MXPA00009057A - Skin moisturizing compositions - Google Patents

Abstract

The present invention relates to methods of improving skin moisturization or skin hydration, and more specifically, to methods improving the skin's absorptive and/or adsorptive capacity for water.

Description

HUMIDANT SKIN COMPOSITIONS TECHNICAL FIELD OF THE INVENTION The present invention relates to methods for improving skin moisturization or hydration of the skin, and more specifically, to methods for improving the skin's ability to absorb or adsorb water.

BACKGROUND OF THE INVENTION Physiologically, the skin is constituted by an outer cellular layer called stratum corneum, an underlying epidermal layer and the dermis. The stratum corneum, which varies in thickness from about 15 microns on the face and back of the hands to 500 microns on the soles of the feet and on the palms of the hands, plays a significant role in controlling the moisture level of the skin. This is composed of keratinized cells, a natural humectant factor and lipids. All these work together as a protective coating, as well as a moisture barrier to keep moisture inside the skin. In the epidermal area, which rests below the stratum corneum, the skin cells undergo changes from the normal structure of living cells to the keratinized layer of the cornea. During this change, some proteins, particularly involucrin, cross over to become the cellular envelope of the stratum corneum. These cells contain keratins, which are also produced in the epidermis, and when hydrated they function to provide flexibility to the stratum corneum. Other proteins, particularly filaggrin, are degraded into products that are located in the cells of the stratum corneum and function as natural wetting compounds. Beneath the epidermal layer, the normal dermis of the skin rests, which maintains and transports water to the epidermal area. Water is extremely important for the proper physical condition and appearance of the skin. Dry and cracked skin is by far the result of an insufficient level of moisture in the stratum corneum. Healthy, soft, collapsible, supple skin can not be maintained in the absence of an adequate level of moisture in the stratum corneum. The moisture level of the skin depends on a number of factors. Among these are the water binding potential of the stratum corneum, the speed at which water is delivered to the inner layers of the stratum corneum, and the speed at which water is lost from the outer surface of the skin. Researchers, considering those factors, have been actively investigating for years certain ways to maintain such adequate levels of moisture in the skin. Traditional methods of maintaining moisture in the skin have involved the use of occlusive agents. The occlusive agents are hydrophobic substances that promote the retention of water forming a barrier on the skin that prevents the loss of moisture. Occlusive agents commonly used include petrolatum, lanolin, cocoa butter, mineral oil and silicones. Despite the existence of such traditional methods for moisturizing the skin, there remains a need for moisturizing products of the skin that hydrate the skin by means other than occlusion. The inventors of the present invention have discovered that the vitamin B3 compounds are effective in providing moisture or hydration to the skin by improving the absorption of water on the stratum corneum or the adsorption of water in the stratum corneum. Specifically, it has been discovered that vitamin B3 compounds improve the production of the stratum corneum cell envelope, the stratum corneum keratins, the precursors of the natural humectant factor (filaggrins), and the natural humectant factors which they promote the ability of the skin to absorb and bind water. Therefore, it is an object of the present invention to provide methods for moisturizing the skin. Another object of the present invention is to provide methods for improving the ability of the skin to adsorb and / or absorb water by applying a safe and effective amount of a composition containing a vitamin B3 compound. These and other objects will become readily apparent from the following detailed description.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to methods for moisturizing or moisturizing the skin, improving the absorption of water to, and / or improving the ability of the skin of mammals to absorb water, especially the epidermis and more especially the stratum corneum of the skin. of mammal, by topically applying a safe and effective amount of a skin care composition comprising: A. an agent that increases the adsorption or absorption of water that is selected from the group consisting of vitamin B3 compounds and mixtures of the same; and B. a dermatologically acceptable vehicle for said vitamin B3 compound. The present invention also relates to articles of manufacture containing a composition for skin care comprising from about 0.1% to about 40% of a vitamin B3 compound in a package for said composition for skin care together with the information about and / or instructions on the use of vitamin B3 compounds to improve skin moisturization or hydration. Unless indicated otherwise, all percentages and ratios used in the present invention are by weight of the total composition. All percentages by weight, unless stated otherwise, are on a weight basis of active ingredients. All measurements are made at approximately 25 ° C, unless stated otherwise. As used in the present invention the terms "wetting", "wetting", "hydration" or "hydrated" mean widely the treatment or prevention of dry, scaly, scaly, stretched or itchy skin to give a smoother skin and more smooth as perceived by visual and / or tactile and / or sensory evaluations. As used in the present invention, the terms "absorb" or "absorption" mean widely the absorption of water in the skin, in particular in the epidermis and more particularly in the stratum corneum. As used in the present invention, the terms "adsorb" or "adsorption" mean widely the absorption of water in the skin, particularly on the proteins of the epidermis and more particularly on the stratum corneum. The term "safe and effective amount" as used in the present invention means an amount of a compound or composition that is sufficient to induce a positive benefit in a significant manner, preferably a positive benefit of sensation or appearance of the skin, including independently the benefits described in the present invention, but low enough to avoid serious side effects, that is, to provide a benefit ratio at reasonable risk, within the field of well-founded judgment of the person skilled in the art.

DETAILED DESCRIPTION OF THE INVENTION The skin moisturizing compositions of the present invention may comprise, consist of, or consist essentially of the essential elements and limitations of the invention described therein, as well as any of the additional or optional ingredients, components, or limitations described in the present invention.

Essential components Component of vitamin B3 The compositions of the present invention comprise a safe and effective amount of a natural or synthetic vitamin B3 compound.

The compositions of the present invention preferably comprise from about 0.01% to about 50%, more preferred more than 1% to about 50%, even more preferred more than 2% to about 40% and still more preferred more than 5% to about 30%, preferably more than 10% up to approximately % of the vitamin B3 compound. As used in the present invention "vitamin B3 compound" means a compound having the formula: isr in which R is -CONH2 (ie, niacinamide), -COOH (ie, nicotinic acid) or -CHOH (ie, nicotinyl alcohol); derivatives thereof; and salts of any of the above. Examples of derivatives of the above vitamin B3 compounds include nicotinic acid esters including non-vasodilating nicotinic acid esters, nicotinyl amino acids, nicotinyl alcohol esters of carboxylic acids, nicotinic acid N-oxide and niacinamide N-oxide. Suitable nicotinic acid esters include nicotinic acid esters of C C 2 alcohols, preferably C 1 -C 16, more preferred Ci-Ce. The alcohols are, appropriately, straight chain or branched, cyclic or non-cyclic, saturated or unsaturated (including aromatic), and substituted or unsubstituted. The esters of preference are non-rubefacient. As used in the present invention, "non-rubefacient" means that the ester does not commonly produce a visible redness response after applying the compositions in question to the skin (the majority of the general population does not experience a visible reddening response). , although said compounds may cause vasodilation not visible to the naked eye). Alternatively, a nicotinic acid-based material that is rubefacient at higher doses could be used at a lower dose in which the redness response is not present. Non-rubefacient nicotinic acid esters include, but are not limited to, tocopherol nicotinate and inositol hexanicotinate; the tocopherol nicotinate is preferred.

Other derivatives of the vitamin B3 compound are the niacinamide derivatives which are the result of the substitution of one or more of the hydrogens of the amide group. Non-limiting examples derived from niacinamide useful in the present invention include nicotinyl amino acids obtained, for example, from the reaction of an activated nicotinic acid compound (e.g., nicotinic acid azide or nicotinyl chloride) with an amino acid, and esters of nicotinyl alcohol of organic carboxylic acids (for example C1-C18). Specific examples of such derivatives include nicotinuric acid and nicotinylhydroxamic acid, which have the following chemical structures: Nicotinuric acid: Nicotinylhydroxamic acid: Some examples of nicotinyl alcohol esters include nicotinyl alcohol esters of the carboxylic acids salicylic acid, acetic acid, glycolic acid, palmitic acid and the like. Other non-limiting examples of vitamin B3 compounds useful in the present invention are 2-chloronicotinamide, 6-aminonicotinamide, 6-methylnicotinamide, n-methyl-nicotinamide, n, n-diethylnicotinamide, n- (hydroxymethyl) -nicotinamide, quinolinic acid, nicotinanilide, n-benzylnicotamide, n-ethylnicotinamide, nifenazone, nicotinaldehyde, isonicotinic acid, methylisonicotinic acid, thionicotinamide, nialamide, 1- (3-pyridylmethyl) urea, 2-mercaptonicotinic acid, nicomol, and niaprazine. Examples of the above vitamin B3 compounds are well known in the art and are commercially available from a large number of sources, for example Sigma Chemical Company (St. Louis, MO); ICN Biomedicals, Inc. (Irvin, CA) and Aldrich Chemical Company (MNwaukee, Wl). One or more vitamin B3 compounds can be used in the present invention. The preferred vitamin B3 compounds are niacinamide and tocopherol nicotinate. Niacinamide is the most preferred. When used, salts, derivatives, and derivatives of niacinamide salts are preferably those which have substantially the same efficacy as niacinamide in the methods for regulating the skin condition described in the present invention. The salts of the vitamin B3 compound are also useful in the present invention. Non-limiting examples of salts of vitamin B3 compound useful in the present invention include organic or inorganic salts such as inorganic salts with anionic inorganic species (eg, chloride, bromide, iodide, carbonate, preferably chloride), and organic salts of acid carboxylic (including C1-C18 mono, di and tricarboxylic acid salts, for example, acetate, salicylate, glycolate, lactate, malate, citrate, preferably salts of monocarboxylic acid such as acetate). These and other salts of the vitamin B3 compound can be readily prepared by those skilled in the art, for example, as described by W. Wenner, "The Reaction of L-Ascorbic and D-lsoascorbic Acid with Nicotinic Acid and Its Amide" , J. Organic Chemistry, VOL. 14, 22-26 (1949), which is incorporated in the present invention for reference. Wenner describes the synthesis of the ascorbic acid salt of niacinamide. In a preferred embodiment, the nitrogen ring of vitamin B3 compound is substantially chemically free (eg, unbound and / or unimpeded), or after being delivered to the skin is substantially chemically free (alternatively "chemically free"). hereafter may be referred to as "without complex"). More preferred, the vitamin B3 compound is essentially uncomplexed. Therefore, if the composition contains vitamin B3 compound in a saline or some other complexed form, said complex is preferably substantially reversible, more preferred essentially reversible, after supplying the composition to the skin. For example, said complex should be substantially reversible at a pH of about 5.0 to about 6.0. Such a reversible character can easily be determined by one skilled in the art. More preferred, the vitamin B3 compound is substantially not complexed in the composition before it is delivered to the skin. Some exemplary methods for minimizing or preventing the formation of undesired complexes include the omission of materials that form substantially irreversible complexes or other complexes with the vitamin B3 compound? adjustment of pH, adjustment of ionic concentration, the use of surfactants and formulation where the vitamin B3 compound and materials that form complexes with it are in different phases. Such methods are well known within the level of those skilled in the art. Therefore, in a preferred embodiment, the vitamin B3 compound contains a limited amount of the salt form and more preferred is substantially free of salts of a vitamin B3 compound. Preferably the vitamin B3 compound contains less than about 50% of said salt, and is preferably essentially free of the salt form. The vitamin B3 compound in the compositions thereof having a pH of from about 4 to about 7, typically contains less than about 50% of the salt form. The vitamin B3 compound may be included as a substantially pure material, or as an extract obtained by suitable chemical and / or physical isolation from natural sources (e.g., plants). Preferably, the vitamin B3 compound is substantially pure, more preferably, essentially pure. Without being limited to the theory, it is believed that the vitamin B3 compounds increase skin moisturization or hydration by several different mechanisms. One mechanism involves the effect of vitamin B3 compounds on natural moisturizing factors. Natural moisturizing factors include the metabolic by-products of skin proteins, which bind water, especially filaggrin. It is believed that the vitamin B3 compounds increase the level of the aforementioned skin proteins, thereby increasing the level of the natural wetting factors and therefore of the wetting. Another mechanism involves the effect of the vitamin B3 compounds on the level and / or molecular weight of the keratin proteins in the stratum corneum. These proteins bind water and help provide flexibility to the cell layer of the cornea. Therefore, an increased level of keratin increases the concentration of proteins that trap moisture, which results in improved skin moisturization. The degree of moisture obtained from the skin is also related to the type of keratin present. Keratin proteins of high molecular weights (ie, molecular weights above) tend to bind more water. A third mechanism involves the effect of vitamin B3 compounds on the level of involucrin and desmosomal proteins. Invincrin is a protein precursor for the stratum corneum cell envelope which surrounds keratin proteins and natural wetting factors. The desmosomic proteins are in close association with the cellular envelope of the stratum corneum and help in the connection of the cells of the stratum corneum. The increased levels of involucrin and desmosomal protein increase and reinforce the stratum corneum cell envelope, helping to delay the dehydration of the keratins and the natural moisturizing factors involved, and therefore, improve the humectation of the skin.

Vehicle Another essential ingredient of the present invention is a dermatologically acceptable vehicle. The phrase "dermatologically acceptable vehicle", as used herein, means that the vehicle is suitable for topical application to the skin, has good aesthetic properties, is compatible with the active ingredients of the present invention and any other components, and will not cause no adverse situation to safety or toxicity. A safe and effective amount of the vehicle is from about 50% to about 99.99%, preferably from about 99.9% to about 80%, most preferred from about 98% to about 90%, much preferred from about 95% to about 90% of the composition. The vehicle can have a wide variety of forms. For example, emulsion vehicles are useful in the present invention, including, but not limited to, oil-in-water, water-in-oil, water-in-oil-in-water, and water-in-silicone emulsions. These emulsions can cover a wide range of viscosity values, for example from about 100 cps to about 200,000 cps. These emulsions can also be supplied in the form of sprays using mechanical pump containers or pressurized aerosol containers using conventional propellants. These vehicles can also be supplied in the form of foam. Other suitable topical vehicles include anhydrous liquid solvents such as oils, alcohols and silicones (for example mineral oil, ethanol, sodium propane, demetone, cyclomethicone and the like); single-phase liquid solvents with aqueous base (for example, hydro-alcoholic solvent systems); and thickened versions of these anhydrous, water-based, single-phase solvents (eg, wherein the viscosity of the solvent has been increased to form a solid or semi-solid by the addition of suitable gums, resins, waxes, polymers, salts and the like) ). Examples of topical vehicle systems useful in the present invention are described in the following four references, which are incorporated herein by reference in their entirety: "Sun Products Formulary" Cosmetics & Toiletries. vol. 105, pp. 122-139 (December 1990); "Sun Products Formulary", Cosmetics & Toiletries, vol. 102, pp. 117-136 (March 1987); patent of E.U.A. No. 4,960,764 of Figueroa et al., Issued October 2, 1990; and the patent of E.U.A. No. 4,254,105 to Fakuda et al., Issued October 31, 1981. The vehicles of the skin care compositions of the present invention may comprise from about 50% to about 99% by weight of the compositions of the invention. present invention, preferably from about 75% to about 99%, and much preferred from 85% to about 95%. Preferred cosmetic and / or pharmaceutically acceptable topical vehicles include hydro-alcoholic systems and oil-in-water emulsions. When the vehicle is a hydro-alcoholic system, the vehicle can comprise from about 0% to about 99% ethanol, isopropanol or mixtures thereof, and from about 1% to about 99% water. There is a greater preference for a vehicle comprising from about 5% to about 60% ethanol, sopropanol or mixtures thereof, and from about 40% to about 95% water. Particular preference is given to a vehicle comprising from about 20% to about 50% ethanol, isopropanol or mixtures thereof, and from about 50% to about 80% water. When the vehicle is an oil-in-water emulsion, the vehicle can include any common excipient ingredients for preparing such emulsions. A more detailed analysis of suitable vehicles is found in the U.S. patent. No. 5,605,894 to Blank et al., And in the U.S. patent. No. 5,681, 852 to Bissett, which are incorporated by reference in their entirety in the present invention.

Optional Components The humectant compositions of the present invention optionally may comprise a film-forming agent or a substantivity enhancer. The film forming agent or the substantivity enhancer of the present invention is, generally, a polymer or an organic resin which are soluble in the vehicle and which during the evaporation of the vehicle will form a relatively thin film, whereby the substantivity of the vitamin B3 compound is increased. The film-forming agent or the substantivity enhancer may be of natural or synthetic origin. Film-forming agents or substantivity enhancers include, but are not limited to, polyvinyl alcohol, ethylcellulose, methoxycellulose, hydroxyethylcellulose, nitrocellulose, beegum, polyvinylpyrrolidone, vinylpyrrolidone / vinyl acetate copolymers, eicosene copolymers and vinylpyrrolidone (an example of which can be obtained from GAF Chemical Corporation such as Ganex.RTM.V-220), vinyl acetate / unsaturated carboxylic acid copolymers, methyl methacrylate terpolymers / stearyl methacrylate / dimethylaminoethyl methacrylate, vinyl acetate terpolymers / allyl stearate / allyloxyacetic acid and maleic anhydride / methylvinyl ether copolymers such as those commercially known as "Gantrez AN" as well as the ethyl, isopropyl and butyl esters of these copolymers, and maleic anhydride / butyl vinyl ether copolymers. In desired form, the plasticizing agents are added to the composition to impart flexibility to the polymeric film. Suitable plasticizer agglomerates include, but are not limited to, polyethylene glycol, polyoxyethylene propylene glycol, polyoxypropylene glycol, polyoxyethylene and polyoxypropylene block copolymers, glycerin and various vegetable oils such as cottonseed oil, palm oil, rapeseed oil, sunflower oil , castor oil, and the like. In the preparation and evaluation of the film-forming polymers, it is known that the rate of release of the active ingredient from the polymer film depends on the nature of the plasticizing agent used. Hydrophobic plasticizing agents, such as vegetable oils, tend to impede the release rate of the active substance while hydrophilic materials such as polyoxypropylene glycol, polyethylene glycols and polyoxyethylene tend to increase the rate of release of the active substance from the movie. The humectant compositions of the present invention may optionally comprise additional skin active ingredients. Non-limiting examples of such active ingredients for the skin include hydroxy acids such as salicylic acid; exfoliation or peeling agents as zwitterionic surfactants; sunscreens such as 2-ethylhexyl-p-methoxycinnamate, 4,4-t-butylmethoxydibenzoyl-methane, octocrylene, phenylbenzimidazole sulfonic acid; sun blockers such as zinc oxide and titanium dioxide; anti-inflammatory agents; radical scavengers / antioxidants such as tocopherol and esters thereof; metal chelators, especially iron chelators; retinoids such as retinol, retina ilpalmitate, retinyl acetate, retinylpropionate and retinal; N-acetyl-L-cysteine and derivatives thereof; hydroxy acids such as glycolic acid, keto acids such as pyruvic acid; benzofuran derivatives; and skin protectors. Mixtures of any of the aforementioned skin active can also be used. A more detailed description of said assets is found in the patent of E.U.A. No. 5,605,894 to Blank et al., (Previously incorporated by reference). Preferred skin active ingredients include hydroxy acids such as salicylic acid, sunscreen, antioxidants and mixtures thereof. Other conventional skin care product additives may also be included in the compositions of the present invention. For example, urea, guanidine, glycerol, petrolatum, mineral oil, sugar esters and polyesters, polyolefins, methylisostearate, ethyl isostearate, cetylricinoleate, isononyl isononanoate, isohexadecane, lanolin, lanolin esters, cholesterol, salt / pyrrolidonecarboxylic acid can be used. (PCA), trimethylglycine (betaine), trans-sesame acid, amino acids (eg, serine, alanine) and / or its salts, panthenol and its derivatives, collagen, hyaluronic acid, elastin, hydrolysates, primrose oil, jojoba oil, factor of epidermal growth, soy saponins, mucopolysaccharides, and mixtures thereof. Other suitable or active additives for the skin are discussed in more detail in PCT application WO 97/39733, published October 30, 1997, by Oblong et al., Previously incorporated by reference in its entirety.

Preparation of the compositions The compositions of the present invention are generally prepared by conventional methods such as those known in the art of making topical compositions. Such methods typically involve mixing the ingredients in one or more steps to a relatively uniform state, with or without heating, cooling, application of vacuum, and the like. Non-limiting examples of the product form may be a gel, an emulsion, a lotion, a cream, a liquid, a solution, an ointment, etc.

Methods for moisturizing the skin The methods of the present invention are useful for moisturizing or moisturizing the skin in mammals (especially human skin, more especially skin of the face and body of human, more especially the skin of hands, legs and face of human), especially the epidermis and more especially the stratum corneum of the human skin. The methods of moisturizing or hydrating the skin of the present invention involve applying topically to the skin a safe and effective amount of the moisturizing or moisturizing composition of the skin of the present invention. Said regulation includes prophylactic and therapeutic regulation. The amount of the composition that is applied, the frequency of application and the period of use will vary widely depending on the level of vitamin B3 compound and / or other components of a certain composition and the level of wetting or hydration desired. However, to achieve the moisturizing or hydrating benefits of the present invention, the moisturizing or moisturizing composition must be applied so as to provide a minimum constant concentration of vitamin B3 on the skin of about 0.001 mg / cm2 to about 1 mg /. cm2. The term "constant", as used in the present invention, means that the level of the vitamin B3 compound does not vary below the minimum concentration by more than about 20%, preferably by no more than about 10% in a period of approximately 1-12 hours. The constant level can be achieved by reapplying the product to the skin, especially in areas of the body that are frequently washed during the day, such as the face and hands. In a preferred embodiment, the composition is topically applied chronically (or applied again such as after washing) to the skin. By "chronic topical application" is meant the continuous topical application of the composition for a prolonged period during the life of the subject, preferably for a period of at least about one week, more preferably for a period of at least about two weeks. weeks, even more preferred for a period of at least one month, even more preferably of at least about three months, even more preferably for at least about six months, and even more preferred for at least about one year. Although benefits are obtained after several maximum periods of use (for example, 5, 10 or 20 years), it is preferred that the chronic application continues throughout the life of the subject to maintain and / or increase the benefits achieved. Typically, applications would be in the order of about one to about four times per day during such extended periods; however, application regimens may be more than four times per day, especially for use on areas of the body that are frequently washed during the day, such as the face and hands. A large scale of amounts of the compositions of the present invention can be used to provide a benefit of appearance and / or skin feel. The amounts of the present compositions that are typically applied per application are, in mg composition / cm2 of the skin, from about 0.1 mg / cm2 to about 10 mg / cm2. A particularly useful application amount is from about 1 mg / cm2 to about 4 mg / cm2, a more particularly useful application amount being about 2 mg / cm2. The regulation of the condition of the skin is preferably practiced by applying a composition in the form of a lotion, cream, cosmetic or the like on the skin, which is desired to remain on the skin for a prolonged period, for a certain aesthetic, prophylactic, therapeutic benefit or of another type (that is, a "non-rinsable" composition). After applying the composition to the skin, it is preferably left on the skin for a period of at least about 5 minutes, more preferably at least about 20 minutes, even more preferably at least about 1 hour, more preferred at less several hours, for example, up to about 12 hours, before eliminating it, for example by washing. Another method to ensure continuous exposure of the skin to at least a minimum level of the vitamin B3 compound is to apply the compound using a patch. Such a method is particularly useful for problematic areas of the skin that need more intensive treatment. The patch may be occlusive, semi-occlusive or non-occlusive. The composition of the vitamin B3 compound can be contained within the patch or applied to the skin before applying the patch. The patch may also include additional active ingredients such as chemical initiators for the exothermic reactions such as those described in PCT application WO 9701313 for Burkett et al., Preferably the patch is applied (eg, on the face) overnight, as a form of night therapy.

EXAMPLES The following examples best describe and demonstrate the embodiments within the scope of the present invention. The examples are given solely for the purpose of illustration, and are not intended to be limiting of the present invention, since many variations thereof are possible without departing from the spirit and scope of the invention.

EXAMPLE 1 The following is an example of a skin cream incorporating the compositions of the present invention. The compositions are formed by combining and mixing the ingredients of each of the columns using conventional technology and then applying to the skin from about 0.5 to about 50 g.

EXAMPLE 2 The following is an example of a skin cream incorporating the compositions of the present invention. The compositions are formed by combining and mixing the ingredients of each of the columns using conventional technology and then applying to the skin from about 0.5 to about 50 g.

EXAMPLE 3 The following is an example of a skin cream incorporating the compositions of the present invention. The compositions are formed by combining and mixing the ingredients of each of the columns using conventional technology and then applying to the skin from about 0.5 to about 50 g. 1. Isohexadecane, Prespare Inc., South Plainfield, NJ. 2. Polyacrylamide (e) lsoparaffin of C13-14 (and) Laureth-7, Seppic Corporation, Fairfield, NJ. 3. Dimethicone (and) dimethiconol, Dow Corning Corp., Midland, MI. 4. Sorbitan monostearate and sucrose cocoate, ICI Americas Inc., Wilmington, DE. 5. Sucrose fatty acid ester, Procter and Gamble, Cincinnati, OH. 6. Stearyl alcohol, Procter and Gamble, Cincinnati, OH. 7.- Fiery 5 n / a, Procter and Gamble, Cincinnati, OH. 8. -DMDM hydantoin (and) iodopropynyl butylcarbamate, Lonza Inc., Fairlawn, NJ. 9. PEG-100 stearate, ICI Americas Inc., Wilmington, DE. 10. Stearic acid, Henkel Corp., Kankakee, IL. 11. Carbomer, BF Goodrich, Cleveland OH. 12. Carbomer, BF Goodrich, Cleveland OH.

Claims (10)

NOVELTY OF THE INVENTION CLAIMS

1. A method for adsorbing water in or absorbing water in the mammalian skin by applying to the skin a safe and effective amount of a skin care composition comprising: A. an agent that increases the adsorption or absorption of water that is selects from the group consisting of vitamin B3 compounds and mixtures thereof; and B. a dermatologically acceptable vehicle for said vitamin B3 compound.

2. A method according to claim 1, further characterized in that the adsorption or absorption of water occurs by increasing the level of concentration of skin proteins that are selected from the group consisting of filaggrin, keratin, involucrin and mixtures of the same.

3. A method according to any of the preceding claims, further characterized in that the concentration of the agent that increases the adsorption or absorption of water is greater than 5%.

4. A method according to any of the preceding claims, further characterized in that said vitamin B3 compound is selected from niacinamide, niacinamide derivatives, non-vasodilating nicotinic acid esters and mixtures thereof.

5. A method according to any of the preceding claims, further characterized in that the composition also comprises an additional active ingredient for the skin that is selected from the group consisting of hydroxy acids, exfoliating agents, sunscreens, antioxidants, retinoids and mixtures of the same.

6. A method according to any of the preceding claims, further characterized in that the hydroxy acid is salicylic acid; the exfoliation agent is selected from the group consisting of zwitterionic surfactants and mixtures thereof; the sunblock is selected from the group consisting of zinc oxide and titanium dioxide and mixtures thereof; the sunscreen is selected from the group consisting of 2-ethylhexyl-p-methoxycinnamate, 4,4'-t-butylmethoxydibenzoyl-methane, phenylbenzimidazole sulfonic acid, octocrylene, and mixtures thereof; the antioxidant is selected from the group consisting of tocopherol, the esters thereof and mixtures thereof; and the retinoid is selected from the group consisting of retinol, retinyl acetate, retinyl propionate and mixtures thereof.

7. A method for moisturizing or hydrating mammalian skin, comprising applying a safe and effective amount of a skin care composition comprising: a) a safe and effective amount of at least one vitamin B3 compound; and b) a cosmetically acceptable vehicle; such that a minimum concentration of about 0.001 mg / cm2 to about 1 mg / cm2 of the vitamin B3 compound is maintained on the skin.

8. - A method according to any of the preceding claims, further characterized in that the minimum concentration of vitamin B3 compound on the skin is achieved by repeated application of the composition to the skin.

9. A method according to any of the preceding claims, further characterized in that the composition for skin care further comprises a film-forming agent or a substantivity enhancer.

10. An article of manufacture containing a composition for skin care comprising from about 0.1% to about 40% of a vitamin B3 compound in a package for said composition for skin care together with the information about and / or instructions on the use of vitamin B3 compounds to improve moisturization or hydration of the skin.