CA2100045A1 - Inclusion complexes of clavulanic acid and of alkali salts thereof with hydrophilic and hydrophobic .beta. - cyclodextrin derivatives, a proce ss for the preparation thereof and the use thereof - Google Patents
Inclusion complexes of clavulanic acid and of alkali salts thereof with hydrophilic and hydrophobic .beta. - cyclodextrin derivatives, a proce ss for the preparation thereof and the use thereofInfo
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- CA2100045A1 CA2100045A1 CA002100045A CA2100045A CA2100045A1 CA 2100045 A1 CA2100045 A1 CA 2100045A1 CA 002100045 A CA002100045 A CA 002100045A CA 2100045 A CA2100045 A CA 2100045A CA 2100045 A1 CA2100045 A1 CA 2100045A1
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- Prior art keywords
- beta
- clavulanic acid
- heptakis
- hydrophobic
- alkali
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y5/00—Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K31/00—Medicinal preparations containing organic active ingredients
- A61K31/33—Heterocyclic compounds
- A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
- A61K31/41—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having five-membered rings with two or more ring hetero atoms, at least one of which being nitrogen, e.g. tetrazole
- A61K31/42—Oxazoles
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K31/00—Medicinal preparations containing organic active ingredients
- A61K31/33—Heterocyclic compounds
- A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
- A61K31/41—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having five-membered rings with two or more ring hetero atoms, at least one of which being nitrogen, e.g. tetrazole
- A61K31/42—Oxazoles
- A61K31/424—Oxazoles condensed with heterocyclic ring systems, e.g. clavulanic acid
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
- A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
- A61K47/69—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit
- A61K47/6949—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit inclusion complexes, e.g. clathrates, cavitates or fullerenes
- A61K47/6951—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit inclusion complexes, e.g. clathrates, cavitates or fullerenes using cyclodextrin
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
- A61P31/04—Antibacterial agents
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P43/00—Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
Abstract
ABSTRACT
Described is a new process for the preparation of alkali clavulanate from an aqueous solution of crude clavulanic acid, which is obtained in a conventional manner after the fermentation with a clavulanic-acid-producing microorganism, extracted with an ethyl acetate solution of a hydrophobic .beta.-CD derivative such as heptakis-(2,3,6-tri-O-acetyl)-.beta.-CD in at least equimolar ratio with regard to clavulanic acid. The result-ing novel inclusion complexes of clavulanic acid and hydrophobic .beta.-CD derivative in a molar ratio about 1:1 are isolated, purified and then converted with an alkali base or alkali alkanoate to the desired alkali clavulanate, which is isolated. Furthermore, there are described new inclusion complexes of clavulanic acid and of its pharma-ceutically acceptable alkali salts both with hydrophilic .beta.-CD derivatives and with hydrophobic .beta.-CD derivatives, processes for the preparation thereof and the use thereof for the preparation of galenic forms with immediate as well as with sustained action, in combination with amoxicillin trihydrate, which are valuable medicaments in the therapy of infectious diseases.
Described is a new process for the preparation of alkali clavulanate from an aqueous solution of crude clavulanic acid, which is obtained in a conventional manner after the fermentation with a clavulanic-acid-producing microorganism, extracted with an ethyl acetate solution of a hydrophobic .beta.-CD derivative such as heptakis-(2,3,6-tri-O-acetyl)-.beta.-CD in at least equimolar ratio with regard to clavulanic acid. The result-ing novel inclusion complexes of clavulanic acid and hydrophobic .beta.-CD derivative in a molar ratio about 1:1 are isolated, purified and then converted with an alkali base or alkali alkanoate to the desired alkali clavulanate, which is isolated. Furthermore, there are described new inclusion complexes of clavulanic acid and of its pharma-ceutically acceptable alkali salts both with hydrophilic .beta.-CD derivatives and with hydrophobic .beta.-CD derivatives, processes for the preparation thereof and the use thereof for the preparation of galenic forms with immediate as well as with sustained action, in combination with amoxicillin trihydrate, which are valuable medicaments in the therapy of infectious diseases.
Description
~ ~la~o~
Novel Inclusion Complexes of Clavulanic Acid and of Alkali Salts thereof with ~Iydrophilic and lIydrophobic ,~-cyclodextrin Dcrivatives, a Process for the Preparation thereof and the Use thereof Technical Field IPC C 07D 498704, A 61K 31/42, C 08B 37/16 The present invention belongs to the field of pharmaceutical industry and relates to novel inclusion complexes of clavulanic acid and of alkali salts thereof, such as potas-sium or sodium clavulanate, with hydrophilic or hydrophobic ,l~-cyclodextrin (abbr.
~-CD for,l~-cyclodextrin), to the preparation thereof and to the use thereof as inter-mediate compounds at the iso]ation of pure clavulanic acid or of alkali salts thereof as well as to the use thereof for the preparation of new stable galenic forms with im-mediate as well as sustained release.
Tech~licnl Problem There exists a constant need for a new and simple process for the preparation ofpure clavulanic acid and of pharmaceutically acceptable alkali salts thereof such as potassium clavulanate, whereby the desired compound with a high total yield and a high purity would be isolated from water solutions obtained in a usual manner after the fermentation by a microorganism producing clavulanic acid.
Furthermore, there existed a need for new stable galenic forms of clavulanic acid or of alkali salts thereof, such as potassium clavulanate, with ,B-lactam penicillinic or cephalosporinic antibiotics such as amoxicillin trihydrate or ticarcillin, wherein the clavulanic acid or alkali clavulanate would have an improved stability in an acidic medium existing in the gastric mucuous membrane, which would result in an im-proved relative biological applicability of the active component.
Pli~rAr~
Clavulanic acid is the generic name for (2R,SR,Z)-3-(2-hydroxyethylidene)-7-oxo-4-oxa-1-azabicyclo~3.2.0]heptane-2-carho~ylic acid, which is a known compound of the f`ollowing formula:
o ~ ~ ~
H T--~C--CHH2H
O N ~.~
H COOH
Alkali salts and esters thereof are active as inhibitors of ,B-lactamases, i.e. they inhibit the action of ,B-lactamases produced by some gram-positive and gram-negative microorganisms.
In addition to being inhibitors of ,B-lactamases, clavulanic acid or its alkali salts also have a synergistic effect in combination with,B-lactam antibiotics of penicillinic and cephalosporin class, therefore clavulanic acid or alkali salts thereof are used in galenic preparations to prevent a deactivation of ,B-lactam antibiotics.
In the literature, there is described the possibility of clavulanic acid production in a fermentative manner by means of various mocroorganisms of the strain Streptomyces such as S. clavuliger~s NRRL 3585, S. jumoninensis NRRL 5741, S. katsl~rahamanusIFO 13716 and Streptomyces sp. P6621 F~ERM P 2804.
Clavulanic acid and its alkali salts were first described in GB 1,508,977. After the fer-mentation by means of the strain S. clavuligerus NRRL 3585, the process for the isolation of clavulanic acid from the fermentation broth, which is based on the use of anionic exchange resins and exacting purifications by chromatographic methods, is time-consuming.
In GB patent 1,543,563 a modified fermentative process using the strain S.
clavuligerus NRRL 3685 is described, whereat the pH value of the medium is main-tained in a range between 6.3 and 6.7, whereby the yield of desired compound is in-creased. Clavulanic acid salts such as potassium clavulanate are prepared by resalting ~rom lithium clavulanate.
An improved process for the isolation and purification of clavulanic acid and of its alkali salts is described in EP patent 0()26044. This process is based on the prepara-tion of an intermecliate salt of clav~llanic acid with tert. butylamine, preferably in the ~lo~
form of its acetone solvate, which is prepared by treating the extract such as ethy]
acetate extract, which was prepared according to the process in GB patent 1,508,977, containing impure clavulanic acid and which was previously discoloured by treating with activated charcoal, with tert. butylamine in an organic solvent, followed by the conversion of the acetone solvate of the sal~ of clawlanic acid with tert. butylamine, which was previously also additionally puri~led by the recrystallization with alkali car-bonates, bicarbonates, hydroxides or salts of alcanoic acid such as potassium 2-ethyl-hexanoate, to the pharmaceutically acceptable alkali salts of clavulanic acid such as potassium clavulanate.
Tec/l)lical Solution This invention is based on the task to isolate clavulanic acid or pharmaceutically ac-ceptable alkali salts thereof such as potassium clavulanate, from concentrated water solutions, which are obtained in the usual manner after the fermentation with a clavulanic-acid-producing microorganism, wherein clavulanic acid is present in acrude form, in a new, rapid and simple manner, whereby the desired compound would be obtained in an excellent total yield and with high purity. This aim wasachieved so that a water solution of crude clavulanic acid in the form of alkali salts was acidified with sulfuric acid to a pH value between 1 and 3, whereupon the acidified water sollltion of crude clavulanic acid was immediately converted with a solution of a,B-cyclodextrin hydrophobic derivative in an inert organic solvent such as ethyl acetate, the inclusion complex of clavulanic acid with the ~-cyclodextrin llydrophobic derivative was isolated from organic phase, which complex was purified and reacted with alkali carbonate, bicarbonate, hydroxide or alkanoate such as potas-sium 2-ethyl-hexanoate in an inert organic solvent such as ispropanol or acetone to the desired alkali clavulanate, which was then isolated.
According to the invention, the water solution (purified concentrate after fermenta-tion) contained from 10 to 20 mg/ml of clavulanic acid in the form of its alkali salt (determined by the HPLC).
The conversion of the acidified water solution of crude clavulanic acid with the solu-tion of ~-CD hydrophobic derivative was carried out in an inert organic solvent such as ethyl acetate. With regard to the concentration of clavulanic acid, which was previ-ously determined by the HPLC, an equimolar amount or excess (up to 10%) of ,B-CDhydrophobic dervative was used. The volume of the used inert organic solvent was 4 ~l~)0~ 3 about three times greater than the volume of the water phase. The obtained inclu-sion complex was very stable in an acidic medium, which also affected the high yie]d of the conversion.
