WO1992017159A2

WO1992017159A2 - Stabilized emulsion compositions for imparting an artificial tan to human skin

Info

Publication number: WO1992017159A2
Application number: PCT/US1992/001980
Authority: WO
Inventors: Frederik Winfield Woodin, Jr.
Original assignee: Richardson-Vicks Inc.
Priority date: 1991-04-03
Filing date: 1992-03-13
Publication date: 1992-10-15
Also published as: AU1775592A; MA22491A1; IE921053A1; WO1992017159A3; MX9201525A; PT100338A; TR25613A; CN1066182A

Abstract

The present invention relates to stabilized emulsion compositions for imparting an artificial tan to human skin. These emulsions contain dihydroxyacetone, at least one alkyl phosphate, and at least one carboxylic acid copolymer in which the ratio of alkyl phosphate to carboxylic acid copolymer is from about 5:1 to about 1:5. In further embodiments, these emulsion compositions contain one or more sunscreens, and are also useful for protecting human skin from the harmful effects of sunlight and other sources of ultraviolet radiation. The present invention also relates to methods for preparing these compositions, methods for providing an artificial tan to human skin, and methods for protecting human skin from the harmful effects of ultraviolet radiation.

Description

STABILIZED EMULSION COMPOSITIONS FOR IMPARTING AN ARTIFICIAL TAN TO HUMAN SKIN

TECHNICAL FIELD

The present invention relates to emulsion compositions having improved stability which are useful for imparting an artificial tan to human skin. These emulsions contain dihydroxyacetone, at least one alkyl phosphate, and at least one carboxylic acid copolymer in which the ratio of alkyl phosphate to carboxylic acid copolymer is from about 5:1 to about 1:5. In further embodiments, these emulsion compositions contain one or more sunscreens, and are also useful for protecting human skin from the harmful effects of sunlight and other sources of ultraviolet radiation. The present invention also relates to methods for preparing these compositions, methods for providing an artificial tan to human skin, and methods for protecting human skin from the harmful effects of ultraviolet radiation.

BACKGROUND OF THE INVENTION

It is generally known that dihydroxyacetone, when applied topically to human skin, will produce a tanned appearance, i.e. an artificial tan. U.S. Patent No. 4,708,865, to Turner, issued November 24, 1987 describes the use of hydro-alcoholic solutions of dihydroxyacetone for tanning the skin; U.S. Patent No. 4,466,805, to Welters, issued August 21, 1984 describes hair and skin coloring formulations containing dihydroxyacetone; and U.S. Patent No. 2,949,493, to Andreadis et al., issued August 16, 1960 describes artificial tanning formulations containing dihydroxyacetone in an oleaginous base. However, it is also known that emulsion products containing dihydroxyacetone have a short shelf life, tending to darken and develop disagreeable off-odors over time with a conco mitant loss of emulsion integrity. Dihydroxyacetone is relatively sensitive to heat, light, moisture, and alkaline pH. Dihydroxyacetone can react with other ingredients in a formulation, especially with nitrogen-containing compounds, such as amines, amino

UB_STIT_UTESHEET acids, and the like. In fact, without being limited by theory, d hydroxyacetone is believed to provide an artificial tan to human skin by its reaction with the nitrogen containing proteins of the skin. See L. Goldman et al., "Investigative Studies with the Skin Coloring Agents Dihyroxyacetone and Glyoxal", The Journal of Investigative Dermatology, vol. 35, pp. 161-164 (1960); and E. Wittgenstein et al., "Reaction of Dihydroxyacetone (DHA) with Human Skin Callus and Amino Compounds", The Journal of Investigative Dermatology, vol. 36, pp. 283-286 (1961).

Currently available artificial tanning products have the disadvantage of not providing the desired control over color development of the tan. Artificial tans are often either too light or too dark, and tend to be too orange, uneven, or unnatural in appearance. Furthermore, artificial tans tend to take too long to develop, and once obtained, tend to fade too quickly and unevenly. Therefore, it would be highly desirable to provide dihydroxyacetone containing products which are chemically and physically stable, which are aesthetically pleasing, and which overcome these color development limitations.

A sun-tanned appearance is a symbol of a healthy, dynamic, and active life. Yet, the damaging effects of sunlight and artificial sources of ultraviolet radiation on the skin are well documented. Furthermore these effects are cumulative and potentially serious. These effects include erythema (i.e. sunburn), skin cancer, and premature aging of the skin. These adverse effects associated with exposure to ultraviolet radiation are more fully discussed in DeSimone, "Sunscreen and Suntan Products", Handbook of Nonprescription Drugs, 7th Ed., Chapter 26, pp. 499-511 (American Pharmaceutical Association, Washington, D.C.; 1982); Grove and Forbes, "A Method for Evaluating the Photoprotection Action of Sunscreen Agents Against UV-A Radiation", International Journal of Cosmetic Science. 4, pp. 15-24 (1982); and U.S. Patent 4,387,089, DePolo, issued June 7, 1983; the disclosures of all of which are incorporated herein by reference.

