WO2002045697A2

WO2002045697A2 - Composite material for counteracting edema

Info

Publication number: WO2002045697A2
Application number: PCT/BE2001/000205
Authority: WO
Inventors: Marie-Thérèse VAN DEN HEEDE; Bernard Hoste
Original assignee: Den Heede Marie Therese Van; Bernard Hoste
Priority date: 2000-12-04
Filing date: 2001-12-04
Publication date: 2002-06-13
Also published as: WO2002045697A3; AU2002215713A1

Abstract

A composite material effective to counteract edema including lymphedema comprises an elastic fabric having a layer of a non-tacky silicone elastomer on the exterior surface. The material is selfadherent, can be washed and is suitable for repeated use.

Description

COMPOSITE MATERIAL FOR COUNTERACTING EDEMA.

The present invention relates to a therapeutic composite material for reducing edema, including lymphedema.

Edema may result from a number of causes e.g. due to increased extracellular fluid volume by fluid retention when a person has difficulty excreting fluids for whatever reason and by blockage of lymphatic vessels as often occurs after a radical mastectomy (breast removal, usually because of cancer). In a radical mastectomy nearby lymph nodes are removed with the breast tissue. Edema occurs in the arm on the same side because lymph drainage is blocked. The accumulated lymph fluid produces subcutaneous tissue swelling.

Edema is counteracted by means of elastic pressure stockings. Before taking the measures for the stockings to be made the arm or the leg has to be reduced in thickness by applying a bandage for several days. Once the measures are known it takes another couple of weeks to make the stockings so that the patient has to remain with the bandages on. The existing self-adhering bandages for single use are expensive and of limited length so that several are needed to cover e.g. an entire leg. Moreover experienced people are needed to correctly apply the bandages. Because this technique for making the correct stockings is expensive and time consuming it is often not applied and too wide or too tight stockings are used with unsatisfactory effect on the edema.

It is an object of the present invention to provide a composite material, in particular a bandage, for effectively counteracting edema that can easily be applied to arms and legs and other body parts by the specialist as well as the patient himself or herself.

It is another object of the present invention to provide such composite material that can be washed by ordinary means and reused. Other objects will become apparent from the description hereinafter. The above objects are accomplished by the composite material according to the present invention.

The present invention provides a composite material for counteracting edema comprising a carrier material carrying on both surfaces silicone coatings characterised in that said carrier material is an elastic fabric and carries on one surface thereof a tacky coating of a silicone gel elastomer and on the other surface a non-tacky fully cured silicone coating.

The material of the present invention has self adherent properties and can be easily applied as a bandage by the patient. The pressure can be corrected to the appropriate degree by adapting the tension. Upon use the material will loose partly its adherent character by adsorption of body exudates such as sweat and other dirt but this can be regained by washing in cold or hot water.

The bandages of the invention can be used in combination with pressure stockings as referred to hereinbefore e.g. when the pressure stockings themselves become insufficiently effective.

Bandages, dressings and the like having one or more silicone coatings are known for use in medical, paramedical and cosmetic applications. For example silicone gels in the form of sheets, dressing and the like have been used in the management of new scar tissue. When the gels are positioned against scar tissue and pressure is applied thereto hypertrophic scar tissue can be reduced.

According to PCT application BE97/00017 a composite material is described for use in medical, paramedical, cosmetic and sports applications. Said material comprises a silicone layer on at least one side of an elastic carrier and exerts an evenly spread pressure on the skin to which it is applied. In EP 0251810 a wound dressing is described that comprises an apertured carrier material coated with a tacky silicone gel or a non-tacky silicone elastomer or coated on one surface with a tacky silicone gel and on the other surface with a non-tacky silicone elastomer. The fibres of the carrier material are to be effectively encapsulated by the gel so that loss of fibres in the wound is eliminated. However the apertures in the material e.g. cotton gauze are not to be occluded by the silicone gel.

In USP 5919476 a bandage in the form of reinforced silicone gel sheet for the treatment of scar tissue is disclosed. The bandage consists of a first layer of silicone adapted to adhere to the skin, a second layer of a perforated polyester mesh fabric with a plurality of holes therethrough which contacts the first layer and a third layer of silicone. The third layer provides a non adherent surface sealing the second layer which enables the bandage to be worn underneath clothing.

It was surpising to have found that a composite material according to the present invention was effective for use in counteracting edema. Nothing of the sort could be expected from the above known uses of silicone containing materials.

The elastic carrier material of the composite material according to the present invention is an elastic woven fabric which is made as is known by providing elastomeric threads in between the natural or synthetic fibres of the fabric. The elastic fabric has an elasticity in the longitudinal and an elasticity in the transverse direction which are the same or different and which can be chosen according to the particular use intended. A particularly preferred carrier material is a polyamide fabric. The fabric can be coloured or can have designs printed on it so that it obtains a less clinical look.

The silicone coatings of the composite material according to the present invention consist on the one hand of a tacky silicone gel on the surface intended for contact with the skin and on the other hand of a non-tacky cured silicone on the exterior surface. Silicones suitable for coatings in the material of the invention are well known and commercially available. Reference can be made to USP5919476 and EP 0251810 referred to hereinbefore. The coating of tacky silicone gel is flexible so that it can follow in use all irregularities of the skin. Its adherence to the skin is such that it is not too high so as to cause pain or irritations upon long time use and not too low to avoid becoming loose e.g. by body sweat. The tacky coating preferably has a thickness between 0.05 and 2 mm, most preferably between 0.1 and 1 mm. The coating of non-tacky cured silicone is not critical ; it preferably has a thickness between 0.05 and 1 mm.

One way of manufacturing the elastic composite material according to the present invention is as follows:

A temporary and releasable support e.g. of paper or film which may be a PE-film, a PVC-film, a PET-film, etc is passed through a coating station for depositing a layer of tacky silicone gel. Several coating techniques can be used: knife coating, roller coating, calender coating. The silicone layer while partly being cured is contacted with the fabric and the whole is passed through an oven for further curing. The reverse side of the fabric is then coated with the non-tacky silicone and this is followed by curing. For a suitable coating technique there can also be referred to EP 0507760. The fabric is chosen and the silicone layers are coated such as to avoid that the silicone coatings substantially penetrate the fabric. For example the number of threads in both directions of the fabric is preferably such so as to obtain apertures of at most 0.1 mm² and most preferably at most 0.05 mm². The silicone layers especially the tacky silicone layer are applied at such a degree of curing that they form a coherent layer that does not permeate the fabric. The thicknesses of the coatings and the thickness and elasticity of the fabric are preferably chosen so as to obtain a silicone coated fabric that has a so-called short to medium elasticity i.e. an elasticity in the longitudinal direction of at most 100 %, preferably at most 70 %, and most preferably at most 30 %. On each side of the fabric the silicone coatings can be obtained by coating two or more layers over each other.

Once the product has been manufactured, different widths can be provided dependent on the body parts that the product will have to treat.

It is preferred to adapt the packaging to the product so that the packaging has more than advertising or "easy storage" function. The packaging together with the cleaning instructions play a part in the longevity of the product. The patients will be using and reusing the product at different time intervals, patients will take it wherever they go and therefore there is a need for a packaging that will allow the patient to safely store his product.

The following example illustrates the present invention.

Example:

1. carrier materal

An elastic polyamide fabric (83 % of polyamide) of 130 g per sq.m. having a longitudinal elasticity of 290 % and a transverse elasticity of 85 % is used. The woven fabric has per cm 68.6 yarns in one direction and 28.7 yarns in the other direction.

2.tacky coating

A mixture was made of components commercially available form

MADRIGAL FINANCES S.A., Vinay, France under the trade name DROP-

ORTHO for a silicone polyaddition gel adhesive FA 111-00. The first component known as part A containing polyorganic siloxanes was intimately mixed at room temperature in a ratio of 50/50 by weight with the second component known as part B containing polyorganic siloxanes and a dimethylpoly (methylhydrogen) dimethylsiloxane. A vacuum of about 30 to 50 mbar was applied to remove air from the liquid. Both components are liquids having a viscosity of about 54.000 mPas at 20° C.

Polymerisation started at roomtemperature from the moment the components were mixed. The mixture was coated at a ratio of 500 g per sq.m. on a temporary paper support and the free surface was contacted with the above fabric. Due to the partial curing before contact and the kind of fabric used, the silicone gel did not penetrate the fabric but adhered very well. The composition was passed through an oven for further curing.

3.non-tacky coating

A mixture was made of components commercially available from

MADRIGAL FINANCES S.A., Vinay, France under the trade name DROP-

MED for a silicone polyaddition product FA557. The first component known as part A containing a mixture of polymethylvinyl, polymethylhydrogenosiloxanes and silica was intimately mixed at roomtemperature in a ratio of 100 to 10 by weight with the second component know as part B, containing a mixture of polymethylvinylsiloxanes, silica and platinum.

Liquid part A has a viscosity at 25°C of 40.000 mPas whereas liquid part B has a viscosity at 25°C of 20.000 mPas. After mixing air was removed from the liquid by applying a vacuum of about 30 to 50 mbar. Curing started at room temperature from the moment the components were mixed.

The mixture was coated at a ratio of 340 g per sq.m. at the free side of the elastic polyamide fabric and fully cured. The temporary support was removed. The % of elasticity in the longitudinal direction of the composite material formed was 75 %.

4. use

A bandage made from the composite material was wound around the arm of a patient having lymphedema and left applied thereto. In this way the lymphedema could be managed.

According to the present invention a constant pressure can be exerted on a determined part of the body by means of the material of the invention applied under tension. The windings once applied do not shift relative to each other and remain in place under tension and no external fastening means is necessary. The windings adhering at least partly over each other can be easily loosened and the self adherent elastic composite material can be removed from the body part to which it is applied as often as desireable e.g. for washing. The composite material withstands multiple reuses and cleaning without degradation.

Claims

CLAIMS:

1. A composition of matter for counteracting edema comprising a carrier material carrying on both surfaces silicone coatings characterised in that said carrier material is an elastic fabric and carries on one surface thereof a tacky coating of silicone gel elastomer and on the other surface thereof a non-tacky coating of cured silicone elastomer.

2. A composition according to claim 1 wherein the fabric is a polyamide fabric.

3. A composition according to claim 1 or 2 wherein the composition of matter has a longitudinal elasticity of at most 100 %.

4. A compostion according to claim 1 or 2 wherein the composition of matter has a longitudinal elasticity of at most 70 %.

5. A composition according to any of the preceding claims wherein the fabric has apertures of at most 0.1 mm².

6. A composition according to any of the preceding claims wherein the fabric has apertures of at most 0.05 mm².

7. Use of a composition of matter according to any of the preceding claims for counteracting edema.