As the,(3-cyclodextrin hydrophobic derivatives there were used: heptakis-(2,3,6-tri-O-acetyl)-,B-CD (a]so abbr. as triacetyl-,~'-CD), in the nomenclature CAS (Chemical Abstracts Service) ~23739-88-0] called ~?-cyclodextrin heneicosa acetate (the litera-ture also reports abbr. TA-,6'-CD), heptakis-(2,6-di-O-ethyl)-,B-CD (abbr. DE-,B-CD), heptakis-(2,3-di-O-ethyl)-,B-CD, heptakis-(2,3,6-tri-O-ethyl)-,6'-CD (abbr. TE-,B-CD), O-carboxymethyl-O-ethyl-,B-CD, heptakis-2,6-di-O-pentyl-~6-CD, heptakis-2,3,6-tri-O-pentyl-,B-CD, heptakis-(3-O-acetyl-2,6-di-O-pentyl)-,B-CD, etc.
A short review of cyclodextrins is reported by O. Bekers et al.in Drug Development and Industrial Pharmacy, 17(11), 1503-1549 (1991), "Cyclodextrins in the pharma-ceutical Field", wherein single cyclodextrin derivatives, terms or abbreviations, processes for the preparation of inclusion complexes, their characterization, the im-portance in pharmacy, etc. are described.
Hydrophobic ,B-CD are very poorly soluble in water. For example, the solubility in water of diethyl-,6'-CD is 5.0 X 10 3 g/100 ml of water, and the solubility of triethyl-,B-CD is 1.8 x 10-3 g/100 ml of water.
Clavulanic acid itself or alkali salts therof are hydrophilic compounds that are very well soluble in water.
Inclusion complexes of clavulanic acid with ~'-CD hydrophobic derivatives such as the inclusion complex of clavulanic acid with heptakis-2,3,6-tri-O-acetyl-,B-CD, which are formed in this step, are novel compounds, not yet described in the literature.
The obtained inclusion complexes are then isolated and, if desired, also purified, most conveniently by washing with water or by the recrystallisation. The yield in this step is very high and amounts to over 90%. In comparison with the process for the isolation of clavulanic acid from ethyl acetate extract prepared in known manners and containing crude clavulanic acid, which is carried out via intermediate salts of clavulanic acid with tert. butylamine as described in EP 0026044, the process of the invention is advantageous because clavulanic acid bound in an inclusion comp]ex such as the complex with triacetyl-,B-CD, is significantly more stable at isolation con-ditions (low pH) than in the noncomplexed form (the complexation is selective for ~ U fl ~
c]avulanic acid). The separation of the water phase from the organic phase contain-ing TA-,~-CD is made easier. Due to its stability, the inclusion complex can be saved for a longer period of time (some weeks), if necessary. Since the complex is crystal-line and water-insoluble, it can be purified simply by washing with water to eliminate the water-soluble accompanying substances.
The intermediate inclusion complex of clavulanic acid with hydrophobic derivative of ,B-CD such as triacetyl-,B-CD, is then reacted with alkali carbonate, bicarbonate, hydroxide or alkanoate such as potassium 2-ethyl-hexanoate, in an inert organic sol-vent such as isopropanol, whereby the desired alkali clavulanate is separated and then isolated.
All steps of the conversion are carried out at about ambient temperature.
The last step of conversion is also carried out easily and rapidly, whereat in a solution of an inert organic solvent such as isopropanol or acetone, the inclusion complex of clavulanic acid with triacetyl-,~-CD is decomposed by the addition of alkali 2-ethyl-hexanoate in the same solvent, and the alka]i clavulanate such as potassium clavulanate is separated.
Though in the step of the preparation of the intermediate complex there are re4uired greater amounts of triacetyl-,B-CD, which is added in at least equimolar ratio with regard to clavulanic acid (the molecular weight of a triacethyl-,B-CD is about 10 times greater than the molecular weight of clavulanic acid), the used ~3-CD
hydrophobic derivative can, after the isolation of the alkali clavulanate from the or-ganic solvent solution, easily be recycled and returned back to the process.
A variant process for the isolation of potassium clavulanate from concentrated water solutions after the fermentation with a clavulanic-acid-producing microorganism is based on the conversion of the inclusion comp]ex of clavulanic acid with triacetyl-,B-CD, prepared in the above mentioned manner, with N,N'-diisopropylethylene-diamine, whereat the obtained N,N'-diisopropilethylenediammonium diclavulanate is converted to the desired compound in the manner described in our Slovenian patent application SI P-92 00 392.
This variant process is applied if a very high purity of the desired compound is re-quired or in the cases when after fermentation the concentrated water solutions of clavu]anic acid are not s-lfficiently pure.
6 ~1UV~-15 The use of,~-CD hydrophobic derivatives for the isolation of therapeutically effective active component such as clavulanic acid or alkali salts thereof is a new and non-obvious process not yet described in the literature and, in addition, these complexes are useful for the preparation of galenic forms with controlled release of the active component since the inclusion complex is retardative by itself.
A further object of the invention is the preparation of inclusion complexes of alkali clavulanate with ,B-CD hydrophilic derivatives and their use in the preparation of stable galenic forms for oral application such as capsules or tablets (effervescent, dis-persive, chewing etc.) containing, in addition to the pharmaceutically acceptable car-rier, a therapeutically effective amount of amoxicillin trihydrate and alkali salt of clavulanic acid, whereat the weight ratio between amoxicillin trihydrate and equiv-alent of alkali clavulanate bound in the complex amounts from 10:1 to 1:1.
From GB patent 2,005,538, there are known solid galenic forms containing, in addi-tion to the pharmaceutically acceptable carrier, amoxicillin trihydrate and potassium clavulanate, whereat the preferred ratio of amoxicillin trihydrate and potassiumclavulanate is 2:1. The recommended dose (in paediatrics) contains 250 mg of amoxicillin (in trihydrate form) and 125 mg of clavulanic acid (in potassium salt form). The recommended ratio of the components for adult patients is 4:1. Solid galenic forms such as capsules and tablets, which are described in this patent, have an improved stability. They are prepared in conditions of low relative humidity (less than 305~o) and the package also contains a drying agent such as silicagel because of the high hygroscopicity of clavulanic acid or alkali salts thereof.
The inclusion complexes of clavulanic acid or of alkali salts thereof, such as potas-sium clawlanate, with ,B-CD hydrophilic derivatives of the invention may be prepared by known processes which are described in the literature, e.g. by 1~.
Kurozumi et al., Chem. Pharm. Bull. 23(12), 3062-3068 (1975) or Acta Pharm.
Technol. 36(1), 1-6 (1990), i.e. by complexing of active component with selectedcyclodextrin, or they may be prepared in a novel manner, not yet described in the literature, which is a further object of the present invention.
~ccording to the invention, the inclusion complex of clavulanic acid is reacted with hydrophobic ~3-CD such as triacetyl-~-CD, which is obtained in the above-mentioned manner, in a water solutioll of an alkali base such as alkali carbonate, bicarbonate, hydroxide or alkanoate such as potassium 2-ethylhexanoate, directly with ,B-CD
hydropllilic clerivative, whereafter the desired compound is isolated and purifiecd if 7 ~ ~ o ~
desired. This process representing substantially a recomplexing of one inclusion com-plex to another is, with regard to the aim of the invention, shorter than the above-mentioned one since no previous prepararation of alkali clavalunate is necessary.
As ,B-CD hydrophilic derivatives there may be used all known compounds of this kind such as heptakis-(2,6-di-0-methyl)-,B-CD, monomethyl-,B-CD (Me-,l~-CD), heptakis-(2,3,6-tri-0-methyl)-,B-CD, hydroxypropyl-~-CD, hydroxyethyl-~3-CD, dihydroxypropyl-,l3-CD"B-CD branched derivatives such as glucosyl-~3-CD, maltosyl-,B-CD, dimaltosyl-,B-CD, diglucosyl-,B-CD and other water soluble or hydrophilicderivatives of ,B-CD.
In a dose unit, galenic forms of the invention may contain, in addition to the phar-maceutically acceptable carrier and other adjuvants, the same amounts of amoxicillin trihydrate and of equivalent of alkali clavulanate such as potassium clavulanate in a complex as commercial preparations.
lt was unexpected]y found that by complexing clavulanic acid or its alkali salt, the stability of clavu]anic acid at pH 1.2 and the temperature of 37 ~C, i.e. in the acidic medium as it is present in gastric juice, is substantially improved, whereby the repeat-ing in the extent of the absorption of clawlanic acid from the gastrointestinal tract or the biological availability of the active component is improved.
The stability of clawlanic acid itself in conditions being present in gastric juice is ex-ceptionally low (the time of 95~o decomposition of clavulanic acid at 37 C is 26 minutes), whereas, due to the complexing of the c]avulanic acid with,B-CD, its acid stability is improved, which makes possible the absorption of clavulanic acid from the gastrointestinal tract to the blood in a greater extent, which is much less dependent on the pH of the medium (as in the gastric mucuous membrane). This further con-tributes to a greater therapeutical effectiveness in a combination with amoxicillin trihydrate since the inhibition of ,l~-lactamases is increased. This certainly means that in order to achieve the same therapeutical effect as by a commercial preparation(Augmentin), lower doses of clavulanic acid or of its alkali salt such as potassium clavulanate may be used.
A furtller object o~ the invention are inclusion complexes of clavulanic acid or of its alkali salts with ,B-CD hydrophobic derivatives such as heptakis-(2,3,6-tri-0-acetyl)-,B-CD, which may be obtained by the above-mentioned process or may be prepared from hoth components in kno-vn manners which are described in the literature, 8 ~ o ~ ~
which represent a sustained release system, wherefrom the active component is released in a contro]led manner as shown in the graph. The inclusion complex itself represents a sustained release complex and therefore no other sustained release components in the galenic form are necessary. To galenic forms with a sustained release of the active component, in addition to the inclusion complex and amoxicillin trihydrate, adjuvants such as desintegrators, fillers, colouring agents, sweetenir~g agents etc. may be added if necessary.
A further object of the invention is to prepare stable galenic forms with a controlled release of the active component, which contain amoxicillin trihydrate and a mixture of two inclusion complexes of clavulanic acid or of its alkali salts, whereat one of the ,B-cyclodextrin derivatives used for complexing is hydrophilic and the other is hydro-phobic.
In this case the release of active component from the galenic form may be controlled in the desired extent by a suitably adapted ratio of the two types of inclusion com-plexes.
Owing to the high stability in the acidic medium of gastric juice and a suitable sus-tained rapidity of releasing clavulanic acid from the system, these complexes have an improved biological applicability.
All inclusion complexes of clavulanic acid and of its alkali salts with hydrophilic or hydrophobic ,B-CD derivatives according to the invention are formed in a molar ratio of about 1:1.
From US patent 4,869,904, a sustained release system of inclusion complexes of the active components with ,B-CD hydrophobic alkylated derivatives such as heptakis-(2,3-di-O-ethyl)-,B-CD is known.
