Curable silicone composition for incorporation and release of actives

Abstract

A silicone curable composition includes a first organopolysiloxane compound having one or more groups comprising a silicon atom bonded to a hydrogen atom and a second organopolysiloxane compound having one or more groups comprising a carbon-carbon multiple bond. The first organopolysiloxane has a molecular weight of 100,000 g / mol or less and the second organopolysiloxane has a molecular weight of 500,000 g / mol or less. The curable silicone composition includes a hydrosilyation catalyst, one or more organosilicon crosslinkers, and a hydrosilylation inhibitor that retards the addition of the one or more organosilicon crosslinkers to one or more of the organopolysiloxanes when the composition is at room temperature. The curable silicone composition also includes a release additive. The release additive is a surfactant having at least one hydrophillic group and at least one hydrophobic group, a hydrophillic silicone excipient, or a mixture of the surfactant and the hydrophillic silicone excipient.

Description

[0001] WS12401 / Ha / Mk

[0002] CURABLE SILICONE COMPOSITION FOR

[0003] INCORPORATION AND RELEASE OF ACTIVES

[0004] BACKGROUND

[0005] The invention relates to a curable silicone composition for use with active compounds and uses of the same.

[0006] Wearable medical devices such as patches, dressings, and skin-wearable articles often contain an adhesive layer and may include one or more active compounds that offer a pharmacological benefit. However, problems are typically encountered when such active compounds are incorporated into a silicone adhesive layer for release therefrom.

[0007] For example, active compounds are often incompatible with the other components of the silicone adhesive composition and phase separation may be observed in the adhesive prior to curing thereof. Phase separation is not desirable because it can lead to an adhesive layer that is not homogenous and / or a reduction in the tack exhibited by the adhesive layer after curing. Additionally, even after successful incorporation and curing, such systems may fail to release the active compound therefrom. In other instances, the active compound may release from the silicone adhesive layer in an uncontrolled manner, which results in delivering an amount of active that is not effective or a system that does not provide a sustained benefit.

[0008] Therefore, it would be desirable to provide a silicone composition that can overcome the aforementioned deficiencies.

[0009] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0010] The above, as well as other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which:

[0011] FIG. 1 is a graph illustrating the release profile of embodiments in accordance with the invention and comparative examples;

[0012] FIG. 2 is a graph illustrating the release profile of embodiments in accordance with the invention; WS12401 / Ha / Mk

[0013] FIG. 3 is a graph illustrating the release profile of an embodiment in accordance with the invention and a comparative example;

[0014] FIG. 4 is a graph illustrating the release profile of an embodiment in accordance with the invention and a comparative example; and

[0015] FIG. 5 is a graph illustrating the release profile of an embodiment in accordance with the invention and a comparative example.

[0016] BRIEF SUMMARY

[0017] Embodiments of a curable silicone composition are provided. In an embodiment, the curable silicone composition comprises a first organopolysiloxane compound having one or more groups comprising a silicon atom bonded to a hydrogen atom. The first organopolysiloxane having a molecular weight of 100,000 g / mol or less. The curable silicone composition also comprises a second organopolysiloxane having one or more groups comprising a carbon-carbon multiple bond. The second organopolysiloxane has a molecular weight of 500,000 g / mol or less. Further, the curable silicone composition comprises a hydrosilyation catalyst, one or more organosilicon crosslinkers, and a hydrosilylation inhibitor that retards the addition of the one or more organosilicon crosslinkers to one or more of the organopolysiloxanes when the composition is at room temperature. The curable silicone composition also comprises a release additive. The release additive being a surfactant having at least one hyd rophi llic group and at least one hydrophobic group, a hydrophil lie silicone excipient, or a mixture of the surfactant and the hy drophi II ic silicone excipient.

[0018] In some embodiments, the curable composition further comprises an active, wherein, if the active is fat soluble, then the release additive comprises the surfactant and, if the active is water soluble, then the release additive comprises the hydrophilic silicone excipient. In an embodiment, the hydrophilic silicone excipient comprises a mixture of a dimethicone and a silicone or is an organopolysiloxane polyoxyalkylene. In another embodiment, the hydrophilic silicone excipient comprises a mixture of a dimethicone and a silicone polyglucoside. In still other embodiments, the hydrophilic silicone excipient is provided in an amount 0.001 to 15 wt%, based on the total weight of the curable composition. In one such embodiment, the hydrophilic silicone excipient is WS12401 / Ha / Mk provided in an amount 0.001 to 5 wt%, based on the total weight of the curable composition.

[0019] In some embodiments, after the curable silicone composition is cured, the active is released from the cured composition in a predetermined manner.

[0020] In other embodiments, the curable composition further comprises a filler and an MQ resin, wherein the filler is provided in an amount of 0.01 to 25 wt%, based on the total weight of the curable composition, and the MQ resin is provided in an amount of 0.01 to 70 wt%, based on the total weight of the curable composition. In some embodiments, the MQ resin is provided in an amount of 0.5 to 10 wt%, based on the total weight of the curable composition.

[0021] In certain embodiments, the at least one hydrophillic group of the surfactant is a carboxylate, sulfate, sulfonate, phosphate, amine, or polyethylene glycol chain, or a polypropylene glycol chain. In other embodiments, the at least one hydrophobic group of the surfactant is a natural fat, natural oil, linear alkyl chain, branched alkyl chain, or a synthetic polymer.

[0022] In another embodiment, the first organopolysiloxane has a molecular weight of 500 - 10,000 g / mol, the second organopolysiloxane has a molecular weight of 200 - 100,000 g / mol, and the curable composition comprises 60 wt.% or more of the first organopolysiloxane and the second organopolysiloxane, which is based on the total weight of the curable composition.

[0023] In an embodiment, the curable composition further comprises a hydrophilic compound, wherein the hydrophilic is provided in an amount 1 to 50 wt%, based on the total weight of the curable composition.

[0024] In an embodiment, after the curable silicone composition is cured, the cured composition exhibits a tack of 50 grams of force (gf) or more.

[0025] In certain embodiments, the surfactant is selected from the group consisting of metal lauryl sulfate, metal laureth sulfonate, dioctyl metal sulfosuccinate, and mixtures thereof. In some embodiments, the metal in the surfactant is sodium or potassium. In other embodiments, the surfactant is sodium lauryl sulfate or potassium lauryl sulfate.

[0026] In further embodiments, the surfactant is provided in an amount of up to 15 wt%, based on the total weight of the curable composition. In one such embodiment, the WS12401 / Ha / Mk surfactant is provided in an amount 0.001 to 5 wt%, based on the total weight of the curable composition.

[0027] DETAILED DESCRIPTION

[0028] It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific materials, compositions, articles, and methods described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific properties, conditions, or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless expressly stated otherwise.

[0029] In certain embodiments, a curable silicone composition is provided. The curable silicone composition is suitable for use in wearable medical devices such as, for example, patches, dressings, and skin-wearable articles. In these embodiments, the composition may be utilized to form an adhesive layer utilized to attach the device to a wearer and a matrix from which an active can be incorporated in and released therefrom. However, the curable silicone composition is not limited to medical device applications and can be utilized in other applications where adhesive properties and active delivery are desired. Such applications may be of the medical or non-medical variety.

[0030] The curable silicone composition comprises a first organopolysiloxane compound. The first organopolysiloxane compound has one or more groups comprising a silicon atom bonded to a hydrogen atom. A silicon atom bonded to a hydrogen atom may also be referred to herein as Si-bonded hydrogen or by using the designation “SiH.” In some embodiments, at least one of the one or more groups comprising a silicon atom bonded to a hydrogen atom is a terminal group. In other embodiments, at least one of the one or more groups comprising a silicon atom bonded to a hydrogen atom is a pendant group. In still other embodiments, the first organopolysiloxane compound has two or more groups comprising a silicon atom bonded to a hydrogen atom and at least one group of the two or more groups is a terminal group and at least one group of the two or more groups is a pendant group. WS12401 / Ha / Mk

[0031] Preferably, the first organopolysiloxane compound has two or more Si-bonded hydrogen atoms, is linear, cyclic, or branched, and composed of units of the general formula (I)

[0032] R4cHdSiO(4-c-d) / 2 (I) where

[0033] R4independently at each occurrence, is a radical that is free from aliphatic carboncarbon multiple bonds, c is 0, 1 , 2, or 3, and d is 0, 1 , or 2, with the proviso that the sum of c + d is less than or equal to 3 and there are at least two Si-bonded hydrogen atoms per molecule.

[0034] In some embodiments, R4may comprise one or more monovalent or polyvalent radicals, in which case the polyvalent radicals, such as divalent, trivalent, and tetravalent radicals, for example, join two or more, such as two, three, or four, for instance, siloxy units of the formula (I) to one another.