Sunscreens are the most common agents used for sun protection. However, sunscreens also have the disadvantage of preventing or greatly diminishing the cosmetically desirable tanning response. Thus, if an individual uses a sunscreen for protection from ultraviolet radiation, he or she is forced to forego a tanned appearance. Therefore, it would be highly desirable to provide protection from the harmful effects of ultraviolet radiation, and yet at the same time deliver a tanned appearance to the skin.

Furthermore, even if an individual is willing to accept the risks associated with exposure to ultraviolet radiation in order to obtain a tan, there are situations in which it may not be practical or even possible to do so because of time constraints, weather conditions, time of day, season of the year, geographic limitations, unavailability of an artificial ultraviolet radiation source, and the like. Therefore, it would be highly desirable to provide products that can deliver a tanned appearance whenever desired without the need for ultraviolet radiation.

Therefore, it would be highly desirable to provide a dihydroxy¬ acetone containing emulsion for delivering both an artificial tan and also for providing protection from ultraviolet radiation. The combination of 3% dihydroxyacetone with 0.25% lawsone as a sunscreen active combination is described in the Federal Register. Vol. 43, No. 166, pp. 38206-38269, August 25, 1978, this reference being incorporated herein by reference in its entirety. However, this combination is unsuitable for high SPF products. Furthermore, lawsone is a high melting bright yellow solid which is difficult to formulate and which is not readily available from suppliers in the United States. U.S. Patent No. 3,177,120, to Black et al., issued April 6, 1965 and U.S. Patent No. 4,434,154, to McShane, issued February 28, 1984 disclose dihydroxyacetone containing formulations which also incorporate a sunscreen. The '120 patent teaches compositions limited to the use of a single sunscreen not containing active amino groups (e.g., either homomenthyl salicylate or 2-ethoxy ethyl p-methoxy cinnamic acid); the '154 patent is limited to the use of octyl dimethyl PABA. However, homomenthyl salicylate is a very weak sunscreen unsuitable for use in products designed to delivered a high sun protection factor (i.e. SPF). Similarly, it is difficult to deliver high SPFs using either 2-ethoxy ethyl p-methoxy cinnamic acid or octyl dimethyl PABA, alone. Furthermore, due to growing consumer concerns over the use of PABA and PABA esters in SUBSTITUTESHEET sunscreen products, it would be preferable to develop dihydroxy¬ acetone containing products which do not contain PABA and PABA derivatives. Therefore, the need exists for stabilized products which are effective for providing an artificial tan and which also provide adequate protection against ultraviolet radiation.

Finally, it is generally known that phosphates and phosphate e ulsifiers are useful for preparing stable emulsions of acidic pH. However, despite this general utility, the prior art actually teaches away from incorporating phosphates into dihydroxyacetone containing emulsions. M.F. Bobin et al . "Etude de la Conservation de la Dihydroxyacetone en Fonction de la Formulation (Study on Dihydroxyacetone Preservation as a Function of Formulation)", Farmaco, Ed. Prat., vol. 38., no. 11, pp. 415-428 (1983), this reference being incorporated herein in its entirety, discloses that phosphates adversely affect the stability of dihydroxyacetone in emulsion systems. In contrast, the present invention clearly demonstrates that the combination of an alkyl phosphate and a carboxylic acid copolymer at certain ratios provides emulsion systems in which the dihydroxyacetone is unexpectedly stable.

It is therefore an object of the present invention to provide emulsion compositions for imparting an artificial tan to human skin. Another object of the present invention is to provide emulsion compositions for imparting an artificial tan which exhibit a high degree of chemical and physical stability. A further object of the present invention is to provide stabilized emulsion compositions which are aesthetically appealing to consumers. A still further object of the present invention is to provide compositions for both imparting an artificial tan to human skin and also for protecting the skin from ultraviolet radiation. It is an even further object of the present invention is provide a method for artificially tanning human skin. It is another object of the present invention to provide a method for both artificially tanning human skin and for providing protection against ultraviolet radiation.

These and other objects of this invention will become apparent in light of the following disclosure.

SUBSTITUTE SHEET SUMMARY OF THE INVENTION The present invention relates to an artificial tanning oil-in-water emulsion composition having improved stability, comprising:

(a) from about 0.1% to about 20% dihydroxyacetone,

(b) from about 0.1% to about 5% of at least one alkyl phosphate, and

(c) from about 0.025% to about 2% of at least one carboxylic acid copolymer, wherein the ratio of said alkyl phosphate to said carboxylic acid copolymer is from about 5:1 to about 1:5, and wherein said emulsion composition has a pH from about 2.5 to about 6.