According to the invention, in addition to the heptakis-(2,3,6-tri-O-acetyl)-,B-CD also O-carboxymethyl-O-ethyl-,B-CD, heptakis-2,6-di-O-pentyl-,B-CD, heptakis-2,3,6-tri-O-pentyl-,B-CD or heptakis-(3-O-acetyl-2,6-di-O-pentyl)-,l3-CD may be used as the hydrophobic ,B-CD derivative.
No toxic effect was observed in any of the performed tests. Thus it may be considered that the toxicity of the inclusion complexes is as low as the toxicity of clavulanic acid or its salts.
9 ~ 5 The invention is illustrated but in no way limited by the following Examp]es.
Examp]e 1 Preparation of the inclusion complex of potassium clavulanate with methyl~ cyclo-dextrin (Me-,B-CD) Me-,B-CD (13.10 g, 10 mmol) was dissolved in water for injections (25 ml) under stir-ring at ambient temperature and then to the solution potassium clavulanate (2.377 g, 10 mmol) was slowly added under constant stirring. The obtained solution was stirred at ambient temperature in the dark for 10 minutes, then it was filtered, the filtrate was frozen in a stream of liquid nitrogen and then it was freeze- dried.
There was obtained a slightly yellowish microcrystalline title complex (15.25 g,98.5%). The complex contained 15.2% of potassium clavulanate as it was determined by the HPLC method.
Figs. 1 and 2 illustrate INMR and DSC (differential scanning calorimetry) spectra of the title complex.
Example 2 Preparation of the inclusion complex of potassium clavulanate with 2-hydroxypropyl-~-CD (2-HP-,B-CD) It was proceeded in the same way as in Example 1, only that methyl-,B-cyclodextrin was replaced by 2-hydroxypropyl-,B-cyclodextrin (13.80 g, 10 mmol).
There was obtained a microcrystalline title complex (16.0 g, 99.3%). The complexcontained 14.6~o of potassium clavulanate as it was determined by the HPLC
method.
Figs. 3 and 4 illustrate INMR and DSC spectra of the title complex.
Example 3 10 ,~
Preparation of the inclusion complex of potassium clavulanate with 2-hydroxyethyl-,l3-cyclodextrin (2-HE-,B-CD) It was proceeded in the same way as in Example 1, only that methyl-,B-cyclodextrin was replaced by 2-hydroxyethyl-,B-CD (14.40 g, 10 mmol).
There was obtained microcrystalline title complex (16.2 g, 96.7%). The complex con-tained 13.9% of potassium clavulanate as it was determined by the HPLC method.
Figs. 5 and 6 illustrate lNMR and DSC spectra of the title complex.
Example 4 Process for the isolation of clavulanic acid or of potassium salt thereof A water solution (1.25 l) containing clavulanic acid (20 g, 0.1 mol) was acidified with conc. sulfuric acid (15 ml) to the pH value of 1.3 and then the acidified water solution was immediately extracted in a centrifuge with ethyl acetate (4.01) in which heptakis-(2,3,6-tri-O-acetyl)-,l~-CD (201.78 g, 0.1 mol) was dissolved. The phases were separated and the organic phase was washed with water (250 ml) on a separative column. Subsequently, the solvent was evaporated from the organic phase and the residue was dried in vacuum at the temperature of 35 C to a constant weight. There was obtained a crude inclusion complex (212.9 g, 96%) of clavulanic acid with heptakis-(2,3,6-tri-O-acetyl)-,B-CD, which was then digested in water (500 ml) under vigorous stirring. The complex was then filtered off, washed with water (3 x 50 ml) and dried in vacuum at a temperature up to 35C to the constant weight (210.4 g).
The complex contained 8.1% of clavulanic acid as it was determined by the HPLC
method.
The purified incll~sion complex (210.4 g) of clavulanic acid with triacetyl-,B-CD was dissolved in acetone (250 ml), the solid particles were filtered off and a solution (100 ml, 20%) of potassium 2-ethyl-hexsanoate in isopropanol was slowly added dropwise under stirring Potassium clavu]anate separated and it was filtered off,washed with isopropanol (3 x 15 ml) and dried in vacuum at a temperature up to 35C to the constant wei~llt. Ihe yield of potassium clavulanate was 18.0 g (88 %) (the clavulanic acid content of 83.() % was determined by the HPLC).
O ~
Figs. 7 and 8 illustrate NMR and DSC spectra of the inclusion complex of clavulanic acid with triacetyl-,B-CD.
Example 5 Preparation of the inclusion complex of potassium clawlanate with methyl-,B-cyclo-dextrin (Me-,B-CD) by recomplexing from the inclusion complex of clavulanic acidwith triacetyl-,B-CD
The inclusion complex (100 g) of clavulanic acid with heptakis-(2,3,6-tri-O-acetyl)-,B-CD, which was prepared in the same way as in Example 4, was suspended in a 3%
aqueous potassium carbonate solution (200 ml), in which methyl-,B-CD (53.6 g, 40.9 mmol) was dissolved. The suspension was stirred for 5 min at ambient tempera-ture, the solid particles were filtered off and the filtrate was frozen in liquid nitrogen and then freeze-dried. There was obtained a yellowish microcrystalline inclusioncomplex (56.7 g, 91.9%) of potassium clawlanate with methyl-,B-CD. The complex contained 14.9% of potassium clawlanate as it was determined by the HPLC
method.
In the same manner inclusion complexes of other alkali clawlanates can be prepared.
Example 6 Stability test of complexed and uncomplexed potassium clawlanate in artificial gastric juice (pH 1.2) at the temperature of 37 C
For the test the following samples were used:
1) potassium clavulanate (abbr. KK) 2) inclusion complex of KK with methyl-,B-CD (abbr. KK-Me-~3-CD) 3) inclusion complex of KK with 2-hydroxypropyl-~-CD (abbr. KK-HP-,B-CD) 4) inclusion complex of clavulanic acid with triacetyl-~-CD (abbr. KA-TA-,B--CD).
Medium: artificial gastric juice - aq.HCl/NaCl buffer, pH ].2, according to USP
XXII.
Concentration of clavulanic acid (al t~r. KA) in samples: 4 mg/ml.
The samples 1 to 3 were dissolved under stirring in an artificial gastric juice (100 ml) thermostated at 37 C, at the concentration of 4 mg/ml with regard to the clavulanic acid. Subsequentlv. 100 ~1 aliquots were taken at 5 min inteIvals for analysis by the HPLC, until a m~Jre than 95% KA decomposition was found. The solution was stirred all the time at the temperature of 37 C + 0.5 C.
Separately, a series of ten 10 ml aliquots of KA-TA-,B-CD suspension in a buffer of a pH of 1.2 (conc. of KA = 4 mg/ml), which were constantly stirred during thermo-stating at 37C, was prepared. At time intervals of 5 to 10 min, the individual aliquots were filtered (membrane filter 0.4 ,um) and in the clear filtrate the concentration of clavulanic acid was determined by HPLC. The KA content at times up to 90 min of thermostating was noted.
The results of measurements after 15, 30, 45, 60 and 90 min of thermostating thesamples at 37C in a buffer at pH 1.2 are shown in following Table.
Thermostating KA (undecomp.) as to the Released and undecomp.
time [min] initial KA conc.(100%) in KA in supernatant above samples [%] suspension [%]
. .
K~C KK- ~C~C- KA-Me-~3-CD HP-,B-CD TA-,B-CD
15 min 18.1 26.6 24.7 9.6 30 min 1.3 11.2 10.2 10.9 45 min 0 4.1 3.4 10.5 60 min 11.0 90 min 10.6 In ~'1gure 9, the times of 95% decomposition of clavlllanic acid (t~5%) are shown:
t~5% KK 26 min KK-Me-~-CD 42 min KK-HP-,B-CD 40 min KA-TA-~-CD > ')() min 13 ~ l V ~
From the obtained results it is evident that the complexing of potassium clavulanate with hydrophilic Me-,B-CD and HP-,B-CD substantially increases the stability of potassium clavulanate and clavulanic acid in artificial gastric juice (pH 1.2, 37 C).
The ratio in undecomposed clavulanis acid after 30 min. is about 1:8 in the favour of complexed potassium clavulanate (see Diagram 1).
It is further evident from ~g~e 9 that within 90 minutes the KA concentration inthe supernatant above suspension of hydrophobic inclusion complex KA-TA-,B-CD
keeps constant (it contains 10 to 11% of the starting KA), which represents a sus-tained and constant release of KA from the complex. The decomposed clavulanic acid is simultaneuosly replaced by a new amount of clavulanic acid from the complex KA-TA-,B-CD as a result of the concentration equilibrium of complexed and un-complexed clavulanic acid. Such a profile of the release of clavulanic acid points to the applicability of the complexes of clavulanic acid with hydrophobic,B-CD deriva-tives for sustained release forms.
After 10 minutes, a 90 ml aliquot of KA-TA-,l3-CD suspension was filtered and the precipitate was washed out with 10 ml of fresh buffer according to the USP XXII.Subsequently, the precipitate was quantitatively transferred to a 10 ml measuring flask, dissolved in a mixture of MeOH:H2O = 1:1 and filled with the solvent up to the mark. By the HPLC analysis it was determined that the sample contained 0.76 mg of KA/ml, which is 1~% of the starting KA amount in the complex. These results showthat from the complex KA-TA-,l3-CD the KA is released constantly and in a sustained manner.
The complexed part of clavulanic acid remained stable in acidic medium and the slow release at simultaneous absorption from the stomach to blood made possible a substantially greater extent of absorption than other hitherto known forms.
There was also determined the release of clavulanic acid or its potassium salt from the complex with hydrophobic triacetyl-,B-CD in artificial intestina] juice (pH 7.2, buffer according to the USP XXII), which also ran constantly and about twice faster than in artificial gastric juice with pH l.2.
From the above discussion it may be concluded that the inclusion complex of clavulanic acid with triacetyl-~3-CD is a suitable sustained release system for peroral forms.
Example 7 X-ray powder diffraction In the Table below there are shown the lattice distances d(nm) and intensity (I) of X-ray powder diffraction patterns of potassium clavulanate (abbr. KK), methyl-,B-CD
(abbr. Me-,l3-CD), 2-hydroxypropyl-,B-CD (HP-,B-CD), 2-hydroxyethyl-,B-CD (abbr.HE-,(3-CD) and of the inclusion complexes of potassium clavulanate with the enumerated ~-CD derivatives (abbr. KK-ME4-CD, KK-HP-,l~-CD and KK-HE-,B-CD), which were taken by Philips PW 1710 diffractometer on an Al-substrate and at )~ - 0.15418 nm (CuKcY).