[0035] In other embodiments, R4may be a monovalent radical of the group comprising - F, -Cl, -Br, OR6, -CN, -SCN, -NCO, and SiC-bonded, substituted, or unsubstituted hydrocarbon radicals which may be interrupted by oxygen atoms or by the group -C(O)-, and also divalent radicals Si-bonded on both sides in accordance with formula (I). If R4comprises SiC-bonded, substituted hydrocarbon radicals, preferred substituents include halogen atoms, phosphorus-containing radicals, cyano radicals, -OR6, -NR6-, -NR62, - NR6-C(O)-NR62, -C(O)-NR62, -C(O)R6, -C(O)OR6, -SO2-Ph, and -CeFs. In such embodiments, R6, independently at each occurrence, identically or differently, denotes a hydrogen atom or a monovalent hydrocarbon radical having 1 to 20 carbon atoms, and Ph is the phenyl radical.

[0036] Further embodiments of R4include alkyl radicals, such as the methyl, ethyl, n- propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl radical, hexyl radicals, such as the n-hexyl radical, heptyl radicals, such as the n-heptyl radical, octyl radicals, such as the n-octyl radical and isooctyl radicals, such as the 2,2,4- WS12401 / Ha / Mk trimethylpentyl radical, nonyl radicals, such as the n-nonyl radical, decyl radicals, such as the n-decyl radical, dodecyl radicals, such as the n-dodecyl radical, and octadecyl radicals, such as the n-octadecyl radical, cycloalkyl radicals, such as cyclopentyl, cyclohexyl, cycloheptyl, and methylcyclohexyl radicals, aryl radicals, such as the phenyl, naphthyl, anthryl, and phenanthryl radical, alkaryl radicals, such as o-, m-, p-tolyl radicals, xylyl radicals, and ethylphenyl radicals, and aralkyl radicals, such as the benzyl radical, the a- and the R-phenylethyl radical.

[0037] When R4is a substituted radical, suitable examples include haloalkyl radicals, such as the 3,3,3-trifluoro-n-propyl radical, the 2,2,2,2’,2‘,2‘-hexafluoroisopropyl radical, the heptafluoroisopropyl radical, haloaryl radicals, such as the o-, m-, and p- chlorophenyl radical, -(CH2)-N(R6)C(O)NR62, -(CH2)o-C(O)NR62, -(CH2)o-C(O)R6, - correspond to the definition indicated therefor above, and 0 and p are identical or different integers between 0 and 10.

[0038] Examples of R4as divalent radicals, where is Si-bonded on both sides in accordance with formula (I), are radicals which derive from the monovalent examples stated above for R4by virtue of an additional bond taking place through substitution of a hydrogen atom; examples of such radicals are -(CH2)-, -CH(CH3)-, -C(CH3)2-, -CH(CH3)- CH2-, -C6H4-, -CH(Ph)-CH2-, -C(CF3)2-, -(CH2)O-C6H4-(CH2)O-, -(CH2)O-C6H4-C6H4-(CH2)O- , -(CH2O)P, (CH2CH2O)O, -(CH2)O-OX-C6H4-SO2-C6H4-OX-(CH2)O-, where x is 0 or 1 , and Ph, 0, and p have the definition stated above.

[0039] Preferably, R4comprises a monovalent, SiC-bonded, optionally substituted hydrocarbon radical which has 1 to 18 carbon atoms and is free from aliphatic carboncarbon multiple bonds, more preferably a monovalent, SiC-bonded hydrocarbon radical which has 1 to 6 carbon atoms and is free from aliphatic carbon-carbon multiple bonds, and more particularly the methyl or phenyl radical.

[0040] In some embodiments, the first organopolysiloxane compound may be, for example, a SiH-functional oligosiloxane that possesses SiH groups terminally and is of relatively low molecular mass or, alternatively, may be a silicone resin having SiH groups or a high-polymeric polydimethylsiloxane that possesses SiH groups terminally. WS12401 / Ha / Mk

[0041] In certain embodiments, the first organopolysiloxane compound preferably contains Si-bonded hydrogen in a range from 0.04 to 1.7 percent by weight (wt%), based on the total weight of the first organopolysiloxane compound.

[0042] The molecular weight of the first organopolysiloxane compound is 100,000 g / mol or less. In some embodiments, the first organopolysiloxane compound has a molecular weight of 500 - 100,000 g / mol. In other embodiments, the first organopolysiloxane compound has a molecular weight of 500 - 10,000 g / mol. Molecular weight ranges like those described above are useful because the desired polymer network, which may also be referred to as “topology,” is formed in a way that good adhesive properties, e.g. tack, peel and cohesion, are obtained.

[0043] In some embodiments, the first organopolysiloxane compound may be provided as all or a portion of a component (A). In certain embodiments, component (A) may comprise a mixture of organopolysiloxanes including one or more embodiments of the first organopolysiloxane compound described above. For example, in an embodiment, component (A) may comprise a mixture of organopolysiloxanes and the mixture may comprise an organopolysiloxane having at least one terminal group comprising a silicon atom bonded to a hydrogen atom and an organopolysiloxane having at least one pendant group comprising a silicon atom bonded to a hydrogen atom. Additional organopolysiloxanes may also be suitable for use in component (A).

[0044] As noted above, component (A) may contain a mixture of molecules including two or more distinct organopolysiloxanes. Particularly preferred is the use of low molecular mass, SiH-functional compounds such as tetrakis(dimethylsiloxy)silane and tetramethylcyclotetrasiloxane, and also of SiH-containing siloxanes of higher molecular mass, such as poly(hydrogenmethyl)siloxane and poly(dimethylhydrogenmethyl)siloxane with a viscosity at 25°C of 10 to 20 000 mPa*s, or similar SiH-containing compounds in which some of the methyl groups have been replaced by 3,3,3-trifluoropropyl or phenyl groups.

[0045] The structure of the molecules included in component (A) is also not fixed; in particular, the structure of a SiH-containing organopolysiloxane of relatively high molecular mass, in other words oligomeric or polymeric, may be linear, cyclic, branched, or else resinous, network-like. Linear and cyclic organopolysiloxanes are composed preferably of units of the formula R43SiOi / 2, HR42SiOi / 2, HR4SiO2 / 2, and R42SiO2 / 2, with WS12401 / Ha / Mk

[0046] R4having the definition indicated above. Branched and network-like organopolysiloxanes additionally include trifunctional and / or tetrafunctional units, with preference being given to those of the formulae R4SiOs / 2, HSiOs / 2, and SiCU / 2, where R4has the definition indicated above.

[0047] The amount of component (A) in the curable composition is preferably such that the molar ratio of SiH groups to aliphatically unsaturated groups in the composition is 0.1 to 20, more preferably between 0.3 and 2.0.

[0048] The curable silicone composition comprises a second organopolysiloxane compound. In certain emboidments, the curable silicone composition comprises 60 wt % or more of the first organopolysiloxane compound and the second organopolysiloxane compound, which is based on the total weight of the curable composition. In these embodiments, the curable silicone composition may comprise 60 to 90 wt % of the first organopolysiloxane compound and the second organopolysiloxane compound, based on the total weight of the curable composition. Preferably, the curable silicone composition may comprise 70 to 90 wt % of the first organopolysiloxane compound and the second organopolysiloxane compound, based on the total weight of the curable composition. In these embodiments, it may be preferred that, on a weight basis, the curable silicone composition comprises less of the first organopolysiloxane compound than the second organopolysiloxane compound. For example, the curable silicone composition may comprise 10 wt% or more of the first organopolysiloxane compound and 50 wt% or more of the second organopolysiloxane compound, based on the total weight of the curable composition. In other embodiments, the curable silicone composition may comprise 10 to 30 wt% of the first organopolysiloxane compound and 30 to 70 wt% or more of the second organopolysiloxane compound, based on the total weight of the curable composition.

[0049] The second organopolysiloxane compound has one or more groups comprising a carbon-carbon multiple bond. In some embodiments, the second organopolysiloxane compound may be a linear organopolysiloxane. In these embodiments, the second organopolysiloxane compound may have one or more terminal groups comprising a carbon-carbon multiple bond, which may also be referred to herein as an aliphatic multiple bond. In one such embodiment, the second organopolysiloxane compound may WS12401 / Ha / Mk comprise an SiC-bonded radical having an aliphatic carbon-carbon multiple bond, which may be referred to herein as an aliphatically unsaturated radical.

[0050] The second organopolysiloxane compound may be provided as a portion of a component (B). In these embodiments, the curable composition may be formed by providing a component (B). Component (B) may comprise the second organopolysiloxane compound or another compound. When component (B) comprises another linear compound, such a compound may comprise aliphatic carbon-carbon multiple bonds.

[0051] In embodiments where component (B) comprises a silicon-free organic compound, such a compound may comprise at least two aliphatically unsaturated groups. In some embodiments, the second organopolysiloxane compound has at least two aliphatically unsaturated groups. In certain embodiments, component (B) may comprise a mixture of compounds. In one such embodiment, component (B) may comprise the second organopolysiloxane compound, wherein the second organopolysiloxane compound has at least two aliphatically unsaturated groups, and a silicon-free organic compound that has at least two aliphatically unsaturated groups. In still other embodiments, component (B) may comprise a mixture of discrete organopolysiloxane compounds, including the second organopolysiloxane compound, and these compounds may each ccomprise aliphatic carbon-carbon multiple bonds. In these embodiments, the aliphatic carbon-carbon multiple bond may be included in a terminal group or be located in another group of the organopolysiloxane compound.

