is liquid at room temperature; and b) an active material, which is an antiperspirant active; wherein the chain-growth polymerisation reaction is a radical polymerisation reaction, preferably of at least one ethylenically unsaturated monomer, and wherein the ethylenically unsaturated, monomer is selected from C1-C20 linear or branched, alkyl acrylates and methacrylates, and wherein the particle has a volume average diameter of less than 1 micron, and wherein the particle further comprises a shell comprising a polymer formed by chain growth polymerisation of non-crosslinked monomers.
2. A composition as claimed in claim 1 , wherein the non-crosslinked monomers are selected from C1-C20 linear or branched, alkyl acrylates and methacrylates.
3. A composition according to any preceding claim, wherein the core further comprises at least one cross-linking agent.
4. A composition according to any preceding claim wherein the particle has an average diameter of from 200 to 300 nm.
5. A composition according to any preceding claim wherein the hydrophobic skin benefit agent is selected from perfumes, anti-aging agents, anti oxidants, vitamins, antimicrobial agents, anti-bacterial agents, anti-inflammatory actives, skin lightening agents, skin conditioning agents, oils, insect repellents and sunscreens.
6. A composition according to any preceding claim wherein the active material is selected from surfactants, cleaning agents, solvents, polymers, antiperspirant actives and mixtures thereof.
7. A composition according to any preceding claim obtainable by a method comprising;
A) forming a particle by:- forming a core by: a) forming an emulsion, preferably having a volume mean dispersed
particle size diameter of less than 10OOnm, more preferably less than 500nm and having a dispersed non-aqueous phase comprising: i) a hydrophobic skin benefit agent, ii) at least one monomer, preferably acrylate or methacrylate,
capable of chain-growth polymerisation, and, a continuous aqueous phase comprising: i) water, and
ii) an emulsifying agent, b) adding an initiator, and c) maintaining the emulsion at a temperature at which the chain-growth polymerisation proceeds to form the core; and forming a shell around the core by:
adding to the core i) at least one monomer, preferably acrylate or methacrylate, capable of chain-growth polymerisation, and ii) an initiator; and c) maintaining the mixture at a temperature at which the chain-growth polymerisation proceeds, and
B) forming a composition comprising the particles of A) by:- combing a carrier, antiperspirant active, and optional further active materials with heating to the desired processing temperature (typically
50 °C), to form a first phase; melting together a hydrophobic skin benefit agent and a surfactant with stirring, to form a second phase, before being cooled to the processing temperature; mixing the first and second phases, followed by the addition of the particles of step A and cooling to a lower temperature, typically 40 °C or below, and adding an optional fragrance.
8. A composition according to claim 8 wherein the at least one monomer capable of chain growth polymerisation for forming the shell, comprises a monomer selected from C1-C20 linear or branched, alkyl acrylates and
methacrylates.
9. A composition as claimed in claim 8 or claim 9, in which the particles and the benefit agent are added separately such that the particles take up the benefit agent in the composition.
10. A method of treatment of skin, which includes the step of applying to the skin a composition as defined in any of claims 1 to 1 1 .
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113383881A (en) * 2021-04-30 2021-09-14 河南中大恒源生物科技股份有限公司 Liquid water-soluble curcumin, and preparation method and application thereof