Sample d(nm) (I) ..
KK 0.35389 1694 0.29359 1426 0.37586 1176 Me-,B-CD 0.49695 1454 0.46853 1422 0.49081 1404 KK-Me-,l~-CD 0.46426 1100 0.49217 1072 0.47133 1068 HP-,~-CD 0.48196 1576 0.46370 1538 0.48650 1532 KK-HP-,B-CD 0.46018 1198 0.45376 1164 0.47544 1140 .
HE-,B-CD 0.47459 1432 0.46811 1360 0.35968 ~298 lS ~ 0 ~ 5 KK-HE-,B-CD 0.45327 1046 0.44711 1018 0.47514 1()18 Example 8 Process for the isolation of clavulanic acid or of potassium salt thereof To an ethylacetate solution (11) of the inclusion complex of clavulanic acid with heptakis-(2,3,6-tri-O-acetyl)-~3-CD (the concentration of clavulanic acid was 10 mg/ml as determined by the HPLC method), which was obtained according to the process of Example 4, N,N'-diisopropylethylenediamine (5 ml) was slowly added dropwise under vigorous stirring within 10 min. The resulting suspension was stirred for another 30 min, the produced precipitate was filtered off and then dissolved in 10 ml of water. Acetone (200 ml) was added to the solution, whereat N,N'-diisopropyl- ethylenediammonium diclavulanate (6.1 g) was separated in the form of fine crystalls, which were filtered off and redissolved in water (5 ml). Isopropanol (95 ml) was added to the solution and then a so]ution of potassium 2-ethylhexanoate (10 ml, 2M) in isopropanol was slowly added dropwise under vigorous stirring within 15 min, whereat potassium clavulanate was separated, which was filtered off, washedwith isopropanol (3 x 10 ml) and dried in vacuum at a temperature up to 35 C toconstant weight. Thus there was obtained potassium c]avulanate (2.64 g, 77%) (USP
grade, clavulanic acid content 82.8% as deterrnined by HPLC method).
Example 9 Preparation of inclusion complex of potassium clavulanate with triacetyl-,B-cyclo-dextr;n Potassium clavulanate (237.3 mg, 1 mmol) was dissolved in water for injections (ln ml) under stirring at ambient temperature and then a solution of triacetyl-,B-cyclodextrin (TA-13-CD; 2.02 g, 1 mmol) in isopropanol (90 ml) was added. The reac-tion mixture was stirred for S min at ambient temperature, subsequently the solvents was evaporated at reduced pressure, at first on a rotary evaporator at the tempera-ture of 30 C and then the residue was frozen and freeze-dried. Microcrystalline title 16 ~V;~ ~
complex (2.25 g, 99%) was obtained. The complex contained 9.1% of potassium clavulanate (co~responding to 0.9 mol of potassium clavulanate/1 mol of triacetyl~
CD) as determined by the HPLC method.
The DSC analysis corresponded to the title complex.
The NMR spectrum corresponded to potassium clawlanate and triacetyl-~-CD.
Example 10 Dispersion tablets containing clavulanic acid (125 mg) and amoxicillin (500 mg) Ingredients mg/tablet %
inclusion complex of potassium clavulanate with Me-~-CD 833.3 27.78 amoxicillin trihydrate (corresponding to 500 mg of anhydrous amoxicillin) 574.0 19.13 crospovidone (Kollidon CL) 50.0 1.67 saccharin 10.0 0.33 flavourings (fruit) 35.0 1.17 magnesium stearate 21.0 0.70 colloidal silica (Aerosil 20()) 10.0 0.33 microcrystalline cellulose (Avicel pH 101) ad3000.0 ad100.00 The equivalents of amoxicillin and clavulanic acid were mixed homogeneously and then briquetted with a part of the filler (microcrystalline cellulose). The briquettes were crushed and sieved through an oscillation sieve with a mesh size of 1.5 mm. The obtained granulate was mixed with the remaining adjuvants and tableted on a rotary tableting machine.
The tablets rapidly disintegrate in water giving a fine dispersion suitable for thera-peutic application.
17 ~ a ~ a Example 11 Chewing tablets containing clavulanic acid (125 mg) and amoxicillin (500 mg) Ingredients mg/tablet ~o inclusion complex of potassium clavulanate with Me-,B-CD 833.3 27.78 amoxicillin trihydrate (corresponding to 500 mg of anhydrous amoxicillin) 574.0 19.13 crospovidone (Kollidon CL) 5.0 0.17 polyvinyl pyrrolidone 60.0 2.00 colloidal silica (Aerosil 200) 10.0 0.33 saccharin 10.0 0.33 flavourings (fruit) 35.0 1.17 magnesium stearate 15.0 0.50 microcrystalline cellulose (AvicelpH 101) 60.0 2.00 mannitol ad3000.0 ad 100.00 .
The equivalents of amoxicillin and clavulanic acid were homogeneously mixed together with a part of the fillers (microcrystalline cellulose and mannitol) and the obtained mixture of powders was briquetted. The briquettes were crllshed and sieved through an oscillation sieve with a mesh size of 1.5 mm. The obtained granulate was mixed with the remaining adjuvants and tableted.
Tablets were suitable for chewing.
Novel Inclusion Complexes of Clavulanic Acid and of Alkali Salts thereof with ~Iydrophilic and lIydrophobic ,~-cyclodextrin Dcrivatives, a Process for the Preparation thereof and the Use thereof Technical Field IPC C 07D 498704, A 61K 31/42, C 08B 37/16 The present invention belongs to the field of pharmaceutical industry and relates to novel inclusion complexes of clavulanic acid and of alkali salts thereof, such as potas-sium or sodium clavulanate, with hydrophilic or hydrophobic ,l~-cyclodextrin (abbr.
~-CD for,l~-cyclodextrin), to the preparation thereof and to the use thereof as inter-mediate compounds at the iso]ation of pure clavulanic acid or of alkali salts thereof as well as to the use thereof for the preparation of new stable galenic forms with im-mediate as well as sustained release.
Tech~licnl Problem There exists a constant need for a new and simple process for the preparation ofpure clavulanic acid and of pharmaceutically acceptable alkali salts thereof such as potassium clavulanate, whereby the desired compound with a high total yield and a high purity would be isolated from water solutions obtained in a usual manner after the fermentation by a microorganism producing clavulanic acid.
Furthermore, there existed a need for new stable galenic forms of clavulanic acid or of alkali salts thereof, such as potassium clavulanate, with ,B-lactam penicillinic or cephalosporinic antibiotics such as amoxicillin trihydrate or ticarcillin, wherein the clavulanic acid or alkali clavulanate would have an improved stability in an acidic medium existing in the gastric mucuous membrane, which would result in an im-proved relative biological applicability of the active component.
Pli~rAr~
Clavulanic acid is the generic name for (2R,SR,Z)-3-(2-hydroxyethylidene)-7-oxo-4-oxa-1-azabicyclo~3.2.0]heptane-2-carho~ylic acid, which is a known compound of the f`ollowing formula:
o ~ ~ ~
H T--~C--CHH2H
O N ~.~
H COOH
Alkali salts and esters thereof are active as inhibitors of ,B-lactamases, i.e. they inhibit the action of ,B-lactamases produced by some gram-positive and gram-negative microorganisms.
In addition to being inhibitors of ,B-lactamases, clavulanic acid or its alkali salts also have a synergistic effect in combination with,B-lactam antibiotics of penicillinic and cephalosporin class, therefore clavulanic acid or alkali salts thereof are used in galenic preparations to prevent a deactivation of ,B-lactam antibiotics.
In the literature, there is described the possibility of clavulanic acid production in a fermentative manner by means of various mocroorganisms of the strain Streptomyces such as S. clavuliger~s NRRL 3585, S. jumoninensis NRRL 5741, S. katsl~rahamanusIFO 13716 and Streptomyces sp. P6621 F~ERM P 2804.
Clavulanic acid and its alkali salts were first described in GB 1,508,977. After the fer-mentation by means of the strain S. clavuligerus NRRL 3585, the process for the isolation of clavulanic acid from the fermentation broth, which is based on the use of anionic exchange resins and exacting purifications by chromatographic methods, is time-consuming.
In GB patent 1,543,563 a modified fermentative process using the strain S.
clavuligerus NRRL 3685 is described, whereat the pH value of the medium is main-tained in a range between 6.3 and 6.7, whereby the yield of desired compound is in-creased. Clavulanic acid salts such as potassium clavulanate are prepared by resalting ~rom lithium clavulanate.
An improved process for the isolation and purification of clavulanic acid and of its alkali salts is described in EP patent 0()26044. This process is based on the prepara-tion of an intermecliate salt of clav~llanic acid with tert. butylamine, preferably in the ~lo~
form of its acetone solvate, which is prepared by treating the extract such as ethy]
acetate extract, which was prepared according to the process in GB patent 1,508,977, containing impure clavulanic acid and which was previously discoloured by treating with activated charcoal, with tert. butylamine in an organic solvent, followed by the conversion of the acetone solvate of the sal~ of clawlanic acid with tert. butylamine, which was previously also additionally puri~led by the recrystallization with alkali car-bonates, bicarbonates, hydroxides or salts of alcanoic acid such as potassium 2-ethyl-hexanoate, to the pharmaceutically acceptable alkali salts of clavulanic acid such as potassium clavulanate.
Tec/l)lical Solution This invention is based on the task to isolate clavulanic acid or pharmaceutically ac-ceptable alkali salts thereof such as potassium clavulanate, from concentrated water solutions, which are obtained in the usual manner after the fermentation with a clavulanic-acid-producing microorganism, wherein clavulanic acid is present in acrude form, in a new, rapid and simple manner, whereby the desired compound would be obtained in an excellent total yield and with high purity. This aim wasachieved so that a water solution of crude clavulanic acid in the form of alkali salts was acidified with sulfuric acid to a pH value between 1 and 3, whereupon the acidified water sollltion of crude clavulanic acid was immediately converted with a solution of a,B-cyclodextrin hydrophobic derivative in an inert organic solvent such as ethyl acetate, the inclusion complex of clavulanic acid with the ~-cyclodextrin llydrophobic derivative was isolated from organic phase, which complex was purified and reacted with alkali carbonate, bicarbonate, hydroxide or alkanoate such as potas-sium 2-ethyl-hexanoate in an inert organic solvent such as ispropanol or acetone to the desired alkali clavulanate, which was then isolated.
