SELF-ADHESIVE SILICONE GEL LOADED WITH MICROPARTICLES WITH ENHANCED ADHESION

Abstract

The present invention relates to the use of microparticles in a self-adhesive silicone gel to increase its adhesion. It relates to a self-adhesive silicone gel comprising microparticles and having improved adhesion properties, particularly when it also comprises additional chemical compounds / derivatives, and more particularly active compounds, soluble or miscible in the silicone gel.

Description

Title of the invention: SELF-ADHERENT SILICONE GEL LOADED WITH MICROPARTICLES PARTICLES WITH IMPROVED ADHESION FIELD OF THE INVENTION.

[0001] The present invention relates to the use of microparticles in a self-adhesive silicone gel to increase the adhesion thereof. It relates to a self-adhesive silicone gel comprising microparticles and having improved adhesion properties, in particular when it also comprises additional chemical compounds / derivatives, and more particularly active compounds, soluble or miscible in the silicone gel. BACKGROUND OF THE INVENTION.

[0002] Cosmetic or pharmaceutical compositions, in particular transdermal compositions, comprising an adherent layer and particles are known, in particular from applications WO 2013 / 127929 or FR 2 781 667. These compositions may comprise an adhesive matrix based on silicones, which are not gels, and mineral or organic particles. However, the addition of particles to these adhesive matrices leads to a reduction in its adhesion properties on the skin, or "tack". This reduction in adhesion limits the possible uses of these compositions.

[0003] The use of self-adhesive silicone gels in the production of active dressings or topical treatments is known in particular from FR 2 735 024 or FR 2 879 931. However, the introduction of liquids into adhesive silicone gels leads to a degradation of their consistency and their adhesion. In addition, the degradation of their consistency and their adhesion can also result from the addition of particles. US2016263270 describes adhesive silicone gels which contain powders of antibacterial agents whose content must be limited to 5% in order not to degrade the performance of the gel.

[0004] Self-adhesive polyaddition silicone gels have various applications, particularly in the medical and cosmetic fields, in which they can be used in the form of dressings or patches to be applied to the skin. These gels are well known to those skilled in the art and are the product of the hydrosilylation of two functionalized organosiloxane components in the presence of a catalyst. They are described in particular in patents and patent applications US 4,072,635, EP 69,451, EP 322,118, EP 737,721, FR 2,856,072, FR 2,879,931 and EP 3,356,490.

[0005] Furthermore, in certain applications, the silicone gel is used as a self-adhesive matrix containing an active substance, liquid or solid, which may be in a pure form or in a solution in a solvent and of which at least a part of this pure form or of this solution is soluble in the silicone gel or miscible with the silicone gel. This makes it possible to confer therapeutic and / or physicochemical properties on an object manufactured with said gel. However, the solubilization of a substance in a silicone gel or the incorporation of a miscible liquid in a silicone gel has the effect of significantly reducing the adhesion and consistency of the latter.

[0006] It is therefore interesting to find a solution which makes it possible to preserve, or even increase, the adhesion of adhesive matrices, in particular for applications on the skin in cosmetics or for therapeutic applications, in particular when the gels contain added dissolved or miscible substances.

[0007] An aim of the invention is to make it possible to increase the adhesion of a self-adhesive silicone gel, whether or not it contains a substance of which at least a part is soluble or miscible in silicone gels; the substance may be a solid, a pure or complex liquid or even a solution. BRIEF DESCRIPTION OF THE INVENTION.

[0008] The present invention relates to a self-adhesive composite silicone gel (SAG), comprising microparticles (pP) in a self-adhesive silicone gel (SAG), characterized in that it comprises by weight relative to the total weight of the SAG at least 0.5%, in particular at least 1% of microparticles whose adsorption capacities are greater than or equal to 0.5 ml / g.

[0009] The invention relates more particularly to a GSCA which comprises at least 0.5% by weight relative to the total weight of the GSCA of porous microparticles whose adsorption capacities are greater than 1 ml / g.

[0010] The invention also relates to a pharmaceutical or cosmetic composition, characterized in that it comprises such a GSCA.

[0011] It also relates to an adhesive film for cutaneous application comprising a layer (back layer), a layer adhering to the skin and a peelable protective layer, characterized in that the layer adhering to the skin is a GSCA according to the invention.

[0012] The invention also relates to GSCA for its use in therapy.

[0013] It also relates to the use of particles, in particular porous ones, to increase the adhesion of self-adhesive composite silicone gels, in particular to the skin. DETAILED DESCRIPTION OF THE INVENTION.

[0014] In the remainder of this text, the following terms are understood to mean:

[0015] Self-adhesive silicone gels (SAG): gels obtained by polyaddition reaction (hydrosilylation reaction) between a polyorganosiloxane bearing alkenylsiloxy units (compound I) and a polyorganosiloxane bearing hydrogensiloxy units (compound II) in the presence of a hydrosilylation catalyst. The catalyst content makes it possible to adjust the speed of the polyaddition reaction which can be carried out cold or hot, between 25°C and 120°C. In this type of composition the reactive alkenyloxy groups are alkenyl groups, comprising 2 to 6 carbon atoms, they are preferably vinyls which are linked to silicon; the polyorganosiloxanes bearing hydrogensiloxy units are polyorganosiloxanes bearing hydrogen atoms linked to silicon; the catalyst is advantageously a platinum derivative.

[0016] They are conventionally constituted by the product of a hydrosilylation reaction occurring in a mixture of constituents essentially comprising:

[0017] - a polyorganosiloxane I formed by a copolymer comprising D= units (R)2SiO2 / 2 and optionally RViSiO2 / 2, terminal units M= (R)3SiOi / 2 and optionally M= (R)2ViSiOi / 2 in which the R groups, identical or different from each other, are linear or branched C1-C6 alkyl groups and / or aryl groups, substituted or not, and Vi representing an alkenyl radical having 2 to 6 carbon atoms and being more preferably a vinyl group;

[0018] - a polyhydrogenosiloxane II of formula X(R)2SiO-((R)2SiO)m-(RXSiO)n-Si(R)2X with R as defined above and X corresponding to H or R,

[0019] - a platinum-based catalyst,

[0020] - and possibly silicone resins.

[0021] The proportions between the alkenyl groups and the hydrogenosilane groups as well as the proportions between the Si-H of the polydimethylsiloxanes I and II constitute a means of controlling the consistency as well as the adhesion of the gels. It is also possible to control the characteristics of the formulations and gels which result from the crosslinking reactions by introducing into these formulations particular constituents such as silicone resins and by adjusting the ratios between the different constituents present in the mixtures.

[0022] They are notably described in patents and patent applications US 4,072,635, EP 69,451, EP 322,118, EP 737,721, FR 2,856,072, FR 2,879,931 or EP3356490 (Al).

[0023] Preferably, the GSAs according to the invention are defined in patent application FR 2 879 931.

[0024] These GSAs are also commercially available, in particular under the references Silpuran 2110, 2112, 2114, 2120, 2130 from the company Wacker, Silbione RT Gel 4317, 4642, 4717, HC2 2022, HC2 2031 from the company Elkem and Dow Corning MG7-9800, MG7-9850, MG7-9900 from the company Dow Corning, or marketed by the companies Shinetsu or Nusil.

[0025] Silicone gels are generally characterized by a penetration value, or consistency, ranging from 90 to 350 tenths of a millimeter according to DIN ISO 2137. They are generally presented in the form of two-component systems which consist of a Part A and a Part B; the mixing in equal quantities of these two parts initiates the crosslinking reaction which leads to the formation of the silicone gel.

[0026] The viscosity and consistency characteristics of commercial silicone gels are given in Table 1 below (consistency is measured according to DIN-ISO 2137 and a 62.5g cone).

