CLIAMS:1. A composite sunscreen material comprising
d. at least one of an organic UV absorber;
e. at least one of an inorganic UV absorber; and
f. at least one stabilizer
wherein said atleast one inorganic UV absorber is formed in-situ from atleast one metal precursor; and
wherein the ratio of said atleast one organic UV absorber : said atleast one inorganic UV absorber is from about 0.05:1 to about 5:1.
2. The composite sunscreen material as claimed in claim 1 wherein said organic UV absorber is selected from cinnamates, salicylates, p-amino benzoic acids, p-amino benzoic esters, anthranilates, octocrylene, octisalateand combination thereof.
3. The composite sunscreen material as claimed in claim 1 or 2 wherein said organic UV absorber is present in an amount from 0.05 to 50% by weight of said composite sunscreen material.
4. The composite sunscreen material as claimed in any of the preceding claims wherein said inorganic UV absorber is selected from TiO2, ZnO, MgO, SiO2 and combinations thereof.
5. The composite sunscreen material as claimed in any of the preceding claims, wherein said inorganic UV absorber is present in an amount of from 0.01% to about 30% preferably from about 0.1 to about 5%.
6. The composite sunscreen material as claimed in any of the preceding claims, wherein said metal precursor is selected from Zn Acetate, TiCl2, ZnSO4, ZnNO3, Zn Stearate, Zn Acetylacetonate, Zn Laurate, Zn Palmitate, Zn Myristate, Mg Acetate, ZnCl2, ZnSO4, ZnNO3, Zn Stearate, Zn Acetylacetonate, Zn Laurate, Zn Palmitate, Zn Myristate and combinations thereof.
7. The composite sunscreen material as claimed in any of the preceding claims, wherein said metal precursor is present in an amount from 0.05% by weight to 50% by weight, preferably from 1% by weight to 25% by weight.
8. The composite sunscreen material as claimed in any of the preceding claims wherein said stabilizer is selected from fatty acids, long chain alcohols, long chain amines, surfactants, polyols, polysaccharides, polyacrylates, polyamides, polyesters, sugar molecules, sugar derivatives, and mixtures thereof.
9. The composite sunscreen material in any of the preceding claims wherein said stabilizer is preferably saturated fatty acids selected from C10-C20 fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, most preferably lauric acid, myristic acid, palmitic acid, stearic acid and combinations thereof.
10. The composite sunscreen material in any of the preceding claims wherein said stabilizer is present in an amount 0.5 to 50% by weight, preferably 1 to 30% by wt, most preferably from 4 to 15% by wt.
11. A cosmetic composition comprising the composite sunscreen material as claimed in claims 1 to 10.
12. The cosmetic composition as claimed in claim 11 wherein said composition can be formulated into cream, lotion, facewash, shampoo, bodywash, shower gel, facial cleanser, leave on gel, conditioner, body conditioner, shaving gel/cream, after shave cream/gel and sunscreen.
13. The cosmetic composition as claimed in claim 11 or claim 12 wherein said composition further comprises cosmetically acceptable excipients selected from preservative, structurant, active agent, humectants, conditioner, binders, emollient, emulsifiers, fragrance and emotives.
14. A process for preparation of a sunscreen composite material comprising the steps of
v) melting at least one stabilizer and solvent/medium and mixing it with at least one metal precursor at a temperature ranging from 75°C to 85°C to obtain a molten mixture;
vi) adding inorganic UV B absorber to the molten mixture of step (i) at 50 to 60°C to obtain a mixture;
vii) adding alkali solution drop-wise to the mixture of step (ii) at 50 to 60°C to generate composite mass; and
viii) drying the composite mass of step (iii) to obtain said composite sunscreen material.
15. The process for preparation of a sunscreen composite material as claimed in claim 14, wherein said alkali is selected from a group consisting of sodium hydroxide, potassium hydroxide, magnesium hydroxide, ammonium hydroxide, preferably sodium hydroxide and potassium hydroxide and combinations thereof.
16. The process for preparation of a sunscreen composite material as claimed in claim 14 or 15, wherein the amount of said alkali is present in amount from 0.2 to 15% by wt, preferably from 0.5 to 10% by wt.
17. The process for preparation of a sunscreen composite material, wherein said sunscreen composite material is as claimed in claim 1 to 10. ,TagSPECI:Field of the Invention
The present invention relates to cosmetic/personal care formulations, more specifically to sunscreen compositions

Background and the prior art
Protecting human skin against the harmful influence of UV solar radiation, harm which includes dangerous diseases as skin cancer is an acute problem. Conventionally, skin is considered a multi-layered medium. The outermost layer, called stratum corneum (or horny layer), serves as a natural barrier for deeper skin layers with living cells. From the optical viewpoint, its property is, in particular, to prevent penetration of UV radiation into the epidermis and dermis. In order to strengthen its protective functions, a variety of sunscreens containing chemical (absorbing) UV filters have been developed. Effective sunscreens are those, which absorb strongly in the appropriate UV region, display good photostability and minor spectral modification upon absorption of the UV radiation and thermally dissipate the absorbed energy harmlessly to the other region. The most effective deactivation routes are internal conversion, vibrational relaxation and photoisomerisation.