According to the invention, the water solution (purified concentrate after fermenta-tion) contained from 10 to 20 mg/ml of clavulanic acid in the form of its alkali salt (determined by the HPLC).
The conversion of the acidified water solution of crude clavulanic acid with the solu-tion of ~-CD hydrophobic derivative was carried out in an inert organic solvent such as ethyl acetate. With regard to the concentration of clavulanic acid, which was previ-ously determined by the HPLC, an equimolar amount or excess (up to 10%) of ,B-CDhydrophobic dervative was used. The volume of the used inert organic solvent was 4 ~l~)0~ 3 about three times greater than the volume of the water phase. The obtained inclu-sion complex was very stable in an acidic medium, which also affected the high yie]d of the conversion.
As the,(3-cyclodextrin hydrophobic derivatives there were used: heptakis-(2,3,6-tri-O-acetyl)-,B-CD (a]so abbr. as triacetyl-,~'-CD), in the nomenclature CAS (Chemical Abstracts Service) ~23739-88-0] called ~?-cyclodextrin heneicosa acetate (the litera-ture also reports abbr. TA-,6'-CD), heptakis-(2,6-di-O-ethyl)-,B-CD (abbr. DE-,B-CD), heptakis-(2,3-di-O-ethyl)-,B-CD, heptakis-(2,3,6-tri-O-ethyl)-,6'-CD (abbr. TE-,B-CD), O-carboxymethyl-O-ethyl-,B-CD, heptakis-2,6-di-O-pentyl-~6-CD, heptakis-2,3,6-tri-O-pentyl-,B-CD, heptakis-(3-O-acetyl-2,6-di-O-pentyl)-,B-CD, etc.
A short review of cyclodextrins is reported by O. Bekers et al.in Drug Development and Industrial Pharmacy, 17(11), 1503-1549 (1991), "Cyclodextrins in the pharma-ceutical Field", wherein single cyclodextrin derivatives, terms or abbreviations, processes for the preparation of inclusion complexes, their characterization, the im-portance in pharmacy, etc. are described.
Hydrophobic ,B-CD are very poorly soluble in water. For example, the solubility in water of diethyl-,6'-CD is 5.0 X 10 3 g/100 ml of water, and the solubility of triethyl-,B-CD is 1.8 x 10-3 g/100 ml of water.
Clavulanic acid itself or alkali salts therof are hydrophilic compounds that are very well soluble in water.
Inclusion complexes of clavulanic acid with ~'-CD hydrophobic derivatives such as the inclusion complex of clavulanic acid with heptakis-2,3,6-tri-O-acetyl-,B-CD, which are formed in this step, are novel compounds, not yet described in the literature.
The obtained inclusion complexes are then isolated and, if desired, also purified, most conveniently by washing with water or by the recrystallisation. The yield in this step is very high and amounts to over 90%. In comparison with the process for the isolation of clavulanic acid from ethyl acetate extract prepared in known manners and containing crude clavulanic acid, which is carried out via intermediate salts of clavulanic acid with tert. butylamine as described in EP 0026044, the process of the invention is advantageous because clavulanic acid bound in an inclusion comp]ex such as the complex with triacetyl-,B-CD, is significantly more stable at isolation con-ditions (low pH) than in the noncomplexed form (the complexation is selective for ~ U fl ~
c]avulanic acid). The separation of the water phase from the organic phase contain-ing TA-,~-CD is made easier. Due to its stability, the inclusion complex can be saved for a longer period of time (some weeks), if necessary. Since the complex is crystal-line and water-insoluble, it can be purified simply by washing with water to eliminate the water-soluble accompanying substances.
The intermediate inclusion complex of clavulanic acid with hydrophobic derivative of ,B-CD such as triacetyl-,B-CD, is then reacted with alkali carbonate, bicarbonate, hydroxide or alkanoate such as potassium 2-ethyl-hexanoate, in an inert organic sol-vent such as isopropanol, whereby the desired alkali clavulanate is separated and then isolated.
All steps of the conversion are carried out at about ambient temperature.
The last step of conversion is also carried out easily and rapidly, whereat in a solution of an inert organic solvent such as isopropanol or acetone, the inclusion complex of clavulanic acid with triacetyl-,~-CD is decomposed by the addition of alkali 2-ethyl-hexanoate in the same solvent, and the alka]i clavulanate such as potassium clavulanate is separated.
Though in the step of the preparation of the intermediate complex there are re4uired greater amounts of triacetyl-,B-CD, which is added in at least equimolar ratio with regard to clavulanic acid (the molecular weight of a triacethyl-,B-CD is about 10 times greater than the molecular weight of clavulanic acid), the used ~3-CD
hydrophobic derivative can, after the isolation of the alkali clavulanate from the or-ganic solvent solution, easily be recycled and returned back to the process.
A variant process for the isolation of potassium clavulanate from concentrated water solutions after the fermentation with a clavulanic-acid-producing microorganism is based on the conversion of the inclusion comp]ex of clavulanic acid with triacetyl-,B-CD, prepared in the above mentioned manner, with N,N'-diisopropylethylene-diamine, whereat the obtained N,N'-diisopropilethylenediammonium diclavulanate is converted to the desired compound in the manner described in our Slovenian patent application SI P-92 00 392.
This variant process is applied if a very high purity of the desired compound is re-quired or in the cases when after fermentation the concentrated water solutions of clavu]anic acid are not s-lfficiently pure.
6 ~1UV~-15 The use of,~-CD hydrophobic derivatives for the isolation of therapeutically effective active component such as clavulanic acid or alkali salts thereof is a new and non-obvious process not yet described in the literature and, in addition, these complexes are useful for the preparation of galenic forms with controlled release of the active component since the inclusion complex is retardative by itself.
A further object of the invention is the preparation of inclusion complexes of alkali clavulanate with ,B-CD hydrophilic derivatives and their use in the preparation of stable galenic forms for oral application such as capsules or tablets (effervescent, dis-persive, chewing etc.) containing, in addition to the pharmaceutically acceptable car-rier, a therapeutically effective amount of amoxicillin trihydrate and alkali salt of clavulanic acid, whereat the weight ratio between amoxicillin trihydrate and equiv-alent of alkali clavulanate bound in the complex amounts from 10:1 to 1:1.
From GB patent 2,005,538, there are known solid galenic forms containing, in addi-tion to the pharmaceutically acceptable carrier, amoxicillin trihydrate and potassium clavulanate, whereat the preferred ratio of amoxicillin trihydrate and potassiumclavulanate is 2:1. The recommended dose (in paediatrics) contains 250 mg of amoxicillin (in trihydrate form) and 125 mg of clavulanic acid (in potassium salt form). The recommended ratio of the components for adult patients is 4:1. Solid galenic forms such as capsules and tablets, which are described in this patent, have an improved stability. They are prepared in conditions of low relative humidity (less than 305~o) and the package also contains a drying agent such as silicagel because of the high hygroscopicity of clavulanic acid or alkali salts thereof.
The inclusion complexes of clavulanic acid or of alkali salts thereof, such as potas-sium clawlanate, with ,B-CD hydrophilic derivatives of the invention may be prepared by known processes which are described in the literature, e.g. by 1~.
Kurozumi et al., Chem. Pharm. Bull. 23(12), 3062-3068 (1975) or Acta Pharm.
Technol. 36(1), 1-6 (1990), i.e. by complexing of active component with selectedcyclodextrin, or they may be prepared in a novel manner, not yet described in the literature, which is a further object of the present invention.
~ccording to the invention, the inclusion complex of clavulanic acid is reacted with hydrophobic ~3-CD such as triacetyl-~-CD, which is obtained in the above-mentioned manner, in a water solutioll of an alkali base such as alkali carbonate, bicarbonate, hydroxide or alkanoate such as potassium 2-ethylhexanoate, directly with ,B-CD
hydropllilic clerivative, whereafter the desired compound is isolated and purifiecd if 7 ~ ~ o ~
desired. This process representing substantially a recomplexing of one inclusion com-plex to another is, with regard to the aim of the invention, shorter than the above-mentioned one since no previous prepararation of alkali clavalunate is necessary.
As ,B-CD hydrophilic derivatives there may be used all known compounds of this kind such as heptakis-(2,6-di-0-methyl)-,B-CD, monomethyl-,B-CD (Me-,l~-CD), heptakis-(2,3,6-tri-0-methyl)-,B-CD, hydroxypropyl-~-CD, hydroxyethyl-~3-CD, dihydroxypropyl-,l3-CD"B-CD branched derivatives such as glucosyl-~3-CD, maltosyl-,B-CD, dimaltosyl-,B-CD, diglucosyl-,B-CD and other water soluble or hydrophilicderivatives of ,B-CD.
In a dose unit, galenic forms of the invention may contain, in addition to the phar-maceutically acceptable carrier and other adjuvants, the same amounts of amoxicillin trihydrate and of equivalent of alkali clavulanate such as potassium clavulanate in a complex as commercial preparations.
lt was unexpected]y found that by complexing clavulanic acid or its alkali salt, the stability of clavu]anic acid at pH 1.2 and the temperature of 37 ~C, i.e. in the acidic medium as it is present in gastric juice, is substantially improved, whereby the repeat-ing in the extent of the absorption of clawlanic acid from the gastrointestinal tract or the biological availability of the active component is improved.
The stability of clawlanic acid itself in conditions being present in gastric juice is ex-ceptionally low (the time of 95~o decomposition of clavulanic acid at 37 C is 26 minutes), whereas, due to the complexing of the c]avulanic acid with,B-CD, its acid stability is improved, which makes possible the absorption of clavulanic acid from the gastrointestinal tract to the blood in a greater extent, which is much less dependent on the pH of the medium (as in the gastric mucuous membrane). This further con-tributes to a greater therapeutical effectiveness in a combination with amoxicillin trihydrate since the inhibition of ,l~-lactamases is increased. This certainly means that in order to achieve the same therapeutical effect as by a commercial preparation(Augmentin), lower doses of clavulanic acid or of its alkali salt such as potassium clavulanate may be used.
