WO2004105821A1

WO2004105821A1 - Scar management composition comprising silicone

Info

Publication number: WO2004105821A1
Application number: PCT/GB2004/002325
Authority: WO
Inventors: Craig Julian Hardy
Original assignee: Medtrade Products Ltd.
Priority date: 2003-05-30
Filing date: 2004-06-01
Publication date: 2004-12-09
Also published as: GB0312428D0; GB0412170D0; GB2402878A

Abstract

A substantially water-free scar management composition in the form of a liquid gel. The composition comprises at least one silicone elastomer and/or gum.

Description

SCAR MANAGEMENT COMPOSITION COMPRISING SILICONE

The present invention relates to a composition which finds particular utility in scar management.

It has been known for some years that the cosmetic severity of tissue scarring as a result of medical treatment and/or injury can be greatly reduced by the application of a silicone-containing sheet to the skin's surface. The mode of action remains unclear.

The first silicone-containing sheets used in order to reduce the visual severity of tissue scarring, based on a rubber containing formulation, were developed approximately 25 years ago and met with limited success since they were difficult to use. These silicone rubber sheets were secured on the skin surface with adhesive tape thereby forming a sealed enclosure. Typically, the silicone rubber sheet would be secured in place for 30 days during which time the skin would 'remodel' itself to a large degree giving rise to a decrease in the cosmetic severity of the scar tissue.

Several theories have been postulated regarding the mode of action of the silicone layers. These include the moisture barrier properties of silicone, the leaching of low molecular weight silicone into the skin and the effect of the ionic content of the silicone.

Despite these silicone rubber sheets being expensive, they were widely used even though the location of their use on the skin surface was limited by their lack of flexibility.

The aforesaid silicone rubber sheets have since been replaced with softer self- adhesive silicone gel sheets, which possess a greater degree of flexibility by virtue of their polymeric oil-containing network structure. Therefore, although easier to apply, their use remains limited as a result of their sheet-like nature.

More recently liquid silicone compositions, which are predominantly composed of water, have been introduced. These are supplied in a tube and are specifically designed to be applied to awkward areas ,of the skins surface. Examples of said compositions include KELO-COTE (TM) or with a roller ball applicator, CICACARE (TM). Unlike the previously described sheets, which are intended to be worn for a period of approximately 30 days, these liquid silicone compositions require re-application every few hours as the silicone layer located over the wound is thinner. However, these compositions remain sticky and tacky after application, some fail to dry, whilst others take 10 to 30 minutes to dry.

Surprisingly, it has been found that it is now possible to provide a composition which delivers the aforesaid cosmetic scar severity reduction which is substantially ater- free, but which is more convenient to use than prdviously available compositions as it dries quickly to a non-sticky film and has a substantially longer wear time than existing products such that it needs to be reapplied considerably less often .

According to the present invention there is provided a scar management composition in the form of a liquid gel wherein the composition is substantially watef- free and comprises at least one silicone elastomer and/or gum.

Advantageously, the composition of the present invention is in the form of a surprisingly stable gel which is easy to manufacture and as such is suitable for application to all skin areas, but it is particularly useful for the application, to areas to which it is

difficult to apply sheet material. By liquid gel it is meant a composition having a viscosity in the range from 0.01

cps to 500 000 cps when measured at 20°C.

By substantially water-free it is meant that the composition does not contain more than 3% water. A further advantage of the composition of the present invention lies with its longer wear time, typically in excess of 8 hours. The longer wear time means that the composition can be worn for sufficiently long periods to enable moisture to develop under the sheet thus giving a skin softening and moisturising effect. A still further advantage of the composition of the present invention is its rapid drying time, typically of about 2 minutes, thereby eliminating the undesirable tack of previously used liquid compositions which have a much longer drying time, typically in the order of 10 to 30 minutes.

Surprisingly, the composition of the present invention results in a greater reduction in the visual severity of a scar than that seen with previous methods of scar management.

Accordingly, the composition of the present invention is not only much easier and quicker to use than its predecessors but results in a greater reduction in the visual severity of scar tissue. Preliminary results obtained from an ongoing clinical study show that 100% of users reported that the appearance of their scars had improved during 6 weeks of treatment.