[0027] [Tables 1] Supplier Reference Part A Viscosity mPa.s Part B Viscosity mPa.s Consistency mm / 10 Silbione RT Gel 4317 Elkem 3000 3000 170 Silbione RT Gel 4642 Elkem 11000 15000 155 Silbione RT Gel 4717 Elkem 45000 45000 170 Silpuran 2112 Wacker 11000 11000 220 Silpuran 2114 Wacker 12000 10000 200 Dow Corning MG 7-9900 Dow Corning 5100 5100 140

[0028] Non-crosslinked self-adhesive silicone gel (SAG-non-crosslinked): precursor of SAG, it is a liquid composition consisting of a mixture of organosilicon derivatives and a catalyst which is capable of leading after a hydrosilylation reaction to the formation of a self-adhesive silicone gel (SAG) network. Non-crosslinked SAGs are in the form of two-component systems A and B.

[0029] Self-adhesive composite silicone gel (SCSG): a highly deformable and self-adhesive elastic material, formed by a hydrosilylation reaction, comprising, in addition to the constituents which make it possible to lead to the formation of the SAGs, the following additional constituents: porous microparticles and / or dense microparticles, and where appropriate microspheres; active derivatives in solid and / or liquid form, solvents and / or solutions of the active derivatives and other additives. All or part of the solid active derivatives, liquid active derivatives, solvents or solutions of the active derivatives may be adsorbed by all or part of the porous microparticles.

[0030] Contents in %: the contents of the different constituents which enter into the compositions of crosslinked or non-crosslinked GSAs, or into the compositions of crosslinked or non-crosslinked GSCAs are expressed in % by weight of the overall compositions.

[0031] Microparticles (pP): powders, microbeads, porous or dense, of organic, mineral or organomineral origin; these microparticles can be constituted by individual particles or agglomerates of smaller particles; the sizes of these microparticles can be mono-dispersed or poly-dispersed; the average sizes are between 0.1 pm and 600 pm; the diameters of the largest pP are preferably less than 0.1-0.3 times the thickness of the gel layer so that the pP are embedded in the gel layer; pP whose diameters are between 3 and 300 pm and preferably 5 and 50 pm will be advantageously used.

[0032] Porous microparticles (pPp): Porous microparticles are well known. The pore diameters can be less than 2nm, microporous type pores, between 2 and 50nm, mesoporous type pores, or greater than 50nm, macroporous type pores.

[0033] Impregnated microparticles (pPI) = porous pP of which all or part of the volume of the pores which are located on the surface or in the volume of the particles contains a liquid (solution or liquid compound or mixture of liquid compounds) and / or a solid.

[0034] Particle Adsorption Capacity (PAC): expressed in ml / g, it is measured according to the method described in ISO 787-5. This method consists of gradually adding linseed oil to 2 lg of powder until a cohesive paste is obtained. A value of the Adsorption Capacity is obtained which is expressed in ml of linseed oil / g of pP.

[0035] Total Adsorption Capacity (TAC), expressed in ml / 100g: it is calculated by the product of the quantity of particles (QpPp) in grams, in 100g of GSCA, by the adsorption capacity of the particles (PAC) in ml / g: TA = QpPp x CAP ml / 100g.

[0036] The Impregnation Rate of the pPI characterizes the fraction of the pore volume of the porous microparticles which is occupied by an active derivative; for a mixture of m grams of active derivative and n grams of pP, its value is given by the following expression:

[0037] (m / density of liquid or solid) / (nx CAP)

[0038] The density is expressed in g / ml at 25°C.

[0039] The Total Impregnation Rate is defined by the ratio between the quantities expressed in ml of active ingredients and solvents present in 100g of GSCA and the total volume of pores of the microparticles present in 100g of GSCA; its value is given by the following relationship:

[0040] (volume (in ml) of active derivatives [solid-liquid-solutions] present in 100g of GSCA) / (QpPp x CAP).

[0041] Adsorption: according to the invention it is understood that the liquids or solids penetrate into the porous particles by filling the volume of the pores of the particles; the process adsorption is carried out without modification of the structure of the material which constitutes the particle.

[0042] Active agent: a pure or complex chemical derivative, liquid or solid, soluble or insoluble in GSA - non-crosslinked or crosslinked, capable of developing a biological, therapeutic or physicochemical activity.

[0043] Soluble active agent: an active derivative soluble at least 4%, between 15° and 120°C, in non-crosslinked GSAs and / or crosslinked GSAs.

[0044] Slightly soluble or insoluble active agent: active derivative soluble at less than 4%, between 15° and 120°C, in non-crosslinked GSAs and / or crosslinked GSAs.

[0045] Miscible solvent: a pure liquid miscible at more than 15% and up to at least 50%, between 15° and 120°C, in non-crosslinked GSAs and / or crosslinked GSAs.

[0046] Partially miscible solvent: pure or complex liquid whose miscibility is between 4% and 15%, between 15° and 120°C, in non-crosslinked or crosslinked GSAs.

[0047] Poorly miscible or immiscible solvent: a liquid whose miscibility with non-crosslinked GSA and / or crosslinked GSA is less than or equal to 4% between 15° and 120°.

[0048] Miscible Liquid: homogeneous liquid phase between 15-120°C and miscible at least 15% with the GSA - non-crosslinked or crosslinked; this liquid phase is constituted by one or more of the above active agents and solvents.

[0049] Partially Miscible Liquid: homogeneous liquid phase between 15-120°C and miscible at less than 15% and more than 4% in GSA-non-crosslinked or crosslinked; this liquid phase is made up of one or more of the preceding derivatives and solvents.

[0050] Non-Miscible Liquid: homogeneous liquid phase between 15-120°C and miscible at less than 4% with the GSA - non-crosslinked or crosslinked; this liquid phase is constituted by one or more of the active agents and solvents.

[0051] Self-leveling: refers to a liquid or viscous material which, when poured into an open container, forms a flat horizontal surface without the need for mechanical leveling action.

[0052] Room temperature: usual temperatures 18°C ​​to 28°C.

[0053] A person skilled in the art will determine the microparticle content in the GSCA according to the invention as a function of the chemical nature of the particles, their particle size, their adsorption capacity, the desired adhesion properties and the presence or absence of a substance or product at least partially soluble or partially miscible with the silicone gel, in particular an active agent.

[0054] The microparticles and in particular the porous microparticles capable of being used according to the invention are well known to those skilled in the art; they can be of organic, mineral or organo-mineral origin, they can be hydrophobic or hydrophilic.

[0055] Among the porous hydrophobic particles, mention will be made in particular of particles of organic origin obtained from:

[0056] polymethyl methacrylates such as “Sun-PMMA H”, “Sun-PMMA P”, “Sun-PMMA PH”, “Sun-PMMA X” which are manufactured by Sunjin Beauty Science or “Micropearl M 100” which are manufactured by Seppic,

[0057] polyamides such as “Orgasol 2002 UD Nat Cos” or “2002 D Nat Cos” which are manufactured by Arkema,

[0058] polyallyl methacrylate, such as “Polypore E-100”,

[0059] copolymers of allyl methacrylate and glycol dimethacrylate, such as “Polytrapp 6603”, manufactured by Health & Beauty Solutions, or

[0060] crosslinked polymethacrylate such as “MSP-HEM-812” distributed by the company Kobo

[0061] Hydrophilic particles or at least particles comprising surface hydroxyl groups, which include the hydroxyl groups present on the surface of the particles and the hydroxyl groups present on the surface of the pores, may also be used according to the invention, provided however that their possible interactions with the catalyst or another constituent of the silicone gels such as polyorganosiloxanes carrying hydrogenosiloxy units are taken into consideration; these reactions may also be catalyzed by the acidic or basic character of the particles. The selection of hydrophilic particles must therefore be carried out according to their hydroxyl group contents and their acid-base character. It is also possible to use microparticles which have been "passivated", that is to say for which the presence of the hydroxyl groups and / or their surface hydroxyl content have been previously masked.The masking of the surface hydroxyl groups can be simply carried out when the particles are impregnated with a substance which may preferably be poorly soluble or insoluble or immiscible or partially miscible in silicone gels. Alternatively, particles may be used whose surface hydroxyls have been previously functionalized, for example by silylation. Such passivation methods are well known to those skilled in the art. In particular, for silica particles, a water-repellent treatment may be carried out, for example, by substituting the hydrogen atoms of the =Si-OH groups with trimethyl silyl groups [-Si(CH3)3] using, for example, hexadimethylsilazane.Evonik's "Aeroerl R806", Dow Corning's "Dow Corning VM 2270", Sunjin Beauty Science's "Sunsil 130H SC", "Sunsil 150H SC", Evonik's "Aerosil RX 50", "Aerosil RX 200" are examples of treated silica particles that are commercially available. "Aerosil RY 50" and "Aerosil RY 200" are examples of silica particles passivated by adsorption of silicone oils that are commercially available from Evonik.