A furtller object o~ the invention are inclusion complexes of clavulanic acid or of its alkali salts with ,B-CD hydrophobic derivatives such as heptakis-(2,3,6-tri-0-acetyl)-,B-CD, which may be obtained by the above-mentioned process or may be prepared from hoth components in kno-vn manners which are described in the literature, 8 ~ o ~ ~
which represent a sustained release system, wherefrom the active component is released in a contro]led manner as shown in the graph. The inclusion complex itself represents a sustained release complex and therefore no other sustained release components in the galenic form are necessary. To galenic forms with a sustained release of the active component, in addition to the inclusion complex and amoxicillin trihydrate, adjuvants such as desintegrators, fillers, colouring agents, sweetenir~g agents etc. may be added if necessary.
A further object of the invention is to prepare stable galenic forms with a controlled release of the active component, which contain amoxicillin trihydrate and a mixture of two inclusion complexes of clavulanic acid or of its alkali salts, whereat one of the ,B-cyclodextrin derivatives used for complexing is hydrophilic and the other is hydro-phobic.
In this case the release of active component from the galenic form may be controlled in the desired extent by a suitably adapted ratio of the two types of inclusion com-plexes.
Owing to the high stability in the acidic medium of gastric juice and a suitable sus-tained rapidity of releasing clavulanic acid from the system, these complexes have an improved biological applicability.
All inclusion complexes of clavulanic acid and of its alkali salts with hydrophilic or hydrophobic ,B-CD derivatives according to the invention are formed in a molar ratio of about 1:1.
From US patent 4,869,904, a sustained release system of inclusion complexes of the active components with ,B-CD hydrophobic alkylated derivatives such as heptakis-(2,3-di-O-ethyl)-,B-CD is known.
According to the invention, in addition to the heptakis-(2,3,6-tri-O-acetyl)-,B-CD also O-carboxymethyl-O-ethyl-,B-CD, heptakis-2,6-di-O-pentyl-,B-CD, heptakis-2,3,6-tri-O-pentyl-,B-CD or heptakis-(3-O-acetyl-2,6-di-O-pentyl)-,l3-CD may be used as the hydrophobic ,B-CD derivative.
No toxic effect was observed in any of the performed tests. Thus it may be considered that the toxicity of the inclusion complexes is as low as the toxicity of clavulanic acid or its salts.
9 ~ 5 The invention is illustrated but in no way limited by the following Examp]es.
Examp]e 1 Preparation of the inclusion complex of potassium clavulanate with methyl~ cyclo-dextrin (Me-,B-CD) Me-,B-CD (13.10 g, 10 mmol) was dissolved in water for injections (25 ml) under stir-ring at ambient temperature and then to the solution potassium clavulanate (2.377 g, 10 mmol) was slowly added under constant stirring. The obtained solution was stirred at ambient temperature in the dark for 10 minutes, then it was filtered, the filtrate was frozen in a stream of liquid nitrogen and then it was freeze- dried.
There was obtained a slightly yellowish microcrystalline title complex (15.25 g,98.5%). The complex contained 15.2% of potassium clavulanate as it was determined by the HPLC method.
Figs. 1 and 2 illustrate INMR and DSC (differential scanning calorimetry) spectra of the title complex.
Example 2 Preparation of the inclusion complex of potassium clavulanate with 2-hydroxypropyl-~-CD (2-HP-,B-CD) It was proceeded in the same way as in Example 1, only that methyl-,B-cyclodextrin was replaced by 2-hydroxypropyl-,B-cyclodextrin (13.80 g, 10 mmol).
There was obtained a microcrystalline title complex (16.0 g, 99.3%). The complexcontained 14.6~o of potassium clavulanate as it was determined by the HPLC
method.
Figs. 3 and 4 illustrate INMR and DSC spectra of the title complex.
Example 3 10 ,~
Preparation of the inclusion complex of potassium clavulanate with 2-hydroxyethyl-,l3-cyclodextrin (2-HE-,B-CD) It was proceeded in the same way as in Example 1, only that methyl-,B-cyclodextrin was replaced by 2-hydroxyethyl-,B-CD (14.40 g, 10 mmol).
There was obtained microcrystalline title complex (16.2 g, 96.7%). The complex con-tained 13.9% of potassium clavulanate as it was determined by the HPLC method.
Figs. 5 and 6 illustrate lNMR and DSC spectra of the title complex.
Example 4 Process for the isolation of clavulanic acid or of potassium salt thereof A water solution (1.25 l) containing clavulanic acid (20 g, 0.1 mol) was acidified with conc. sulfuric acid (15 ml) to the pH value of 1.3 and then the acidified water solution was immediately extracted in a centrifuge with ethyl acetate (4.01) in which heptakis-(2,3,6-tri-O-acetyl)-,l~-CD (201.78 g, 0.1 mol) was dissolved. The phases were separated and the organic phase was washed with water (250 ml) on a separative column. Subsequently, the solvent was evaporated from the organic phase and the residue was dried in vacuum at the temperature of 35 C to a constant weight. There was obtained a crude inclusion complex (212.9 g, 96%) of clavulanic acid with heptakis-(2,3,6-tri-O-acetyl)-,B-CD, which was then digested in water (500 ml) under vigorous stirring. The complex was then filtered off, washed with water (3 x 50 ml) and dried in vacuum at a temperature up to 35C to the constant weight (210.4 g).
The complex contained 8.1% of clavulanic acid as it was determined by the HPLC
method.
The purified incll~sion complex (210.4 g) of clavulanic acid with triacetyl-,B-CD was dissolved in acetone (250 ml), the solid particles were filtered off and a solution (100 ml, 20%) of potassium 2-ethyl-hexsanoate in isopropanol was slowly added dropwise under stirring Potassium clavu]anate separated and it was filtered off,washed with isopropanol (3 x 15 ml) and dried in vacuum at a temperature up to 35C to the constant wei~llt. Ihe yield of potassium clavulanate was 18.0 g (88 %) (the clavulanic acid content of 83.() % was determined by the HPLC).
O ~
Figs. 7 and 8 illustrate NMR and DSC spectra of the inclusion complex of clavulanic acid with triacetyl-,B-CD.
Example 5 Preparation of the inclusion complex of potassium clawlanate with methyl-,B-cyclo-dextrin (Me-,B-CD) by recomplexing from the inclusion complex of clavulanic acidwith triacetyl-,B-CD
The inclusion complex (100 g) of clavulanic acid with heptakis-(2,3,6-tri-O-acetyl)-,B-CD, which was prepared in the same way as in Example 4, was suspended in a 3%
aqueous potassium carbonate solution (200 ml), in which methyl-,B-CD (53.6 g, 40.9 mmol) was dissolved. The suspension was stirred for 5 min at ambient tempera-ture, the solid particles were filtered off and the filtrate was frozen in liquid nitrogen and then freeze-dried. There was obtained a yellowish microcrystalline inclusioncomplex (56.7 g, 91.9%) of potassium clawlanate with methyl-,B-CD. The complex contained 14.9% of potassium clawlanate as it was determined by the HPLC
method.
In the same manner inclusion complexes of other alkali clawlanates can be prepared.
Example 6 Stability test of complexed and uncomplexed potassium clawlanate in artificial gastric juice (pH 1.2) at the temperature of 37 C
For the test the following samples were used:
1) potassium clavulanate (abbr. KK) 2) inclusion complex of KK with methyl-,B-CD (abbr. KK-Me-~3-CD) 3) inclusion complex of KK with 2-hydroxypropyl-~-CD (abbr. KK-HP-,B-CD) 4) inclusion complex of clavulanic acid with triacetyl-~-CD (abbr. KA-TA-,B--CD).
Medium: artificial gastric juice - aq.HCl/NaCl buffer, pH ].2, according to USP
XXII.
Concentration of clavulanic acid (al t~r. KA) in samples: 4 mg/ml.
The samples 1 to 3 were dissolved under stirring in an artificial gastric juice (100 ml) thermostated at 37 C, at the concentration of 4 mg/ml with regard to the clavulanic acid. Subsequentlv. 100 ~1 aliquots were taken at 5 min inteIvals for analysis by the HPLC, until a m~Jre than 95% KA decomposition was found. The solution was stirred all the time at the temperature of 37 C + 0.5 C.
Separately, a series of ten 10 ml aliquots of KA-TA-,B-CD suspension in a buffer of a pH of 1.2 (conc. of KA = 4 mg/ml), which were constantly stirred during thermo-stating at 37C, was prepared. At time intervals of 5 to 10 min, the individual aliquots were filtered (membrane filter 0.4 ,um) and in the clear filtrate the concentration of clavulanic acid was determined by HPLC. The KA content at times up to 90 min of thermostating was noted.
The results of measurements after 15, 30, 45, 60 and 90 min of thermostating thesamples at 37C in a buffer at pH 1.2 are shown in following Table.
Thermostating KA (undecomp.) as to the Released and undecomp.
time [min] initial KA conc.(100%) in KA in supernatant above samples [%] suspension [%]
. .
K~C KK- ~C~C- KA-Me-~3-CD HP-,B-CD TA-,B-CD
15 min 18.1 26.6 24.7 9.6 30 min 1.3 11.2 10.2 10.9 45 min 0 4.1 3.4 10.5 60 min 11.0 90 min 10.6 In ~'1gure 9, the times of 95% decomposition of clavlllanic acid (t~5%) are shown:
t~5% KK 26 min KK-Me-~-CD 42 min KK-HP-,B-CD 40 min KA-TA-~-CD > ')() min 13 ~ l V ~
From the obtained results it is evident that the complexing of potassium clavulanate with hydrophilic Me-,B-CD and HP-,B-CD substantially increases the stability of potassium clavulanate and clavulanic acid in artificial gastric juice (pH 1.2, 37 C).
The ratio in undecomposed clavulanis acid after 30 min. is about 1:8 in the favour of complexed potassium clavulanate (see Diagram 1).
It is further evident from ~g~e 9 that within 90 minutes the KA concentration inthe supernatant above suspension of hydrophobic inclusion complex KA-TA-,B-CD
keeps constant (it contains 10 to 11% of the starting KA), which represents a sus-tained and constant release of KA from the complex. The decomposed clavulanic acid is simultaneuosly replaced by a new amount of clavulanic acid from the complex KA-TA-,B-CD as a result of the concentration equilibrium of complexed and un-complexed clavulanic acid. Such a profile of the release of clavulanic acid points to the applicability of the complexes of clavulanic acid with hydrophobic,B-CD deriva-tives for sustained release forms.