To increase the amount of backscattered UV radiation and avoid allergic reaction of individuals, chemical components are partially replaced nowadays by so-called ‘physical components’ e.g. titanium dioxide (TiO2) or zinc oxide (ZnO). In addition to absorption (within the definite UV spectral region) they have pronounced scattering properties and decrease the amount of transmitted light through absorption and scattering.

However organic UV absorbers have the potential to relatively long-lived triplet states, which can stimulate single oxygen production, effect transformations in biological substrates, such as thymine or in constituents of sunscreen formulations. Whereas, inorganic sunscreens such as titanium dioxide and zinc oxides are known to degrade the organic material and produce hydroxyl radicals, although this is somewhat overcome by surface treatment. Physical sunscreens, particularly those containing zinc oxide, are sometimes preferable over chemical sunscreens because they are known to be UV stable and exhibit no known adverse effects associated with long-term contact with the skin. The major limiting factor in the use of conventional physical UV screening agents is the tendency for sunscreen formulations including such physical UV screening agents to appear white on the skin due to excessive scattering of light from the particles contained within such sunscreen formulations. This results in low cosmetic acceptability and marketability of sunscreen formulations which rely on conventional physical UV screening agents alone.

In recent years, there is a trend in the cosmetic sunscreen industry to develop and use sunscreen formulations containing zinc oxide of smaller and smaller particle size to reduce the whiteness and improve the transparency of sunscreen formulations. Many inventions relating to the preparation of small metal oxide nanoparticles have been reported. In addition to the formation of the metal oxide, a vital aspect of most recent developments is the stabilization of the particles against precipitation and/or aggregation, either during or after formation. In the case of insufficient stabilization, random coagulation of particles will occur, resulting in decreased transparency of films and coatings formed from them. It would appear that for best optical performance particles should be small but effective UV absorber and well-dispersed in the cosmetic medium.

WO2009101016 discloses particles P, which can be obtained by the reaction of inorganic nanoparticles N with organic molecules M, which contain functional groups Z, wherein: a) said inorganic nanoparticles N are provided in a dispersion D, through the reaction of compounds V in a solvent, and b), immediately after step (a), said organic molecules M are added to said dispersion D. Furthermore, the invention discloses liquid and solid formulations, containing particles P, methods for the production of particles P, method for suppressing the photocatalytic activity of inorganic nanoparticles N, methods for stabilizing UV absorbers, methods for stabilizing polymers against the effect of light, radicals, or heat, and the use of particles in cosmetic applications. WO2009101016 mentions that UV absorber preferably organic molecules are used as M and lists a wide range of UV organic absorbers such as cinnamate, salicylates, p-amino benzoic acid, p-amino benzoic esters, anthranilates, etc. According to WO’016, the inorganic nanoparticles may be metal or semi-metal oxides, metal or semi-metal sulfides, selenides, nitrides, sulfates or carbonates. Very particular preference is as metal oxides ZnO, TiO2, ZrO2, CeO2, Ce2O3, SnO2, SnO, Al2O3, SiO2, and Fe2O3. The process described in WO2009101016 is a multistep process and the material used is not cosmetic friendly and requires preformed nanoparticles being added to the UV absorbers.

US2004197359 discloses fine particles for cosmetics which are excellent in smoothness upon application to the skin or hydrophilic nature and powdery texture. These modified inorganic fine particles comprise, on the surface of inorganic fine particles, a polymer layer (I) prepared by plasma-polymerizing one of monomers selected from among fluorinated monomers, silicone-based monomers, aromatic monomers and alicyclic monomers; a polymer layer (II) obtained by plasma graft-polymerizing a monomer having a functional group; or a polymer layer (III) prepared by plasma graft-polymerizing a monomer having a functional group modified with a functional organic compound(s). The functional organic compound(s) are one or more members selected from among dyes, UV absorbers and skin-chapping inhibitors. US2004197359 discloses the preparation of inorganic fine particles by plasma graft polymerization which is a multistep process.

CN102675568 discloses a preparation method for an organic-inorganic hybrid skin-friendly efficient sunscreen product. The method comprises the following steps of: performing macromolecular self-assembly on a synthesized amphiphilictriblock polymer PEO-b-PDMA-b-PS to obtain polymer nanoparticles with uniform particle size distribution; and performing in-situ reaction on a deposited titanium precursor on the nanoparticles, drying in-situ reaction products to obtain organic-inorganic hybrid titanium dioxide nanoparticles, and further calcining the organic-inorganic hybrid titanium dioxide nanoparticles to obtain titanium dioxide nanoparticles. The method is characterized in that the skin-friendly titanium dioxide nanoparticles with high sunscreen performance can be prepared, are harmless to skin, have good ultraviolet resistant effects, and have high dispersion performance in water; the particle sizes of the ultraviolet resistant nanoparticles can be randomly controlled. It describes the preparation of inorganic fine particles by plasma graft polymerization which is a multistep process.