The silicone elastomer and/or gum preferably constitutes from 0.01% to 80%, by weight, of the total composition of the present invention.

Silicone elastomers suitable for use with the composition of the present invention include any of the following either alone or in combination:- silicone elastomers, silicone crosspolymers, dimethicone crosspolymer, elastomer 10 (Dow Corning),

Elastomer 40 (Dow Corning), silicone elastomer copolymers and partially reacted silicone elastomer (silicone elastomer prepolymers which will when reacted further give rise to silicone elastomers or crosspolymers).

Silicone gums suitable for use with the present invention include any of the following either alone or in combination:- silicone gum, dimethiconols, dimethiconol esters, dimethiconol copolymers, dimethiconol crosspolymers, dimethiconol blends, dimethiconol blend 20 (Dow Corning) and partial reacted silicone gums (prepolymers which will wne further reacted guve rise to silicone gums).

In addition to silicone elastomers and gums the composition of the present invention may comprise additional silicone components.

Additional silicone components suitable for use with the present invention include any of the following either alone or in combination:-silicone oils, silicone fluids, silicone solvents, silicone gels, silicone wax, silicone grease, silicone crosspolymers, silicone adhesives, silicone emulsifier, silicone wax emulsifier, silicone copolymer, silicone

PSA's and other curing or partially cured silicone cotøpounds.

Preferably the composition of the present invention shall contain at least one volatile solvent and most preferably at least one volatile organic solvent, for example isopropyl alcohol (IPA), ethanol, methanol, low molecular weight silicone, cyclomethicone, volatile silicone fluids, ethoxydiglycol, hexane or any other skin compatible organic solvent.

Preferably the composition of the present invention comprises at least one thickening agent.

The said solvent may constitute from 0 % to 80%, by weight, of the total composition of the present invention.

The thickening agent preferably comprises from 0 to 50 % by weight of the total composition.

Thickening agents suitable for use with the present invention include any of the following either alone or in combination:- high viscosity silicone fluids, silicone gels, silicone grease, silicone elastomer or cross polymer, silicone gum, silicone adhesive, silicone emulsifier, silicone wax emulsifier, reactive silicone component, silicone _, prepolymer and silicone co-polymer, hydroxypropyl cellulose, ethyl cellulose, cetyl hydroxyethyl cellulose, polyurethane, polyurethane copolymers, or any other polymer which is soluble or partial soluble in organic solvents.

In addition to the foregoing the composition of the present invention may also comprise any of the following, either alone or in combination:- active agents such as antibacterial agents, surfactants, antimicrobial agents, essential oil skin occlusion agents, copolymers and skin moisturisers, skin healing agents, scar healing agents, growth factors, or any compound which effects the level of growth factors in the skin, wound or scar, herbal agents, plant oils, essential oils or other plant extracts.

According to a second aspect of the present invention there is provided the use of a scar management composition as hereinbefore described to apply a coating of silicone elastomer and/or gum to human skin.

According to a further aspect of the present invention there is provided a method for forming a scar management coating of at least one silicone elastomer and/or gum to human skin comprising the step of applying the composition as hereinbefore described to

a desired area of the skin.

According to a still further aspect of the present invention therefore there is provided a method of preparing a scar management composition as hereinbefore described comprising the steps:- mixing together at least a first and a second two formulation wherein at least one of the first and second formulations comprises at least one silicone component.

During preparation of the composition of the present invention the first formulation may be added to the second formulation with vigorous mixing, again until a homogeneous gel ensues.

In order that the present invention be more readily understood the composition of the present invention will now be described further by way of example only with relation to the following examples :-

Example 1

Cyclomethicone 5 and isopropyl Myristate were pre-mixed to form the first formulation as a homogenous mixture.

The first formulation was then added to Elastomer 10 (the second formulation) with vigorous stirring to furnish a surprisingly stable clear gel.

NB: Drying time 485 seconds

Example 2

Simogen carrier and isopropyl Myristate were pre-mixed to form the first formulation as a homogenous mixture.

NB: Drying time 123 seconds

Example 3

Cetyl hydroxyl cellulose, propylene glycol and ethanol were pre-mixed to form

the first formulation as a homogenous mixture.