After 10 minutes, a 90 ml aliquot of KA-TA-,l3-CD suspension was filtered and the precipitate was washed out with 10 ml of fresh buffer according to the USP XXII.Subsequently, the precipitate was quantitatively transferred to a 10 ml measuring flask, dissolved in a mixture of MeOH:H2O = 1:1 and filled with the solvent up to the mark. By the HPLC analysis it was determined that the sample contained 0.76 mg of KA/ml, which is 1~% of the starting KA amount in the complex. These results showthat from the complex KA-TA-,l3-CD the KA is released constantly and in a sustained manner.
The complexed part of clavulanic acid remained stable in acidic medium and the slow release at simultaneous absorption from the stomach to blood made possible a substantially greater extent of absorption than other hitherto known forms.
There was also determined the release of clavulanic acid or its potassium salt from the complex with hydrophobic triacetyl-,B-CD in artificial intestina] juice (pH 7.2, buffer according to the USP XXII), which also ran constantly and about twice faster than in artificial gastric juice with pH l.2.
From the above discussion it may be concluded that the inclusion complex of clavulanic acid with triacetyl-~3-CD is a suitable sustained release system for peroral forms.
Example 7 X-ray powder diffraction In the Table below there are shown the lattice distances d(nm) and intensity (I) of X-ray powder diffraction patterns of potassium clavulanate (abbr. KK), methyl-,B-CD
(abbr. Me-,l3-CD), 2-hydroxypropyl-,B-CD (HP-,B-CD), 2-hydroxyethyl-,B-CD (abbr.HE-,(3-CD) and of the inclusion complexes of potassium clavulanate with the enumerated ~-CD derivatives (abbr. KK-ME4-CD, KK-HP-,l~-CD and KK-HE-,B-CD), which were taken by Philips PW 1710 diffractometer on an Al-substrate and at )~ - 0.15418 nm (CuKcY).
Sample d(nm) (I) ..
KK 0.35389 1694 0.29359 1426 0.37586 1176 Me-,B-CD 0.49695 1454 0.46853 1422 0.49081 1404 KK-Me-,l~-CD 0.46426 1100 0.49217 1072 0.47133 1068 HP-,~-CD 0.48196 1576 0.46370 1538 0.48650 1532 KK-HP-,B-CD 0.46018 1198 0.45376 1164 0.47544 1140 .
HE-,B-CD 0.47459 1432 0.46811 1360 0.35968 ~298 lS ~ 0 ~ 5 KK-HE-,B-CD 0.45327 1046 0.44711 1018 0.47514 1()18 Example 8 Process for the isolation of clavulanic acid or of potassium salt thereof To an ethylacetate solution (11) of the inclusion complex of clavulanic acid with heptakis-(2,3,6-tri-O-acetyl)-~3-CD (the concentration of clavulanic acid was 10 mg/ml as determined by the HPLC method), which was obtained according to the process of Example 4, N,N'-diisopropylethylenediamine (5 ml) was slowly added dropwise under vigorous stirring within 10 min. The resulting suspension was stirred for another 30 min, the produced precipitate was filtered off and then dissolved in 10 ml of water. Acetone (200 ml) was added to the solution, whereat N,N'-diisopropyl- ethylenediammonium diclavulanate (6.1 g) was separated in the form of fine crystalls, which were filtered off and redissolved in water (5 ml). Isopropanol (95 ml) was added to the solution and then a so]ution of potassium 2-ethylhexanoate (10 ml, 2M) in isopropanol was slowly added dropwise under vigorous stirring within 15 min, whereat potassium clavulanate was separated, which was filtered off, washedwith isopropanol (3 x 10 ml) and dried in vacuum at a temperature up to 35 C toconstant weight. Thus there was obtained potassium c]avulanate (2.64 g, 77%) (USP
grade, clavulanic acid content 82.8% as deterrnined by HPLC method).
Example 9 Preparation of inclusion complex of potassium clavulanate with triacetyl-,B-cyclo-dextr;n Potassium clavulanate (237.3 mg, 1 mmol) was dissolved in water for injections (ln ml) under stirring at ambient temperature and then a solution of triacetyl-,B-cyclodextrin (TA-13-CD; 2.02 g, 1 mmol) in isopropanol (90 ml) was added. The reac-tion mixture was stirred for S min at ambient temperature, subsequently the solvents was evaporated at reduced pressure, at first on a rotary evaporator at the tempera-ture of 30 C and then the residue was frozen and freeze-dried. Microcrystalline title 16 ~V;~ ~
complex (2.25 g, 99%) was obtained. The complex contained 9.1% of potassium clavulanate (co~responding to 0.9 mol of potassium clavulanate/1 mol of triacetyl~
CD) as determined by the HPLC method.
The DSC analysis corresponded to the title complex.
The NMR spectrum corresponded to potassium clawlanate and triacetyl-~-CD.
Example 10 Dispersion tablets containing clavulanic acid (125 mg) and amoxicillin (500 mg) Ingredients mg/tablet %
inclusion complex of potassium clavulanate with Me-~-CD 833.3 27.78 amoxicillin trihydrate (corresponding to 500 mg of anhydrous amoxicillin) 574.0 19.13 crospovidone (Kollidon CL) 50.0 1.67 saccharin 10.0 0.33 flavourings (fruit) 35.0 1.17 magnesium stearate 21.0 0.70 colloidal silica (Aerosil 20()) 10.0 0.33 microcrystalline cellulose (Avicel pH 101) ad3000.0 ad100.00 The equivalents of amoxicillin and clavulanic acid were mixed homogeneously and then briquetted with a part of the filler (microcrystalline cellulose). The briquettes were crushed and sieved through an oscillation sieve with a mesh size of 1.5 mm. The obtained granulate was mixed with the remaining adjuvants and tableted on a rotary tableting machine.
The tablets rapidly disintegrate in water giving a fine dispersion suitable for thera-peutic application.
17 ~ a ~ a Example 11 Chewing tablets containing clavulanic acid (125 mg) and amoxicillin (500 mg) Ingredients mg/tablet ~o inclusion complex of potassium clavulanate with Me-,B-CD 833.3 27.78 amoxicillin trihydrate (corresponding to 500 mg of anhydrous amoxicillin) 574.0 19.13 crospovidone (Kollidon CL) 5.0 0.17 polyvinyl pyrrolidone 60.0 2.00 colloidal silica (Aerosil 200) 10.0 0.33 saccharin 10.0 0.33 flavourings (fruit) 35.0 1.17 magnesium stearate 15.0 0.50 microcrystalline cellulose (AvicelpH 101) 60.0 2.00 mannitol ad3000.0 ad 100.00 .
The equivalents of amoxicillin and clavulanic acid were homogeneously mixed together with a part of the fillers (microcrystalline cellulose and mannitol) and the obtained mixture of powders was briquetted. The briquettes were crllshed and sieved through an oscillation sieve with a mesh size of 1.5 mm. The obtained granulate was mixed with the remaining adjuvants and tableted.
Tablets were suitable for chewing.
Claims (20)
1. Inclusion complexes of clavulanic acid and of pharmaceutically acceptable alkali salts thereof of the formula wherein R represents hydrogen or an alkali metal, with hydrophilic and hydrophobic .beta.-cyclodextrin derivatives.
2. Inclusion complexes according to claim 1, characterized in that the molar ratio of clavulanic acid or of pharmaceutically acceptable alkali salts thereof and of hydrophilic or hydrophobic .beta.-cyclodextrin derivatives amounts to about 1:1.
3. Inclusion complexes according to claim 1, characterized in that the hydrophilic .beta.-cyclodextrin derivatives are selected from the group comprising heptakis-(2,6-di-O-methyl)-.beta.-cyclodextrin, heptakis-(2,3,6-tri-O-methyl)-.beta.-cyclo-dextrin, monomethyl-.beta.-cyclodextrin, 2-hydroxypropyl-.beta.-CD, 3-hydroxypropyl-.beta.-CD, 2-hydroxyethyl-.beta.-CD, 2,3-dihydroxypropyl-.beta.-CD, 6-O-.alpha.-D-glucosyl-.beta.-CD, 6-O-.alpha.-D-maltosyl-.beta.-CD, diglucosyl-.beta.-CD, dimaltosyl-.beta.-CD, maltotriosyl-.beta.-CD, carboxy-methyl-.beta.-CD, carboxyethyl-.beta.-CD.
4. Inclusion complexes according to claim 1, characterized in that the hydrophobic .beta.-cyclodextrin derivatives are selected from the group comprising heptakis-(2,3,6-tri-O-acetyl)-.beta.-CD, heptakis-(2,6-di-O-ethyl)-.beta.-CD, heptakis-(2,3-di-O-ethyl)-.beta.-CD and heptakis-(2,3,6-tri-O-ethyl)-.beta.-CD, O-carboxymethyl-O-ethyl-.beta.-CD, heptakis-2,6-di-O-pentyl-.beta.-CD, heptakis-2,3,6-tri-O-pentyl-.beta.-CD, heptakis-(3-O-acetyl-2,6-di-O-pentyl)-.beta.-CD.
5. A process for the preparation of inclusion complexes of clavulanic acid and of pharmaceutically acceptable alkali salts thereof of the formula I with hydrophobic .beta.-CD derivatives, characterized in that a solution of clavulanic acid or of pharma-ceutically acceptable alkali salts thereof in an inert organic solvent is reacted with hydrophobic .beta.-CD derivatives at a temperature from 10 to 30 °C and the desired compound is isolated and purified.
6. A process for the preparation of inclusion complexes of clavulanic acid and of pharmaceutically acceptable alkali salts thereof of the formula I with hydrophilic .beta.-CD derivatives, characterized in that a solution of clavulanic acid or of pharma-ceutically acceptable alkali salts thereof in water or in lower aliphatic alcohols or in their aqueous solutions is reacted with hydrophilic .beta.-CD derivatives at a tempera-ture from 10 to 30°C and the desired compound is isolated.
7. A process for the preparation of inclusion complexes of clavulanic acid and of pharmaceutically acceptable alkali salts thereof with hydrophilic .beta.-CD derivatives, characterized in that the inclusion complex of clavulanic acid with a hydrophobic .beta.-CD derivative is reacted with a hydrophilic .beta.-CD derivative in an aqueous solution of an alkali carbonate, bicarbonate, hydroxyde or alkanoate at a temperature from 10 to 30 °C and the desired compound is isolated.
8. A process according to claim 7, characterized in that in the starting inclusion complex of clavulanic acid with a hydrophobic .beta.-CD derivative, heptakis-(2,3,6-tri-O-acetyl)-.beta.-CD is used as the hydrophobic component.