KR20090056658 discloses an organic-inorganic complex powder of which an organic UV protector and metal oxide are mixed and dipped in a mesoporous silica molecule. This provides increase UV protection effect and the protection area of UV-A and UV-B, and improves stability. An organic-inorganic complex is made by dipping a metal oxide and organic UV protector in a pore of mesoporous silica molecule. The metal oxide is an UV-B protection component of cerium oxide(CeO2) or titanium oxide(TiO2) and UV-A protection component of ferric oxide(Fe2O3) or zinc oxide(ZnO). The organic UV protector is a cinnamate, salicylate, benzophenone, triazine or the triazone based UV protector. The silica molecule is a porous silica having 200~900m2/g of specific surface area, 0.3-1.5cc/g of pore volume (Vp), and 5-15nm range of pore size. KR20090056658 further discloses a method for manufacturing the mesoporous organic-inorganic complex powder comprises: a step of dipping the mesoporous silica molecule in solution in which the cerium chloride or titanium alkoxide is resolved to produce a metal oxide-dipped mesoporous complex powder which protects the UV-B; a step of dipping the produced powder in solution in which a ferric chloride or zinc chloride is resolved to produce a metal oxide-dipped mesoporous complex powder which protects the UV-A; and a step of mixing 1-26 weight% of complex powder and organic UV protector. KR20090056658 thus describes a method of preparing organic-inorganic complex in a pore of mesoporous silica molecule. These are not cosmetically relevant and the preparation process is multistep process.

US5733531 discloses a topical sunblock agent for shielding skin from ultraviolet radiation, and a composite sunblocking component thereof. The sunblocking component of the formula includes an effective amount of a plurality of particles having diameters in the range of about 0.01-100 microns, each particle including a matrix and a UV-attenuating compound incorporated into the matrix. US5733531 mentions that the invention encompasses first and second UV-attenuating compounds that are together encapsulated in a matrix. The first and second UV-attenuating compounds may be organic or inorganic sunscreen agents. Organic agents include but are not limited to chemical sunscreens such as benzophenones, PABA and PABA derivatives, cinnamates, salicylates, anthranilates such as menthylanthranilate, 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, 2-phenyl benzimidazole-5-sulfonic acid, digalloyltrioleate, 3-(4-methyl benzylidene) camphor, 4-isopropyl dibenzoyl methane, butyl methoxydibenzoylmethane, 2-ethyl-2-cyano-3,3'-diphenyl acrylate. Inorganic agents include but are not limited to kaolin, talc, titanium dioxide, and zinc oxide. US5733531 discloses the preparation of a typical sunblocking agent for shielding skin from ultraviolet radiation where both organic and inorganic molecules are encapsulate in matrix. US5733531 does not disclose anything related to stabilization of the organic sunscreen.

US 20120263769 provides an ultraviolet absorber-including clay mineral, which allows an ultraviolet absorber to be blended, as a powder component, into cosmetic preparations, can effectively absorb a wide range of ultraviolet light, and has excellent inclusion amount and inclusion strength; and cosmetics containing the same. The ultraviolet absorber-including clay mineral is characterized in that a polybase and an anionic ultraviolet absorber are intercalated between the layers of a water-swellable clay mineral. The polybase is preferably a polymer having a nitrogen-containing group that can become a cation. The anionic ultraviolet absorber is preferably one or more selected from 2-phenylbenzimidazole-5-sulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, and their sodium salts. However the process is a multistep process and hence time consuming while yield of the final product is less.

Object of the Invention

It is an object of the invention to provide a composite material which enhances the photostability of an organic sunscreen.
It is another object of the invention to provide a composite material which when added to sunscreen formulations enhances the photostability of organic sunscreens in the formulation.
It is yet another object of the invention to provide a composite material which has a combination of both UVA absorber and UV B absorber and provides a broad and better sun protection.
It is a further object of the invention to provide a process of synthesis of a composite material by a “solvent free”, single step process.
It is still further the objective of the present invention to provide a high yielding process for preparation of a composite material comprising both organic and inorganic UV absorber.

Summary of the Invention
According to one aspect of the present invention there is provided a composite sunscreen material comprising
a. at least one of an organic UV absorber;
b. at least one of an inorganic UV absorber; and
c. at least one stabilizer
wherein said atleast one inorganic UV absorber is formed in-situ from atleast one metal precursor; and
wherein the ratio of said atleast one organic UV absorber : said atleast one inorganic UV absorber is from about 0.05:1 to about 5:1.

According to another aspect of the present invention there is provided a cosmetic composition comprising the composite sunscreen material of the present invention.

According to a further aspect of the present invention there is provided a process for preparation of a sunscreen composite material comprising the steps of
i) melting at least one stabilizer and solvent/medium and mixing it with at least one metal precursor at a temperature ranging from 75°C to 85°C to obtain a molten mixture;
ii) adding inorganic UV B absorber to the molten mixture of step (i) at 50 to 60°C to obtain a mixture;
iii) adding alkali solution drop-wise to the mixture of step (ii) at 50 to 60°C to generate composite mass; and
iv) drying the composite mass of step (iii) to obtain said composite sunscreen material.

Brief Description of the Invention
Figure 1 illustrates the SEM image of the composite material of the present invention. While figure 1A illustrates SEM image of composite material, and figure 1B illustrates the SEM image of the composite material with higher magnification.
Figure 2 illustrates the degradation when OMC was irradiated with lamp which mimics sunlight for different time interval.
Figure 3 illustrates the degradation when the composite material of the present invention was irradiated with lamp which mimics sunlight for different time interval.
Figure 4 illustrates the UV-vis spectra of the degradation of the composite of the present invention, a physical mixture of organic and inorganic sunscreen and only OMC.