[0062] Among the hydrophilic particles, we will mention in particular:

[0063] silica gels such as Merck's “Kieselgel”,

[0064] silica particles “Sipernat 50”, “Sipernat 60”, “Sipernat 320”, “Zeopharm 80”, “Aeroperl 300-30” from Evonik, “Sunsphere H 122” from Asahi, “Sunsil 130H”, “Sunsil 130SH”, “Sunsil 150H” from Sunjin Beauty Science,

[0065] calcium silicate particles such as "Zeopharm 600" from Evonik,

[0066] diatomaceous earths such as "Celite 266" from Celite Corporation,

[0067] calcium phosphate particles such as "Fujicalin" from Fuji Chemical Industry,

[0068] calcium silicates such as “Hubersorb 250” from Huber Engineered Materials,

[0069] hydrophilic particles of organic origin such as microcrystalline cellulose particles such as, for example, “Avicel” of the “PH” series supplied by the company Danisco or “Vivapur 105” and “Prosolv SMCC” from JRS Pharma, or crosslinked polyvinyl pyrrolidones such as “Vivapharm PVPP XL10” from JRS Pharma,

[0070] The GSCAs may also contain so-called dense microparticles, particles whose adsorption capacity is less than 0.75 ml / g which may be silicone elastomer particles such as “KSP 101” and “KSP 300” from Shin Etsu or “Dow Corning 9506” and “Dow Corning 9701”, polyethylene particles such as “Flo-Bead 2080” or “3040” from Sumitomo. These dense particles may also be active particles such as “Microsilver BG” from the company Impag, or zeolites impregnated with silver salts such as “Agion Antimicrobial type AJ” supplied by Sciessent.

[0071] The content of microparticles in the GSCA according to the invention will depend in particular on their adsorption capacity. A person skilled in the art will be able to determine the quantities of particles according to their objective of adhesion ("tack") and / or rigidity. It has been determined that the effects of the microparticles increase according to the CAT. Thus, for an improvement of approximately 20% in adhesion and shear modulus, a CAT of 3 to 8 ml / 100g of GSCA is required.

[0072] Generally, the GSCA according to the invention may comprise up to 50% of microparticles, in particular from 0.5 to 40% by weight, preferably from 0.5 to 25%. According to a particular embodiment of the invention, the GSCA comprises from 0.5 to 15% of microparticles. According to another particular embodiment, it comprises from 0.5% to 8% of microparticles.

[0073] For so-called dense microparticles whose adsorption capacity is less than 0.75 ml / g, the GSCA will advantageously comprise at least 6% of microparticles.

[0074] For porous microparticles with an adsorption capacity of at least 0.75 ml / g, the GSCA will advantageously comprise at least 0.5% of microparticles. porous, or even at least 1%, or even at least 2% of porous microparticles and advantageously up to 8% or even up to 15% or more.

[0075] When porous microparticles are used, porous microparticles which have an adsorption capacity (ACP) of more than 1 ml / g to more than 15 ml / g will advantageously be used. The content of these microparticles in the GSCA according to the invention will generally be from 0.5 to 30%, advantageously from 0.5 to 15%.

[0076] Among the porous microparticles which have a CAP of at least 0.75 ml / g and up to 1.25 ml / g, mention will be made of “Orgasol 2002 UD Nat Cos” and “Orgasol 2002 D Nat Cos”.

[0077] According to a particular embodiment of the invention, the porous microparticles have a CAP of 1.25 to 3 ml / g. Mention will be made in particular of “Celite 266”, “Kieselgel 60” treated with HMDZ, Aerosil RY 200, “Aeroperl R806” of silylated silica, “Sunsphere H 122” and “Sunsphere H 122” treated with HMDZ, “Aeroperl 300-30” and “Aeroperl 300-30” treated with HMDZ, “Sun PMMA-P” and “Sun PMMA PH”.

[0078] According to another embodiment of the invention, the porous microparticles have a CAP of at least 3 ml / g. Mention will be made in particular of “Polypore E100”, “Sipernat 50” and “Sipernat 50” treated with HMDZ, “Sun PMMA-X”, “Polytrap 603” and “Dow Corning VM 2270”.

[0079] Generally, the porous microparticles have an average particle size of 0.1 μm to 600 μm, preferably less than 500 μm, more preferably less than 100 μm. A person skilled in the art will determine the appropriate particle size depending on the thickness of the materials that will be prepared from the GSCAs and the viscosity of the non-crosslinked GSCAs; in order to limit the increase in the viscosity of the non-crosslinked GSCAs, it is preferable to use pPs with larger particle sizes. Advantageously, the microparticles have an average particle size of at least 0.1 μm, in particular from 0.1 μm to 300 μm, more particularly from 1 μm to 100 μm, advantageously from 5 μm to 50 μm.

[0080] According to a preferred embodiment of the invention, the porous microparticles have an average particle size of between 5 μm and 50 μm.

[0081] According to one embodiment of the invention, mixtures of microparticles of different average particle sizes and / or different CAPs can be used.

[0082] Table 2 in [Fig.l] [Fig.l] gives a non-exhaustive list of commercially available microparticles, with their properties.

[0083] A means for a person skilled in the art to determine the quantity of particles used in the GSCA according to the invention consists of calculating the Total Adsorption Capacity (TAC) of all the particles used per 100 g of GSA.

[0084] Advantageously, the GSCA according to the invention has a CAT greater than or equal to 3 ml per 100 g of GSCA. According to a particular embodiment, the GSCA has a CAT of at least 5 ml / 100 mg, which can go up to 30 ml / 100 mg, or even more.

[0085] The invention also relates to a GSCA as defined above which also comprises one or more additional chemical compounds / derivatives, and more particularly active compounds, soluble or miscible in the silicone gel. These chemical compounds, in particular active agents, can be advantageously adsorbed in the pores of the microparticles. They can be liquid at room temperature, miscible or partially miscible with the GSA or with one of its constituents. When the liquid chemical compound is little or not miscible with the crosslinked or non-crosslinked GSCA, it can be solubilized in a solvent miscible with the crosslinked or non-crosslinked GSCA in order to form a solution which will be at least partially miscible with the crosslinked or non-crosslinked GSCA. They can also be solid and at least partially soluble in the crosslinked or non-crosslinked GSA.When the additional solid chemical compounds / derivatives are poorly or not soluble in the crosslinked or non-crosslinked GSA, they can then be dissolved in a solvent miscible with the crosslinked or non-crosslinked GSA; this solution must form a liquid at least partially miscible with the crosslinked or non-crosslinked GSA.

[0086] These chemical compounds, in particular these active agents, can be used in cosmetics or therapy, depending on the biological or therapeutic effects sought.

[0087] The active agents used in cosmetics are well known to those skilled in the art, notably marketed in products from companies specializing in the manufacture and marketing of cosmetic products such as L'OREAL, PROCTER & GAMBLE, UNILEVER, SHISHEIDO, CLARINS, CAUDALIE, etc.

[0088] The cosmetic active agents may be chosen for their antiseptic, antibiotic, emollient, moisturizing, photoprotective, astringent, exfoliating, skin renewal and cell renewal stimulating, slimming, and skin absorption promoting activity.

[0089] They may be of natural or synthetic origin.

[0090] They may be in the form of plant powder or nebulized plant extracts, concrete oils, oleoresins, essential oils, oily extracts, or liposoluble molecules. These ingredients must be compatible with the GSCA according to the invention, and will be chosen in particular from the following derivatives:

[0091] extracts in particular in the form of powder and nebulizates such as those of aloe, turmeric, citrus, centella asiatica, mimosa tenuiflora;

[0092] essential oils in general, in particular, essential oils of thyme, wintergreen, peppermint, turmeric, helichrysum;

[0093] vegetable or animal oils rich in saturated fatty acids, for example palm oil, coconut oil rich in palmitic, myristic, stearic acid;

[0094] vegetable or animal oils rich in monounsaturated fatty acids: for example palmitoleic or oleic acids, in particular hazelnut, olive and / or mustard oils;

[0095] vegetable or animal oils rich in polyunsaturated fatty acids, in particular those rich in linoleic acid (omega3) and linolenic acid (omega6), in docosahexaenoic acid, eicosapentaenoic acid, docosahexaenoic acid, arachidonic acid, such as sunflower, grape seed, sesame, macadamia, cumin, canola, fish oil, argan, safflower, argemone, passionflower, calophyllum, chaulmoogra, etc.;

[0096] oils of animal origin such as shark or mink oils rich in squalane, squalene, essential fatty acids, vitamins A, D, E, liquid or acetylated lanolin;

[0097] oily extracts: chamomile oil, St. John's wort, arnica, rosehip, evening primrose, calendula rich in liposoluble active ingredients such as retinol, alpha tocopherols and its derivatives, phytosterols, arnicine, hypericin, faradiol;

[0098] synthetic oils, in particular linear or branched esters: purcelin, myristic acid esters, isopropyl palmitate or lanilate, decyl isostearate, butyl stearate, propylene glycol dipelargonate, decyl oleate, oleyl oleate, octyldodecanol isopropyl palmitate, myristyl stearate, octyl palmitate, butyl arichidonate isostearyl isostearate, isostearyl neopentanoate, miglyol, acetylated lanolin; or polyol esters: palmitate, stearate, propylene or diethylene glycol isostearate, glycol caprylate, polyethylene glycol stearate or isostearate;

[0099] oleoresins of capsicum, turmeric, pepper;

[0100] lipoamino acids such as dipalmitoylhydroxyproline, palmitoylkeratin, undecylenoylglycine, caprilylcholine;

[0101] liquid surfactants such as oxyethylenated fatty alcohols: laureth 4, sorbitan diisostearate;

[0102] antibiotics: erythromycin, clindamycin palmitate;

[0103] preservatives: parabens, in particular butyl parabens, isothiazolinone, dibromodicyanobutane;

[0104] antioxidants: alpha tocopherol and its acetate, ascorbyl palmitate, rosemary and ginkgo extracts, in particular ginkgolic acid, butylhydroxy toluene, butylhydroxyanisole, propyl gallate, octyl gallate;

[0105] absorption promoters: propylene glycol esters such as propylene glycol dilaurate, 4 cyclohexyl benzyl methyl nicotinate, dimethyl sulfoxide, xylene, isopropyl myristate, azone, glycol palmitate, polyol esters such as glycerol or ethylene glycol octanoates or decanoates, trimellitic acid esters such as tridecyl trimellilate, acid esters palmitic such as erythritol tetrapalmitate, esters of stearic or isostearic acid such as glycol tristearate or glycol triisostearate;

[0106] exfoliants: azelaic acid, ivy or burdock extracts, kojic acid, agaric acid, ursolic acid, adapalene, retinoids;

[0107] antiseptics: chlorosol, benzyl benzoate; fatty acid triglycerides of 4 to 18 carbon atoms.

[0108] The active agents used for their therapeutic activities are well known to those skilled in the art, in particular those used by cutaneous or transdermal administration routes.Examples of active agents according to the invention include antibacterial agents, antiseptics, antivirals, keratolytics, antiedematous agents, antinauseants, protein and thyrosine kinase inhibitors, anticholinergics, monoclonal antibodies, withdrawal agents, antianginal agents, local anesthetics, analgesics, antimycotic agents, antiacne agents, sedatives and tranquilizers, anxiolytics, hormones, androgenic steroids, estrogenic steroids, progestin steroids, analgesics, hypoglycemics, antispasmodics, beta blockers, nonsteroidal anti-inflammatory agents, steroidal anti-inflammatory agents, antiosteoporotic agents, skin bleaching agents, vasodilators, antihypertensives, antiparkinsonians, antimigraine drugs, antineoplastics, vitamins, essential amino acids, essential fatty acids.

[0109] They may be in the form of powder, liquid, or in adsorbed, absorbed or encapsulated forms. These ingredients will preferably be compatible with the GSCA according to the invention, and in particular:

[0110] bactericides: beta di ketone metal chelates such as pentane dione chelates, chelates of 3-Octylpentane-2,4-dione of silver, copper and cerium, cineole 1-8, thymol, linear or branched fatty acid salts of silver, copper, cerium such as stearate, isostearate, palmitate, oleate of silver, copper, cerium, salts and oxides of Zinc, Copper, Cerium, Titanium;

[0111] antiseptics: alkyl benzoate, chlorocresol, chloroxylenol;

[0112] antibiotics: mupirocin, fusidic acid, clindamycin palmitate, tiamulin, erythromycin;

[0113] steroidal anti-inflammatory drugs: betamethasone, triamcinolone, dexamethasone;

[0114] nonsteroidal anti-inflammatory drugs: ibuprofen, indomethacin, salicylate methyl, diclofenac, enoxolone;

[0115] anti-edematous drugs: menthol, helenalin;

[0116] antinauseants: metopimazine, domperidone, scopolamine;

[0117] protein kinase inhibitors such as everolimus; thyrosine kinase inhibitors such as: temsirolimus, afatinib; monoclonal antibody inhibitors such as trastuzumab;

[0118] anticholinergics: rivastigmine;

[0119] withdrawal agents: nicotine, methadone, buprenorphine;

[0120] vasodilators: hederagenine methyl ester, verapamil, propanolol, candesartan, clonidine;

[0121] antianginal drugs: trinitrin, isosorbide laurate;

[0122] antivirals: adefovir, dipevoxil;

[0123] local anesthetics: butamben, prilocaine;

[0124] analgesics: fentanyl, tramadol, capsaicin;

[0125] antimycotics: econazole, terbinafine, clotrimazol;

[0126] anti-acne agents: benzoyl peroxide;

[0127] sedatives, tranquilizers and anxiolytics: mirtazapine, hydroxyzine, prazepam, venlafaxine, dimenhydrate, acetophenazine, haloperidol;

[0128] hormones and antihormones: cyproterone, thyroxine, triamcinolone, aldosterone, tamoxifen, equol;

[0129] steroid hormones: androgens such as testosterone or androsterone, estrogens such as estriol or ethynylestradiol, progestins such as progesterone;

[0130] antispasmodics: trimebutine, trifluoroglucinol, atropine, benzatropine, papaverine;

[0131] diuretics: furosemide;

[0132] antiparkinsonians: adamantine, arachidonoyl dopamine;

[0133] antimigraine drugs: pizotifen, dihydroergotamine;

[0134] bleaching agents: benzyl ether of hydroquinone;

[0135] antineoplastics: imiquimod, fluouracil, bexarotene;

[0136] immunosuppressants: tacrolimus.

[0137] It is understood that the active ingredients identified for each category above are as representative examples of the class of activity, but are in no way intended to limit the list. Those skilled in the art will know, as needed, how to identify and use other active ingredients of a given category to implement the invention.

[0138] The active agents can be used alone or in mixtures.

[0139] The GSCA according to the invention may comprise:

[0140] at least 50% silicone gel,

[0141] at least 2.5% by weight, preferably at least 5%, of one or more additional compounds in solubilized form or of one or more liquid additional compounds or of a solution of one or more additional compounds,

[0142] at least 0.5% by weight of microparticles whose adsorption capacity is greater than or equal to 1 ml / g.

[0143] The amount of additional chemical compounds / derivatives will be determined based on the use of the prepared GSCA, and the nature of the additional compound in combination with the microparticles that will be selected.

[0144] It has been observed that the addition of these soluble or miscible compounds will reduce the adhesion and rigidity properties of the GSCA. A person skilled in the art will therefore be able to determine the quantities of microparticles and soluble or miscible compounds according to his objective, both in terms of the content of additional compounds and the desired adhesion and rigidity properties according to the use to be made of the GSCA.

[0145] Thus, the GSCA according to the invention makes it possible to obtain silicone gels which comprise from 5% to 40% by weight of liquid compounds or in solutions which have adhesion and rigidity properties at least equal to those of the corresponding pure silicone gel, i.e. without microparticles and without additional compounds.

[0146] According to a particular embodiment of the invention, the GSCAs may contain up to 10% to 25% by weight of additional chemical compounds / derivatives, in particular active agents relative to the total weight of GSCA, from 15 to 20%.

[0147] These percentages apply to both the additional compounds alone or to the solutions that comprise them. For an additional compound alone, in particular an active agent alone or a mixture of active agents alone, the percentage applies to the compound alone or to the mixture of compounds. If the additional compound must be solubilized in a compatible solvent to be miscible with the GSCA, then the percentage applies to the solution that contains the additional compound(s), in particular the active agent(s).

[0148] These additional chemical compounds, in particular active agents alone, in mixtures or in solution, can be introduced directly into one of the constituents of the GSA or by introducing microparticles which will have been previously impregnated with these active agents or solutions of active agents. When the active agents are slightly / not soluble or slightly / not miscible in / with the GSA, they must preferably be introduced in the form of solutions in a solvent so as to be able to form a liquid which will be at least partially miscible with the GSA.

[0149] Solvents miscible with the constituents of the GSCA according to the invention will be used as solvents and more particularly usual solvents suitable for cosmetic or pharmaceutical use. These solvents may, if appropriate, be active agents themselves due to their properties. In particular, organic solvents such as isopropyl myristate, isopropyl palmitate, isononylnonanoa will be mentioned. isotridecyl te, neopentyl glycol dioctanoate, branched parafins such as isododecane; cyclic derivatives of silicones which are constituted by 4, 5, 6, 7 siloxyl units; phenyl derivatives of silicones such as diphenylsiloxy phenyl trimethylcone; organofunctional silicones. Mention may also be made, for example, of copolyols of the comb copolymer type which comprise a polydimethylsiloxane chain onto which polyether and alkyl chains are grafted such as: KF-6016 which is constituted by a polydimethylsiloxane chain onto which polyether links are grafted or KF-6038 which is constituted by a polydimethylsiloxane chain onto which polyether links and alkyl chains are grafted and is marketed by Shinetsu.

[0150] Liquid active agents which are at least partially miscible or miscible with crosslinked or non-crosslinked GSAs can also be used as solvents.

[0151] The GSCA according to the invention may also contain, with the additional chemical compounds, liquid, in mixture or in solution, other additional compounds such as dense microparticles of solid active ingredients, microcapsules, etc.

[0152] In this case, the GSCA according to the invention will advantageously comprise from 5 to 40% of additional compound(s).

[0153] According to a particular embodiment, the GSCA will comprise at least 50% silicone gel, at least 5% of an additional chemical compound, at least 1% of microparticles whose adsorption capacity is greater than or equal to 1 ml / g, in particular from 1 to 15%, and from 5 to 30% of additional compound(s).

[0154] A person skilled in the art will be able to determine the total quantity of liquid (solution, liquid additional compound or mixture of liquid additional compounds) in the GSCA according to the invention as a function of the desired adhesion properties, but also of the microparticles and the chemical compatibility, the miscibility, of the liquid with the silicone gels.

[0155] In particular, a maximum ratio can be identified between the contents of liquid or solid active derivatives and the contents of pP identified by a Total Impregnation Rate (TIT) determined according to the following formula:

[0156] [quantities (in ml) of liquids or solids] / [quantities of pP (in g) x Adsorption capacities of pP (in ml / g)]

[0157] The quantities correspond to those present in 100g of GSCA.

[0158] When the GSCAs do not contain dense microparticles of solid active ingredients, the TIT value should advantageously be less than a value between 0.45 and 1.2.

[0159] When the GSCAs according to the invention are used to manufacture films or patches, they advantageously have a thickness of 0.015 mm to 5 mm, preferably 0.015 to 3 mm. This thickness can be several cm when GSCAs are used to manufacture castings.

[0160] The GSCAs according to the invention can be prepared according to one of the following methods:

[0161] Direct mode 1: first, parts A and B are mixed, then the desired quantity of microparticles is introduced into the mixture (A+B); the mixture (A+B)+microparticles is homogenized, the desired quantity of liquid phase is added to the mixture [(A+B)+microparticles], the mixture [(A+B)+microparticles]+liquid phase is homogenized and then degassed under 20-50 mBar for 10 min; the degassed mixture is used to obtain the desired adhesive material. It is also possible to add the liquids before the microparticles.

[0162] When the composition does not contain microparticles, the liquid phase is added to the mixture (A + B), the latter mixture is homogenized then degassed.

[0163] Indirect method 1: according to this process, microparticles are successively added to each of Parts A and B, then the miscible or partially miscible liquid phase, the mixtures are homogenized after each addition then degassed under 20-50 mbar; parts A' and B' are obtained, which will contain microparticles and the miscible or partially miscible liquid phase. As far as possible, equivalent quantities of microparticles and active agents and liquids will be added to each of Parts A and B. These parts A' and B' can then be mixed, after degassing under 20-50 mbar these mixtures are used to prepare the GSCA.This method can also be used to introduce a partially soluble solid by adding the same quantities of this solid to each of Parts A and B, thus obtaining Parts A' and B'; in the latter case it may be advantageous to subject Parts A' and B' to heat treatments in order to facilitate the solubilization of a solid and / or the distribution of the constituents.

[0164] When the substance to be introduced into the mixture [(A + B) + microparticles] is a solid, direct mode 2 or indirect mode 2 is preferably used; these modes can also be used, advantageously, to prepare GSCAs from microparticles impregnated with liquids.

[0165] Direct mode 2: in this case, microparticles are used which have been previously impregnated with active agents, solid or liquid, and / or solutions of active agents. These impregnated particles are used as in the case of direct mode 1. First, parts A and B are mixed, then the desired quantity of impregnated microparticles is introduced into the mixture (A+B); the mixture (A+B)+impregnated microparticles is homogenized, the addition of the quantity of a possible additional liquid phase, desired, is added to the mixture [(A+B)+impregnated microparticles], the mixture [(A+B)+impregnated microparticles]+possible liquid phase is homogenized then degassed under 20-50 mbar for 10 minutes; the degassed mixture is used to obtain the desired adhesive material.

[0166] Indirect mode 2: this time, microparticles which have been previously impregnated with the active agents or solutions of active agents are introduced into each of parts A and B; it is also possible to add other constituents in the same way. The mixtures are homogenized and degassed under the conditions which have just been described in the previous cases. After degassing, parts A' and B' are obtained which are used to prepare the GSCAs. In the case of this indirect mode 2, it may be advantageous to subject the mixtures A' and B' to heat treatments.

[0167] These methods of preparation are given for information purposes only. Those skilled in the art will be able to adapt them according to specific constraints, in particular the presence or absence of volatile derivatives, the distribution of impregnated or non-impregnated pPs, active agents, liquids or solvents in a heterogeneous manner in parts A and B, etc.

[0168] The mixtures [A+B + microparticles], [A+B + microparticles + active agents and / or liquids] as well as the mixtures [A'+B'] can be implemented by casting, injection and / or coating techniques in order to be able to lead, after crosslinking, to handleable materials: films, coated fabrics, molded parts, etc. In the context of the intended applications, formulations will be preferred whose viscosities of the mixtures [A+B + microparticles + active agents and / or liquids] or the mixtures [A' + B'] are between 1000 and 500000 mPa.s or at the very least correspond to a self-leveling mixture at a temperature between 15° and 120°C. In the case where the mixtures are implemented using a coating technique on a support, compositions with a viscosity between 25,000 mPa.s and 50,000 mPa.s will be preferred.

[0169] This viscosity will depend on the combination of parts A and B, the CAT and the content of active agents and / or liquids.

[0170] In the case where the formulation contains liquid ingredients of a volatile nature, the crosslinking reaction must be able to be carried out under temperature and duration conditions compatible with the thermal stabilities and the volatile nature of the liquid ingredients; silicone formulations will then be preferred whose crosslinking can be carried out at temperatures below 120° and preferably between 40° and 80°C; the reactivity of the mixtures can be adjusted by varying the Pt catalyst contents.

[0171] The GSCAs according to the invention can be used in multiple fields due to their advantageous properties, both in cosmetics, in therapy or in any industry which has a use for such GSCAs. In particular, therapeutic uses, transdermal in particular, in cosmetology, for parts of protection for orthoses and prostheses, for cushioning, electrical insulation, assembly, etc.

[0172] The GSCAs according to the invention can be prepared in various forms depending on their applications, occlusive strips, liquid-permeable strips, films, molded parts, composite parts (reinforced GSCA parts), etc.

[0173] The invention also relates to an adhesive dressing or patches for cutaneous application comprising an external layer (back layer) which is arranged on the face of the GSCA opposite that which will be applied to the skin, an adherent layer on the skin, characterized in that the adherent layer on the skin is a GSCA according to the invention as defined previously.

[0174] For storage of the dressing, it also includes a peelable protective layer on the face of the GSCA intended to be applied to the skin.

[0175] The outer layers are made of the usual materials in the field. They are chosen according to their mechanical properties, their compatibility with silicone gels, their permeability to water vapor and their ability to act as a barrier to UV rays; they must also be impermeable to the active ingredients. These materials can be chosen from thermoplastic polymers such as high or low density polyethylenes, polypropylenes, ethylene and vinyl acetate copolymers, polyethylene terephthalates, or complexes of these materials with an aluminum foil. The support can also be made of an elastic material such as polyurethanes, or silicone elastomers. These elastic supports can also be made of composite materials formed by combinations of an elastic fabric and a polyurethane sheet such as that described in FR 2904214 or application EP0976383.

[0176] The GSCAs according to the invention can also be used to manufacture liquid-permeable dressings such as those described in US patent 4,921,704.

[0177] The GSCAs according to the invention can also be used for the production of molded parts, composite parts (reinforced gels) or coated textiles, in particular for the manufacture of prostheses, orthoses, etc. which are also part of the present invention. EXAMPLES. MATERIALS AND METHODS.

[0178] 1. Preparation of Materials intended for Performance Characterizations.

[0179] Characterization of rheological properties: in the case of these characterizations, a sample of ~ 0.6 g of the non-crosslinked GSCA must be placed in the measuring cell. In the case of mixtures which are obtained according to the direct mode, it is a sample of the degassed mixture whose preparation has just been described is used. In the case where Parts A' and B' are available which have been obtained using the indirect method, the two Parts A' and B' are rehomogenized if necessary, equivalent masses of A' and B' are weighed and mixed with a spatula; after degassing at 20-50 mbar at room temperature, until the bubbles have disappeared (approximately 10 min), a sample of the mixture can be taken and placed in the measuring cell. When Parts A' and B' do not contain the same quantities of additional compounds, the weighings of A' and B' must take these compositional differences into account.

[0180] Characterization of adhesion (Tack): in this case, 2 mm films of the crosslinked GSCAs must be prepared. Depending on their densities, 3.5 to 5.5 g of the degassed mixtures, the preparation of which has just been described, are poured into a transparent polystyrene Petri dish 5.6 cm in diameter. If necessary, a second vacuum degassing is carried out. After replacing the lid of the dish, it is then placed on a flat, horizontal support for 24 hours at a temperature of 20-26°C and then for 48 hours at 70°C to complete the crosslinking. After crosslinking, a self-adhesive film is obtained whose surface is flat and parallel to the bottom of the Petri dish; the thickness of this film is equal to 2 ± 0.2 mm. When active ingredients or solvents can degrade or solubilize polystyrene, polystyrene Petri dishes are replaced by glass Petri dishes with flat bottoms and diameters of 5.3 cm.

[0181] Furthermore, when the formulations contain volatile constituents, the boxes are sealed by applying a Teflon tape; then after the first phase of crosslinking at room temperature on the horizontal plate, the boxes are introduced into a container which can be sealed tightly before being treated at 70° for 48 hours. This procedure makes it possible to minimize losses during the two phases of crosslinking; the contents of volatile derivatives can be checked by subjecting the films to drying at 70° in an oven.

[0182] 2. Characterization of gel adhesion.

[0183] Since patches constitute one of the main applications for which these self-adhesive silicone layers are intended and since in the context of this type of application the patches are applied to the skin without exerting strong pressure, the measurement of the Tack has been preferred as a means of characterizing the adhesion. The Tack is conventionally characterized according to the so-called “Probe Tack” test which is described in the ASTM D 2979 standard. It consists of applying to the surface of the silicone gel film a cylindrical bar of 5.2 mm in diameter and then measuring the tearing force when the bar is vertically torn off the surface of the gel film. The bar is applied to the surface of the gel film until a force of 2 N is reached (application speed 10 mm / min), after holding the bar for 1 s, the The bar is pulled vertically from the surface at a speed of 250 mm / min. The Tack corresponds to the maximum value of the tear-off force that is recorded. This test procedure was developed for the characterization of thin adhesive films with thicknesses well below 100 μm. In the case of layers with greater thicknesses (thickness from 500 μm to more than 2 mm) this method is no longer applicable.

[0184] The tack measurement is therefore carried out according to the Probe Tack method, the test procedure of which is derived from that which has just been described in the case of the ASTM 2979 standard.

[0185] The device used is the RS-6000 Rheometer marketed by the company Thermofischer equipped with a 10mm diameter bar. The roughness of the end of the bar meets the criteria of the ASTM 2979 standard.

[0186] The samples are discs 2 mm thick and 54 mm or 50 mm in diameter which are respectively prepared extemporaneously in polystyrene Petri dishes 56 mm in diameter or in glass Petri dishes 53 mm in diameter according to the method just described above. The 2 mm thick samples contained in the Petri dishes are fixed on the plate of the Rheometer.

[0187] Test procedure:

[0188] Determination of zero: an empty Petri dish is fixed on the Rheometer plate. The 10mm diameter bar is lowered vertically at a speed of 50mm / min until contact is made with the surface of the bottom of the Petri dish (detection by the device of a force other than zero); the position of the bar is recorded by the device; it corresponds to the 0 dimension of the bar.

[0189] Tack measurement: the control Petri dish is replaced by a dish containing the 2mm thick disc whose Tack is to be determined. The 10mm bar is lowered vertically at a speed of 3mm / min until a force of 0.2N is applied to the surface of the sample. This force of 0.2N is maintained for a period of 30s then the bar is pulled off vertically at a speed of 150 mm / min.

[0190] Tack is expressed by the maximum value of the tearing force and is expressed in g / cm2.

[0191] We carry out 3 measurements on 3 different samples, we obtain under these conditions standard deviations which are less than or equal to 10.

[0192] 3. Measurement of the consistency of gels.

[0193] The consistency of gels is characterized by their elastic shear moduli which is measured as follows:

[0194] rheometer: Thermofisher RS ​​6000.

[0195] Plan-Plan cell: 20 mm radius rotor, rotor / stator space = 0.5 mm.

[0196] mode: imposed stress = 10 Pa.

[0197] oscillation frequency: 1Hz.

[0198] temperature: installation of the sample at 30°.

[0199] closing of the cell in two stages: 3mm / min up to D=1.5mm, then 0.15mm / min up to D=0.5mm.

[0200] temperature rise to 70° in 60 s.

[0201] G'-G” measurement at 70° for 4000s, return to 30°.

[0202] This type of measurement makes it possible to characterize the value of the elastic component of the shear modulus G', as well as the gel time which corresponds to the time which elapses between the moment when the temperature of the sample reaches the value of 70°C and the moment when the value of G' becomes greater than that of G” (G” corresponds to the loss component of the shear modulus). When the gels develop strong damping capacities which result in a value of the ratio G” / G' equal to 1 after total crosslinking, the value of G' at 4000s is assimilated to that of G” at 4000s. These values ​​are expressed in Pa.

[0203] 4. Measurement of adsorption capacity.

[0204] Adsorption capacities are measured according to the method described in ISO 787-5. This method consists of gradually adding linseed oil to 2 lg of powder until a cohesive paste is obtained. A value of the Adsorption Capacity is obtained which is expressed in ml of linseed oil / g of pP. EXAMPLES OF IMPLEMENTATION

[0205] 1. Effects of Adsorption Capacities.

[0206] The following examples describe the effects of adding 2.4% to 9.9% pP in the compositions of the GSCAs, which are described in Table 4 in [Fig.3] (different pP and pPp which are described in Table 2 in [Fig.l]) on the performances of the GSAs which bear the references RT Gel 4317 and Silpuran 2112. The GSCAs containing 2.4% to 9.9% of microparticles were prepared according to direct method 1.

[0207] Table 3 in [Fig.2] [Fig.2] describes the compositions, characteristics and performances of GSCA based on RT gel 4317. These results show that the addition of pP makes it possible to increase the values ​​of Tack or Elastic Shear Modulus by more than 50% and that the improvement in adhesion and consistency is all the more significant as the adsorption capacity of the microparticles is higher.

[0208] Table 4 in [Fig.3] [Fig.3] relates to the GSCAs that were obtained from Silpuran 2112. The results in Table 4 show that the addition of microparticles to this gel leads to the same type of results: the addition of microparticles leads to an improvement in adhesion, the effect of the microparticles increases with their Adsorption capacities, it is even possible to multiply by a factor greater than 2 the adhesion of Silpuran 2112.

[0209] 2. Effects of Microparticle Contents and CATs.

[0210] The following examples describe the influence of the additions of different quantities of particles to the following two GSAs: RT Gel 4317 and RT Gel 4642. The GSCAs were prepared according to direct mode 1; Tables 5 and 6 in Figures 4 and 5 [Fig.4] [Fig.5] describe the results that were obtained with RT Gel 4317 and RT Gel 4642 respectively.

[0211] All these results show that the effects of microparticles systematically increase with their contents and their adsorption capacities. From the data concerning the compositions, it is possible to calculate the total adsorption capacity (TAC) which is equal to the content of microparticles of the GSCA multiplied by their adsorption capacities. These results also allow us to note that overall the values ​​of Tack and G' increase with the values ​​of the TAC.

[0212] 3. Degradation of performance by introduction of a liquid or solubilization of a solid.

[0213] The following examples describe the degradation of GSA performance by introduction of miscible, partially miscible liquids or solubilization of a solid.

[0214] In these tests, Isopropyl Myristate, Methyl Salicylate and Thymol represent respectively examples of a completely miscible liquid, a partially miscible liquid and a partially soluble solid in GSA. Isopropyl Myritate is miscible to more than 50% with GSA, the miscibility of methyl salicylate is limited to 12-15%, the solubility of Thymol is between 4 and 5%.

[0215] Samples containing isopropyl myristate and methyl salicylate were prepared according to direct method-1 using glass Petri dishes; in the case of methyl salicylate, this derivative is volatile, samples intended for Tack measurements must be prepared under the specific conditions described above.In the case of Thymol, a variant of indirect mode-1 was implemented; this derivative is a solid whose melting point is 55°C; in order to facilitate its solubilization in the silicone gel, the procedure is as follows: the appropriate quantities of Thymol are added to each of Part-A and Part-B; thus, Parts A' and B' are obtained, which contain the same quantities of Thymol; these parts A' and B' are bottled; the stoppered bottles are placed for 20 minutes in an enclosure heated to 70°; each of parts A' and B' is then homogenized and stored in the stoppered bottles; after return. At room temperature, Parts A' and B' are found to be transparent and homogeneous. Parts A' and B' are used as described in the procedure for active derivatives of a volatile nature, which has just been described in the case of Methyl Salicylate.

[0216] Thymol is a crystallized Thymol supplied by Roth, lot 14110049 / B; Methyl Salicylate corresponds to the pure derivative supplied by Cooper, lot 15050195 / E; Isopropyl Myristate is supplied by Roth, lot 306199473. These are also the same products that were used in all the examples that appear in Tables 3 to 15.

[0217] The results presented in Table 7 in [Fig.6] [Fig.6] show that the introduction of active derivatives systematically causes the performance of GSCAs to drop compared to those of the controls (pure gels).

[0218] 4. Effect of the microparticles according to the invention.

[0219] 4.1 Compositions RT Gel 4317 / Aeroperl 300-30 / isopropyl myristate.

[0220] Table 8 in [Fig.7] [Fig.7] describes the results concerning mixtures of "RT Gel 4317 / Aeroperl 300-30 / Isopropyl myristate". These samples were prepared according to indirect method-1 by proceeding as follows: to each of Parts A and B the microparticles are successively added (dried for 24 hours at 70°), after dispersion of the pP, the isopropyl myristate is added, the mixture is homogenized; thus Parts A' and B' are obtained which are degassed under vacuum and then bottled; the stoppered bottles are then placed for 24 hours in a thermostatically controlled chamber at 70°C. Parts A' and B' are then used to prepare the samples which are intended for the characterizations of the Tack and the shear modulus.

[0221] The results shown in Table 8 show that the introduction of microparticles makes it possible to compensate for the effects of the presence of isopropyl myristate; whereas the presence of 4.8% of isopropyl myristate causes the Tack and G' values ​​to fall by 20% (see Table 7), the presence of Aeroperl 300-30 makes it possible to obtain GSCAs which contain from 6% to 23% of isopropyl myristate whose Tack and G' values ​​are greater than or equal to those of the pure gel.

[0222] But for a given quantity of microparticles the quantity of Myristate must not exceed certain limits beyond which the microparticles can no longer compensate for the effects of the additions of isopropyl Myristate as shown by the examples which are gathered in Table 9 in [Fig.8] [Fig.8]. These examples relate to compositions which contain 55 to 89% of RT Gel 4317, 4 to 13% of Aeroperl 300-30 and 6 to 33% of isopropyl Myristate. The GSCAs were prepared according to the particular indirect method 1 which is described in the case of the tests whose results appear in Table 8.

[0223] These results indicate that in the case of this type of composition, the value of the total impregnation rate must be less than 0.98-0.86 so that the values ​​of Tack and G' are equal to or greater than those of the pure gel.

[0224] 4.2 Compositions RT Gel 4317 / Dow Corning VM 2270 / isopropyl myristate.

[0225] The same type of result is obtained with the Dow Corning VM 2270 microparticles reported in Table 10 on [Fig.9] [Fig.9]. The tests were carried out under conditions identical to those described in the case of the RT Gel 4317 / Aeroperl 300-30 / Isopropyl Myristate mixtures. The results are similar: it is possible to prepare compositions containing 23% of Isopropyl Myristate whose performance will be at least equal to that of the pure gel and the value of the Saturation Rate must remain below a limit value.

[0226] 4.3 Other examples.

[0227] Tables 11 to 13 respectively in Figures 10 to 12 give similar results for other examples of gels, particles and chemical compounds.

[0228] [Fig.10] Table 11. “RT Gel 4317 / Sun PMMA-X / Isopropyl myristate” The products intended for carrying out the characterizations of Tack and G' were prepared according to indirect method 1, however subjecting parts A' and B' to a heat treatment of 48 hours at 70° in order to facilitate the distribution of the isopropyl myristate.

[0229] The results show that all mixtures containing between 6 and 10% isopropyl myristate and 4.5 and 10% Sun PMMA-X microparticles exhibit Tack and G' values ​​that are higher than those of the pure gel.

[0230] [Fig.11] Table 12. RT Gel 4317 / {Aeroperl 300-30 / Methyl Salicylate]

[0231] These mixtures were prepared according to indirect method 2 using Aeroperl 300-30 impregnated with methyl salicylate; the impregnation rates of the Aeroperl 300-30 are 0.33, 0.47, 0.51 and 0.6. In the case of these mixtures, the impregnation rates of the microparticles are equal to the total impregnation rates. These tests were carried out according to indirect method 2 by additionally carrying out a 24-hour heat treatment at 70°C of Parts A' and B'. In the case of the tests which were carried out with pP whose impregnation rate is less than 0.6, compositions are obtained which contain from 4.8 to 17.7% of methyl salicylate and whose performances are equal to or superior to that of the pure gel. In the case of the SDE-161 test, which was obtained with pp whose impregnation rate is 0.9 0.6, only the Tack value is higher than that of the gel; the value of the elastic component of the shear modulus, G', is just 12% lower than that of pure gel.

[0232] [Fig.12] Table 13. “RT Gel 4642 / {Aeroperl 300-30+Thymol} / Isopropyl myristate: Table 13 groups together the results which were obtained from compositions which contain:

[0233] a / RT Gel 4642, microparticles impregnated with Thymol (at an impregnation rate of 0.49) and isopropyl myristate.

[0234] b / a mixture of RT Gel 4642 and Thymol.

[0235] The RT Gel 4642 / {Aeroperl 300-30+Thymol} / isopropyl myristate mixtures are prepared according to indirect method 2 by adding to each of Parts A and B the same quantities of impregnated microparticles and then the isopropyl myristate. Parts A' and B' are subjected to a heat treatment at 40° for 24 hours in stoppered bottles. The 2 mm films are prepared under the conditions which are described in the case where the GSCAs contain volatile derivatives.

[0236] The mixture of RT Gel 4642 and Thymol is prepared according to indirect method 1 by adding the same quantities of crystallized Thymol to each of Parts A and B; Parts A' and B' are then heated at 70°C for 20 minutes in stoppered flasks. The 2 mm films are also prepared under the conditions which are described in the case where the GSCAs contain volatile derivatives.

[0237] These heat treatments make it possible to melt the Thymol or to promote the distribution of the constituents of the mixtures.

[0238] The results shown in Table 13 lead to similar findings to those made previously. The addition of 4.2% of Thymol to RT Gel 4642 degrades the performance of the gel (SDE test 439). As shown in SDE test 391, the presence of 7.9% of microparticles makes it possible to obtain GSCAs which contain a mixture of 13% of Thymol and isopropyl myristate while developing performances which are at least equal to those of the pure gel; in the case of this test, the value of the Total Impregnation Rate is 0.66. In the case of SDE-392 test for which the value of the Total Impregnation Rate is 0.83 the values ​​of tack and G' are lower than those of the pure gel; this result also shows that the value of the Total Impregnation Rate must be lower than a limit value. REFERENCES

[0239] FR 2 735 024, FR 2 781 667, FR 2 856 072, FR 2 879 931

[0240] EP 69 451, EP 322 118, EP 737 721, EP 3 356 490

[0241] US 4 072 635, US 2016 / 263270

[0242] WO 2013 / 127929

Claims

Claims

1. Self-adhesive composite silicone gel (SAG), comprising microparticles (pP) in a self-adhesive silicone gel (SAG), characterized in that it comprises by weight relative to the total weight of the SAG at least 0.5% of microparticles whose adsorption capacities are greater than or equal to 0.5 ml / g.

2. Self-adhesive composite silicone gel (GSCA) according to claim 1, characterized in that it comprises at least 0.5% by weight relative to the total weight of the GSCA of porous microparticles whose adsorption capacities are greater than or equal to 1 ml / g.

3. Self-adhesive composite silicone gel (SCSG) according to one of claims 1 or 2, characterized in that it comprises up to 50% microparticles.

4. Self-adhesive composite silicone gel (SCSG) according to one of claims 1 or 2, characterized in that it comprises from 0.5% to 40% of microparticles.

5. Self-adhesive composite silicone gel (SCSG) according to one of claims 1 to 4, characterized in that the microparticles are porous microparticles having an adsorption capacity of more than 1 ml / g to 15 ml / g.

6. Self-adhesive composite silicone gel (SCSG) according to one of claims 1 to 5, characterized in that the microparticles are porous microparticles having an average particle size of 0.1 pm to 600 pm, preferably less than 100 pm.

7. Self-adhesive composite silicone gel (SCSG) according to one of claims 1 to 6, characterized in that it comprises additional chemical compounds.

8. Self-adhesive composite silicone gel (SCSG) according to claim 7, characterized in that the additional chemical compounds are active agents.

9. Self-adhesive composite silicone gel (SCSG) according to one of claims 7 or 8, characterized in that the additional chemical compounds are miscible with the SCSG or with one of its constituents.

10. Self-adhesive composite silicone gel (SCSG) according to one of claims 7 or 8, characterized in that the additional chemical compounds are in solution in a solvent miscible with the SCSG.

11. Self-adhesive composite silicone gel (SCSG) according to one of claims 7 to 10, characterized in that it has the following composition: • at least 50% by weight of silicone gel, • at least 2.5% by weight, preferably at least 5%, of one or more additional compounds in solubilized form or of one or more liquid additional compounds or of a solution of one or more additional compounds, • at least 0.5% by weight of microparticles whose adsorption capacity is greater than or equal to 1 ml / g.

12. Self-adhesive composite silicone gel according to one of claims 1 to 11, characterized in that it has a thickness of 0.015 mm to 5 mm, preferably 0.015 to 3 mm.

13. Adhesive dressing for skin application comprising an outer layer (back layer), a layer adhering to the skin and a peelable protective layer, characterized in that the layer adhering to the skin is a self-adhering composite silicone gel according to one of claims 1 to 12.

14. Use of a GSCA according to one of claims 1 to 11 for the manufacture of molded parts, composite parts or coated textiles, in particular for the manufacture of prostheses and orthoses.

15. Use of porous microparticles defined according to one of claims 2 to 6 to increase the adhesion of self-adhesive composite silicone gels.