All percentages and ratios used herein are by weight and all measurements are at 25°C, unless otherwise indicated. DETAILED DESCRIPTION OF THE INVENTION Emulsion Compositions

The compositions of the instant invention are in the form of oil-in-water emulsions whereby the oil phase can contain typical oil-soluble components and the water phase can contain typical water-soluble materials. These types of emulsions are preferred because of their desirable aesthetic properties and their utility as vehicles for the dihydroxyacetone and the other essential and optional components of this invention. These emulsions can cover a broad range of consistencies including lotions, light creams, heavy creams, and the like.

To obtain an artificial tan using the emulsions of the instant invention, an effective amount of the emulsion is topically applied to human skin. By "effective" is meant an amount sufficient to provide an artificial tan when the composition is topically applied, but not so much as to cause any side effects or skin reactions. Quantities of emulsion which can be topically applied to provide an artificial tan are about, but not limited to, 2 mg/cm². pH Reouirements

The pH of a formulation is an important factor in determining the stability of the dihydroxyacetone. For example, it is well known that dihydroxyacetone rapidly degrades at extremes of alkaline pH. Suppliers of dihydroxyacetone suggest a preferred formulation pH range of between 4 and 6, and recommend the use of a buffer

SUBSTITUTESHEET syste to stabilize the pH value at about 5. See "Dihydroxyacetone for Cosmetics", E. Merck Technical Bulletin, 03-304 110, 319 897, 180588, this reference being incoporated herein by reference in its entirety. However, the compositions of the instant invention preferably do not contain a buffer, because it has been determined that unbuffered formulations demonstrate improved chemical and physical stability compared to buffered formulations. The unbuffered compositions of the instant invention preferably have a pH range from about 2.5 to about 7, more preferably from about 2.5 to about 6, even more preferably from about 3.5 to about 4.75, and most preferably from about 3.85 to about 4.50. Dihydroxyacetone

An essential component of the present compositions is dihydroxyacetone. Dihydroxyacetone, which is also known as DHA or l,3-dihydroxy-2-propanone, is a white to off-white, crystalline powder having a characteristic sweet, cooling taste. The compound can exist as a mixture of monomers and dimers, with the dimer predominating. Heating or melting dimeric dihydroxyacetone converts the material into the monomeric form. The conversion of the dimer to the monomer also takes place in aqueous solution. See The Merck Index, Tenth Edition, entry 3167, p. 463 (1983), this reference being incorporated herein by reference in its entirety.

Without being limited by theory, it is believed that dihydroxyacetone reacts with the amino acids and amino groups of the skin keratin forming the brown colored compounds which provide an artificial tan. The process takes place in the outer layers of the epidermis. It is believed that the monomer is the active form responsible for this phenomenon. There is much evidence to suggest that the reaction of dihydroxyacetone with the components of the skin is similar to the Maillard Reaction. In this reaction, reducing sugars react with amino acids, proteins, and peptides to form various adducts which are ultimately converted into brown-colored compounds. See V.R. Usdin, Artificial Tanning Preparations, Cosmetics and Toiletries, vol. 91 pp. 29-32 (March 1976), this reference being incorporated herein by reference in its entirety. Dihydroxyacetone is commercially available from E. Merck

B_STITUTESHEET (Darmstadt, F.R. Germany) and Gist-Brocades Food Ingredients, Inc. (King of Prussia, PA).

The dihydroxyacetone of the emulsion compositions of the instant invention is present from about 0.1% to about 20%, more preferably from about 2% to about 7%, and most preferably from about 3% to about 5%. Alkyl Phosphate

An essential component of the present compositions is an alkyl phosphate. These alkyl phosphates correspond to the general formula:

0 R---0---P---0X OH

wherein R is alkyl or alkenyl having an average of from about 10 to about 20 carbon atoms, and X is selected from the group consisting of hydrogen, alkali metal, ammonium, and substituted ammonium (e.g. alkylammonium, alkoxylated ammonium, and polyethoxylated ammonium). Mixtures of more than one alkyl phosphate component are useful in the compositions disclosed herein.