Detailed Description of the Invention

The present invention relates to a composite material which can be used in the personal care product formulation e.g. in both rinse-off and leave on products for skin care and hair care category to provide better sun protection covering both UVA and UVB region of solar spectrum. The composite material of the present invention enhances the phtostability of organic sunscreens in cosmetic formulations thereby providing enhanced sun protection. This provides a broad range UV protection to the hair and skin when delivered through a formulation.

The composite material of the present invention comprises:
a. at least one of an organic UV absorber;
b. at least one of an inorganic UV absorber; and
c. at least one stabilizer
wherein said atleast one inorganic UV absorber is formed in-situ from atleast one metal precursor; and
wherein the ratio of said atleast one organic UV absorber : said atleast one inorganic UV absorber is from about 0.05:1 to about 5:1, preferably from about 0.1:1 to 0.5:1.0.

The present invention also discloses a process of preparation of the composite material comprising at least one organic, at least one inorganic UV absorber and at least one stabilizer.

The inorganic UV absorber of the present invention may be selected from but not limited to TiO2, ZnO, MgO, SiO2 and combinations thereof. The inorganic UV absorber may be present in an amount of from about 0.01% to about 30% preferably from about 0.1 to about 5%.

The organic UV absorber of the present invention may be selected from a group comprising but not limited to cinnamates, salicylates, p-amino benzoic acids, p-amino benzoic esters, anthranilates, octocrylene, octisalateand combination thereof. The organic sunscreen may be present in an amount of from about 0.05 to about 50%.

The metal precursor of the present invention may be selected from a group comprising but not limited to metal salts such as Zn Acetate, TiCl2, ZnSO4, ZnNO3, Zn Stearate, Zn Acetylacetonate, Zn Laurate, Zn Palmitate, Zn Myristate, Mg Acetate, ZnCl2, ZnSO4, ZnNO3, Zn Stearate, Zn Acetylacetonate, Zn Laurate, Zn Palmitate, Zn Myristate and combinations thereof. These precursors of micronized particles may be present in the composition of the present invention in the range of from about 0.05% by weight to about 50% by weight, preferably from about 1% by weight to about 25% by weight.

The stabilizer of the present invention stabilizes the composite material of the present invention. It may be selected from a group comprising but not limited to fatty acids, long chain alcohols, long chain amines, surfactants, polyols, polysaccharides, polyacrylates, polyamides, polyesters, sugar molecules, sugar derivatives, and mixtures thereof. The stabilizer may be present in an amount 0.5 to 50 % by weight. Stabilizers preferably are saturated or unsaturated fatty acids. selected from C10-C20 fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and the like. Most preferable saturated/unsaturated fatty acids for the preparation of composite material in the present invention are lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, erucic acid, elaidic acid, myristoleic acid, palmitoleic acid, and combinations thereof. The amount of the stabilizers ranges from 1 to 30% by wt, preferably from 4 to 15% by wt.

It has also been observed that the composite material of the present invention provides strong anti-microbial and anti-acne activity. The active material, i.e., the composite of the present invention, provides colour protection to the hair when delivered through a rinse-off or leave on product.

The composite material according to the present invention comprises organic and inorganic sunscreens in the ratio 0.05:1 to 5:1

The composite material is an off white colored waxy solid. The size of the composite material is about 5µm to 250µm. The SEM image of the composite material is illustrated in Figure 1(a) and 1(b). The present inventors have found that the composite material gets deposited on the skin even through wash-off products.
The composite material when used in the product imparts SPF value in the range of 5 to 30.

The process for preparing the composite material of the present invention comprises the steps of:
i) melting at least one stabilizer and solvent/medium and mixing it with at least one metal precursor at a temperature ranging from 75°C to 85°C to obtain a molten mixture;
ii) add inorganic UV B absorber to the molten mixture of step (i) at 50 to 60°C to obtain a mixture;
iii) adding alkali solution drop-wise to the mixture of step (ii) at 50 to 60°C to generate composite mass; and
iv) drying the composite mass of step (iii) to obtain the composite material of the present invention.
The obtained composite material can be stored at room temperature for use as active ingredient in different personal care formulations.

Alkali solution as may be added during the process of preparation of the composite material of the present invention may be selected from a group comprising but not limited to sodium hydroxide, potassium hydroxide, magnesium hydroxide, ammonium hydroxide etc. The preferable alkalis for the preparation of composite material of the present invention are sodium hydroxide and potassium hydroxide and combinations thereof. The amount of the alkali ranges from 0.2 to 15% by wt, preferably from 0.5 to 10% by wt. The precursor to alkali ratio is in the range from 1:0.2 to about 1:2. It had been observed that if the ratio is not maintained then the composite material destabilizes due to presence of extra alkali in the system.

In a specific embodiment of the present invention the process for preparing the composite material of the present invention comprises the steps of:
a) melting of fatty acid along with propylene glycol and mineral oil at a temperature around 50 to 65°C;
b) mixing of metal precursor at a temperature ranging from 75°C to 85°C;
c) addition of UV B absorber to the mixture obtained from step (ii) at 50 to 60°C under continuous stirring condition;
d) addition of alkali solution drop-wise to the mixture obtained from Step (iii) at 50 to 60°C under continuous stirring condition for about 30 minutes to generate the composite material which is a single phasic semi-solid material;
e) drying on a hot air oven at 60°C for 3-4 hours to obtain the composite material of the present invention.

The invention further discloses cosmetic and personal care formulations as may be prepared using the composite material. These cosmetic /personal care formulationsmay further comprise cosmetically acceptable excipients selected from preservative, structurant, active agent, humectants, conditioner, binders, emollient, emulsifiers, fragrance and emotives.

Preservatives according to the present invention include BHT, EDTA, phenoxy ethanol. Preservatives can be present in the range of from about 0.01% by weight to about 0.1% by weight, preferably from about 0.02% by weight to about 0.05% by weight.

Active agent that may be used in the present invention include lipophilic or hydrophilic active ingredients. As used herein an 'active agent is meant to comprise a compound that has a cosmetic or therapeutic effect on the skin, hair, or nails, e.g., lightening agents, darkening agents such as self-tanning agents, anti-acne agents, shine control agents, anti-microbial agents, anti-inflammatory agents, anti-aging agents, in particular anti-wrinkle agents, anti-mycotic agents, anti-parasite agents, external analgesics, sunscreens, photoprotectors, antioxidants, keratolyticagents, detergents/surfactants, moisturizers, nutrients, vitamins, energy enhancers, anti-perspiration agents, astringents, deodorants, hair removers, firming agents, anti-callous agents, and agents for hair, nail, and/or skin conditioning. Active ingredients may be added in the range of from about 0.001% by weight to about 10% by weight, preferably from about 0.1% by weight to about 5% by weight.

The conditioners as used herein are selected from but not limited to linear and/or branched chain Silicones and/or ethoxylatedamodimeticones, and or non-ethoxylatedamodimethocones and/or linear chain polyquarterniumHydroxy ethyl cellulose and/or branched hydrophobically modified polyquarternium hydroxyl ethyl cellulose.

The humectant in accordance with the present invention is selected from group comprising polyhydric alcohols, water soluble alkoxylated nonionic polymers, and mixtures thereof such as glycerin, sorbitol, propylene glycol, butylene glycol, hexylene glycol, ethoxylated glucose, 1, 2-hexane diol, hexanetriol, dipropylene glycol, erythritol, trehalose, diglycerin, xylitol, maltitol, maltose, glucose, fructose, sodium chondroitin sultate, sodium hyaluronate, sodium adenosin phosphate, sodium lactate, pyrrolidone carbonate, glucosamine, cyclodextrin, and mixtures thereof. The humectants herein are preferably used at levels by weight of the composition of from about 0.1% to about 20%, more preferably from about 0.5% to about 15%, and more preferably from about 1% to about 10%.

The structurant in accordance with the present invention is selected from group comprising biopolymers such as starch, modified starch, guar gum, tamarind kernel polysaccharide or psyllium husk; inorganics particles such as talc, calcite, clays, alumino silicate, calcium silicate, calcium alumino silicate, boro silicate, boroalumino silicate, alumina, sodium phosphate, aluminophospho silicate or silica and combinations thereof. The structurant is present in 2 to 35%, preferably 4 to 25%, more preferably 5 to 15% by weight of the composition.

Binders according to the present invention includes high molecular weight PEGs like PEG 6000, PEG 8000, poly acrylates, high molecular weight poly-ox, silicates, fatty alcohols, lanolin, sugars, tallow alcohol ethoxylates, and mixtures thereof. Other plastic binders are identified in the published literature, such as J. Amer. Oil Chem. Soc. 1982, 59, 442. Binders can be present in amounts 0.2 to 4 % by weight in the final product.

Emollients are substance which soften or improve the elasticity, appearance, and youthfulness of the skin (stratum corneum) by increasing its water content, and keeps it soft by retarding the decrease of its water content. Emollients that may be used in the present invention include but are not limited to silicone oils and modifications thereof such as linear and cyclic polydimethylsiloxanes; polyols such as glycerol, sorbitol; amino, alkyl, alkylaryl, and aryl silicone oils; fats and oils including natural fats and oils such as jojoba, soybean, sunflower, rice bran, avocado, almond, olive, sesame, persic, castor, coconut, mink oils; cacao fat; beef tallow, lard; hardened oils obtained by hydrogenating the aforementioned oils; and synthetic mono, di and triglycerides such as myristic acid glyceride and 2-ethylhexanoic acid glyceride; waxes such as carnauba, spermaceti, beeswax, lanolin, and derivatives thereof; hydrophobic plant extracts; hydrocarbons such as liquid paraffin, petrolatum, microcrystalline wax, ceresin, squalene, pristan and mineral oil; higher fatty acids such as lauric, myristic, palmitic, stearic, behenic, oleic, linoleic, linolenic, lanolic, isostearic, arachidonic and poly unsaturated fatty acids (PUFA); higher alcohols such as lauryl, cetyl, stearyl, oleyl, behenyl, cholesterol and 2-hexydecanol alcohol; esters such as cetyloctanoate, myristyl lactate, cetyl lactate, isopropyl myristate, myristylmyristate, isopropyl palmitate, isopropyl adipate, butyl stearate, decyloleate, cholesterol isostearate, glycerol monostearate, glycerol distearate, glycerol tristearate, alkyl lactate, alkyl citrate and alkyl tartrate; essential oils and extracts thereof such as mentha, jasmine, camphor, white cedar, bitter orange peel, ryu, turpentine, cinnamon, bergamot, citrus unshiu, calamus, pine, lavender, bay, clove, hiba, eucalyptus, lemon, starflower, thyme, peppermint, rose, sage, sesame, ginger, basil, juniper, lemon grass, rosemary, rosewood, avocado, grape, grapeseed, myrrh, cucumber, watercress, calendula, elder flower, geranium, linden blossom, amaranth, seaweed, ginko, ginseng, carrot, guarana, tea tree, jojoba, comfrey, oatmeal, cocoa, neroli, vanilla, green tea, penny royal, aloe vera, menthol, cineole, eugenol, citral, citronelle, borneol, linalool, geraniol, evening primrose, camphor, thymol, spirantol, penene, limonene and terpenoid oils; and mixtures of any of the foregoing components, and the like. Advantageously emollients may be used from about 0.5 to about 3 % by weight in the final product.

