WO2013040149A1

WO2013040149A1 - Microcapsules and methods for producing microcapsules

Info

Publication number: WO2013040149A1
Application number: PCT/US2012/055050
Authority: WO
Inventors: Heng Cai; Alan Meyers
Original assignee: Revlon Consumer Products
Priority date: 2011-09-16
Filing date: 2012-09-13
Publication date: 2013-03-21

Abstract

Microcapsules containing oxide particles, methods of production of microcapsules, and cosmetic compositions including microcapsules are provided.

Description

MICROCAPSULES AND METHODS

FOR PRODUCING MICROCAPSULES

Field of the Invention

[0001] The present invention relates to microcapsules. In particular, the present invention relates to microcapsules containing oxides. In addition, the present invention relates to cosmetic compositions including said microcapsules and methods of producing said microcapsules.

DESCRIPTION OF RELATED ART

[0002] Oxide particles have many different uses. For instance, these particles may be included in cosmetic compositions to confer a certain benefit. When applied to skin, the benefit may include prevention of various forms of skin damage.

[0003] Skin, the largest organ in the human body, constitutes a physical barrier between the body and its environment. Appearance of the skin is affected by both intrinsic skin aging (i.e., natural skin aging, which is commonly genetically controlled) and extrinsic skin aging (i.e., skin aging due to environmental factors such as UV exposure, pollution, oxidizing stress, irritant stress, etc.). All these processes lead to visible signs of skin aging, such as skin thinning, sagging, wrinkling, and dryness. [0004] For most people, maintaining beautiful skin is highly desirable. Thus, there is a need for compositions that slow down, prevent, or reverse effects of intrinsic and extrinsic skin aging. Since generation of free oxygen radicals is a major cause of skin aging, compositions that slow down, prevent, or reverse the effects of skin aging may be those that possess antioxidant properties allowing them to scavenge free oxygen radicals generated in the skin.

[0005] In order for oxide particles to be included in cosmetic compositions, it may be helpful to encapsulate them.

SUMMARY OF THE INVENTION

[0006] In an aspect of the present invention, a microcapsule includes a first particle, less than IS microns in size, the first particle about SO to 100% covered in a silane; a second particle, pretreated with an mq resin, the second particle about SO to 100% covering the first particle to form a combined particle; and the combined particle is encapsulated in a wax, a wall-forming material, or a combination of the wax and the wall-forming material to form the microcapsule. The first particles may possess skin anti-aging properties. In an embodiment of the invention, the first particles are oxide particles, such as copper oxide particles. In a further embodiment, the first particles are cuprous oxide particles.

[0007] In an embodiment the second particles are titanium dioxide particles that are pretreated with a composition including an agent that reduces particle agglomeration. In an embodiment, the titanium dioxide particle is pretreated with a composition that includes tritnethylatcd silica, e.g.,

trimethylsiloxysilicate. In another embodiment of the invention, the encapsulate surrounding the first and second particles includes a wax, a wall- forming material, or a combination of the wax and the wall-forming material to form the microcapsule and the microcapsule is reduced in size to less than 1 S microns by a mechanical method such as jet mill.

[0008] Thus, a microcapsule according to the above aspect of the invention may be formed of (1) cuprous oxide particle less than I microns in size and coated with silane and titanium dioxide particles, wherein the titanium dioxide particles are pretreated with a composition mat includes trimethylisiloxysilicate, and this combined particle is encapsulated by (2) a wax; or a wall-forming polymer, or a combination of the wax and the wall- forming polymer and the encapsulated combined particle is reduced to a microcapsule of less than 15 microns in size.

[0009] In some embodiments, the first particles and the second particles, e.g., the cuprous oxide particles and the titanium dioxide particles, are present at a ratio of first particle to second particle of about 1 to 6 of the first particle to about 0.5 to 2 of the second particle. In one embodiment the ratio of the first particle to second particle is 1:1.

[0010] In an embodiment the wax may be selected from, but not limited to, the group consisting of tribehinin, bayberry wax, beeswax, candelilla wax, carnauba, ceresin, cetyl esters, hydrogenated jojoba oil, hydrogenated jojoba wax, hydrogenated rice bran wax, japan wax, jojoba butter, jojoba oil, jojoba wax, lanolin wax, microcrystalline, mink, montan acid, montan, ouricury, ozokerite, rice bran, shellac, synthetic beeswax, and synthetic wax. In an embodiment, the wax is tribehenin.