Preferred are the alkyl phosphates in which R is a C-16 alkyl moiety and X is selected from the group consisting of hydrogen, potassium, ethanolamine, diethanolamine, and triethanolamine. Preferred alkyl phosphates useful in the present invention include potassium cetyl phosphate, ethanolamine cetyl phosphate, diethanolamine cetyl phosphate, triethanolamine cetyl phosphate, cetyl phosphate, and mixtures thereof. Most preferred are potassium cetyl phosphate, diethanolamine cetyl phosphate, cetyl phosphate, and mixtures thereof. Potassium cetyl phosphate (provisional CTFA designation) is commercially available from L. Givaudan & Cie SA (Geneva, Switzerland) under the Amphisol^R K trademark. Diethanolamine cetyl phosphate (CTFA designation DEA-Cetyl Phosphate) and cetyl phosphate (CTFA designation) are commercially available from L. Givaudan & Cie SA (Geneva, Switzerland) under the Amphisol^R trademark. These alkyl phosphates are further described in "AmphisolR", Givaudan Technial Bulletin E-11012R1/1286/500 (1986); "Amphisol^R K", Givaudan Technical Bulletin 015/1187/2500 (1987); and CTFA Cosmetic Ingredient Dictionary, Third Edition (1982), pp. 47 and 72; these references being incorporated herein in their entirety.

The alkyl phosphate of the instant invention is present from about 0.1% to about 5%, more preferably from about 0.25% to about 1.5%, and most preferably from about 0.5% to about 1.0%. Carboxylic Acid Copolymer

Another essential component of the compositions of the present invention is a carboxylic acid copolymer (i.e. an acrylic acid copolymer). These copolymers consist essentially of a colloidally water-soluble polymer of acrylic acid crosslinked with a polyalkenyl polyether of a polyhydric alcohol, and optionally an acrylate ester or a polyfunctional vinylidene monomer.

Preferred copolymers useful in the present invention are polymers of a monomeric mixture containing 95.9 to 98.8 weight percent of an olefinically unsaturated carboxylic monomer selected from the group consisting of acrylic, methacrylic and ethacrylic acids; about 1 to about 3.5 weight percent of an acrylate ester of the formula:

Rl 0 CH₂=C—C---0—R wherein R is an alkyl radical containing 10 to 30 carbon atoms and Rl is hydrogen, methyl or ethyl; and 0.1 to 0.6 weight percent of a polymerizable cross-l nking polyalkenyl polyether of a polyhydric alcohol containing more than one alkenyl ether group per molecule wherein the parent polyhydric alcohol contains at least 3 carbon atoms and at least 3 hydroxyl groups.

Preferably, these polymers contain from about 96 to about 97.9 weight percent of acrylic acid and from about 2.5 to about 3.5 weight percent of acrylic esters wherein the alkyl group contains 12 to 22 carbon atoms, and R¹ is methyl, most preferably the acrylate ester is stearyl methacrylate. Preferably, the amount of crosslinking polyalkenyl polyether monomer is from about 0.2 to 0.4 weight percent. The preferred crosslinking polyalkenyl polyether monomers are allyl pentaerythritol, trimethylolpropane diallylether or allyl sucrose. These polymers are fully described in U.S. Patent

SUB^STITUTESHEET 4,509,949, to Huang et al . , issued April 5, 1985, this patent being incorporated herein by reference.

Other preferred copolymers useful in the present invention are the polymers which contain at least two monomeric ingredients, one being a monomeric olefinically-unsaturated carboxylic acid, and the other being a polyalkenyl, polyether of a polyhydric alcohol. Additional monomeric materials can be present in the monomeric mixture if desired, even in predominant proportion.

The first monomeric ingredient useful in the production of these carboxylic polymers are the olefinically-unsaturated carboxylic acids containing at least one activated carbon-to-carbon olefinic double bond, and at least one carboxyl group. The preferred carboxylic monomers are the acrylic acids having the general structure R2 CH2=C---C00H, wherein R2 is a substituent selected from the class consisting of hydrogen, halogen, and the cyanogen (--C=N) groups, monovalent alkyl radicals, monovalent alkaryl radicals and monovalent cycloaliphatic radicals. Of this class, acrylic, methacrylic, and ethacrylic acid are most preferred. Another useful carboxylic monomer is maleic anhydride or the acid. The amount of acid used will be from about 95.5 to about 98.9 weight percent of the total monomers used. More preferably the range will be from about 96 to about 97.9 weight percent.

The second monomeric ingredient useful in the production of these carboxylic polymers are the polyalkenyl polyethers having more than one alkenyl ether grouping per molecule. The most useful possess alkenyl groups in which an olefinic double bond is present attached to a terminal methylene grouping, CH2=C<.

The additional monomeric materials which can be present in the polymers include polyfunctional vinylidene monomers containing at least two terminal CH2< groups, including for example, butadiene, isoprene, divinyl benzene, divinyl naphthalene, allyl acrylates, and the like. These polymers are fully described in U.S. Patent 2,798,053, to Brown, H.P., issued July 2, 1957, this patent being incorporated herein by reference.

SUBSTITUTESH€ET Examples of carboxylic acid copolymers useful in the present invention include Carbomer 934, Carbomer 941, Carbomer 950, Carbomer 951, Carbomer 954, Carbomer 980, Carbomer 981, Carbomer 1342, and Acrylates/Cιo-30 Alkyl Acrylate Cross Polymers (available as CarbopolR 934, CarbopolR 941, CarbopolR 950, CarbopolR 951, CarbopolR 954, CarbopolR 980, CarbopolR 981, CarbopolR 1342, and the Pemulen Series, respectively, from B.F. Goodrich).

Other carboxylic acid copolymers useful in the present invention include sodium salts of acrylic acid/acrylamide copolymers sold by the Hoechst Celanese Corporation under the trademark of Hostaceren PN73. Also included are the hydrogel polymers sold by Lipo Chemicals Inc. under the trademark of HYPAN hydrogels. These hydrogels consist of crystalline pucks of nitrites on a C-C backbone with various other pendant groups such as carboxyls, amides, and amidines. An example would include HYPAN SA100 H, a polymer powder available from Lipo Chemical.

The carboxylic acid copolymers can be used individually or as a mixture of two or more polymers and comprise from about 0.025% to about 2.00%, preferably from about 0.1% to about 1.50% and most preferably from about 0.40% to about 1.25% percent of the compositions of the present invention. Ratio of Alkyl Phosphate Salt to Carboxylic Acid Copolymer

An important criticality of the compositions of the instant invention is that the alkyl phosphate component(s) and the carboxylic acid copolymer component(s) are present in a proper ratio. Preferably, the ratio of the total amount of alkyl phosphate to carboxylic acid copolymer should be from about 5:1 to about 1:5, more preferably from about 2.5:1 to about 1:2.5, and most preferably from about 1.5:1 to about 1:1.5.

Optional Components Each of the water and oil phases of the oil-in-water emulsions can comprise a wide variety of optional components. Typical of such optional components are: Sunscreens

A wide variety of one or more conventional sunscreening agents are suitable for use in the present invention. Segarin, et al., at Chapter VIII, pages 189 et seq., of Cosmetics Science and Technology, disclose numerous suitable agents. Specific suitable sunscreening agents include, but are not limited to, for example: Ethylhexyl-p-methoxycinnamate (available as Parsol MCX from Givaudan Corporation), p-Aminobenzoic acid, its salts and its derivatives (ethyl, isobutyl, glyceryl esters; p-dimethylaminobenzoic acid; 2-ethylhexyl N,N-dimethylaminobenzoate); p-Methoxycinnamic Acid Diethanolamine Salt (available as Bernel Hydro from Bernel Chemical Co.); Anthranilates (i.e., o-aminobenzoates; methyl, octyl, a yl , menthyl, phenyl, benzyl, phenylethyl, linalyl, terpinyl, and cyclo- hexenyl esters); Salicylates (octyl, amyl, phenyl, benzyl, menthyl, glyceryl, and dipropyleneglycol esters); Cinnamic acid derivatives (menthyl and benzyl esters, -phenyl cinna onitrile; butyl cinnamoyl pyruvate); Dihydroxycinna ic acid derivatives (umbel!iferone, methylumbelliferone , methylaceto-umbelliferone); Trihydroxycinnamic acid derivatives (esculetin, methylesculetin, daphnetin, and the glucosides, esculin and daphnin); Hydrocarbons (diphenylbutadiene, stilbene); Dibenzalacetone and benzalacetophenone; 2-Phenyl-benzimidazole-5-sulfonic acid and its salts; Naphtholsulfonates (sodium salts of 2-naphthol 3,6-disulfonic and of 2-naphthol-6,8-disulfonic acids); Dihydroxy-naphthoic acid and its salts; o- and p-Hydroxybiphenyldisulfonates; Cou arin derivatives (7-hydroxy, 7-methyl, 3-phenyl); Diazoles (2-acetyl-3-bromoindazole, phenyl benzoxazole, methyl naphthoxazole, various aryl benzothi- azoles); Quinine salts (bisulfate, sulfate, chloride, oleate, and tannate); Quinoline derivatives (8-hydroxyquinoline salts, 2-phenyl- quinoline); Hydroxy- or methoxy-substituted benzophenones; Uric and vilouric acids; Tannic acid and its derivatives (e.g., hexaethyl- ether); (Butyl carbityl) (6-propyl piperonyl) ether; Hydroquinone; Benzophenones (Oxybenzene, Sulisobenzone, Dioxybenzone, Benzoresorcinol , 2,2',4,4'-Tetrahydroxybenzophenone , 2,2'- Dihydroxy-4,4'-dimethoxybenzophenone, Octabenzone; 4-1sopropyldiben- zoylmethane; Butylmethoxydibenzoyl ethane; Octocrylene; 4-isopropyl- di-benzoylmethane; and camphor derivatives such as methyl benzylidene or benzylidene camphor; and mixtures thereof. Other sunscreens include the solid physical sunblocks such as titanium dioxide (micronized titanium dioxide, 0.03 microns), zinc oxide, silica, iron oxide and the like. Without being limited by theory, it is believed that these inorganic materials provide a sunscreening benefit through reflecting, scattering, and absorbing harmful UV, visible, and infrared radiation.

Typically, a safe and photoprotectively effective amount of sunscreen(s) can be used in the artificial tanning emulsions of the present invention. By "safe and photoprotectively" is meant an amount sufficient to provide photoprotection when the composition is applied, but not so much as to cause any side effects or skin reactions. Generally, the sunscreen(s) can comprise from about 0.5% to about 20% of the composition. Exact amounts will vary depending upon the sunscreen chosen and the desired Sun Protection Factor (SPF). SPF is a commonly used measure of photoprotection of a sunscreen against erythema. See Federal Register, Vol. 43, No. 166, pp. 38206-38269, August 25, 1978.

Other useful sunscreens are those disclosed in U.S. Patent 4,937,370, to Sabatelli, issued June 26, 1990; and U.S. Patent 4,999,186, to Sabatelli et al., issued March 12, 1991; these two references being incorporated by reference herein. The sunscreening agents disclosed therein have, in a single molecule, two distinct chromophore moieties which exhibit different ultra-violet radiation absorption spectra. One of the chromophore moieties absorbs pre¬ dominantly in the UVB radiation range and the other absorbs strongly in the UVA radiation range.

These sunscreening agents provide higher efficacy, broader UV absorption, lower skin penetration and longer lasting efficacy rela¬ tive to conventional sunscreens.

Preferred members of this class of sunscreening agents are 4- N,N-(2-ethylhexyl)methylaminobenzoic acid ester of 2,4-dihydroxybenzophenone; N,N-di-(2-ethylhexyl)-4-aminobenzoic acid ester with 4-hydroxydibenzoylmethane; 4-N,N(2-ethylhexyl) methylaminobenzoic acid ester with 4-hydroxydibenzoylmethane; 4-N,N-(2-ethylhexyl)methylaminobenzoic acid ester of 2-hydroxy-4-(2-hydroxyethoxy)benzophenone; 4-N,N-(2-ethylhexyl) methylaminobenzoic acid ester of 4-(2-hydroxyeth- oxy)dibenzoylmethane; N-N-di-(2-ethylhexyl)-4-aminobenzoic acid ester of 2-hydroxy-4-(2-hydroxyethoxy)benzophenone; and

TE SHEET N,N-di-(2-ethylhexyl)4-aminobenzoic acid ester of 4-(2-hydroxyethoxy)dibenzoylmethane; and mixtures thereof. Humectants/Moisturizers

The artifical tanning compositions of the instant invention can also contain one or more humectants/moisturizers. A variety of humectants/moisturizers can be employed and can be present at a level of from about 1% to about 30%, more preferably from about 2% to about 8% and most preferably from about 3% to about 5%. These materials include urea; guanidine; glycolic acid and glycolate salts (e.g. ammonium and quaternary alkyl ammonium); lactic acid and lactate salts (e.g. ammonium and quaternary alkyl ammonium); polyhydroxy alcohols such as sorbitol, glycerin, hexanetriol, propylene glycol, hexylene glycol and the like; polyethylene glycol; sugars and starches; sugar and starch derivatives (e.g. alkoxylated glucose); D-panthenol ; hyaluronic acid; lactamide monoethanolamine; acetamide monoethanolamine; and mixtures thereof.

Preferred humectants/moisturizers for use in the compositions of the present invention are the C3-C6 diols and triols. Especially preferred is the triol, glycerin. Emollients

The compositions of the present invention can also optionally comprise at least one emollient. Examples of suitable emollients include, but are not limited to, volatile and non-volatile silicone oils, highly branched hydrocarbons, and non-polar fatty acid and fatty alcohol esters, and mixtures thereof. Emollients useful in the instant invention are further described in U.S. Patent No. 4,919,934, to Deckner et al., issued April 24 1990, which is incorporated herein by reference in its entirety.

The emollients can typically comprise in total from about 1% to about 50%, preferably from about 1% to about 25%, and more preferably from about 1% to about 10% by weight of the compositions of the present invention. E ulsifiers

The compositions of the present invention can also comprise additional emulsifiers and surfactants. Suitable emulsifiers can include, but are not limited to, polyethylene glycol 20 sorbitar. monolaurate (Polysorbate 20), polyethylene glycol 5 soya sterol .

SUBSTITUTE SHEET polyethylene glycol 100 stearate, polyethylene glycol 20 stearyl ether, Ceteareth-20, Ceteth-2, Ceteth-10, Polysorbate 80, and mixtures thereof. Examples of a broad variety of additional emulsifiers and surfactants useful herein are described in McCutcheon's, Detergents and Emulsifiers. North American Edition (1986), published by Allured Publishing Corporation, which is incorporated herein by reference in its entirety. Vitamins

Various vitamins can also be included in the compositions of the present invention. Non-limiting examples include Vitamin A, and derivatives thereof, ascorbic acid, Vitamin B, biotin, Vitamin D, Vitamin E and derivatives thereof such as tocopheryl acetate, panthothenic acid, and mixtures thereof can also be used. Other Optional Components

A variety of additional ingredients can be incorporated into the emulsion compositions of the present invention. Non-limiting examples of these additional ingredients include various polymers for aiding the film-forming properties and substantivity of the formulation; gums, resins, and thickeners; preservatives for maintaining the antimicrobial integrity of the compositions; antioxidants; chelators and sequestrants; and agents suitable for aesthetic purposes such as fragrances, pigments, and colorings.

EXAMPLES

The following examples further describe and demonstrate embodiments within the scope of the present invention. The examples are given solely for the purpose of illustration and are not to be construed as limitations of the present invention, as many variations thereof are possible without departing from the spirit and scope of the invention.

Ingredients are identified by chemical or CTFA name.

EXAMPLE I Artificial Tanning Lotion

An oil-in-water emulsion is prepared by combining the following components utilizing conventional mixing techniques. Ingredients % Weight

Phase A

SUBSTITUTESHEET

^Available as CarbopolR 934 from B.F. Goodrich. 2Available as CarbopolR 980 from B.F. Goodrich. ³AvaiTable as Pemulen TRl from B.F. Goodrich.

SUBSTITUTE SHEET In a suitable vessel the Phase A ingredients are dispersed in the water and heated to 75-85°C. In a separate vessel the Phase B ingredients are combined and heated to 85-90°C until melted. Next, the DEA-Cetyl Phosphate is added to the liquid Phase B and stirred until dissolved. This mixture is then added to Phase A to form the emulsion. The emulsion is cooled to 40-45°C with continued mixing. Next, in a separate vessel, the dihydroxyacetone is dissolved in water and the resulting solution is mixed into the emulsion. In another vessel, the Phase E ingredients are heated with mixing to 40-45°C until a clear solution is formed and this solution is then added to the emulsion. Finally, the Phase F ingredients are added to the emulsion with mixing, which is then cooled to 30-35°C, and then to room temperature.

This emulsion is useful for topical application to the skin to provide an artificial tan.

EXAMPLE II Artificial Tanning Cream

An oil-in-water emulsion is prepared by combining the following components utilizing conventional mixing techniques. n redients % Weight

SUBST Phase C

DEA-Cetyl Phosphate 0.40

Potassium Cetyl Phosphate 0.40

Phase D

Dihydroxyacetone 3.00

Phase E

Butylene Glycol 2.00

Imidazolidinyl Urea 0.25

Phase F

Fragrance 1.00

Cyclomethicone 2.00

Dimethicone 1.00

^Available as CarbopolR 980 from B.F. Goodrich. 2Available as Pemulen TR2 from B.F. Goodrich, available as Pemulen TRl from B.F. Goodrich.

An emulsion is prepared from the above ingredients employing the method described in Example I.

EXAMPLE III Low SPF Artificial Tanning Lotion

Phase A

Water qs 100

Carbomer 9541 n.30

Acrylic Acid Copolymer² 0.30

Xanthan Gum 0.35

Phase B

SUBSTITUTE SHEET Octyl Methoxycinnamate 3.00 Octyl Salicylate 0.50 Isostearyl Benzoate 9.50 Myristyl Myristate 1.00 Stearyl Alcohol 1.00 Shea Butter 1.00 Cetyl Alcohol 1.00

Phase C

DEA-Cetyl Phosphate 0.75

Phase D Dihydroxyacetone 3.00

Phase E

Butylene Glycol 2.00

DMDM Hydantoin (and)

Iodopropynyl Butylcarbamate 0.25

Phase F

Fragrance 1.00

Cyclometh cone 2.00

lAvaiTable as Carbopol 954 from B.F. Goodrich. ²AvaiTable as Pe uTen TRl from B.F. Goodrich.

This emulsion is useful for topical application to the skin to provide an artificial tan and to provide protection to the skin from the harmful effects of ultraviolet radiation.

EXAMPLE IV Moderate SPF Artifical Tanning Cream

An oil-in-water emulsion is prepared by combining the following components utilizing conventional mixing techniques. Ingredients % Weight Phase A

Butylene Glycol 2.00

DMDM Hydantoin (and)

Iodopropynyl Butylcarbamate 0.25

Phase F

Fragrance 1.00

Cyclomethicone 2.00

lAvailable as CarbopolR 980 from B.F. Goodrich. ²AvaiTable as PemuTen TR2 from B.F. Goodrich. ³AvaiTable as PemuTen TRl from B.F. Goodrich.

SUBSTITUTE SHEET This emulsion is useful for topical application to the skin to provide an artificial tan and to provide protection to the skin from the harmful effects of ultraviolet radiation.

EXAMPLE V High SPF Artificial Tanning Cream

An oil-in-water emulsion is prepared by combining the following components utilizing conventional mixing techniques. In redients % W i

Butylene Glycol 2.00

DMDM Hydantoin (and)

Iodopropynyl Butylcarbamate 0.25

SUBSTITUTE SHEET Phase F

Fragrance 1.00

Cyclomethicone 2.00

lAvailable as CarbopolR 954 from B.F. Goodrich. ²Available as Pemulen TR2 from B.F. Goodrich, available as Pemulen TRl from B.F. Goodrich.

SUBSTITUTE SHEET

Claims

WHAT IS CLAIMED IS:

1. An artifical tanning oil-in-water emulsion composition having improved stability, comprising:

(a) from 0.1% to 20% dihydroxyacetone,

(b) from 0.1% to 5% of at least one alkyl phosphate, and

(c) from 0.025% to 2% of at least one carboxylic acid copolymer, wherein the ratio of said alkyl phosphate to said carboxylic acid copolymer is from 5:1 to 1:5, and wherein said emulsion composition has a pH from 2.5 to 6.

2. The emulsion composition according to Claim 1 wherein said ratio is from 2.5:1 to 1:2.5, more preferably from 1.5:1 to 1:1.5.

3. The emulsion composition according to Claim 2 wherein said composition has a pH from 3.5 to 4.75, more preferably from 3.85 to 4.50.

4. The emulsion composition according to Claim 3 wherein said dihydroxyacetone comprises from 2% to 7%, more preferably from 3% to 5%.

5. The emulsion composition according to Claim 4 wherein said alkyl phosphate is selected from the group consisting of potassium cetyl phosphate, ethanolamine cetyl phosphate, diethanolamine cetyl phosphate, triethanolamine cetyl phosphate, cetyl phosphate, and mixtures thereof.

6. The emulsion composition according to Claim 5 wherein said alkyl phosphate is selected from the group consisting of potassium cetyl phosphate and diethanolamine cetyl phosphate and mixtures thereof.

SUBSTITUTE S

7. The emulsion composition according to Claim 6 wherein said carboxylic acid copolymer is selected from the group consisting of Carbomer 954, Carbomer 980, Carbomer 1342, Acrylic Acid Copolymer Pemulen TRl, Acrylic Acid Copolymer Pemulen TR2, and mixtures thereof.

8. The emulsion composition according to Claim 7 wherein said composition further comprises from 0.5% to 20% of at least one sunscreen agent selected from the group consisting of ethylhexyl-p-methoxycinnamate, octyl salicylate, octocrylene, 2-ethylhexyl N,N-dimethylaminobenzoate, 2-Phenyl-benzimidazole-5-sulfonic acid, 4-N,N-(2-ethylhexyl )- methylaminobenzoic acid ester of 2,4-dihydroxybenzophenone, N,N-di-(2-ethylhexyl)-4-aminobenzoic acid ester with 4-hy- droxydibenzoylmethane, 4-N,N(2-ethylhexyl) methylaminobenzoic acid ester with 4-hydroxydibenzoylmethane, 4-N,N-(2-ethylhexyl)methylaminobenzoic acid ester of 2-hydroxy-4-(2-hydroxyethoxy)benzophenone, 4-N,N-(2-ethylhexyl) methylaminobenzoic acid ester of 4-(2-hydroxyeth- oxy)dibenzoylmethane, N-N-di-(2-ethylhexyl)-4-aminobenzoic acid ester of 2-hydroxy-4-(2-hydroxyethoxy)benzophenone, N,N-di-(2-ethylhexyl)4-aminobenzoic acid ester of 4-(2-hydroxyethoxy)dibenzoylmethane, titanium dioxide, zinc oxide, and mixtures thereof, preferably wherein said sunscreen agent is selected from the group consisting of ethylhexyl-p-methoxycinnamate, octocrylene, octyl salicylate, titanium dioxide, and mixtures thereof.

9. A method for providing an artificial tan to human skin, said method comprising topically applying to the skin of the human an effective amount of an emulsion composition according to any of Claims 1 through 6.

SUBSTITUTE SHEET

10. A method for providing both an artifi ci al tan to human skin and protecting human ski n from the effects of ultraviolet radiation, said method comprising topical ly applying to the skin of the human an effective amount of an emul sion composition according to either of Cl aims 7 or 8.

SUBSTITUTE SHEET