Further the composition of the present invention may comprise 0.5 to 1.5 % by weight of fragrance, 0.005 to 0.5 % by weight of emotives.

Further the composition of the present invention may comprise secondary emulsifiers. Secondary emulsifiers that may be added to compositions of the present invention can be of the W/O type or O/W type. The addition of an emulsifier allows the incorporation of hydrophilic components or agents into the wax phase. Preferred are non-ionic emulsifiers which typically have good skin compatibility. Non-ionic emulsifiers of the present invention may be selected from group comprising addition products of 2 to 50 moles of ethylene oxide and/or 0 to 20 moles propylene oxide to linear fatty alcohols having 8 to 40 C-atoms, to fatty acids with 12 to 40 C-atoms and to alkylphenols with 8 to 15 C-atoms in the alkyl rest; C12-18-fatty acid mono- and -diesters of addition products of 1 to 50 moles of ethylene oxide and glycerine; glycerine mono- and -diesters and sorbitan mono- and -diesters of saturated and unsaturated fatty acids with 6 to 22 C-atoms and their ethylene oxide addition products; alkyl mono- and -oligoglycosides with 8 to 22 C-atoms in the alkyl rest and their ethoxylated analogs; addition products of 7 to 60 moles of ethylene oxide to castor oil and/or hardened castor oil; Polyol- and in particular polyglycerine esters, such as e.g. polyol poly-12-hydroxystearate, polyglycerinepolyricinoleate, polyglycerinediisostearate or polyglycerinedimerate. Also applicable are mixtures of compounds of several of these substance classes; addition products of 2 to 15 moles of ethylene oxide to castor oil and/or hardened castor oil; partial esters derived from linear, branch chained, unsaturated or saturated C6-C22-fatty acids, ricinoleic acid as well as 12-hydroxystearic acid and glycerine, polyglycerine, pentaerythrite, dipentaerythrit, sugar alcohols (e.g. sorbitol), alkylglucosides (e.g. methylglucoside, butylglucoside, laurylglucoside), as well as polyglucosides (e.g. cellulose), or mixed esters such as e.g. glyceryl stearate/citrate and glyceryl stearate/lactate;Wool wax alcohols; Polysiloxane-polyalkyl-polyether-copolymers and derivatives thereof; Mixed esters from pentaerythrite, fatty acids, citric acid and fatty alcohols and/or mixed esters of fatty acids with 6 to 22 C-atoms with methylglucose and polyols, respectively glycerine or polyglycerine; Polyalkylene glycols. Emulsifiers can be present in amounts 0.5 to 5 % by weight in the final product.

The personal care formulations of the present invention can be in the form of a cream, lotion, facewash, shampoo, bodywash, shower gel, facial cleanser, leave on gel, conditioner, body conditioner, shaving gel/cream, after shave cream/gel, sunscreen, etc.

The present invention is now being illustrated by way of non-limiting examples.

Example 1:
It was noted that when the ratio of organic UV sunscreen to inorganic UV sunscreen was maintained within the specified ratio of 0.05:1 to 5:1 as shown in Table 1, the desired composite material was formed.
Table 1

Process:

Step 1: Melting of fatty acid along with propylene glycol and mineral oil at 75°C for 10 minutes
Step 2: Mixing of metal precursor (zinc acetate is the precursor for ZnO, an UV A absorber) at a temperature ranging from 75°C to 85°C for about 10-15 minutes.
Step 3: Addition of OMC (UV B absorber) to the mixture obtained from step 2 at 75°C and mixing for 5 minutes.
Step 4: Addition of alkali solution (48% sodium hydroxide solution) drop-wise to the mixture obtained from step 3 at 75°C under continuous stirring condition for 30 minutes to generate the composite material containing both UV A and UV B absorber.

Observations: The material turned to single phasic semi-solid material which was dried on a hot air oven at 60°C for 3-4 hours and stored at room temperature to use as active ingredient in different personal care formulations.
The ratio of organic and inorganic UV absorber above is 2.9:1, 3.02:1, 2.62:1
The amount of zinc oxide generated was calculated based on the following chemical reactions
Zn-acetate + 2NaOH Zn(OH)2 ZnO + H2O
It can be noted that 1% Zinc acetate generates 0.435% of zinc oxide

Example 2
Composite material was prepared with components as shown in Table 2; however the process for preparing the composite is as mentioned below.
Table 2

Process:
Step 1: Melting of fatty acid along with propylene glycol and mineral oil at 75°C for 10 minutes
Step 3: Addition of alkali solution (48% sodium hydroxide solution) drop-wise to the mixture obtained from Step 3 at 75°C under continuous stirring condition for 30 minutes
Step 2: Mixing of metal precursor (zinc acetate is the precursor for ZnO, an UV A absorber) at a temperature ranging from 75°C to 85°C for about 10-15 minutes.
Step 4: Addition of OMC (UV B absorber) to the mixture obtained from step 2 at 75°C and mixing for 5 minutes.

Observation: The composite material was not formed. The materials were separated in oil and water phase and could not be processed further. From the above it is evident that when the alkali is added after the metal precursor and OMC, the composite material is not formed.

Example 3: Facewash Formulations containing the Composite Material
A facewash formulation was prepared in accordance with the present invention with components as shown in Table 3
Table 3

Process:
Step 1: Melting the fatty acid/acids at 75°C for 5 minutes
Step 2: Addition of active ingredient (obtained from example 1) to the mixture obtained from step 1 and mixing it for 15 minutes at 75°C.
Step 3: Addition of ethyleneglycoldistearate and cocamide DEA to the mixture obtained from step 2 and mixing at 75°C for 15 minutes
Step 4: Addition of butylatedhydroxy toluene at 75°C and mixing for 2 minutes obtained from step 3
Step 5: Addition of surfactants to the mixture obtained from step 4 at 70°C and homogenized at 5000 rpm for 10 minutes
Step 6: Addition of steareth 20 to the mixture obtained from step 5 at 70°C and mixing for 5 minutes
Step 7: Addition of tetrasodium EDTA to the mixture obtained from step 6 at 70°C and mixing for 1 minute
Step 8: Addition of DI water drop-wise to the mixture obtained from step 7 at 60°C and the concoction was homogenized for 10 minutes at 5000 rpm.
Step 9: Addition of phenoxyethanol along with fragrance to the mixture obtained from step 8 at 40°C and mixing for 2 minutes.
Step 10: Collecting the facewash in a container and storing at room temperature.
The formulation obtained above was stable for more than six months at room temperature band the SPF of the formulation is 10.

Example 4: Bodywash Formulations containing the Composite Material
A bodywash formulation was prepared in accordance with the present invention with components as shown in Table 4
Table 4

Process:
Step 1: Melting the fatty acid/acids at 75°C for 5 minutes
Step 2: Addition of active ingredient (obtained from example 1) to the mixture obtained from step 1 and mixing it for 15 minutes at 75°C.
Step 3: Addition of ethyleneglycoldistearate and cocamide DEA to the mixture obtained from step 2 and mixing at 75°C for 15 minutes
Step 4: Addition of butylatedhydroxy toluene at 75°C and mixing for 2 minutes obtained from step 3
Step 5: Addition of surfactants to the mixture obtained from step 4 at 70°C and homogenized at 5000 rpm for 10 minutes
Step 6: Addition of steareth 20 to the mixture obtained from step 5 at 70°C and mixing for 5 minutes
Step 7: Addition of tetrasodium EDTA to the mixture obtained from step 6 at 70°C and mixing for 1 minute
Step 8: Addition of DI water drop-wise to the mixture obtained from step 7 at 60°C and the concoction was homogenized for 10 minutes at 5000 rpm
Step 9: Addition of phenoxyethanol along with fragrance to the mixture obtained from step 8 at 40°C and mixing for 2 minutes
Step 10: Collecting the bodywash in a container and storing at room temperature

The formulation obtained above was stable for more than six months at room temperature and the SPF of the formulation is 5.

Example 5 : Body Lotion Formulation containing the Composite Material
A Body Lotion formulation was prepared in accordance with the present invention with components as shown in Table 5
Table 5

Process:
Step 1: Melting of microcrystalline wax along with PEG-7 hydrogenated castor oil, hydrogenated poly-isobutane and caprylic/capric triglyceride at 65°C
Step 2: Addition of active ingredient (obtained from example 1) to the mixture obtained from step 1 and mixing it for 15 minutes at 65°C.
Step 3: Addition of p-Dimethylaminobenzoic acid 2-ethylhexyl ester to the mixture obtained from step 2 and mixing it for 5 minutes at 65°C.
Step 4: Addition of propylene glycol and glycerine to the mixture obtained from step 3 and mixing at 65°C for 15 minutes
Step 5: Addition of DI water drop-wise to the mixture obtained from step 4 at 65°C and the concoction was homogenized for 20 minutes at 5000 rpm
Step 6: Addition of phenoxyethanol along with fragrance to the mixture obtained from step 5 at 40°C and mixing for 2 minutes
Step 7: Collecting the body lotion in a container and storing at room temperature.
The formulation obtained above was stable for more than six months at room temperature and the SPF of the formulation is 7.

Example 6: Skin Cream Formulation containing the Composite Material
A Skin Cream formulation was prepared in accordance with the present invention with components as shown in Table 6
Table 6

Process:
Step 1: Melting of microcrystalline wax along with mineral oil and caprylic/capric triglyceride at 65°C
Step 2: Addition of active ingredient (obtained from example 1) to the mixture obtained from step 1 and mixing it for 15 minutes at 65°C
Step 3: Addition of PEG-7 hydrogenated castor oil, hydrogenated poly-isobutane and dimethicone to the mixture obtained from step 2 mixing it for 15 minutes at 65°C
Step 4: Additionof glyceryl stearate and myristylmyristate to the mixture obtained from step 3 mixing it for 20 minutes at 65°C
Step 5: Addition of p-Dimethylaminobenzoic acid 2-ethylhexyl ester to the mixture obtained from step 4 and mixing it for 5 minutes at 65°C.
Step 4: Addition of propylene glycol and glycerine to the mixture obtained from step 3 and mixing at 65°C for 15 minutes
Step 5: Addition of DI water drop-wise to the mixture obtained from step 4 at 65°C and the concoction was homogenized for 20 minutes at 5000 rpm
Step 6: Addition of phenoxyethanol along with fragrance to the mixture obtained from step 5 at 40°C and mixing for 2 minutes
Step 7: Collecting the skin cream in a container and storing at room temperature.
The formulation obtained above was stable for more than six months at room temperature and the SPF of the formulation is 6.

Example 7
The photo stability of organic sunscreen (OMC), a physical mixture of organic sunscreen (OMC) and inorganic sunscreen (ZnO) has been compared with the composite of the present invention (having OMC and ZnO).

Experimental Details:
Experiment 1: Organic sunscreen – OMC was taken in a small beaker. It was irradiated with lamp which mimics the sunlight. Samples were collected at different time interval and UV-vis spectra.
Experiment 2: Physical mixture of organic sunscreen (OMC) and inorganic sunscreen (ZnO) was prepared by mixing them in a beaker. It was irradiated with lamp which mimics the sunlight. Samples were collected at different time interval and UV-vis spectra.
Experiment 3: The composite of the present invention was prepared by the following steps.
a) melting of fatty acid along with propylene glycol and mineral oil at a temperature around 50 to 65°C;
b) mixing of metal precursor at a temperature ranging from 75°C to 85°C;
c) addition of UV B absorber to the mixture obtained from step (ii) at 50 to60°C under continuous stirring condition;
d) addition of alkali solution drop-wise to the mixture obtained from Step (iii) at 50 to 60°Cunder continuous stirring condition for about 30 minutes to generate the composite material which is a single phasic semi-solid material;
e) drying on a hot air oven at 60°C for 3-4 hours to obtain the composite material of the present invention.
f) the composite material of the present invention was irradiated with lamp which mimics the sunlight. Samples were collected at different time interval and UV-vis spectra.

Observations:
It was observed that whereas OMC (organic UV sunscreen) alone degrades within a period of 1 hour, the composite material of the present invention comprising an equal amount of organic UV sunscreen the UV protection obtained after 7 hours remains photostable when irradiated with sun light. Figure 2 shows that OMC starts degrading and turns from colorless to light yellow upon irradiation with lamp that mimics sunlight. On the other hand the composite material when irradiated with lamp which mimics sunlight was found to be stable and does not change colour while irradiated for different time interval as evident from Figure 3. The composite is white in colour. As can be noted it remains white throughout. This essentially means that the product is stable all through.

It is known that organic sunscreens such as OMC are not stable over time and loose their potency. Figure 4 also shows that after irradiating with sunlight for 1 hour, only OMC degrades as reflected by the decrease in absorbance value. On the other hand in the physical mixture of OMC and ZnO the absorbance value decreases but to a lesser extent compare to only OMC. The composite material shows maximum absorbance among all the three systems.

Example 8
Experiments were performed varying the combining ratio of the organic and inorganic sunscreen.
Table 7

The ratio of organic and inorganic UV absorber is 5.7:1

Process:
Step 1: Melting of fatty acid along with propylene glycol and mineral oil at 75°C for 10 minutes
Step 2: Mixing of metal precursor (zinc acetate is the precursor for ZnO, an UV A absorber) at a temperature ranging from 75°C to 85°C for about 10-15 minutes.
Step 3: Addition of OMC (UV B absorber) to the mixture obtained from step 2 at 75°C and mixing for 5 minutes.
Step 4: Addition of alkali solution (48% sodium hydroxide solution) drop-wise to the mixture obtained from Step 3 at 75°C under continuous stirring condition for 30 minutes to generate the composite material containing both UV A and UV B absorber.
Observations: The composite material was formed but was unstable. The materials were separated in oil and water phase.
Example 9
Experiments were performed varying the combining ratio of the organic and inorganic sunscreen.

Table 8

The ratio of organic and inorganic UV absorber is 0.03:1

Process:
Step 1: Melting of fatty acid along with propylene glycol and mineral oil at 75°C for 10 minutes
Step 2: Mixing of metal precursor (zinc acetate is the precursor for ZnO, an UV A absorber) at a temperature ranging from 75°C to 85°C for about 10-15 minutes.
Step 3: Addition of OMC (UV B absorber) to the mixture obtained from step 2 at 75°C and mixing for 5 minutes.
Step 4: Addition of alkali solution (48% sodium hydroxide solution) drop-wise to the mixture obtained from Step 3 at 75°C under continuous stirring condition for 30 minutes to generate the composite material containing both UV A and UV B absorber.
Observations: The composite material was formed but was unstable. The materials were separated in oil and water phase.