[0052] Examples of silicon-free organic compounds suitable for use in component (B) are 1 ,3,5-trivinylcyclohexane, 2,3-dimethyl-1 ,3-butadiene, 7-methyl-3-methylene-1 ,6- octadiene, 2-methyl-1 ,3-butadiene, 1 ,5-hexadiene, 1 ,7-octadiene, 4,7-methylene- 4,7,8,9-tetrahydroindene, methylcyclopentadiene, 5-vinyl-2-norbornene, bicyclo[2.2.1]hepta-2,5-diene, 1 ,3-diisopropenylbenzene, polybutadiene containing vinyl groups, 1 ,4-divinylcyclohexane, 1 ,3,5-triallylbenzene, 1 ,3,5-trivinylbenzene, 1 ,2,4- trivinylcyclohexane, 1 ,3,5-triisopropenylbenzene, 1 ,4-divinylbenzene, 3-methylhepta-1 ,5- diene, 3-phenylhexa-1 ,5-diene, 3-vinylhexa-1 ,5-diene, and 4,5-dimethyl-4,5-diethylocta- 1 ,7-diene, N,N’-methylenebisacrylamide, 1 ,1 ,1-tris(hydroxymethyl)propane triacrylate, 1 ,1 ,1-tris(hydroxymethyl)propane trimethacrylate, tripropylene glycol diacrylate, diallyl ether, diallylamine, diallyl carbonate, N,N’-diallylurea, triallylamine, tris(2- WS12401 / Ha / Mk methylallyl)amine, 2,4,6-triallyloxy-1 , 3, 5-triazine, triallyl-s-triazine-2,4,6(1 H,3H,5H)- trione, diallyl malonate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol) methacrylate.

[0053] Organopolysiloxane compounds known in the art are suitable for use in component (B) and as the second organopolysiloxane compound. Examples of such organopolysiloxanes include, for example, silicone block copolymers having urea segments, silicone block copolymers having amide segments and / or imide segments and / or ester-amide segments and / or polystyrene segments and / or silarylene segments and / or carborane segments, and silicone graft copolymers having ether groups.

[0054] Organopolysiloxane compounds suitable for use as the second organopolysiloxane compound are preferably linear or branched organopolysiloxanes comprising units of the general formula (II)

[0055] R4aR5bSiO(4-a-b) / 2 (I I) where

[0056] R4independently at each occurrence, is a radical free from aliphatic carbon-carbon multiple bonds,

[0057] R5independently at each occurrence, identically or differently, is a monovalent, substituted or unsubstituted, SiC-bonded hydrocarbon radical having at least one aliphatic carbon-carbon multiple bond, a is 0, 1 , 2, or 3, and b is 0, 1 , or 2, with the proviso that the sum a + b is less than or equal to 3 and there are at least 2 radicals R5per molecule.

[0058] R4has the definition indicated above. In some embodiments, R5comprises any desired groups amenable to an addition reaction (hydrosilylation) with an SiH-functional compound. WS12401 / Ha / Mk

[0059] If R5comprises SiC-bonded, substituted hydrocarbon radicals, preferred substituents are halogen atoms, cyano radicals, and -OR6, where R6has the abovestated definition.

[0060] Preferably, R5comprises alkenyl and alkynyl groups having 2 to 16 carbon atoms, such as vinyl, allyl, methallyl, 1 -propenyl, 5-hexenyl, ethynyl, butadienyl, hexadienyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, vinylcyclohexylethyl, divinylcyclohexylethyl, norbornenyl, vinylphenyl, and styryl radicals, with vinyl, allyl, and hexenyl radicals being particularly preferred for use.

[0061] The molecular weight of the second organopolysiloxane compound is 500,000 g / mol or less. In some embodiments, the second organopolysiloxane compound has a molecular weight of 200 - 500,000 g / mol. In other embodiments, the first organopolysiloxane compound has a molecular weight of 200 - 100,000 g / mol. Molecular weight ranges like those described above are useful because the desired polymer network, or topology, is formed in a way that good adhesive properties, e.g. tack, peel and cohesion, are obtained.

[0062] In some embodiments, the second organopolysiloxane compound may be a relatively low molecular mass, alkenyl-functional oligosiloxane such as, for example, 1 ,2- divinyltetramethyldisiloxane, or is a polydimethylsiloxane with a molecular weight of 105g / mol (number average determined by means of NMR) that possesses in-chain or terminal Si-bonded vinyl groups. The structure of the second organopolysiloxane compound may vary between embodiments depending on the desired properties of the composition. Thus, in certain embodiments, in which the second organopolysiloxane compound has a relatively high molecular mass, in other words an oligomeric or polymeric siloxane, the structure may be linear, cyclic, branched, resinous, network-like or another type polymer matrix. Linear and cyclic polysiloxanes are preferably composed of units of the formula R43SiOi / 2, R5R42SiOi / 2, R5R4SiOi / 2, and R42SiO2 / 2, where R4and R5have the definition indicated above. Branched and network-like polysiloxanes additionally include trifunctional and / or tetrafunctional units, with preference being given to those of the formula R4SiOs / 2, R5SiO3 / 2, and SiCU / 2. Also, as noted above, mixtures of these different organopolysiloxanes may be utilized in component (B).

[0063] Preferably, the second organopolysiloxane compound is a vinyl-functional, substantially linear polydiorganosiloxane having a viscosity of 0.01 to 500 000 Pa*s, WS12401 / Ha / Mk more preferably of 0.1 to 100 000 Pa*s, in each case the viscosity being measured at 25°C.

[0064] In some embodiments, the curable composition may contain 30-95 wt%, preferably 30-80 wt%, and more preferably 40-70 wt% of the organopolysiloxane compound(s) of component (B). In other embodiments, the curable composition may contain 0.1 -60 wt%, preferably 0.5-50 wt%, and more preferably 1 -30 wt% of the organopolysiloxane compound(s) of component (A). If the curable composition comprises an alternative to the organopolysiloxanes described above for use in components (A) and (B), then such an alternative molecule may be present at SO- 95 wt%, preferably 30-80 wt%, more preferably 40-70 wt% in the curable composition.

[0065] In some embodiments, the curable composition is an emulsion before being cured. In such embodiments, the curable composition has a continuous phase and a discontinuous phase. In one such embodiment, the continuous phase comprises a polysiloxane network and the discontinuous phase is dispersed in the continuous phase. The polysiloxane network may be formed by the product of combining the first organopolysiloxane compound and the second organopolysiloxane compound. In certain embodiments, the continuous phase may also be formed by utilizing one or more additional organopolysiloxane compounds and / or a component (C).

[0066] Component (C) may comprise an organopolysiloxane compound. In some embodiments, the organopolysiloxane compound may have one or more terminal groups comprising a silicon atom bonded to a hydrogen atom. In other embodiments, the organopolysiloxane compound may have one or more terminal groups comprising a carbon-carbon multiple bond. In still other embodiments, component (C) may comprise a mixture of organopolysiloxanes. For example, in an embodiment, component (C) may comprise organopolysiloxane compounds having one or more terminal groups comprising a silicon atom bonded to a hydrogen atom, organopolysiloxane compounds having one or more terminal groups comprising a carbon-carbon multiple bond, and / or organopolysiloxane compounds that do not include any reactive groups. Component (C) may also comprise a reinforcing filler. In other embodiments, component (C) may comprise an a nonsilicone oligomeric compound such as, for example, a polyether or a polymeric compounds such as, for example, acrylates, urethanes, polyesters, and copolymers of the same with siloxanes. In still other embodiments, component (C) may WS12401 / Ha / Mk comprise a release additive such as a surfactant or an excipient. In an embodiment, component (C) comprises an active.

[0067] Further, and instead of utilizing different organopolysiloxane compounds, the polysiloxane network may be formed by providing a single organopolysiloxane compound that simultaneously has aliphatic carbon-carbon multiple bonds and Si- bonded hydrogen atoms. In this embodiment, the first organopolysiloxane compound and the second organopolysiloxane compound are chemically the same. However, in this embodiment, first organopolysiloxane compound and the second organopolysiloxane compound may still be provided as portions of separate components.

[0068] If an organopolysiloxane compound has aliphatic carbon-carbon multiple bonds and Si-bonded hydrogen atoms is provided, suitable examples are preferably composed of units of the general formula (III), (IV), and (V)

[0069] R4fSiO4 / 2 (III)

[0070] R4gR5SiO3-g / 2 (IV)

[0071] R4hHSiO3-h / 2 (V) where

[0072] R4and R5have the definitions indicated for them above, f is 0, 1 , 2, or 3, g is 0, 1 , or 2, and h is 0, 1 , or 2, with the proviso that per molecule there are at least 2 radicals R5and at least 2 Si- bonded hydrogen atoms.

[0073] Organopolysiloxane compounds that have aliphatic carbon-carbon multiple bonds and Si-bonded hydrogen atoms preferably possess an average viscosity of 0.01 to 500 000 Pa*s, more preferably 0.1 to 100 000 Pa*s, in each case at 25°C. Such organopolysiloxanes are preparable by techniques that are known in the art. WS12401 / Ha / Mk

[0074] Preferably, the curable composition is cured through crosslinking of the first and second organopolysiloxane compounds. In certain embodiments, the curable composition is formed by addition-crosslinking.