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3792068A (en) 1971-04-02 1974-02-12 Procter & Gamble Dry powder aerosol antiperspirant composition incorporating dry powder antiperspirant active complex and process for its preparation
EP0191628A2 (en) 1985-02-13 1986-08-20 Unilever Plc Preparation of basic aluminium halides
EP0451395A1 (en) 1986-03-27 1991-10-16 Unilever Plc Preparation of basic aluminium chlorides
JP2000143483A (en) 1998-11-06 2000-05-23 Kao Corp Cosmetic
US20030039671A1 (en) 2001-07-16 2003-02-27 Florence Tournilhac Cosmetic composition comprising a particle dispersion
US20030044440A1 (en) 2001-07-16 2003-03-06 Beatrice Toumi Cosmetic composition comprising a particle dispersion
US20030053976A1 (en) 2001-07-16 2003-03-20 Florence Tournilhac Cosmetic composition comprising a particle dispersion
WO2005107683A1 (en) 2004-04-30 2005-11-17 The Procter & Gamble Company Long-wearing cosmetic compositions
WO2005107684A1 (en) 2004-04-30 2005-11-17 The Procter & Gamble Company Long-wearing cosmetic compositions with improved shine
WO2012006402A1 (en) 2010-07-09 2012-01-12 Lubrizol Advanced Materials, Inc. Structured acrylate copolymer thickeners
WO2012007438A1 (en) 2010-07-15 2012-01-19 Unilever Plc Benefit delivery particle, process for preparing said particle, compositions comprising said particles and a method for treating substrates
WO2012044929A2 (en) 2010-09-30 2012-04-05 Lubrizol Advanced Materials, Inc. Structured acrylate copolymer for use in multi-phase systems

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0513803D0 (en) * 2005-07-06 2005-08-10 Unilever Plc Fabric care composition
GB0524665D0 (en) * 2005-12-02 2006-01-11 Unilever Plc Laundry composition
US9186642B2 (en) * 2010-04-28 2015-11-17 The Procter & Gamble Company Delivery particle
WO2013107586A2 (en) * 2012-01-17 2013-07-25 Unilever Plc Benefit delivery particle, process for preparing said particle, compositions comprising said particles and a method for treating substrates
WO2013107581A1 (en) * 2012-01-18 2013-07-25 Unilever Plc Gelled cosmetic compositions with encapsulated fragrance

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3792068A (en) 1971-04-02 1974-02-12 Procter & Gamble Dry powder aerosol antiperspirant composition incorporating dry powder antiperspirant active complex and process for its preparation
EP0191628A2 (en) 1985-02-13 1986-08-20 Unilever Plc Preparation of basic aluminium halides
EP0451395A1 (en) 1986-03-27 1991-10-16 Unilever Plc Preparation of basic aluminium chlorides
JP2000143483A (en) 1998-11-06 2000-05-23 Kao Corp Cosmetic
US20030039671A1 (en) 2001-07-16 2003-02-27 Florence Tournilhac Cosmetic composition comprising a particle dispersion
US20030044440A1 (en) 2001-07-16 2003-03-06 Beatrice Toumi Cosmetic composition comprising a particle dispersion
US20030053976A1 (en) 2001-07-16 2003-03-20 Florence Tournilhac Cosmetic composition comprising a particle dispersion
WO2005107683A1 (en) 2004-04-30 2005-11-17 The Procter & Gamble Company Long-wearing cosmetic compositions
WO2005107684A1 (en) 2004-04-30 2005-11-17 The Procter & Gamble Company Long-wearing cosmetic compositions with improved shine
WO2012006402A1 (en) 2010-07-09 2012-01-12 Lubrizol Advanced Materials, Inc. Structured acrylate copolymer thickeners
WO2012007438A1 (en) 2010-07-15 2012-01-19 Unilever Plc Benefit delivery particle, process for preparing said particle, compositions comprising said particles and a method for treating substrates
WO2012044929A2 (en) 2010-09-30 2012-04-05 Lubrizol Advanced Materials, Inc. Structured acrylate copolymer for use in multi-phase systems

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
"Fenaroli's Handbook of Flavour Ingredients", 1975, CRC PRESS
M. B. JACOBS: "Synthetic Food Adjuncts", 1947
PAUL J. FLORY: "Principles of Polymer Chemistry", 1953, CORNELL UNIVERSITY PRESS, ISBN: 0801401348, pages: 39
S. ARCTANDER: "Perfume and Flavour Chemicals", 1969

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113383881A (en) * 2021-04-30 2021-09-14 河南中大恒源生物科技股份有限公司 Liquid water-soluble curcumin, and preparation method and application thereof
CN113383881B (en) * 2021-04-30 2023-08-29 河南中大恒源生物科技股份有限公司 Liquid water-soluble curcumin and preparation method and application thereof

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