[0011] In an embodiment, the wall-forming polymer is a polymer that may be selected from the group consisting of a polyacrylate polymer, a

polymethacrylate polymer, a cellulose ether polymer, and a cellulose ester polymer. In a further embodiment, the polymer is poIy(methylacrylic acid co- methyl methacrylate).

[0012] In an aspect of the invention, the size of the first particles, e.g., cuprous oxide particles, is less than about 15 microns. In a further aspect, the size of the first particles is less than about 10 microns. In yet a further aspect, the size of the first particles is from about 0.8 to about 4 microns. In another aspect, the size of the core is less than about 15 microns. In a further aspect, the size of the core is from about 3 to about 8 microns. In an embodiment of the invention, the size of the microcapsule is from about 25 to about 50 microns, such as from about 28 to about 32 microns, for example, 30 microns.

[0013] In some embodiments, the microcapsule includes about 30-70% by weight of titanium dioxide and trimethylsiloxysilicate. The microcapsule may also include about 10-30% by weight of cuprous oxide, about 5-15% by weight of tribehcnin, and/or about 10-20% by weight of poly(mcthylacrylic acid co- methyl mcthacrylate). The microcapsule may be adapted for cosmetic application to the skin.

[0014] In another aspect of the invention, a cosmetic composition that includes any of the above microcapsules is provided. The cosmetic composition may be selected from the group consisting of a skin moisturizer, sunscreen, self tanning composition, after-sun care composition, makeup, protein concentrate, antiwrinkle composition, anti-aging composition, skin-firming composition, skin-lightening composition, topically applied therapeutic composition, shaving preparation composition, depilatory composition, and cleanser. In an embodiment, the cosmetic composition is an anti-aging composition.

[0015] In a further aspect of the present invention, a method of producing a microcapsule is provided. The method includes: providing first particle of less than IS microns in size; mixing the first particle with a silane to cover 50 to 100% of the first particle with a second particle pretreated with an mq resin until the first particle is about 50 to 100% covered with the second particle and a combined particle is formed; applying a wax to the combined particle to encapsulate and form a microcapsule.

[0016] Thus, a method of producing a microcapsule, e.g., a microcapsule described above, may include: providing cuprous oxide particles; mixing the cuprous oxide particles with titanium dioxide particles to obtain a mixture, wherein the titanium dioxide particles are pretreated with a composition that includes trimethylsiloxysilicate; applying a wax to the mixture to obtain a combined particle; and encapsulating the combined particle in a shell that includes a wall-forming polymer.

[0017] In an embodiment, the step of providing the first particles, e.g., cuprous oxide particles, further includes reducing the size of the first particles. Thus, the size of the first particles may be less than about 1 microns, such as about 5 microns, for example, from about 0.8 to about 4 microns. In another embodiment, the step of applying the wax to the mixture further includes reducing the size of the core. Thus, the size of the core may be less than 15 microns, for example, from about 3 to about 8 microns. In such embodiments of the present invention, the size of the first particles and/or the core is reduced by a jet mill.

[0018] In an embodiment of the invention, a wall-forming polymer includes, but is not limited to, polyacrylates, polymethacrylates, cellulose ethers, and cellulose esters. In an embodiment, the wall-forming polymer is a

polymethacrylate. The polymethacrylate may be a poly(methyl methacrylate), such as poly(methacrylic acid-co methyl methacrylate) (e.g., polymethacrylate is poly(methacrylic acid-co methyl methacrylate) 1 :2, otherwise known by the trade name EudragitS®).

[0019] In an example embodiment, the first particles and the second particles, e.g., the cuprous oxide and the titanium dioxide particles, are mixed at a ratio of 1 : 1 by weight. In some embodiments, the microcapsule is adapted for cosmetic application to the skin.

[0020] In another aspect of the invention, kits, e.g., cosmetic kits (such as skincare kits), are provided. The kits include compositions having

microcapsules according to the embodiments of the present invention. Such cosmetic kits may be provided with instructions for their use for topical application to the skin. The instructions may be printed on the container, or as a label applied to the container, or as a separate sheet, pamphlet, card, or folder supplied in or with the container.

DETAILED DESCRIPTION OF THE INVENTION

[0021] The terms used in this specification generally have their ordinary meanings in the art, within the context of the invention, and in the specific context where each term is used. Certain terms are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner in describing the compounds, compositions, and methods of the invention and how to make and use them. Moreover, it will be appreciated that the same thing can be said in more than one way. Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. The use of examples anywhere in this specification, including examples of any terms discussed herein, is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to the examples presented.

[0022] As used herein, "about" or "approximately " shall generally mean within 20 percent, preferably within 10 percent, and more preferably within 5 percent of a given value or range. Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients and or reaction conditions are to be understood as being modified in all instances by the term "about".

[0023] Cosmetic compositions (composition) of the invention possess several characteristics. First, according to the embodiments, the size of the particles, e.g., anti-aging particles (such as oxide particles), is minimized in the composition, such that the composition does not feel sandy or gritty, but appears smooth when applied to the skin. In addition, the particles do not impart color to the cosmetic composition, and the cosmetic composition is transfer resistant with long lasting adherence to the skin. Finally, the cosmetic composition may be formulated such that it allows for controlled release of the particles into the skin. At least some of these characteristics are included in the cosmetic compositions according to the present invention.

Microcapsules

[0024] Microcapsules in accordance with embodiments of the present invention include a core, wherein the core includes first particles and second particles, and a wax; and a shell surrounding the core.

[0025] As used herein, the term "microcapsule" refers to a microparticle including a wax, a wall-forming material, or a combination of the wax and the wall-forming material, and completely or almost completely encapsulated particles. Encapsulation in microcapsules is suitable for drugs, vitamins, food supplements, and cosmetics, since this process is easily adaptable through use of various solvents and/or polymers. The microcapsule may be spherical in shape. In topical compositions, the spherical shape of the microcapsule aids in homogenous distribution of the particles on the skin. The encapsulation can be used to protect the particles within it from chemical and physical degradation, to allow separation of incompatible substances within compositions, and to prevent undesirable release of substances within it.

[0026] The term "wall-forming material" typically refers to a material, e.g., a polymers), which forms a component of the external wall or layer or shell of the microcapsule. The wall -forming material of the microcapsule may be semipermeable to allow for controlled release of the encapsulated first and second particles.

[0027] The first particle (particles) within the microcapsule can be any particles that possess skin anti-aging properties, such as any particles that improve the visible signs of skin aging, e.g., skin thinning, sagging, wrinkling, and dryness. Such particles may be oxides. Particularly, such particles may be metal oxides, an example includes, copper oxide particles, such as a cuprous oxide (Cu₂0).

[0028] Copper is an essential metal in the body that has multiple benefits. Copper is beneficial because it has been found to have anti-microbial, antifungal, and anti-viral properties. T us, copper can be used in various medical applications, such as for fighting infection and inflammation, and for promoting wound healing. In addition, copper has been found to reduce the incidence of some cancers and cardiovascular disease, and to promote immune system function. In the skin, copper is thought to promote deposition of structural protein collagen and serve an anti -oxidant role. Since collagen degradation and free oxygen radical generation are prime causes of skin aging, copper and copper-containing compositions (e.g., copper-containing cosmetic

compositions) may be highly beneficial in slowing down, preventing, and or reversing skin aging.

[0029] The first particle has a silane exterior coating which can cover about SO to 100% of the exterior of the first particle. A coating does not need to cover the entire exterior of the first particle but may cover the entire exterior of the particle. [0030] In addition to the first particles, the core of the microcapsule includes second particles. The second particles can be for example titanium dioxide particles. The titanium dioxide particles are specially treated micronized titanium dioxide particles (pretreated).

[0031] In an embodiment, the titanium dioxide, e.g., the micronized titanium dioxide, is pretreated with a composition comprising an agent that reduces particle agglomeration. The pretreatment of the titanium dioxide is described in U.S. Patent No. 5,91 1,974, which is incorporated by reference herein in its entirety. Briefly, the micronized titanium dioxide may be pretreated with a composition, wherein, in addition to the titanium dioxide, the composition includes (a) about 0.1-60% by weight of trimethylated silica, (b) about 0.1 to 60% by weight of a volatile solvent having a viscosity of 0.5 to 100 centipoise at 25°C, and (c) about 0.1-60% of a nonvolatile oil having a viscosity of 200 to 1,000,000 centipoise at 25°C. The titanium dioxide may be pretreated with a composition that includes trimethylated silica; for example, the mq resin may be trimethylsiloxysilicate. Mq resin particles in combination with volatile silicone are set forth in U.S. Pat. No. 4,983,388, which is hereby incorporated by reference. In an embodiment, trimethylsiloxysilicate is available from Dow Corning Corporation under the trade name Dow 2-0747 and 2-0749, which includes a blend of 40-60% volatile solvent (volatile silicone) and 40-60% of trimethylsiloxysilicate. Specifically, Dow 2-0749 is a fluid containing about 50% trimethylsiloxysilicate and 50% cyclomethicone. The mq resin may be formed by the reaction of trimcthylchlorosilane and an aqueous silica sol; more particularly the reaction of trimethylchlorosilane, an aliphatic alcohol such as ethanol or 2-propanol, and an aqueous silica sol.

[0032] The titanium dioxide may provide several benefits to the first particles, which may be copper oxide particles. First, titanium dioxide is used as a color masking agent In other words, the presence of titanium dioxide within the microcapsules may prevent the development of color in the resultant cosmetic composition. For instance, it is known that a copper metal is orange-brown in color, and when it is complexed with other molecules, it can turn blue or green. For example, copper is known to generate color when complexed with water, sodium EDTA, and nitrogen-containing compounds. The titanium dioxide particles within the microcapsules mask the color of the copper oxide particles such that the copper oxide particles do not impart orange-brown, green, or blue color to the cosmetic composition.

[0033] Pretreated titanium dioxide, e.g., the titanium dioxide pre treated with a composition that includes trimethylated silica, may be more resistant to agglomeration. In addition, as described in U.S. Patent No. 5,91 1,974, supra, pretreated titanium dioxide may impart onto the cosmetic composition improved transfer resistance and long lasting adherence to the skin. In other words, pretreated titanium dioxide may reduce the running or smearing of the cosmetic composition, and may prevent removal of the cosmetic composition when it comes in contact with fingers or clothing.

[0034] The first and the second particles within the core of the microcapsule, e.g., the copper oxide particles and the pretreated titanium dioxide particles, may be present at a ratio of 1 : 1 by weight. The second particle forms a coating over the silane coated first particle covering 50 - 100% of the surface of the silane coated first particle.

[0035] Such ratio may also aid in reducing agglomeration of the particles and, consequently, may reduce the overall size of the microcapsule.

[0036] The microcapsule core may also contain a binding agent such as a wax. By applying the wax the wax may be used to surround the mixture of the first and the second particles, e.g., the copper oxide and the titanium dioxide mixture. Suitable waxes have a melting point ranging from 35°C to 120°C, and include any one or a combination of natural and synthetic waxes, such as bayberry wax, beeswax, candelilla wax, carnauba, ceresin, cetyl ester, hydrogenated jojoba oil, hydrogenated jojoba wax, hydrogenated rice bran wax, japan wax, jojoba butter, jojoba oil, jojoba wax, lanolin wax, macrocrystalline, mink, montan acid, montan, ouricury, ozokerite, rice bran, shellac, synthetic beeswax, and synthetic wax, etc. A suitable wax also may include a substance such as tribehenin Cosmetic Compositions and Kits

[0037] An aspect of the present invention relates to cosmetic compositions (composition) mat include microcapsules. As used herein, the term "cosmetic composition" means a combination of raw materials or ingredients suitable for application to the human body. A cosmetic composition is typically applied to the body for beautifying, cleansing, moisturizing, or otherwise treating the external surface of the body, including by cleansing, coloring, conditioning, or protecting the external surface of the body part such as, for example, the skin, nails, lips, scalp, or hair. Examples of cosmetic compositions in which microcapsules can be used include skin moisturizers, sunscreens, self tanning compositions, after-sun care compositions, makeup, protein concentrates, antiwrinkle compositions, anti-aging compositions, skin-firming compositions, skin-lightening compositions, topically applied therapeutic compositions, hair- care compositions, shaving preparation compositions, depilatory compositions, and cleansers. In an embodiment, the cosmetic composition is an anti-aging composition. In another embodiment, the microcapsules are in the form of a powder or an emulsion.

[0038] In an embodiment, a cosmetic composition for topical application, e.g., a lotion, may include from about 0.1 to about 10% by weight of microcapsules, such as from about 0.2 to about 0.5% by weight of microcapsules, or about 0.35% by weight of microcapsules.

[0039] "Cosmetic application to the skin" or "topical application" refer to external application to the skin, lips, scalp, nails, or hair. Commonly, these terms imply that the cosmetic compositions will include a physiologically acceptable medium, i.e., a medium that is compatible with the skin of the face and or body. Such medium may be a cosmetically acceptable medium or a medium that has a color, odor, and feel that are pleasant and do not cause unacceptable discomfort, which may dissuade the consumer from using the composition.

[0040] The cosmetic composition may optionally include a carrier. The carrier for use in formulating the cosmetic composition may include one or more compounds selected based on the particular intended use of the composition. The carrier may be inorganic or organic in nature; it should be non-toxic and non-irritating. The carrier should also be compatible with the microcapsules and the components of the microcapsules, e.g., copper oxide and titanium dioxide particles.

[0041] The cosmetic compositions may also include one or more optional ingredients. Examples of the optional ingredients include but are not limited to lubricants, preservatives, perfumes, and colorants. The optional ingredients should be' chemically inert with respect to each other, and with respect to the microcapsules and the components of the microcapsules, e.g., copper oxide and titanium dioxide particles.

[0042] Lists of carriers and optional ingredients, which are well known in the art, are disclosed, for example, in "Cosmetics: Science and Technology," edited by M. S. Balsam and E. Sagarin, 2nd Edition, 1972, Wiley Pub. Co.; "The Chemistry and Manufacture of Cosmetics" by M. G. DeNavasse; and "Harry's Cosmeticology," J. B. Wilkinson et al., 7th Edition, 1982, Chem. Pub. Co.; the disclosures of each of the above being incorporated herein by reference.

[0043] The cosmetic compositions may include absorption enhancing agents. An absorption enhancing agent may be an agent that promotes the absorption of a substance, e.g., an anti-aging substance such as a copper oxide particle, by the skin. Examples of enhancing agents include, but are not limited to, alcohols, such as short chain alcohols, long chain alcohols, or polyalcohols; amines and amides, such as urea, amino acids or their esters, ΑΖΟ ΕΦ, derivatives of AZONE®, pyrrolidones, or derivatives of pyrrolidones; terpenes and derivatives of terpenes; fatty acids and their esters; macrocyclic compounds; tensides; sulfoxides such as, dimethylsulfoxide and decylmethylsulfoxide; liposomes; transfersomes; lecithin vesicles; ethosomcs; surfactants, such as anionic, cationic, and nonionic surfactants; polyols; and essential oils.

Methods of Producing Microcapsules

[0044] Aspects of the present invention are directed to methods of producing microcapsules.

[0045] Numerous techniques for encapsulation are available depending on the nature of the encapsulated substance and on the type of polymer used. A widely used method for encapsulation of water insoluble substances within water insoluble polymers is the solvent removal method. Generally, the desired polymer is dissolved in a suitable organic solvent, which is followed by the addition of the desired substance to be encapsulated. This substance is either dissolved or dispersed in the organic solvent. The resulting organic solution/dispersion is dispersed in aqueous phase to obtain an oil-in-water emulsion where oily particles are dispersed in the aqueous phase.

Microcapsules are formed upon complete removal of the solvent. An example of an encapsulation method that uses physiologically acceptable solvents, i.e., solvents acceptable for use in pharmaceuticals, vitamins or cosmetics, may be found in U.S. Patent No. 6,932,984, incorporated by reference in its entirety.

[0046] A method of producing a microcapsule includes providing first particles; mixing the first particles with second particles to obtain a combined particle; and encapsulating the combined particle to form a microcapsule.

[0047] The first particles may be particles that possess skin anti-aging properties. Such particles may be oxide particles, e.g., copper oxide particles such as cuprous oxide particles. For example, the size of the first particles is less than about 1 S microns, such as less than about 10 microns, and may be from about 0.8 to about 4 microns.

[0048] As used herein, "size" refers to the longest linear distance between the sides of an object, such as a particle, core or a microcapsule. For a spherical object, "size" refers to the length of its diameter.

[0049] As used herein the first particle is a metal particle. A metal is defined by the location on the periodic table of elements. In one embodiment the metal is a transition metal. The metal particle can be in combination with another element to provide stability. An example of a transition metal combine with another element is a cuprous oxide.

[0050] In order to obtain the desired size of the first particles, the step of providing first particles may further include reducing the size of the first particles. The size reduction may be accomplished by various techniques known in the art. For example, the size reduction may be accomplished by grinding. In a preferred embodiment, the size reduction may be accomplished with a use of a mill, such as a jet mill. The size reduction of the first particles, e.g., copper oxide particles, is to reduce the size of the resultant microcapsules. Reduction in size of the copper oxide particles, and in turn, the resultant microcapsules, may advantageously result in a cosmetic composition that does not feel sandy or gritty, but appears smooth when applied to the skin.

[0051] Optionally, the first particles may be mixed in a blender to reduce particle agglomeration. For example, the particles may be mixed in a blender for 60 seconds, or 90 seconds, or 180 seconds.

[0052] The particles that have obtained the desired size can be separated using conventional methods.

[0053] The first particles are mixed with second particles to obtain a mixture. The second particles may be titanium dioxide particles, which may be pretreated with a composition that includes mq resin such as

trimethylsiloxysilicate. In an embodiment, the first and the second particles are mixed at a ratio of 1 : 1 by weight.

[0054] The copper oxide particles and the pretreated titanium dioxide may be mixed using any conventional method. In an embodiment, the copper oxide particles and the pretreated titanium dioxide may be mixed in a chemical blender. The two particles may be mixed in a blender for 60 seconds or longer, such as 90 seconds, or 180 seconds, for example. Such mixing reduces agglomeration of the mixture of copper oxide and pretreated titanium dioxide particles.

[0055] In the next step, a wax is applied to the mixture of the first and second particles to obtain a core. In an example embodiment, the mixture is sprayed with a molten wax to produce a coat surrounding the particles. [

[0056] The size of the core may be less than about 15 microns, such as from about 3 to about 8 microns. The size of the core may also be from about 1 to about S microns. Thus, in an embodiment of the method, the step of applying wax to the mixture may further include reducing the size of the core. In this step, the size reduction may also be accomplished by a grinder. The size reduction may also be accomplished by a micronizer, such as a mill, e.g., a jet mill. The cores that have obtained a desired size can be separated for encapsulation in a shell.

[0057] The encapsulation step includes completely or almost completely surrounding a core with a wall-forming material (SO - 100%). Such wall- forming material may be a polymer. The wall-forming material may be selected from the group consisting of a polyacrylate, polymethacrylate, cellulose ether, and cellulose ester. In an embodiment, the wall-forming polymer is a polymethacrylate, such as poly(methacrylic acid-co methyl methacrylate), e.g., a polymethacrylate known by the trade name Eudragit® S.

[0058] The thickness of wall-forming polymer applied to the core is such that a microcapsule of about 25 to about SO microns in size is produced. For example, the resultant size of the microcapsule may be from about 28 to about 32 microns, e.g., about 30 microns.

[0059] The entire contents of all references, patent applications, and patents cited throughout this specification are hereby incorporated by reference herein.

EXAMPLE

[0060] The Example set forth below is intended to aid in the understanding of an embodiment of the invention but is not intended to, and should not be construed to limit its scope in any way. The Example does not include detailed descriptions of conventional methods that are well known to those of ordinary skill in the art.

[0061] An example microcapsule includes about 30-70% by weight of titanium dioxide and trimethylsiloxysilicate; about 10-30% by weight of cuprous oxide; about 5-15% by weight of tribehenin; and about 10-20% by weight of poly(methacrylic acid-co methyl methacrylate). One such microcapsule is described in greater detail in the following paragraphs.

[0062] Method of treating a first particle:

Octyhriethoxysilane 2.0 parts

Isopropanol 40 parts

Water 2 parts

Copper Oxide 98.0 parts Dissolvc octyltriethoxysilane in isopropanol with mixing. Add water and mix. While mixing add the copper oxde. Continue mixing for 1 hour. After one hour pour into trays and dry at 60C until water and isopropanol are completely removed from the mixture. Reduce the copper particle size to less than about 30 microns.

[0063] Method of preparing a microcapsule:

Add treated first particle to the second particle that has been pretreated with ttrimemylsiloxysilicate. Combine until the second particle covers 50 - 100% of the surface of the first particle to form a combined particle. Encapsulate the combined particle with tribehenin. Grind the wax encapsulated particle and encapsulate with a polymethacrylate polymer. Reduce the size to less than 15 microns to achieve a better texture prior to adding to a cosmetic formulation.

[0064] A sunscreen lotion, skin-care cream, or a serum formulation may be prepared using the microcapsules described herein, with the microcapsule component breakdown, in % by weight, as follows:

[0065] Stability tested emulsion formula

Water 70%

Trisiloxane Dimethicone 7%

microcapsules 0.4 - 0.1%

PEG 2%

Isodecyl neopentanoate, 10%

Dimethicone bis-isobutyl

PPG-20 crosspolymer

[0066] Jet milled encapsulated microcapsules showed little or no color change in the formula during stability testing. Untreated microcapsules caused a color change in the formula during stability testing. A formula that has a green color is not marketable.

Claims

WHAT IS CLAIMED IS: . A microcapsule comprising:

A first particle, less than 15 microns in size, the first particle about SO to 100% covered in a silane;

a second particle, pretreated with an mq resin, the second particle about SO to 100% covering the first particle to form a combined particle; and the combined particle is encapsulated in a wax, a wall-forming material, or a combination of the wax and the wall-forming material to form the microcapsule. . The microcapsule of claim 1, wherein the microcapsule is less than IS microns in size. . The microcapsule of claim 1, wherein the first particle is an oxide particle. . The microcapsule of claim 3, wherein the oxide particle is a copper oxide particle. . The microcapsule of claim 4, wherein the copper oxide particle is a cuprous oxide particle. . The microcapsule of claim 1 , wherein the second particle is a titanium

dioxide particle. . The microcapsule of claim 6, wherein the titanium dioxide particle is

pretreated with a trimethylated silica. . The microcapsule of claim 1, wherein the mq resin is

trimethylsiloxysilicate. The microcapsule of claim 1 , wherein the wax is selected from the group consisting of tribehinin, bayberry wax, beeswax, candeli!la wax, carnauba, ceresin, cetyl esters, hydrogenated jojoba oil, hydrogenated jojoba wax, hydrogenated rice bran wax, japan wax, jojoba butter, jojoba oil, jojoba wax, lanolin wax, microcrystalline, mink, montan acid, montan, ouricury, ozokerite, rice bran, shellac, synthetic beeswax, and synthetic wax. The microcapsule of claim 9, wherein the wax is tribchenin. The microcapsule of claim 1 , wherein the wall-forming material is a polymer. The microcapsule of claim 1 1 , wherein the wall-forming material a polyacrylate polymer, a polymethacrylate polymer, a cellulose ether polymer, In a further embodiment, poly(methylacr lic acid co-methyl methacrylate) polymer, and a cellulose ester polymer. The microcapsule of claim 2, wherein the microcapsule is reduced by a mechanical method. The microcapsule of claim 2, wherein the microcapsule is^' reduced by a jet- mill. A cosmetic composition comprising the microcapsule of claim 1 adapted for cosmetic application to the skin. The cosmetic composition of claim 1 S, wherein the cosmetic composition is selected from the group consisting of a skin moisturizer, a sunscreen, a self tanning composition, an after-sun care composition, a makeup, a protein concentrate, an antiwrinkle composition, an anti-aging composition, a skin-firming composition, a skin-lightening composition, a topically applied therapeutic composition, a shaving preparation composition, a depilatory composition, and a cleanser. The cosmetic composition of claim 16, wherein the composition is an anti-aging composition. A method of producing a microcapsule, comprising:

a. providing a first particle of less than IS microns in size;

b. mixing the first particle with a silane to cover SO to 100% of the first particle;

c. mixing the first particle in step (b) with a second particle, pretreated with an mq resin, until the first particle is about SO to 100% covered with the second particle and a combined particle is formed;

d. applying a wax, a wall-forming material, or a combination of the wax and the wall-forming material to the combined particle in (c) to form the microcapsule. The microcapsule of claim 1 , wherein the ratio of the first particle to second particle is about 1 to 6 of the first particle to about O.S to 2 of the second particle.

The microcapsule of claim 1, wherein the silane is octyltriethoxysilane.