9. A process for the preparation of an alkali clavulanate, characterized in thatthe concentrate of a clear aqueous solution of crude clavulanic acid in the form of an alkali salt is acidified with sulfuric acid to a pH value between 1 and 3 and sub-sequently the acidified aqueus solution of crude clavulanic acid is immediately reacted with the solution of a hydrophobic .beta.-CD derivative in an inert organic sol-vent, the inclusion complex of clavulanic acid with hydrophobic .beta.-CD derivative is isolated from the organic phase, purified and, with an alkali carbonate, bicarbonate, hydroxyde or alkanoate in an inert organic solvent, converted to the desired com-pound, which is then isolated.
10. A process for the preparation of an alkali clavulanate according to claim 9,characterized in that the hydrophobic .beta.-CD derivative is selected from the group comprising heptakis-(2,3,6-tri-O-acetyl)-.beta.-CD, heptakis-(2,6-di-O-ethyl)-.beta.-CD, heptakis-(2,3-di-O-ethyl)-.beta.-CD and heptakis-(2,3,6-tri-O-ethyl)-.beta.-CD.
11. A process for the preparation of an alkali clavulanate according to claim 9,characterized in that alkali 2-ethyl hexanoate is used as the alkali alkanoate.
12. The use of inclusion complexes of clavulanic acid with hydrophobic .beta.-CDderivatives according to claims 9 and 10 as intermediate compounds for the prepara-tion of alkali clavulanate.
13. The use of the inclusion complex of clavulanic acid with heptakis-(2,3,6-tri-O-acetyl)-.beta.-CD as intermediate compound for the preparation of alkali clavulanate.
14. The use of inclusion complexes of clavulanic acid and of pharmaceutically ac-ceptable alkali salts thereof with hydrophilic .beta.-CD derivatives for the preparation of stable galenic forms for oral application, characterized in that the galenic forms con-tain a therapeutically effective amount of amoxicillin trihydrate and of the inclusion complex of clavulanic acid and of its alkali salts with a hydrophilic .beta.-CD derivative and a pharmaceutically acceptable carrier, whereat the ratio of amoxicillin trihydrate and of clavulanic acid and its alkali salts is from 10:1 to 1:1.
15 The use of inclusion complexes of clavulanic acid and of pharmaceutically ac-ceptable alkali salts thereof with hydrophilic .beta.-CD derivatives according to claim 14, characterized in that the hydrophilic .beta.-CD derivatives are selected from the group comprising heptakis-(2,6-di-O-methyl)-.beta.-CD, heptakis-(2,3,6-tri-O-methyl)-.beta.-CD, monomethyl-.beta.-CD, 2-hydroxypropyl-.beta.-CD, 2-hydroxyethyl-.beta.-CD, glucosyl-.beta.-CD, maltosyl-.beta.-CD, dimaltosyl-.beta.-CD and diglucosyl-.beta.-CD.
16. The use of inclusion complexes of clavulanic acid and of pharmaceutically ac-ceptable alkali salts thereof with hydrophilic .beta.-CD derivatives according to claims 14 and 15, characterized in that the galenic forms can be tablets, capsules, granules, syrups, suspensions, intramammar suspensions and optionally also injections.
17. Stable galenic forms with sustained release of the active component, charac-terized in that they contain a therapeutically active amount of amoxicillin trihydrate and of the inclusion complex of clavulanic acid or of its alkali salts with a hydro-phobic .beta.-CD derivative selected of the group comprising heptakis-(2,3,6-tri-O-acetyl)-.beta.-CD, O-carboxymethyl-O-ethyl-.beta.-CD, heptakis-2,6-di-O-pentyl-.beta.-CD, heptakis-2,3,6-tri-O-pentyl-.beta.-CD and heptakis-(3-O-acetyl-2,6-di-O-pentyl)-.beta.-CD
and other adjuvants, whereat the ratio of amoxicillin trihydrate and of clavulanic acid or of its pharmaceutically acceptable alkali salts is from 10:1 to 1:1.
and other adjuvants, whereat the ratio of amoxicillin trihydrate and of clavulanic acid or of its pharmaceutically acceptable alkali salts is from 10:1 to 1:1.
18. Stable galenic forms with sustained release of the active component according to claim 17, characterized in that they are formed in a form suitable for oral applica-tion such as a tablet or capsule or optionally in the form of an oil intramuscular injec-tion.
19. Stable galenic forms with sustained release of the active component, charac-terized in that they contain a therapeutically active amount of amoxicillin trihydrate and of a mixture of the inclusion complex of clavulanic acid or of its alkali salts with a hydrophobic .beta.-CD derivative and a hydrophilic .beta.-CD derivative and other adjuvants, whereat the ratio of amoxicillin trihydrate and of clavulanic acid or its pharmaceuti-cally acceptable alkali salts is from 10:1 to 1:1.
20. A method for treating bacterial infections in humans and animals, charac-terised in that the stable galenic forms according to any one of claims 14 to 19 are used.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SIP-9200139 | 1992-07-08 | ||
| SI9200139A SI9200139A (en) | 1992-07-08 | 1992-07-08 | New inclusion complex of clavulanic acid with hydrophylyc and hydropholyc beta-cyclodextrin derivates for production of them |
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|---|---|
| CA2100045A1 true CA2100045A1 (en) | 1994-01-09 |
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ID=20430975
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|---|---|---|---|
| CA002100045A Abandoned CA2100045A1 (en) | 1992-07-08 | 1993-07-07 | Inclusion complexes of clavulanic acid and of alkali salts thereof with hydrophilic and hydrophobic .beta. - cyclodextrin derivatives, a proce ss for the preparation thereof and the use thereof |
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| Country | Link |
|---|---|
| US (3) | US5498788A (en) |
| EP (1) | EP0578231A1 (en) |
| JP (1) | JPH072905A (en) |
| KR (1) | KR970001653B1 (en) |
| AU (1) | AU662986B2 (en) |
| CA (1) | CA2100045A1 (en) |
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| US9241745B2 (en) | 2011-03-07 | 2016-01-26 | Biomet Manufacturing, Llc | Patient-specific femoral version guide |
| CN102258521B (en) * | 2011-06-03 | 2016-05-04 | 艾美科健（中国）生物医药有限公司 | Cefodizime Sodium composition and method of making the same |
| US9051479B2 (en) * | 2012-10-12 | 2015-06-09 | Empire Technology Development Llc | Paints and coatings containing cyclodextrin additives |
| HUE048496T2 (en) * | 2013-09-20 | 2020-07-28 | Centrient Pharmaceuticals Netherlands B V | Tablet comprising crospovidone |
| WO2017222575A1 (en) | 2016-06-23 | 2017-12-28 | Collegium Pharmaceutical, Inc. | Process of making more stable abuse-deterrent oral formulations |
| US10722310B2 (en) | 2017-03-13 | 2020-07-28 | Zimmer Biomet CMF and Thoracic, LLC | Virtual surgery planning system and method |
| CN115364057B (en) * | 2021-05-20 | 2024-01-30 | 内蒙古联邦动保药品有限公司 | Amoxicillin and clavulanate potassium compound preparation and preparation method thereof |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1508977A (en) * | 1974-04-20 | 1978-04-26 | Beecham Group Ltd | Beta-lactam antibiotic from streptomyces clavuligerus |
| IE41110B1 (en) * | 1974-04-20 | 1979-10-24 | Beecham Group Ltd | Esters of clavulanic acid |
| GB1589917A (en) * | 1976-11-27 | 1981-05-20 | Beecham Group Ltd | Pharmaceutical composition containing a clavulanic acid derivative |
| IL58461A0 (en) * | 1978-10-27 | 1980-01-31 | Beecham Group Ltd | Intramammary compositions comprising a clavulanic acid salt |
| US4454069A (en) * | 1979-08-24 | 1984-06-12 | Beecham Group Limited | Clavulanic acid salts and their preparation from the tertiary butyl amine salt |
| DE3063683D1 (en) * | 1979-08-24 | 1983-07-14 | Beecham Group Plc | Amine salt of clavulanic acid, its preparation and use |
| EP0080862B1 (en) * | 1981-12-02 | 1985-09-25 | Beecham Group Plc | Pharmaceutical formulation comprising beta-lactam antibiotics |
| US4616008A (en) * | 1984-05-02 | 1986-10-07 | Takeda Chemical Industries, Ltd. | Antibacterial solid composition for oral administration |
| JPH0819004B2 (en) * | 1986-12-26 | 1996-02-28 | 日清製粉株式会社 | Sustained-release pharmaceutical preparation |
| AT399155B (en) * | 1992-03-26 | 1995-03-27 | Lek Tovarna Farmacevtskih | NEW ALKYLENE DIAMMONIUM DICLAVULANATE DERIVATIVES, METHOD FOR THE PRODUCTION AND USE THEREOF |
-
1992
- 1992-07-08 SI SI9200139A patent/SI9200139A/en unknown
-
1993
- 1993-07-07 KR KR1019930012769A patent/KR970001653B1/en not_active IP Right Cessation
- 1993-07-07 AU AU41824/93A patent/AU662986B2/en not_active Ceased
- 1993-07-07 EP EP93110883A patent/EP0578231A1/en not_active Withdrawn
- 1993-07-07 HU HU9301968A patent/HUT64961A/en unknown
- 1993-07-07 FI FI933113A patent/FI933113A/en not_active Application Discontinuation
- 1993-07-07 CA CA002100045A patent/CA2100045A1/en not_active Abandoned
- 1993-07-08 JP JP5169361A patent/JPH072905A/en active Pending
-
1995
- 1995-01-06 US US08/369,301 patent/US5498788A/en not_active Expired - Fee Related
- 1995-06-06 US US08/470,267 patent/US5614199A/en not_active Expired - Fee Related
- 1995-06-06 US US08/469,870 patent/US5608052A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| EP0578231A1 (en) | 1994-01-12 |
| AU662986B2 (en) | 1995-09-21 |
| US5608052A (en) | 1997-03-04 |
| JPH072905A (en) | 1995-01-06 |
| FI933113A0 (en) | 1993-07-07 |
| AU4182493A (en) | 1994-01-13 |
| KR970001653B1 (en) | 1997-02-13 |
| US5614199A (en) | 1997-03-25 |
| FI933113A (en) | 1994-01-09 |
| US5498788A (en) | 1996-03-12 |
| HU9301968D0 (en) | 1993-09-28 |
| HUT64961A (en) | 1994-03-28 |
| SI9200139A (en) | 1994-03-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |