SKIN TREATMENT COMPOSITION

Abstract: A skin treatment composition which inhibits generation of or deactivates the free radicals in the skin which free radicals may form upon exposure of the skin to ultraviolet radiation or air pollutants, in the form of an ointment, cream, lotion, or liquid comprising water, at least one humectant, at least one thickener, at least one preservative and from about 0.01 to about 5% by weight of the composition of at least one free radical inhibitor or deactivator which is 6-hydroxy-2,5,7,8-tetramethylchroman-­ 2-carboxylic acid, 6-ethoxy-1,2-dihydro-2,2,4-trimethyl­ quinoline or mixtures thereof. The discoloration or oxidation of the acid is inhibited by a stabilizer therefor which is monoethanolamine sulfite or sodium bisulfite, which is employed in a molar ratio to said acid of within the range of from about 10:1 to about 0.5:1.

Description: The present invention relates to improved skin treatment compositions including cosmetics which have improved skin penetrating properties and inhibit generation of free radicals in the skin which may form upon exposure to ultraviolet radiation or air pollutants, to a method for controlling free radical formation on the skin by applying such skin treatment composition to the skin, and to a method of stabilizing Vitamin E-like preparations for use in the above compositions. Free radical formation plays a destructive role in biological processes of living things, Pryor, W.A., Free Radicals in Biological Systems, Scientific American, Vol. 223, No. 2, pp. 70-83, August 1970, Pryor, W. A., Free Radical Pathology, Chemical and Engineering News, June 7, 1971, p. 34ff, and Harman, D., The Aging Process, Proc. Natl. Acad. Sci., U.S.A., Vol. 78, No. 11, pp 7124-7128, Nov. 1981. It has been found that exposure of human skin to ultraviolet radiation and air pollutants could result in the generation of free radicals in the exposed skin which could lead to premature aging of such skin. Accordingly, a topical skin treatment composition which could inhibit generation or deactivation of free radicals in the skin resulting from exposure to ultraviolet radiation and/or air pollutants would indeed be most a welcome addition to the skin treatment field. Vitamin E (alpha-tocopherol) which has the structure has been employed to inhibit oxidation of oils and fats in foods, cosmetic preparations and drugs and for its soothing and antiinflammatory properties. It has also been found that a number of 6-hydroxychromans, including rac-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox C) which has the structure exhibits antioxidant activity (Scott et al, "Antioxidant Properties of 6-Hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid", Cosmetics and Toiletries, Vol. 91, November 1976). Reference may also be made to the following three publications, cited in the European examination report. Chem. Abs. Vol. 81, 1974, 49523j discloses 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid as an antioxidant. Reference is made to the use of antioxidants in animal fats, vegetable oils and emulsion systems. The Merck Index, Tenth Edition, 1983, page 3707, No. 3703 discloses 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline as an antioxidant in feed and food, and as an antidegradation agent for rubber. The Encyclopedia of Chemical Technology, Kirk-Othmer, Third Edition, Vol. II, page 159 discloses the use of sulphur dioxide and sulphites as food preservatives. We have now discovered that the carboxylic acid and the methylquinoline mentioned above, and known as antioxidants, can deactivate or inhibit generation of free radicals and can provide a useful skin treatment composition. Thus, the invention provides a skin treatment composition (including cosmetics) which inhibits generation of or deactivates free radicals in the skin, which free radicals may form upon exposure of the skin to ultraviolet radiation or air pollutants, in the form of an ointment, cream, lotion, or liquid, said composition being characterized by water, at least one humectant, at least one thickener, at least one preservative and from 0.01 to 5% (preferably 0.010.5%) by weight of the composition of at least one free radical inhibitor or deactivator which is 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox C), 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline (ethoxyquin) or mixtures thereof. In particular embodiments the composition is further characterized by a stabilizer for the carboxylic acid which is monoethanolamine sulfite or sodium bisulfite, the acid being employed in a molar ratio to the stabilizer within the range of from 10:1 to 0.5:1; by from 0.01 to 0.5% by weight of the composition of at least one chelating agent which is disodium ethylene diamine tetraacetic acid, ethylene diamine tetraacetic acid, tetrasodium ethylene diamine tetraacetic acid or citric acid; or by from 0.001 to 2% by weight of the composition of at least one enzyme or modified enzyme. The invention also provides use of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid and/or 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline for the manufacture of a medicament for skin for inhibition or deactivation of free radicals. It has unexpectedly been found that the Trolox C compound not only has antioxidant activity and antiinflammatory activity similar to that of Vitamin E, but that Trolox C by itself or formulated in skin treatment compositions in accordance with the present invention, has skin penetrating capacity which is surprisingly superior to that of Vitamin E. Accordingly, the skin treatment compositions of the invention contain a more skin penetrating form and thus a faster acting form of Vitamin E, that is Trolox C, than heretofore known. In addition, there is provided a more stable form of Trolox C and a method for stabilizing Trolox C by employing Trolox C together with a stabilizer therefor, namely, sodium bisulfite or monoethanolamine sulfite and a method for stabilizing Trolox C against discoloration and oxidation by employing such stabilizer in composition with Trolox C. A stabilized form of Trolox C in accordance with the present invention will comprise a stabilized composition containing from 0.01 to 5% Trolox C and preferably from 0.1 to 0.5% by weight Trolox C; and if necessary for solubility, an equivalent weight of strong base such as potassium hydroxide, sodium hydroxide, or lithium hydroxide (in an amount within the range of from 0.02 to 0.1% by weight) or organic amine, such as triethanolamine (in an amount within the range of from 0.06 to 0.3% by weight), from 50 to 90% and preferably from 60 to 80% by weight water; from 0.05 to 2% and preferably from 0.1 to 1% by weight preservative; and from 0.02 to 0.5% and preferably from 0.05 to 0.1% by weight stabilizer which is sodium bisulfite or monoethanolamine sulfite which inhibits discoloration and oxidation of the Trolox C, all of the above % by weight being based on the weight of said stabilized composition. In the above composition, the Trolox C will be employed in a molar ratio to the stabilizer of within the range of from 10:1 to 0.5:1 and preferably from 5:1 to 1:1. In addition, depending upon the form that the skin treatment composition of the invention will take, for example, moisturizing composition, skin toner, skin cleanser, night cream, day lotion, shampoo or cosmetic preparation, it will also include water, at least one preservative, preferably, at least one humectant, at least one emulsifier and/or thickener, and optionally may contain one or more chelating agents, one or more gelling agents, one or more emollients, one or more solvents for the free radical inhibitor or deactivator, one or more sun screen agents, and/or one or more fragrances and/or one or more coloring agents. The skin treatment composition of the invention is preferably an oil-in-water type emulsion since this type of emulsion affords better cosmetic feel to the product. However, the product could also be formulated as a water-in-oil emulsion, cream base, oil base or agueous/alcoholic or glycol solution, microemulsion or liposome. Depending upon the choice of ingredients, the formulation has a semi-solid cream-like consistency which can be packaged in a plastic sgueeze tube, a lotion-type consistency which can be packaged in a plastic squeeze container, an ointment-type consistency which can be packaged in a squeeze-type container or a liquid consistency which may be packaged in a bottle. The container can include a flow-type cap or pump-type dispenser. In addition, in accordance with the present invention, a method is provided for controlling free radical formation in skin, which includes the step of applying to the skin an effective amount of a skin treatment composition as disclosed herein. The skin treatment composition of the invention may take the form of a lotion, cream, liquid, or ointment. In general, regardless of the form of the skin treatment composition of the invention, it will include from 0.01 to 5%, and preferably from 0.1 to 0.5% by weight of the free radical inhibitor or deactivator, and, if necessary for solubility, an equivalent weight of caustic hydroxide, such as potassium hydroxide, (in an amount within the range of from 0.02 to 0.1% by weight) or organic amine, such as triethanolamine (in an amount within the range of from 0.06 to 0.3% by weight), from 50 to 90% and preferably from 60 to 80% by weight water, from 1 to 25% and preferably from 5 to 10% by weight of one or more humectants, from 1 to 10% and preferably from 1 to 5% by weight of one or more emulsifiers when the composition is a cream, lotion or ointment, from 0.05 to 4% and preferably from 0.05 to 3% by weight of one or more thickeners or gelling agents where the composition is a cream, lotion or ointment, optionally from 0.001 to 2% and preferably from 0.01 to 1% by weight of an enzyme or modified enzyme to enhance free radical inhibitor activity, optionally from 0.01 to 5% and preferably from 1 to 3% by weight of one or more adjuvant oxygen deactivators, from 0.05 to 2% and preferably from 0.1 to 1% by weight of one or more preservatives, and the following optional ingredients: from 0.01 to 0.5% and preferably from 0.05 to 0.1% by weight of one or more chelating agents, from 1 to 30% and preferably from 1 to 10% by weight of one or more emollients when the composition is a cream, lotion or ointment, from 1 to 50% and preferably from 5 to 10% by weight of one or more solvents for the free radical inhibitor or deactivator, from 1 to 15% and preferably from 1.5 to 10% by weight of one or more sun screen agents, less than 1% by weight of one or more fragrances and/or less than 1% by weight of one or more colorants. In addition, the skin treatment composition of the invention may also optionally include various other conventional ingredients normally employed in skin conditioning or moisturizing compositions or sunscreen compositions such as skin conditioning agents, moisturizers, waxes, polymers or other active ingredients. Where the free radical inhibitor employed is Trolox C, the composition of the invention may optionally contain from 0.02 to 0.5% and preferably from 0.05 to 0.1% by weight stabilizer for the Trolox C. The skin treatment composition of the invention may optionally contain enzymes of modified (PEG-, dextran PVP) enzymes to enhance activity, for example, polyethylene glycol modified superoxide dismutase or catalase. The composition may also optionally contain adjuvants to deactivate singlet oxygen or other active chemicals including but not limited to carotenoids (beta carotene, canthaxanthin, bixin), sulfur compounds (glutathione, cysteine, thioglycerol, dilaurylthiodiproprionate) or aromatic hydroxy or quinone compounds (e.g., quercetin, curcumin, hydroquinone) or vitamins (ascorbic acid, alpha-tocopherol). Suitable preservatives include imidazolidinyl urea (Germall 115), methylparaben (Tegosept M), quaternium-15 (N-(3-chloroallyl)hexaminium chloride, Dowicil 200), propylparaben (Tegosept P), dimethyldimethoyl hydantoin, benzyl alcohol and/or phenoxyethanol, etc., and a preferred antioxidant is a mixture of butylated hydroxyanisole, propylene glycol, propyl gallate and citric acid (Tenox 2). The formulation will preferably contain the antioxidant mixture and one or more of the preservatives or any other preservatives and antioxidants approved for cosmetic use. Where the skin treatment composition of the invention is in the form of a lotion, cream, or ointment, it will preferably include one or more emulsifiers, thickeners, humectants and emollients. Suitable emulsifiers include polyethylene glycol 20 sorbitan monolaurate (Polysorbate 20), polyethylene glycol 5 soya sterol, sorbitan tristearate, sorbitan trioleate, glyceryl monopalmitate, diethanolamine cetyl phosphate, glyceryl monopalmitate, glyceryl monostearate, polyethylene glycol 100 stearate, polyethylene glycol 20 stearyl ether (Brij 78, Steareth 20), polyethylene glycol ether of lauryl alcohol (Laureth 23), polysorbate 80 (Tween 80), lecithin, etc. The formulation will preferably contain a mixture of two or more of these emulsifiers or others which are approved for cosmetic use. Thickeners or gelling agents which may be present include Carbopol 934 or Carbomer 940 which is a hydrophilic acrylic polymer cross-linked with a polyfunctional agent and employed with an organic or inorganic base, preferably triethanolamine. Other examples of thickeners which may be employed herein include, but are not limited to, stearic acid, fatty alcohols, such as cetyl alcohol, stearyl alcohol, magnesium aluminum silicate, stearoxydimethicone, hydroxyethyl cellulose, propylene glycol monostearate, hydroxypropyl cellulose, carboxymethyl cellulose, xanthan gum, myristyl stearate, or cetyl stearate. Suitable emollients or oleaginous materials include mineral oil, petrolatum, glyceryl monooleate, myristyl alcohol, isopropyl palmitate, avocado oil, squalane, octyl palmitate, cocoa butter, sesame oil, propylene glycol dicaprylate/dicaprate, isopropyl myristate, diisopropyl dimerate (that is, the diester of isopropyl alcohol and dimer acid), dimethicone, stearoxydimethicone, and the like. The formulation will preferably contain a mixture of several of these emollients or others which are approved for cosmetic use. Skin conditioning agents which may optionally be present in the composition of the invention include allantoin, d- or dl-panthenol, hydrolyzed animal protein and the like. Such conditioning agents may be present in an amount within the range of from 0.01 to 10% and preferably from 0.05 to 2% by weight and optimally from 0.1 to 2% by weight depending upon the ultimate use of the skin preparation. Solvents for the free radical inhibitors which may be present include polyethylene glycol wax (such as Carbowax 400), propylene glycol or ethanol (for Trolox C) and/or an equivalent weight of strong base such as potassium hydroxide or organic amine such as triethanolamine (based on M.W. of Trolox C of 250.3), and mineral oil, vegetable oils, synthetic esters for ethoxyquin. Chelating agents for sequestering metal ions in aqueous solution which may be present herein include disodium ethylenediamine tetraacetic acid, EDTA, tetrasodium EDTA, or citric acid. As indicated, the skin treatment compositions of the invention may include one or more known ultraviolet absorbing agents, preferably at least one compound which absorbs in the UV-B region (wavelength 290 to 320 nanometers) and optionally one or more other compounds which absorb in the UV-A region (wavelength 320 to 400 nanometers). The total amount of UV absorbing agents included within the formulation will be from 2% to 15% by weight, which amount will determine whether it is a sunscreen or sunblock. Suitable UV-A absorbing agents which may be employed include 2-(2'-hydroxy-5'-methylphenyl)benztriazole (Tinuvin P); 2-(2'-hydroxy-5'- t -octylphenyl)benztriazole (Spectra-Sorb UV 5411); 2,4dihydroxybenzophenone (Uvinul 400); 2-hydroxy-4methoxybenzophenone (oxybenzone, Spectra-Sorb UV9, Uvinul M-40); 2,2',4,4'-tetrahydroxybenzophenone (Uvinul D50); 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (Uvinul D49); 2,2'-dihydroxy-4-methoxybenzophenone (dioxybenzone, Spectra-Sorb UV24); 2-ethylhexyl-4-phenylbenzophenone carbonate (Eusolex 3573); 2-hydroxy-4-methoxy-4'-methylbenzophenone (mexenone, Uvistat 2211); 2-hydroxy4-( n -octyloxy)benzo-phenone (octabenzone, SpectraSorb UV531); 4-phenylbenzophenone (Eusolex 3490); and 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate (Uvinul N539); butyl methoxydibenzoyl methane (Parsol 1789), and benzphthalide (Escalol 547). The UV-A absorbing agent or agents are present in the final product at from 0 to 10% by weight of the formulation. The amount will vary according to the particular agent selected and whether the formulation is intended to minimize or permit tanning. Where a UV-A absorbing agent is employed, the preferred UV-A absorbing agent is 2hydroxy-4-methoxybenzophenone alone or in combination with 2,2'-dihydroxy-4-methoxybenzophenone. Suitable UV-B absorbing agents include 4-(dimethylamino)benzoic acid, ethyl ester; 4-(dimethylamino)benzoic acid, 2-ethylhexyl ester (Escalol 507); 4-(dimethylamino)benzoic acid, pentyl ester (Escalol 506); glyceryl p-aminobenzoate (Excalol 106); isobutyl pamino-benzoate (Cycloform); and isopropyl p-amino-benzoate; 2-ethylhexyl methoxy cinnamate (Parsol MCX); phenylbenzimidazole sulfonic acid (Eusolex 232); homomenthyl salicylate, and ethyl hexyl salicylate. The UV-B absorbing agent or agents are present in the final product at from 1% to 15% by weight of the formulation. The amount will vary according to the particular agent selected and degree of protection desired in the final product. The preferred UV-B absorbing agent is 4-(dimethylamino)benzoic acid, 2-ethyl-hexyl ester (Escalol 507). Where the skin treatment composition is in the form of a lotion, cream, or liquid, the free radical inhibitor or deactivator as well as any other actives that may be present will be "allin-solution" (i.e., solubilized or emulsified) so that substantially no active ingredient crystallises out at room temperature. With regard to the cream formulations of the invention where the active ingredients are to be all-in-solution, the cream will contain from 0.01 to 5% and preferably from 0.1 to 0.5% by weight of the free radical inhibitor based on the weight of the entire cream formulation, and from 1 to 50% and preferably from 5 to 10% by weight of solvents for the free radical inhibitor based on the weight of the entire cream formulation. Examples of such solvents include Carbowax 400, propylene glycol, and/or an equivalent weight of strong base such as potassium hydroxide or organic amine such as triethanolamine (based on M.W. of Trolox C of 250.3) (for Trolox), and mineral oil or C₁₂-C₁₅ alcohols benzoate (for the ethoxyquin). The all-in-solution cream formulation will also include in the oil phase, from 2 to 15% and preferably from 5 to 10% by weight of the emulsifier-thickener based on the weight of the entire cream formulation, and from 2 to 30% and preferably from 3 to 15% by weight of oleaginous material or emollient based on the weight of the entire cream formulation. The oil phase may also include one or more preservatives similar to that present in the aqueous phase described below. The aqueous phase of the all-in-solution cream formulation may contain a glycol type preservative or humectant such as propylene glycol and/or a paraben or other conventional type preservative such methyl and/or propyl paraben, and purified water in amount within the range of from 30 to 80% by weight and preferably from 35 to 65% by weight of the entire cream formulation. With regard to the lotion formulation of the invention where the free radical inhibitor is to be all-in-solution, the lotion will contain from 0.01 to 5% and preferably from 0.1 to 0.5% by weight of the free radical inhibitor based on the weight of the entire lotion formulation, and, if necessary, for solubility an equivalent amount of strong base such as potassium hydroxide or organic amine such as triethanolamine. The active ingredient in the all-in-solution lotion formulation can have part of it also solubilized in the oil phase. The lotion may contain from about 1 to 10% and preferably from 2 to 5% by weight emulsifierthickener based on the weight of the entire lotion formulation, and from 2 to 20% and preferably from 4 to 10% by weight of oleaginous material or emollient based on the weight of the entire lotion formulation. The oil phase may also optionally include one or more preservatives. The aqueous phase of the all-in-solution lotion formulation may contain one or more preservatives and purified water in an amount within the range of from 60 to 90% by weight and preferably from 70 to 85% by weight of the entire lotion formulation. Where the free radical inhibitor is to be employed in liquid solution, the concentration of free radical inhibitor will be in amounts ranging from 0.01 to 5% by weight together with from 2 to 99% by weight solvent therefor and, if necessary, for solubility, a strong base or organic amine as described hereinbefore. The ointment formulation of the invention comprises a free radical inhibitor as described herein and an oleaginous material, and optionally a wax. The term "ointment" or "ointment formulation" as employed herein includes non-aqueous formulations such as gels, ointments, lipophilic sticks, and the like. The oleaginous material or emollient will generally be present in amount within the range of from 30 to 99% by weight, and preferably from 50 to 90% by weight. The ointments of the invention may include the free radical inhibitor solubilized in both the aqueous phase and in the oil phase. The percentage of water in the aqueous phase may vary from 5 to 20% of the ointment. The ointment will contain from 0.01 to 5%, and preferably from 0.025 to 0.5% by weight of the free radical inhibitor and from 2 to 99% by weight solvent therefor such as set out above. The all-in-solution ointment formulation (exclusive of the gel and lipophilic stick) will also include, in addition to the free radical inhibitor from 85 to 99% and preferably from 85 to 95% by weight of oleaginous material based on the weight of the entire formulation. The formulation may also optionally include an opacifying agent, such as titanium dioxide, serving as indicator for homogeneity of dispersion, in an amount within the range of from 0.2 to 1% and preferably from 0.3 to 0.8% by weight based on the entire formulation. When the free radical inhibitor is mechanically dispersed in the oleaginous material, the latter may be mineral oil thickened with polyethylene as disclosed in U.S. Patent No. 2,627,938; 2,628,187; 2,628,205; and 3,733,403. The disclosures of the foregoing patents are incorporated herein by reference. The all-in-solution ointment may simply be prepared by dissolving the active ingredient in a solvent therefor such as propylene glycol and/or polyethylene glycol wax (for Trolox) or C₁₂-C₁₅ alcohol benzoate (for ethoxyquin), with gentle heat not over 90°C, cooling to room temperature and then incorporating the same into the oleaginous material by slow mixing until homogeneous. The gel formulation of the invention is preferably in the form of a lipophilic clear gel, and will contain from 0.01 to 5%, and preferably from 0.1 to 0.5% by weight of the free radical inhibitor based on the weight of the entire formulation, and from 10 to 99% and preferably from 50 to 80% by weight of a solvent for the free radical inhibitor (as described above) based on the weight of the entire formulation, depending upon the solubility of the particular inhibitor ingredient in the particular solvent employed. The gel formulation will also include from 30 to 99% and preferably from 60 to 85% by weight of the oleaginous material. The formulation may also optionally include a surfactant, such as Span 65 (sorbitan tristearate), as well as Span 60 (sorbitan monostearate), Span 40 (sorbitan monopalmitate) or butylene glycol distearate in amounts up to about 8% by weight based on the entire formulation. An antioxidant, such as butylated hydroxyanisole or butylated hydroxytoluene may also optionally be included in amounts up to 0.1% and preferably up to 0.05% by weight based on the entire formulation. In the non-aqueous gel formulation of the invention, the oleaginous material includes mineral oil gelled with waxes such as high molecular weight paraffin wax (Paraflint RG), mono and diglycerides of fatty acids such as Arlacel 186 (Atlas Co.) as well as propylene glycol isostearate (Emery 2389A) or isostearyl alcohol (Adol 66), gelled with high molecular weight fatty acids such as Emery 865A (Emery Industries), and/or polyamide complex of hydroxystearate (Acrowax, Glyco). The lipophilic stick of the invention may contain from 0.01 to 5%, and preferably from 0.1 to 0.5% by weight free radical inhibitor and from 10 to 80% and preferably from 40 to 60% by weight of the solvent therefor (such as described above) and from 20 to 50% and preferably from 25 to 45% by weight oleaginous material. Oleaginous materials which may be employed include high melting waxes, such as carnauba wax, in amounts ranging from 6 to 10% and preferably from 7 to 9%, beeswax in amounts ranging from 14 to 18% and preferably from 15 to 17%, as well as petrolatum in amounts ranging from 2 to 5% and preferably from 3 to 4%, and isotearyl neo pentanoate (Ceraphyl 375, Van Dyk) in amounts ranging from 8 to 11% and preferably from 9 to 10.5%. In the case of ointments, lipophilic gels and sticks where the formulation is substantially free of water, the free radical inhibitor will be dissolved in the solvent vehicle and, in part, in the oil material employed. Examples of preferred formulations in accordance with the present invention include, but are not limited to, the following: The various formulations of the invention may be prepared employing conventional procedures as outlined in the working Examples. Example 1 A skin treatment (moisturizer) composition in the form of a lotion of the following composition was prepared as described below. Aqueous Blend I was prepared by dispersing the ingredients in the deionized water. Blend II (prepared by simple mixing of ingredients) was then mixed with Blend I. The combined Blend I-II was then heated to 75°C. Blend III was formed by simple mixing of the 30 ingredients in a separate vessel while heating to 75°C. Blend III (heated at 75°C) was then added to the combined Blend I-II (also at 75°C) with sweep mixing. The combined Blend I-II-III was heated at 75°C for 30 minutes, allowed to air cool to 60°C, and then Blend IV (prepared by simple mixing of ingredients) was added with sweep mixing. The resulting batch was then allowed to air cool to 30°C to form the moisturizer lotion formulation of the invention. Example 2 A solution of Trolox and polyethylene glycol is formed by gentle heating of a mixture thereof at not over 90°C. The parabens are then dissolved in the Trolox and polyethylene glycol solution with gentle heat, not over 90°C. Petrolatum and Promulgen D are melted together. After mixing, the mixture is added to the solution with thorough mixing, maintaining the temperature at 75°-80°C. Water is heated to 80°C to form the agueous phase which is added with vigorous agitation to the oil phase to emulsify. Agitation is continued until the temperature drops down to 48°C. Sufficient 50°C water is added to make 100 g. Mixing is continued at a slow rate to congeal the mixture, until the temperature drops to 30°C. Example 3 The free radical inhibitor is dissolved with gentle heat not over 90°C. The solution is cooled to room temperature and titanium dioxide is dispersed homogeneously into the oil. The suspension is incorporated into the Plastibase by slow rate of mixing until homogeneous to form the ointment. Example 4 Paraflint RG and Span 65 are melted and heated to 100°C. The molten mixture is incorporated in hot (100°C) mineral oil and mixed well. The temperature of the oil is quickly brought to 50°C to form a gel. The free radical inhibitor is dissolved in the polyethylene glycol by gentle heat, the oil is cooled to room temperature and then is incorporated in the gel homogeneously. Example 5 A sunscreen oil-in-water formulation in the form of a lotion having the following composition is prepared as described below. Aqueous Blend I is prepared by mixing the thickener ingredients in the deionized water. Blend II, prepared by simple mixing of ingredients, is then mixed with Blend I. The combined Blends I-II is then heated to 75°C. Blend III is formed by simple mixing of the ingredients in a separate vessel while heating at 75°C. Blend III (heated at 75°C) is then added to the combined Blend I-II (also at 75°C) with sweep mixing. The combined Blend I-II-III was heated at 75°C for 30 minutes, allowed to air cool to 60°C and then Blends IV and V each formed by simple mixing of ingredients are separately added with sweep mixing. The resulting batch is then allowed to air cool to 30°C to form the sunscreen formulation of the invention. Example 6 A protective daytime lotion/moisturizer having the following composition is prepared as described below. Each of Mixes A and B are heated to 75°C and Mix B is added to Mix A with propeller type mixing while maintaining the 75°C temperature for 1 hour. The resulting mixture is cooled to 65°C and Mix C is added. The mixture is then cooled to 50°C and Mix D is added. Cooling is continued to 30°C to form the protective daytime lotion/moisturizer of the invention which is found to have improved feel and barrier properties, is naturally compatible with the skin and has improved skin penetrability. Example 7 A soothing facial make-up having the following composition is prepared as described below. The Phase A ingredients are homomixed for 15 minutes. Thereafter, a mix of the Phase B ingredients are added to the Phase A mixture with mixing for 1 hour. Phase C is then mixed with Phase AB for hour under slow speed mixing. Phase D is then added to the aforementioned mix with mixing for hour. Phase E is then added and thereafter Phase F is sweep mixed therein for 15 minutes. The so-formed mix is then heated to 75°C. While maintaining the mix at 75°C, Phase G is added. Phase H, heated at 80°C, is then added to the above mix with fast mixing to form an emulsion. The mix is then mixed with moderate speed, cooled to 50°C and then combined with Phase I and mixed for 5 minutes. Thereafter Phase J is added and the mixture is cooled to 30°C to form the make-up of the invention. The so-formed make-up of the invention is found to be soothing and noncomedongenic. Example 8 Cosmetic Formulation A cosmetic formulation in the form of a facial makeup having the following composition is prepared as described below. Glycerin, 2-pyrrolidone-5-carboxylic acid and methyl paraben are heated together to 70° to 75°C with propeller mixing to form a first mix. Octyl palmitate, dimethicone, polysorbate 15 60, propyl paraben, glyceryl monostearate and Promulgen D (cetearyl alcohol and Cetearth 20) are heated together to 70° to 75°C with propeller mixing to form a second mix. The second mix is then added to the first mix with propeller mixing and the mixture is then cooled to 60°C while sweep mixing. Thereafter, aqueous Dowicil 20 (Quaternium 15) and Trolox C are added at 50°C and the mixture is cooled to 30°C to form the cosmetic of the invention. Example 9 Shampoo Formulation A shampoo having the following composition is prepared as described below. A first mix is formed by sweep mixing 20 deionized water, Standapol ES2, Glydant and Standapol AB 45% while heating to 60°-65°C. The first mix is cooled to 50°C and then perfume oil, Triton X102, Tegin and the FDC color are added to the first mix with sweep mixing to form a second mix. The pH of the second mix is adjusted to 6.0 with phosphoric acid, at 50°C and then the troxerutin and Trolox C and KOH are added at 50°C and the mix is cooled to 30°C to form the shampoo formulation of the invention. Example 10 Topical Moisturizer Lotion Composition A topical moisturizer lotion having the following composition is prepared as described below. Blend I was formed by premixing the carboxymethyl cellulose and Carbowax 400 and adding the water under homomixing while heating at 50°C. The Blend II ingredients were mixed together and added to Blend I to form Blend I-II. The Blend III ingredients were stirred at 80°C until uniform and the resulting Blend III was sweep mixed into Blend I-II to form Blend I-II-III. Blend IV and V ingredients were then sweep mixed as two separate blends into the Blend I-II-III to form the final blend. The so-formed topical moisturizer lotion of the invention was found to have excellent moisturizing properties and excellent skin penetrating power. In addition, the Trolox C free radical inhibitor was found to be stabilized against decoloration and oxidation by the monoethanolamine sulfite. The Trade Marks in the specification listed below are acknowledged. Acrowax, Adol 66, Amerchol, Alcolec 413S, Arlacel 186, Arlacel 165; Blue 3516, Butoben, Brij 78; Carbopol 934, Carbomer 940, Carbowax 400, Ceraphyl 368, Ceraphyl 375, Cetearth 20, Cycloform; Dowicil 200, dl-Panthenol; Emery 2389A, Emery 865A, Escalol 547, Escalol 507, Escalol 506, Excalol 106, Eusolex 3573, Eusolex 3490, Eusolex 232, Exaltolide; Finsolv TN, FDC Red 4, FDC; Germall 115, Glydant, Glyco, Generol 122 E5; Keltol F, Keltrol F, Klearol, Kaolin 2749; Laureth 23; Miglyol 840; Paraflint RG, Parsol 1789, Parsol MCX, Plastibase 50W, Plastibase, Polysorbate 20, Promulgen Type D, Promulgen D; Quaternium 15; Russet C33-2527; Silicon 225, Spar, 65, Span 60, Span 40, Spectra-Sorb UV9, , Spectra-Sorb UV24, Spectra-Sorb UV511, Spectra-Sorb UV531, Spectra-Sorb UV5411, Steareth 20, Standapol ES2, Standapol AB; Tegin 515, Tegosept B, Tegosept M, Tegosept P, Tenox 2, Tinuvin P, Troxerutin, Triton X102, Tween 20, Tween 60, Tween 80; Umber 1985R, Uvinul 400, Uvinul M-40, Uvinul D49, Uvinul N539, Uvistat 2211; Veegum R; and Yellow 2576.

Claims: A skin treatment composition which inhibits generation of or deactivates free radicals in the skin, which free radicals may form upon exposure of the skin to ultraviolet radiation or air pollutants, in the form of an ointment, cream, lotion, or liquid, said composition being characterised by water, at least one humectant, at least one thickener, at least one preservative and from 0.01 to 5% by weight of the composition of at least one free radical inhibitor or deactivator which is 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline or mixtures thereof. A skin treatment composition as defined in claim 1, further characterised by from 0.01 to 0.5% by weight of the composition of at least one chelating agent which is disodium ethylene diamine tetraacetic acid, ethylene diamine tetraacetic acid, tetrasodium ethylene diamine tetraacetic acid or citric acid. A skin treatment composition as defined in claim 1 or 2, further characterised by from 0.001 to 2% by weight of the composition of at least one enzyme or modified enzyme. The composition as defined in claim 1, 2 or 3, characterised in that said humectant is present from 1 to 25% by weight of the composition, said thickener is present from 0.05 to 4% by weight of the composition and said preservative is present from 0.1 to 1% by weight of the composition. The composition as defined in any preceding claim, further characterised by a stabilizer for said 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid which is monoethanolamine sulfite or sodium bisulfite. The composition as defined in claim 5, characterised in that said stabilizer is present in an amount from 0.02 to 0.5% by weight of said composition. The composition as defined in any preceding claim, in the form of a cream, lotion or ointment, characterised in that said thickener is a cross-linked acrylic acid polymer and including triethanolamine as a neutralizer for said thickener, or said thickener is xanthan gum, magnesium aluminium silicate, hydroxyethyl cellulose, carboxymethyl cellulose, cetyl alcohol or stearic acid. The composition as defined in any preceding claim, characterised in that said humectant is propylene glycol, polyethylene glycol, glycerine, sorbitol or butylene glycol. The composition as defined in any preceding claim, further characterised by an emulsifier including polyethylene glycol 20 sorbitan monolaurate, polyethylene glycol 5 soya sterol, sorbitan tristearate, sorbitan trioleate, glyceryl monopalmitate, diethanolamine cetyl phosphate, glyceryl monostearate, polyethylene glycol 100 stearate, polyethylene glycol 20 stearyl ether, polyethylene glycol ether of lauryl alcohol, polysorbate 80, lecithin or mixtures thereof. The composition as defined in any preceding claim, further characterised by an emollient including dimethicone, stearoxydimethicone, diisopropyl dimerate or mineral oil. The composition as defined in any preceding claim, characterised in that said preservative is benzyl alcohol, phenoxyethanol, butyl paraben, propylparaben, methyl paraben, imidazolidinyl urea, dimethyl-dimethoyl hydantoin, or a mixture thereof. The composition as defined in any preceding claim, further characterised by a solvent for said free radical inhibitor or deactivator. The composition as defined in claim 12, characterised in that said solvent is propylene glycol, polyethyline glycol, ethanol and/or strong base or organic amine for 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid and vegetable oil or synthetic fatty acid esters for 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. The composition as defined in any preceding claim, characterised in that said free radical inhibitor or deactivator is present in an amount within the range of from 0.1 to 0.5% by weight and is 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid or 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, said humectant is polyethylene glycol or propylene glycol, said emulsifier is polyethylene glycol ether of lauryl alcohol, glyceryl monostearate, said thickener is cetyl alcohol or stearic acid, and said preservative is benzyl alcohol, methyl paraben, propyl paraben or butylparaben. The composition as defined in claim 14, further characterised by disodium ethylenediamine tetraacetic acid as a chelating agent, diisopropyl dimerate, dimethicone or stearoxy dimethicone as an emollient, and polyethylene glycol as a solvent for 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid. The composition as defined in claim 3, characterised in that the enzyme is glycol modified superoxide dismutase or catalase. The composition as defined in any preceding claim, further characterised by at least one adjuvant oxygen deactivator. The composition as defined in any preceding claim, characterised in that said free radical inhibitor or deactivator is present in an amount from 0.1 to 0.5% by weight of the composition. Use of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid and/or 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline for the manufacture of a medicament for skin for the inhibition or deactivation of free radicals.

Inventors: DECKNER, GEORGE E., GEORGALAS, ARTHUR C.W.
Applicants: RICHARDSON-VICKS, INC.
Application year: 1987
Main classification: A61K7
IPC codes: A61K8, A61Q17