[0075] In some embodiments, the curable composition may comprise one or more organosilicon crosslinkers. Preferably, the one or more organosilicon crosslinkers includes an organopolysiloxane compound. Thus, in these embodiments, the curable composition may comprise a third organopolysiloxane compound. Preferred organopolysiloxane compounds suitable for use as a crosslinker has one or more groups comprising a silicon atom bonded to a hydrogen atom. Preferably, the crosslinker includes an SiH-functional organopolysiloxane compound having an average of at least two SiH groups. In certain embodiments, the crosslinker may be a mixture of various SiH-functional organosilicon compounds. Preferably, the crosslinker includes a linear, cyclic, branched or resinous organopolysiloxane having Si-bonded hydrogen atoms, composed of units of the formula R4cHdSiO(4-c-d) where

[0076] R4has the definition given above, c is 0, 1 , 2 or 3 and d is 0, 1 or 2, with the proviso that the sum total of (c+d) is not more than 3 and there is an average of at least two Si-bonded hydrogen atoms per molecule.

[0077] Preferably, the crosslinker contains SiH groups in the range from 0.04 to 1.7 percent by weight (% by weight) based on the total weight of the organopolysiloxanes utilized as crosslinkers. In these embodiments, the molecular weight of the crosslinker may vary within wide limits, for instance between 700 and 150000 g / mol. For example, in some embodiments, the crosslinker may be an SiH-functional organopolysiloxane compound of relatively low molecular weight, such as tetramethyldisiloxane, a high- polymeric polydimethylsiloxane having SiH groups in chain or terminal positions, or a silicone resin having SiH groups. Preference is given to the use of organopolysiloxane crosslinkers of low molecular weight, such as tetrakis(dimethyl-siloxy)silane and tetramethylcyclotetrasiloxane and SiH-containing organopolysiloxanes, such as, for example, poly(hydrogenmethyl)siloxane and poly(dimethylhydrogenmethyl)siloxane WS12401 / Ha / Mk having a viscosities in the range of 10 to 1000 mPa s (at 25°C. and 0.8 sec-1). Preferably, the crosslinker is compatible with RTV-2 siloxane systems (homogeneously miscible or at least emulsifiable).

[0078] In order to crosslink the organopolysiloxanes provided in the composition, a hydrosilylation catalyst is provided. The hydrosilyation catalyst may be provided as a portion of one of the components mentioned above.

[0079] When the composition is formed by mixing a component (A) and a component (B), the two components may comprise all constituents referred to above in any desired combinations, generally with the proviso that one component does not simultaneously comprise organopolysiloxane compounds with aliphatic multiple bonds, organopolysiloxane compounds with Si-bonded hydrogen atoms, and the hydrosilylation catalyst. Thus, in the case of a two-component composition, the hydrosilyation catalyst may be provided as a portion of component (A) or component (B). However, the hydrosilyation catalyst may be provided as a portion of component (A) or component (B).

[0080] Hydrosilylation catalysts known in the art are suitable for use in the curable composition. The hydrosilylation catalyst may include a platinum-group metal such as, for example, platinum, rhodium, ruthenium, palladium, osmium, or indium, or may be an organometallic compound, or a combination thereof. Suitable examples of hydrosilylation catalysts are compounds such as hexachloroplatinic(IV) acid, platinum dichloride, platinum acetylacetonate, and complexes of said compounds encapsulated in a matrix or in a core / shell-like structure. Other suitable platinum complexes with a low molecular weight of organopolysiloxanes include 1 ,3-diethenyl-1 ,1 ,3,3- tetramethyldisiloxane complexes with platinum. Other examples of suitable hydrosilylation catalysts are platinum-phosphite complexes, platinum-phosphine complexes, or alkylplatinum complexes such as derivatives of cyclopentadienyltrimethylplatinum(IV), cyclooctadienyldimethylplatinum(ll), or diketonato complexes, such as bisacetylacetonatoplatinum(ll), for example. In certain embodiments, the platinum-containing compound may be encapsulated within a resin matrix.

[0081] The concentration of catalyst for catalyzing the hydrosilylation crosslinking reaction may be in an amount between 0.1 and 1000 parts per million (ppm), 0.5 and WS12401 / Ha / Mk

[0082] 100 ppm, or 1 and 25 ppm of the platinum group metal, depending on the total weight of the curable composition.

[0083] The curable composition comprises a hydrosilyation inhibitor. Such inhibitors enable the curable composition to exhibit a predetermined processing life, curing onset temperature, and curing rate by retarding the addition of the one or more organosilicon crosslinkers to one or more of the organopolysiloxanes when the composition is at room temperature. Examples of suitable inhibitors are acetylenic alcohols, such as 1 -ethynyl- 1 -cyclohexanol, 2-methyl-3-butyn-2-ol, and 3,5-dimethyl-1 -hexyn-3-ol, 3-methyl-1- dodecyn-3-ol, polymethylvinylcyclosiloxanes such as 1, 3,5,7- tetravinyltetramethyltetracyclosiloxane, low molecular mass silicone oils with methylvinyl-SiOi / 2 groups and / or R2vinylSiOi / 2 end groups, such as divinyltetramethyldisiloxane, tetravinyldimethyldisiloxane, trialkyl cyanurates, alkyl maleates, such as diallyl maleates, dimethyl maleate, and diethyl maleate, alkyl fumarates, such as diallyl fumarate and diethyl fumarate, organic hydroperoxides such as cumene hydroperoxide, tert-butyl hydroperoxide, and pinane hydroperoxide, organic peroxides, organic sulfoxides, organic amines, diamines and amides, phosphanes and phosphites, nitriles, triazoles, diaziridines, and oximes. In certain embodiments, the hydrosilylation inhibitor is provided in the curable composition in a quantitative fraction of 0.00001 to 5 wt%, based on the total weight of the curable composition. Preferably, the hydrosilylation inhibitor is provided in the curable composition in an amount of 0.00005 to 2 wt%, and more preferably at 0.0001 to 1 wt%, which in each case is based on the total weight of the composition.

[0084] In the embodiments described above, after curing, the composition may be a gel. In these embodiments, the gel has a crosslinked structure. A crosslinked structure can form when the total number of reacting groups is greater than 4. However, it is preferred that, after curing, the composition is in a solid state. The solid is formed by a platinum catalyzed hydrosilylation reaction, wherein sufficient crosslinking happens, for example, between a first organopolysiloxane compound, which contains more than two Si-bonded hydrogen atoms, and a second organopolysiloxane compound, which includes at least two reactive al iphatical ly unsaturated groups, or alternatively between a first organopolysiloxane compound containing two Si-bonded hydrogen atoms and a second organopolysiloxane compound with more than two aliphatically unsaturated radicals. WS12401 / Ha / Mk

[0085] Preferably, in these embodiments, the first organopolysiloxane compound and the second organopolysiloxane compound are crosslinked to the solidification point of the mixture. In such embodiments and before curing, the curable composition may exhibit a viscosity of 50-1 ,000,000 centipoise.

[0086] The curable silicone composition may comprise an organopolysiloxane resin. Organopolysiloxane resin may be included in the curable composition because of its use with or in the formation of another element of the composition. Thus, organopolysiloxane resin included in the curable silicone composition may be in relatively low amounts, e.g. less than 2 wt% of the total weight of the composition, and intrinsically provided. Alternatively, organopolysiloxane resin may be included in the curable silicone composition intentionally to provide or enhance a functional aspect of curable silicone composition. For example, in some embodiments, the organopolysiloxane resin may be utilized to increase in compatibility of the other components of the curable silicone composition and / or to modify the rheology of the curable silicone composition.

[0087] In some embodiments, the curable silicone composition may comprise 0.01 wt% or more organopolysiloxane resin, based on the total weight of the composition. In some embodiments, the curable silicone composition comprises 0.01 to 70 wt% organopolysiloxane resin, which is based on the total weight of the composition. Preferably, the curable silicone composition comprises 0.5 to 10 wt% organopolysiloxane resin, which is based on the total weight of the composition.

[0088] In an embodiment, the organopolysiloxane resin is a vinyl functional MQ resin or similar, highly crosslinked resin containing M, Q, and / or T moieties, and optionally a minor amount of D moieties. As used herein, the term "resin" is used in its customary meaning, i.e. a highly three dimensionally crosslinked polymer containing a majority of M units, and T and / or Q units. In certain embodiments, an MT, MQ, and MQT resin is preferred. An organopolysiloxane resin that comprises M and Q units is particularly preferred.

[0089] The term "M" refers to monofunctional units while the term "Q" refers to tetrafunctional units. In other words, an MQ resin comprises predominantly M units, wherein silicon is attached to only one oxygen in the cross-linked molecules, and SiO4,2 "Q" units, wherein each silicon atom is attached to four other oxygen atoms, resulting in a high level of crosslinking. In some embodiments, the MQ resin may comprise small WS12401 / Ha / Mk amounts of difunctional R2SiO2 / 2 units and trifunctional RSiOs / 2 units ("D" and "T" units, respectfully). MQ resins suitable for use in the curable composition may be produced by the hydrolysis of silanes such as tetraethoxysilane, vinyldimethylethoxysilane and trimethylethoxysilane. In some embodiments, the MQ resin may retain some residual alkoxy functionality as a result of the method of its preparation and will occasionally include other functionalities such as silanol or halo functionality as well. Preferably, the MQ resin contains approximately 1.2 to 1.8 weight percent vinyl functionality. MQ resins having unsaturated groups other than vinyl, including vinyloxy, allyl, allyloxy, propenyl, etc., may also be utilized.

[0090] In certain embodiments, MQ resins formed as a co-hydrolysis product of tetraalkoxy silane and trimethylalkoxy silane may be suitable. Such MQ resins may comprise a three-dimensional network of polysilicic acid units that has trimethylsilyl end groups. The average molecular weight of such MQ resins can be controlled by the ratio of M to Q units in the resin. Preferably, the ratio of M to Q units is from 0.5 to 1 , with a ratio of approximately 0.67 being preferred.

[0091] The embodiments of the MQ resins mentioned above may be used alone, in combination with each other, or with other unsaturated resins. Preferred commercially available MQ resins include MQ resin 804 and MQ resin 803, both are available from Wacker Chemical Corporation.

[0092] The organopolysiloxane resin, as indicated, may contain a variety of unsaturated groups for the above-mentionedhydrosilylation reactions, including both ethylenic and unsaturation. It is preferable, although not mandatory, that the unsaturation be at a terminal location. For example, when hexenyl unsaturated groups are present, terminal (co-) hexenyl groups are preferred. The unsaturated groups may also, as indicated, be unsaturated ether groups such as vinyl ether groups, and may be other heteroatom containing groups as well, i.e. (meth)acryloxy groups. Vinyl and allyl groups are most preferred.

[0093] An advantage of the curable silicone composition is its ability to incorporate and release actives. Incorporation can be achieved using commercially available mixing methods and devices. Release of actives can be achieved by inclusion of a release additive. The release additive may be provided as a portion of a component (A), component (B), component (C), in two or more of these components, or as a separate WS12401 / Ha / Mk addition to the composition. The release additive is a surfactant having at least one hydrophil lie group and at least one hydrophobic group, a hydrophi llic silicone excipient, or a mixture of the surfactant and the hydrophi llic silicone excipient.

[0094] In embodiments where the release additive is a surfactant, it is preferred that a hydrophil lie group of the at least one hydrophil lie group is a terminal group. It may also be preferred that that a hydrophobic group of the at least one hydrophobic group is a terminal group. In some embodiments, it may be desired that a hydrophillic group of the at least one hydrophillic group is a pendent group or that a hydrophobic group of the at least one hydrophobic group is a pendent group. In an embodiment, the at least one hydrophillic group of the surfactant is a carboxylate, sulfate, sulfonate, phosphate, amine, or polyethylene glycol chain, or a polypropylene glycol chain. In another embodiment, the at least one hydrophobic group of the surfactant is a natural fat, natural oil, linear alkyl chain, branched alkyl chain, or a synthetic polymer.

[0095] Preferably, when the release additive is a surfactant, the surfactant is selected from the group consisting of metal lauryl sulfate, metal laureth sulfonate, dioctyl metal sulfosuccinate, and mixtures thereof. In some embodiments, it may be preferred that the metal in the surfactant is sodium or potassium. In such embodiments, the surfactant may be sodium lauryl sulfate or potassium lauryl sulfate.

[0096] In an embodiment, when the release additive is a hydrophilic silicone excipient, the excipient may comprise a mixture of a dimethicone and a silicone copolymer with polyglucoside. In embodiments where the hydrophilic silicone excipient is a mixture of a dimethicone and a silicone polyglucoside, it is preferred that the hydrophilic silicone excipient is a hydrophilic resin elastomer gel. Suitable hydrophilic resin elastomers may exhibit a viscosity of approximately 150,000 mPa s. In one such embodiment, the amount of the hydrophilic silicone excipient in the curable silicone composition is up to 15 wt%, based on the total weight of the curable silicone composition. Preferably, the hydrophilic silicone excipient in the curable silicone composition is 0.01 to 5 wt%, based on the total weight of the curable silicone composition. Preferably, the silicone polyglucoside is nonionic with a hydrophilic-lipophilic balance in the range of 6 to 7. An example of a commercially available mixture of a dimethicone and a silicone polyglucoside suitable as the hydrophilic silicone excipient is sold under the name BELSIL® REG 1103 B and by Wacker Chemie AG. WS12401 / Ha / Mk

[0097] In other embodiments, where the release additive is a hydrophilic silicone excipient, it may be preferred that the excipient is an organopolysiloxane polyoxyalkylene. In such embodiments, the hydrophilic silicone excipient may be provided in a mixture with dimethicone and include a silicone copolymer with organic glycol. Preferably, in these embodiments, the excipient is an organopolysiloxane polyoxyalkylene of the general formula:

[0098] In certain embodiments, the organopolysiloxane polyoxyalkylene may be covelantly bonded. An example of a commercially available organopolysiloxane polyoxyalkylene suitable as the excipient is sold under the name BELSIL® OW1500 and by Wacker Chemie AG.

[0099] The release additive may be provided in the curable silicone composition at about 0.001 wt% to about 30 wt%, preferably, about 1 to 20 wt%, in all cases based on the total weight of the composition. However, it is preferred that when the release additive is a surfactant, the surfactant is provided in an amount of up to 15 wt%, based on the total weight of the curable composition. More preferably, when the release additive is a surfactant, the surfactant is provided in an amount 0.001 to 5 wt%, based on the total weight of the curable composition. In other embodiments, it is preferred that when the release additive is a hydrophilic silicone excipient, the hydrophilic silicone excipient is provided in an amount 0.001 to 15 wt%, based on the total weight of the curable composition. More preferably, when the release additive is a hydrophilic silicone excipient, the hydrophilic silicone excipient is provided in an amount of 0.001 to 5 wt%, based on the total weight of the curable composition.

[0100] It has been surprisingly discovered that through proper selection of the release additive(s), the curable silicone composition, when cured, can release a wide variety of WS12401 / Ha / Mk actives. For example, the curable silicone composition, when cured, can release fat soluble actives, water soluble actives, or other types of actives, which could be those that exhibit neither strong fat solubility or water solubility. Examples of water soluble actives that can be released from the curable silicone composition, after curing, include, for example, niacinimide, caffeine, D-panthenol, and sodium hyaluronate. Examples of fat soluble actives that can be released from the curable silicone composition, after curing, include for example, a-tocopherol, tocopheryl acetate, phytosqualan, DL-A- tocopheryl acetate, ubiqinone, and squalane. Examples of other actives that can be released from the curable silicone composition, after curing, include, for example, melatonin and curcumin. Preferably, if the active is fat soluble, then the release additive comprises the surfactant. Also, it is preferred that if the active is water soluble, then the release additive comprises the hydrophilic silicone excipient.

[0101] It has also been surprisingly discovered that through proper selection of the release additive(s), that after the curable silicone composition is cured, the active can be released from the cured composition in a predetermined manner. For example, in certain embodiments, the active may be released from the cured curable silicone composition in a controlled manner. In these embodiments, the active may be released from the cured curable silicone composition at an increased rate or a decreased rate as desired. In other embodiments, the active may be released from the cured curable silicone composition at a rate that increases gradually over time, decreases gradually over time, or occurs initially at a high rate or as a burst and then at a lower rate. Advantageously, the curable silicone composition allows for active release which can vary from known compositions. Thus, the cured curable silicone composition can be utilized to provide active release which is greater than the release of the active from known compositions. For example, utilizing the cured curable silicone composition over known compositions can increase active release by 40% or more over the first four hours of use.

[0102] The curable composition may comprise one or more additional additives, which may be provided as a portion of component (A), component (B), or component (C). For example, as mentioned above, the anti-microbial composition may comprise a reinforcing filler. Suitable reinforcing fillers include fumed or precipitated silicas having BET surface areas of at least 50 m2 / g, carbon blacks, activated carbons such as furnace black and acetylene black, or mixtures thereof. The stated silica fillers may have a WS12401 / Ha / Mk hydrophilic character or may have been made hydrophobic by known methods. The amount of reinforcing filler in the curable composition may be within the range from 0.01 to 25 wt%, based on the total weight of the curable composition.

[0103] In certain embodiments, it is preferred that the filler utilized is surface-treated. The surface treatment is obtained by the methods known in the art for hydrophobizing finely divided fillers. As a result of a surface treatment, the filler utilized may have a carbon content of at least 0.01 up to a maximum of 20 wt%, preferably between 0.1 and 10 wt%, more preferably between 0.5 to 5 wt%. Preferably, in these embodiments, the filler is a surface-treated silica having 0.01 to 2 wt% of Si-bonded, al iphatical ly unsaturated groups. These groups are, for example, Si-bonded vinyl groups. In the curable composition, the filler is provided as a single species or as a mixture of two or more finely divided filler(s).

[0104] Further additives may be provided in the curable composition in a fraction of up to 70 wt%, preferably 0.0001 to 40 wt%, based on the total weight of the composition. These additives may be, for example, inert fillers, resinous polyorganosiloxanes, different from the siloxanes described above, reinforcing and non reinforcing fillers, fungicides, fragrances, rheological additives, corrosion inhibitors, oxidation inhibitors, light stabilizers, flame retardants, and agents for influencing the electrical properties, dispersing assistants, solvents, adhesion promoters, pigments, dyes, plasticizers, organic polymers, heat stabilizers, etc. These include additives, such as finely ground quartz, diatomaceous earth, clays, chalk, lithopone, carbon blacks, graphite, metal oxides, metal carbonates, metal sulfates, metal salts of carboxylic acids, metal dusts, fibers, such as glass fibers, polymeric fibers, polymeric powders, metal dusts, dyes, pigments, etc. Additional fillers may be heat-conducting or electrically conducting. A combination of fillers with different particle sizes and different particle size distributions may also be utilized.

[0105] Further, the curable composition may comprise additional additives such as one or more solvents and / or one or more inhibitors.

[0106] The curable silicone composition may comprise a hydrophilic compound. The hydrophillic compound is provided to enhance active release from the composition. Preferably, the hydrophillic compound is a polyol. Preferred polyols include those that are polyhydric alcohols or polyethers. Examples of suitable polyhydric alcohols for use in WS12401 / Ha / Mk the curable silicone compositon may be selected from the group consisting of sorbitol and mannitol. Examples of suitable polyethers for use in the curable compositon may be selected from the group consisting of polyethylene gylcol and polypropylene gylcol. A preferred polyol is glycerol. In certain embodiments, the hydrophillic compound is present in the composition at 1 to 50 wt%, preferably, about 1 to 15 wt%, in all cases based on the total weight of the composition.

[0107] As noted above, after being cured, the curable silicone composition may also function as an adhesive. In these embodiments, the adhesive may be utilized as the adhesive portion of a wound care dressing, patch for delivering the active(s), or in another application. Advantageously, when cured, the curable silicone composition can function as an adhesive because the tack exhibited is sufficiently high despite the presence of the release additive and any excipient(s), which in the prior art systems leads to uncontrolled release of the additive. For example, in certain embodiments, the tack exhibited by the cured silicone composition may be greater than 50 grams of force (gf). Preferably, the tack exhibited by the cured silicone composition is greater than 100 gf. However, the tack must not be so strong that the skin of the user is damaged when the cured silicone composition is separated from the skin of the user. Thus, in some embodiments, the tack exhibited by the cured silicone composition is less than 1000 gf. In these embodiments, the tack exhibited by the cured silicone composition may be 50 to 1000 gf. Preferably, the tack exhibited by the cured silicone composition is 100 to 800 gf. The tack exhibited by the cured silicone composition can be measured by known methods. For example, the tack of the cured silicone composition can be measured with a TA.XT Plus Texture Analyzer using a TA-57R probe and a TA-303 apparatus.

[0108] In addition to a suitable tack, it is preferred that the cured silicone composition is cohesive. A cohesive cured silicone does not break apart or leave a significant visible residue when removed from a surface it has been adhered to. In some embodiments, the cured silicone composition may exhibit a post-cure penetration hardness of 25 to 500 1 / 10 mm measured according to DIN ISO 2137 using a hollow cone of 62.5 grams for 60 seconds after curing for 60 minutes at 120°C.

[0109] As noted above, the curable silicone composition forms a cured silicone layer after being applied to a substrate. The cured silicone layer is preferably in a solid state after curing. However, in certain embodiments, the cured silicone layer could be a gel. In WS12401 / Ha / Mk some embodiments, the curable silicone composition may coat a substrate such as, for example, a dressing or backing layer. In these embodiments, the curable silicone composition may be cast and cured on the substrate to form the silicone layer. The curable silicone composition can be applied to the substrate to provide any desired thickness, pattern, or morphology. Suitable substrates are known in the medical device, active delivery, and / or therapeutics art.

[0110] In advance of forming the cured silicone layer, the curable silicone composition may be made by preparing component (A). Preferably, component (A) comprises the organopolysiloxane(s) described above for component (A). Additionally, component (A) may comprise an active, one or more excipients, a hydrosilyation catalyst, the organopolysiloxane resin, one or more release additives and / or one or more additional additives. When included in component (A), the active, one or more excipients, hydrosilyation catalyst, organopolysiloxane resin, one or more release additives and / or the one or more additional additives may be mixed with the organopolysiloxane(s) to form a mixture. Mixing can be done at a predetermined rate, for a predetermined period of time, and utilizing commercially available mixing devices such as, for example, a Speedmixer® or a Dispermat® fitted with a dissolver blade. The active, excipient(s), hydrosilyation catalyst, release additive(s) and the one or more additonal additives may be as described above.

[0111] In certain embodiments, the curable silicone composition may be made by preparing component (B). Preferably, component (B) comprises the organopolysiloxane described above for component (B). Additionally, component (B) may comprise the active, excipient(s), hydrosilyation catalyst, organopolysiloxane resin, release additive(s), and / or additonal additive(s). When included in component (B), the active, excipient(s), hydrosilyation catalyst, organopolysiloxane resin, release additive(s), and the additional additive(s) may be mixed with the organopolysiloxane to form a mixture. Mixing can be done at a predetermined rate, for a predetermined period of time, and utilizing commercially available mixing devices such as, for example, the mixing devices mentioned above. The active, excipient(s), hydrosilyation catalyst, organopolysiloxane resin, release additive(s) and the additional additive(s) may be as described above.

[0112] In embodiments where the curable silicone composition comprises component (C), the curable silicone composition is made by preparing component (C). In these WS12401 / Ha / Mk embodiments, the curable silicone composition may be made by preparing three mixtures and combining those mixtures. Preferably, component (C) comprises an organopolysiloxane like those described above for component (C). Additionally, component (C) may comprise the active, excipient(s), hydrosilyation catalyst, release additve(s) and / or the additional additive(s). When included in component (C), the active, excipient(s), hydrosilyation catalyst, release additive(s) and / or the additional additive(s) may be mixed with the organopolysiloxane to form a mixture. Thus, in these embodiments, the curable silicone composition may be made by initially preparing three mixtures. Mixing can be done at a predetermined rate, for a predetermined period of time, and utilizing commercially available mixing devices as described above. The active, excipient(s), hydrosilylation catalyst, release additive(s) and the additional additive(s) may be as described above.

[0113] In certain embodiments, and prior to coating the substrate, component (A) and component (B) may be mixed to form a mixture. Mixing can be done at a predetermined rate, for a predetermined period of time, and utilizing commercially available mixing devices such as, for example, the mixing devices mentioned above. In some embodiments, the mixture may also include component (C). If not included in components (A), (B) or (C) or if additional amounts are desired to be included in the curable silicone composition, the active, excipient(s), hydrosilyation catalyst, organopolysiloxane resin, release additive(s) and / or additional additive(s) can be added to the mixture. The addition of one or more of these components can be achieved at the time of mixing component (A), component (B), component (C) or can occur simultaneously or sequentialy by way of further mixing.

[0114] Once mixed and prior to curing, the curable silicone composition can be stored under commercially standard conditions, e.g. time, temperatures, and pressures. Further, once mixed, the curable silicone composition can be applied to a substrate prior to curing. In some embodiments, the curable silicone composition may coat a substrate such as, for example, a dressing. In these embodiments, the curable silicone composition may be cast and cured on the substrate to form the gel. The curable silicone composition can be applied to the substrate to provide any desired thickness, pattern, or morphology. Suitable substrates are known in the art. WS12401 / Ha / Mk

[0115] The composition can be cured at a predetermined temperature and for a predetermined period of time. For example, the mixture can be cured at a temperature of 40 to 140°C, preferably 60 to 130°C, for 5 seconds to 2 hours, preferably 10 seconds to 30 minutes. Curing the curable silicone composition provides a gel. After being applied to a substrate and cured, the curable silicone composition to be utilized in traditional wound care dressings and form a homogenous gel adhesive layer.

[0116] In certain embodiments, component (A) is prepared such that it comprises an organopolysiloxane having one or more groups comprising a silicon atom bonded to a hydrogen atom. In one embodiment, the curable silicone composition may be made by mixing an active and a release additive with the organopolysiloxane having one or more groups comprising a silicon atom bonded to a hydrogen atom, which may already be mixed with a small amount of organopolysiloxane resin. In an embodiment, component (B) is prepared such that it comprises an organopolysiloxane having one or more terminal groups comprising a carbon-carbon multiple bond. The organopolysiloxane having one or more terminal groups comprising a carbon-carbon multiple bond may already be mixed with a small amount of organopolysiloxane resin when provided in component (B). In some embodiments, component (B) may also comprise one or more additives such as, for example, a reinforcing filler. However, in certain embodiments, it may be preferred that component (B) is formed by mixing the active with the organopolysiloxane having one or more terminal groups comprising a carbon-carbon multiple bond. In these embodiments, component (A) may not comprise the active. In still other embodiments, it may be preferred that the curable silicone composition is formed by providing a component (C). In these embodiments, component (C) may comprise an organopolysiloxane having one or more groups comprising a silicon atom bonded to a hydrogen atom or organopolysiloxane having one or more groups comprising a silicon atom bonded to a hydrogen atom, an excipient, a release additive, organopolysiloxane resin, and an active.

[0117] The curable silicone composition is preferrable formed by forming a mixture. In certain embodiments, the mixture comprises component (A), component (B), optionally, component (C), a hydrosilylation catalyst, and a hydrosilylation inhibitor. A cured silicone is formed by curing the mixture as described above. WS12401 / Ha / Mk

[0118] Examples

[0119] The following examples are presented solely for the purpose of further illustrating and disclosing the embodiments of the curable silicone composition. Examples of the curable silicone composition include Examples 1 -7, which are described below. Comparative Examples, which are not part of the invention, are also described below.

[0120] The release of actives incorporated in the Examples of the curable silicone composition and the Comparative Examples was assessed using the orbital shaker method described below. In order to utilize the orbital shaker method the curable silicone compositions and the compositions of the Comparative Examples were cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0121] Orbital Shaker Method

[0122] Coated articles were formed by cutting the cured films and substrates so that each coated article had dimensions of 7x1 .5 cm2. Each coated article was placed in 30 milliliters of extraction media. The extraction media for the fat-soluble actives comprised a solution of 5 wt% polyethylene glycol (PEG) 400, 25 wt% ethanol and 70 wt% water, based on the total weight of extraction media. The extraction media for the water-soluble actives comprised a solution of phosphate buffer and saline. Extraction media for curcumin comprised the 5 wt% polyethylene glycol (PEG) 400, 25 wt% ethanol and 70 wt% water solution and the extraction media for melatonin comprised the phosphate buffer and saline solution. Samples of the active(s) in the extraction media were collected and then fresh media was added to replace the media removed with each sample at specified intervals up to 48 hours. The actives released into the extraction media were measured via high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection.

[0123] HPLC / UV measurement

[0124] The HPLC / UV measurement was conducted using the following instrumentation, mobile phase, column specifications, detector wavelength, sample prep, injection volume and at a temperature of 30°C and a flow rate of 1 .0 ml / min:

[0125] Instrumentation: Thermo Fisher UltiMate 3000 HPLC WS12401 / Ha / Mk

[0126] Pump LPG-3400SD Sampler WPS-3000 Column Oven TCC-3200 Detector DAD-3000

[0127] Mobile Phase: 80:20 H2O:CH3CN

[0128] Column: Cogent Type C Bidentate C18 100 x 3.0mm 4.0pm spherical particle

[0129] Detector wavelength: 214nm

[0130] Sample Prep: dilutions in 80:20 H2O:CH3CN

[0131] Injection volume: 10pl

[0132] Comparative Example 1 :

[0133] A composition was formed by providing WACKER VI PO 1000 polymer, which includes an organopolysiloxane having two terminal groups, each terminal group comprising a carbon-carbon multiple bond. The organopolysiloxane has a molecular weight of about -16,000 g / mol (viscosity of -1 ,000 cSt.). The composition included 58.86 wt% VIPO 1000, based on the total weight of the composition. The composition also included WACKER VIPO 20000, which is an a, co-dimethylvinylsiloxy-terminated polydimethylsiloxane having a molecular weight of about -X g / mol and a viscosity of -20,000 cSt. The composition included 1.12 wt% VIPO 20000, based on the total weight of the composition. The composition also included 32.81 wt% of WACKER H polymer 1000, which includes an organopolysiloxane having a molecular weight of about -16000 g / mol (-1000 cSt.) and one or more groups comprising a silicon atom bonded to a hydrogen atom. The composition included 0.56 wt% of WACKER H018, which was based on the total weight of the composition. WACKER H018 is a dimethylhydrosiloxy- terminated poly(dimethylsiloxy) (methylhydrosiloxy) copolymer crosslinker having a viscosity of 1360 cSt. The composition also included a resin, an excipient and an active. The composition included 0.57 wt% of the resin, which was based on the total weight of the composition and was a Vi-substituted MQ (Me3SiOi / 2 / Me2ViSiOi / 2 / SiO4 / 2) resin having an average molecular weight of -2500 g / mol, 1 .95% by weight vinyl, SiOH content -0.2% by weight, all based on the total weight of the resin. The composition included 5.88 wt% niacinamide, which was based on the total weight of the composition. WS12401 / Ha / Mk

[0134] A catalytic amount of platinum-containing hydrosilylation catalyst was included in the composition. The catalyst was a platinum-1 , 3-diviny1 -1 ,1 , 3, 3-tetramethyldisi-loxane complex. The composition also included 0.13 wt% of an inhibitor known as PT 730 VSWACKER, which is a divinyldimethylsiloxane, based on the total weight of the composition.

[0135] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0136] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0137] Comparative Example 2:

[0138] A composition was formed by providing 54.38 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.03 wt% VIPO 20000, based on the total weight of the composition. The composition also included 30.32 wt% of WACKER H polymer 1000, which was based on the total weight of the composition. The composition included 0.52 wt% of WACKER H018, which was based on the total weight of the composition. The composition included 0.53 wt% of the resin of Comparative EXAMPLE 1 , which was based on the total weight of the composition. The composition included 8.7 wt% glycerol, which was based on the total weight of the composition. The composition included 4.35 wt% niacinamide, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst of Comparative Example 1 was included in the composition. The composition also included 0.12 wt% of the PT 730 VS WACKER, which was based on the total weight of the composition.

[0139] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0140] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above. WS12401 / Ha / Mk

[0141] Comparative Example 3:

[0142] A composition was formed by providing 58.86 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.12 wt% VIPO 20000, based on the total weight of the composition. The composition also included 32.81 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.56 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.57 wt% of the resin used in Comparative Example 1 , which was based on the total weight of the composition. The composition included 5.88 wt% melatonin, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst described in Comparative Example 1 was included. The composition also included 0.13 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0143] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0144] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0145] Comparative Example 4:

[0146] A composition was formed by providing 58.27 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.10 wt% VIPO 20000, based on the total weight of the composition. The composition also included 33.53 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.57 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.56 wt% of the resin used in Comparative Example 1 , which was based on the total weight of the composition. The composition included 5.78 wt% curcumin, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst described in Comparative Example 1 WS12401 / Ha / Mk was included. The composition also included 0.13 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0147] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0148] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0149] Comparative Example 5:

[0150] A composition was formed by providing 58.85 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.12 wt% VIPO 20000, based on the total weight of the composition. The composition also included 32.83 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.56 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.57 wt% of the resin used in Comparative Example 1 , which was based on the total weight of the composition. The composition included 5.89 wt% caffeine, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst described in Comparative Example 1 was included. The composition also included 0.13 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0151] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0152] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0153] Example 1 :

[0154] A composition was formed by providing 52.54 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.0 wt% VIPO 20000, based WS12401 / Ha / Mk on the total weight of the composition. The composition also included 29.24 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.5 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.51 wt% of the resin used in Comparative Example 1 , which was based on the total weight of the composition. The composition included 0.50 wt% of a second resin, which was based on the total weight of the composition and was a Me3SiOi / 2 / SiO4 / 2 resin having an average molecular weight of -3100 g / mol, SiOH content -0.3% by weight. The composition included 8.35 wt% glycerol, which was based on the total weight of the composition, and 1.34 wt% BELSIL® OW1500, which was based on the total weight of the composition. The composition included 5.85 wt% niacinamide, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst described in Comparative Example 1 was included. The composition also included 0.12 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0155] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0156] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0157] Example 2:

[0158] A composition was formed by providing 52.50 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.0 wt% VIPO 20000, based on the total weight of the composition. The composition also included 29.27 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.52 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.51 wt% of the resin used in Example 1 , which was based on the total weight of the composition. The composition included 0.50 wt% of the second resin used in Example 1 , which was based on the total weight of the composition. The WS12401 / Ha / Mk composition included 8.36 wt% glycerol, which was based on the total weight of the composition, and 1.34 wt% BELSIL® REG 1103 B, which was based on the total weight of the composition. The composition included 5.85 wt% niacinamide, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst used in Comparative Example 1 was included. The composition also included 0.12 wt% of PT 730 VS WACKER.

[0159] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0160] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0161] Example 3:

[0162] A composition was formed by providing 56.73 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.08 wt% VIPO 20000, based on the total weight of the composition. The composition also included 31.53 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.54 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.55 wt% of the resin used in Example 1 , which was based on the total weight of the composition. The composition also included 3.61 wt% sodium lauryl sulfate, which was based on the total weight of the composition. The composition included 5.78 wt% a-tocopherol, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst used in Example 1 was inlcuded. The composition also included 0.13 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0163] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes. WS12401 / Ha / Mk

[0164] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0165] Example 4:

[0166] A composition was formed by providing 50.69 wt% VIPO 1000, based on the total weight of the composition. The composition also included 0.96 wt% VIPO 20000, based on the total weight of the composition. The composition also included 28.17 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.48 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.49 wt% of the resin used in Example 1 , which was based on the total weight of the composition. The composition included 0.48 wt% of the second resin used in Example 1 , which was based on the total weight of the composition. The composition included 8.06 wt% glycerol, which was based on the total weight of the composition, and 1.29 wt% BELSIL® OW1500, which was based on the total weight of the composition. The composition also included 3.55 wt% sodium lauryl sulfate, which was based on the total weight of the composition. The composition included 5.65 wt% a- tocopherol, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst used in Example 1 was included. The composition also included 0.12 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0167] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0168] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0169] Example 5:

[0170] A composition was formed by providing 52.62 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.00 wt% VIPO 20000, based WS12401 / Ha / Mk on the total weight of the composition. The composition also included 29.23 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.50 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.51 wt% of the resin used in Example 1 , which was based on the total weight of the composition. The composition included 8.31 wt% glycerol, which was based on the total weight of the composition, and 1.34 wt% BELSIL® OW1500, which was based on the total weight of the composition. The composition included 5.85 wt% melatonin, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst used in Example 1 was included. The composition also included 0.12 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0171] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0172] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0173] Example 6:

[0174] A composition was formed by providing 51.29 wt% VIPO 1000, based on the total weight of the composition. The composition also included 0.97 wt% VIPO 20000, based on the total weight of the composition. The composition also included 28.65 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.49 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.5 wt% of the resin used in Example 1 , which was based on the total weight of the composition. The composition included 12.3 wt% BELSIL® OW1500, which was based on the total weight of the composition. The composition included 5.7 wt% caffeine, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst used in Example 1 was WS12401 / Ha / Mk included. The composition also included 0.12 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0175] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0176] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0177] Example 7:

[0178] A composition was formed by providing 49.31 wt% VIPO 1000, based on the total weight of the composition. The composition also included 1.0 wt% VIPO 20000, based on the total weight of the composition. The composition also included 27.50 wt% WACKER H polymer 1000, based on the total weight of the composition. The composition included 0.47 wt% of WACKER H018, which was based on the total weight of the composition. The composition also included resin, an excipient and an active. The composition included 0.48 wt% of the resin used in Example 1 , which was based on the total weight of the composition. The composition also included 15.2 wt% sodium lauryl sulfate, which was based on the total weight of the composition. The composition included 5.93 wt% curcumin, which was based on the total weight of the composition. A catalytic amount of the platinum-containing hydrosilylation catalyst used in Example 1 was included. The composition also included 0.12 wt% of PT 730 VS WACKER, which was based on the total weight of the composition.

[0179] The aforementioned components were mixed together at room temperature using a SpeedMixer® at 2000 rpm. The resulting composition was cast as a film onto a substrate and cured at 120°C for 12 minutes.

[0180] The release of niacinamide from the cured curable silicone composition (film) was assessed using the orbital shaker method described above and measured via HPLC / UV as described above.

[0181] The release rate of niacinamide from the cured curable silicone compositions (films) of Examples 1 and 2 and Comparative Examples 1 and 2 was assessed as described above over time and is illustrated in FIG. 1. As illustrated, the curable silicone WS12401 / Ha / Mk compositions allow for a desired release rate to be achieved. In fact, the curable silicone compositions of Examples 1 and 2 illustrate that the release rate of niacinamide from the cured curable silicone compositions can be preselected. In fact, when comparing the release rates of Example 1 and Example 2 with the release rate of Comparative Example 1 , the release rate can be moderately or significantly increased as desired. For example, as illustrated in FIG. 1 , after four hours, the release rate of niacinamide can be increased about tenfold from the rate obtained utilizing the composition of Comparative Example 1 if utilizing the curable silicone composition of Example 2.

[0182] The release rate of a-tocopherol from the cured curable silicone compositions (films) of Examples 3 and 4 was assessed as described above over time and is illustrated in FIG. 2. As illustrated, the curable silicone compositions can also be utilized to provide release rates that vary over time. For example, for certain applications, it may be desirable that the release rate be greater at the beginning of delivering an active. This initial burst of active can be desirable when releasing a vitamin such as, for example, vitamin E. Also, as illustrated in FIG. 2, the curable silicone composition of Examples 3 and 4 can be utilized to provide active release that is greater at the beginning of use when compared to the release after 2, 4 or 6 hours of use.

[0183] The release rate of melatonin from the cured curable silicone composition (film) of Example 5 and Comparative Example 3 was assessed as described above over time and is illustrated in FIG. 3. As illustrated, the curable composition of Example 5 allows for a desired release rate to be achieved. In fact, the curable silicone composition of Example 5 provides an increase in the release rate of melatonin when compared with the release rate of melatonin from Comparative Example 3. Furthermore, the release of melatonin from the curable silicone composition of Example 5 is essentially linear indicating that the release can be highly controlled when compared with the release rate of melatonin from Comparative Example 3.

[0184] The release rate of curcumin from the cured curable silicone composition (film) of Example 6 and Comparative Example 4 was assessed as described above over time and is illustrated in FIG. 4. As illustrated, the curable composition of Example 6 allows for a controlled and increased release rate of curcumin when compared with the release rate of curcumin from Comparative Example 4. WS12401 / Ha / Mk

[0185] The release rate of caffeine from the cured curable silicone composition (film) of Example 7 and Comparative Example 5 was assessed as described above over time and is illustrated in FIG. 5. As illustrated, the curable composition of Example 7 allows for an increased release rate of caffeine when compared with the release rate of caffeine from Comparative Example 5.

[0186] From the foregoing detailed description, it will be apparent that various modifications, additions, and other alternative embodiments are possible without departing from the true scope and spirit. The embodiments and examples discussed herein were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to use the invention in various embodiments and with various modifications as are suited to the particular use contemplated. As should be appreciated, all such modifications and variations are within the scope of the invention.

Claims

WS12401 / Ha / MkCLAIMS1 . A curable silicone composition, comprising: a first organopolysiloxane having one or more groups comprising a silicon atom bonded to a hydrogen atom, the first organopolysiloxane having a molecular weight of 100,000 g / mol or less; a second organopolysiloxane having one or more groups comprising a carboncarbon multiple bond, the second organopolysiloxane having a molecular weight of 500,000 g / mol or less; a hydrosilyation catalyst; one or more organosilicon crosslinkers; a hydrosilylation inhibitor that retards the addition of the one or more organosilicon crosslinkers to one or more of the organopolysiloxanes when the composition is at room temperature; and a release additive, the release additive being a surfactant having at least one hydrophil lie group and at least one hydrophobic group, a hydrophi llic silicone excipient, or a mixture of the surfactant and the hydrophi llic silicone excipient2. The curable composition of claim 1 , further comprising an active, wherein, if the active is fat soluble, then the release additive comprises the surfactant and, if the active is water soluble, then the release additive comprises the hydrophilic silicone excipient.

3. The curable composition of claim 1 , further comprising a filler and an MQ resin, wherein the filler is provided in an amount of 0.01 to 25 wt%, based on the total weight of the curable composition, and the MQ resin is provided in an amount of 0.01 to 70 wt%, based on the total weight of the curable composition.

4. The curable composition of claim 1 , wherein the at least one hydrophi llic group of the surfactant is a carboxylate, sulfate, sulfonate, phosphate, amine, or polyethylene glycol chain, or a polypropylene glycol chain.39WS12401 / Ha / Mk5. The curable composition of claim 1 , wherein the at least one hydrophobic group of the surfactant is a natural fat, natural oil, linear alkyl chain, branched alkyl chain, or a synthetic polymer.

6. The curable composition of claim 1 , wherein the first organopolysiloxane has a molecular weight of 500 - 10,000 g / mol, the second organopolysiloxane has a molecular weight of 200 - 100,000 g / mol, and the curable composition comprises 60 wt.% or more of the first organopolysiloxane and the second organopolysiloxane, which is based on the total weight of the curable composition.

7. The curable composition of claim 1 , further comprising a hydrophilic compound, wherein the hydrophilic compound is provided in an amount 1 to 50 wt%, based on the total weight of the curable composition.

8. The curable composition of claim 1 , wherein, after the curable silicone composition is cured, the cured composition exhibits a tack of 50 grams of force (gf) or more.

9. The curable composition of claim 1 , wherein the surfactant is selected from the group consisting of metal lauryl sulfate, metal laureth sulfonate, dioctyl metal sulfosuccinate, and mixtures thereof.

10. The curable composition of claim 1 , wherein the surfactant is provided in an amount of up to 15 wt%, based on the total weight of the curable composition.11 . The curable composition of claim 2, wherein the hydrophilic silicone excipient is provided in an amount 0.001 to 15 wt%, based on the total weight of the curable composition, and comprises a mixture of a dimethicone and a silicone or is an organopolysiloxane polyoxyalkylene.40WS12401 / Ha / Mk12. The curable composition of claim 9, wherein the metal in the surfactant is sodium or potassium.

13. The curable composition of claim 10, wherein the surfactant is provided in an amount 0.001 to 5 wt%, based on the total weight of the curable composition.

14. The curable composition of claim 11 , wherein the hydrophilic silicone excipient is provided in an amount 0.001 to 5 wt%, based on the total weight of the curable composition, and is a mixture of a dimethicone and a silicone polyglucoside.

15. The curable composition of claim 12, wherein the surfactant is sodium lauryl sulfate or potassium lauryl sulfate.41

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