The first formulation was then added to a mixture comprising Elastomer 10 and dimethicone blend 20 (the second formulation) with vigorous stirring to furnish a

surprisingly stable clear gel

Drying time : 525 seconds

Wear Time Experiments

0.07g of the test scar management composition was applied to a 5 cm² area of the skin. The area was wetted with water after Ih, 2hrs, 4hrs and every 2hrs thereafter.

The scar management composition 'passes' if the water forms an elevated bubble indicating that a significant amount of silicone is still present on the skin.

The scar management composition 'fails' if the water does not form an elevated bubble indicating that little, if any, of the composition is still present on the skin.

Comparative example 1

Comparative example 2

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiments which are described by way of example only.

Claims

1. A scar management composition in the form of a liquid gel wherein the . composition is substantially water-free and comprises at least one silicone elastomer and /or gum.

2. A composition according to claim 1, wherein the silicone elastomer or gum constitutes from 0.01% to 80% by weight of the total composition.

3. A composition according to claim 1 or claim 2, wherein the silicone elastomer is selected from any of the following either alone or in combination:- silicone elastomers, silicone crosspolymers, dimethicone crosspolymer, Elastomer 10, Elastomer 40, silicone elastomer copolymers, partially reacted silicone elastomers (prepolymers which when reacted further will give rise to silicone elastomer).

4. A composition according to claim 1 or claim 2, wherein the silicone gum component is selected from any of the following either alone or in combination:- silicone

gum, dimethiconols, dimethiconol esters, dimethiconol copolymers, dimethiconol

crosspolymers, Dimethiconol blends, Dimethicinol blend 20, partially reacted silicone gums (prepolymers which when reacted further will give rise to silicone gum).

5. A composition according to any one of claims 1 to 4 wherein the additional silicone component is selected from any of the following either alone or in combination; silicone oil, silicone fluids, silicone solvents, silicone gels, silicone wax, silicone grease, or silicone cross polymer, silicone adhesive, silicone emulsifier, silicone wax emulsifier, silicone co-polymer, silicone PSAs.

6. A composition according to any one of claims 1 to 5 wherein the composition comprises at least one volatile solvent.

7. A composition according to claim 6, wherein the volatile solvent is organic.

8. A composition according to claim 6 or claim 7, wherein the solvent constitutes from 0% to 80% by weight of the total composition.

9. A composition according to any one of claims 1 to 8 wherein the solvent is selected from any of the following either alone or in combination:- volatile silicone fluids, cyclomethicone, ethanol, acetone, iso propyl alcohol, methanol, ethoxydiglycol, hexane or other organic skin compatible solvent.

10. A composition according to any one of claims 1 to 9 wherein the composition comprises a thickening agent.

11. A composition according to claim 10, wherein the thickening agent constitutes from 0 to 50%) by weight of the total composition.

12. A composition according to any one of claims 1 to 12 wherein the thickening agent is selected from any of the following either alone or in combination:- high viscosity silicone fluids, silicone gels, silicone grease, silicone elastomer or cross polymer, silicone gum, silicone adhesive, silicone emulsifier, silicone wax emulsifier, reactive silicone component, silicone prepolymer and silicone co-polymer, hydroxypropyl cellulose, ethyl cellulose, cetyl hydroxyethyl cellulose, polyurethane, polyurethane copolymers, or any other polymer which is soluble or partially soluble in organic

solvents.

13. A composition according to any one of claims 1 to 12 wherein the composition further comprises active agents such as antibacterial agents, surfactants, antimicrobial

agents, waterproofing agents, essential oils, skin occlusion agents, copolymers and skin moisturisers, skin healing agents, scar healing agents, growth factors, or any compound which effects the level of growth factors in the skin, wound or scar, herbal agents, plant oils, pharmaceutical agent or other plant extracts.

14. The use of a scar management composition as described in claim 1 to apply a coating of silicone elastomer and/or gum to human skin.

15. A method of forming a coating of silicone elastomer and/or gum upon human skin comprising the step of applying a scar management composition as described in claim 1 to a desired area of the skin.

16. A method for the preparation of a scar management composition wherein the composition is substantially free of water comprising the steps: mixing together at least a first and second formulation wherein at least one of the first and second formulations comprises at least one silicone component.