WO2015196392A1

WO2015196392A1 - An oil-in-water composition, reparation and use thereof

Info

Publication number: WO2015196392A1
Application number: PCT/CN2014/080741
Authority: WO
Inventors: Le SHENG; Saijuan NI; Cyril Lemoine
Original assignee: L'oreal
Priority date: 2014-06-25
Filing date: 2014-06-25
Publication date: 2015-12-30
Also published as: CN106659645A

Abstract

An oil-in-water composition, in particular a skincare composition, preparation and use thereof are provided. The oil-in-water composition comprises a) water; b) at least one colorant selected from i) the organic pigments of xanthene or fluorane colorants; ii) the organic lakes of xanthene or fluorane colorants, or iii) a mixture thereof; and c) at least one hydrocarbon-based oil, and has a pH value of less than or equal to 5.

Description

An oil-in-water composition, preparation and use thereof Technical field

This invention relates to an oil-in-water composition, in particular to an oil-in-water skincare composition for providing instant and long-lasting skin tone modifications to the skin so that the skin possesses a natural and healthy glow look. This invention further relates to a method for preparing the oil-in-water composition and use of same in instantly modifying the skin tone into a pinkish color and providing to the skin long lasting pinkish effect.

Background arts

A natural and healthy glow of the skin has always been a pursue of the consumers worldwide. More specifically, consumers are not satisfied with their yellow skin tone in many Asian countries, such as China, Japan, or Korea. Nowadays, pigmented products, such as foundations, makeup bases, or BB creams, which contain relatively high amount of pigments, are used aiming at skin tone modifications. However, products as such are feared by consumers, in particular those who do not use makeup products frequently, due to the synthetic feeling and appearance of these products, especially at the first sight of the product per se. In particular, Chinese consumers don't like these pigmented products also because they, after application, render the skin with an appearance of make up. They yearn for a more natural feeling from the products, both in terms of the appearance of the products per se and that after application. In response to these requests, efforts have been made on the biological actions inside the skin. Unfortunately, consumers have to wait a relatively long time, for example, few days or even weeks, for achieving a visible skin tone modification result. It is therefore not immediate and thus unsatisfying.

There still remains a need for a composition, which possesses a natural and pleasant appearance which is favored by the consumers, and is able to instantly modify the skin tone into a natural and pinkish color and healthy glow look, and moreover, is able to provide to the skin such an effect in a relative long time, such as 24 hours. Invention disclosure

This invention will be described in details hereinafter with reference to the following specific embodiments. However, it should be noted that the protection scope of this invention should not be construed as limited to these specific embodiments, but rather determined by the attached claims.

Further, to the extent thin any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

Unless otherwise specified, percents, parts or ratios or the like mentioned in this specification are all on a weight basis.

The first objective of this invention is to provide an oil-in- water composition with a low amount of pigment(s), especially a skincare composition, which, different from a makeup product, is able to instantly modify the skin tone into a pinkish color to achieve a natural "healthy glow" effect in a natural way, i.e. without a make-up appearance. Meanwhile, the composition as such is able to maintain such skin tone modification effect on the skin in a long period of time, i.e., it is long lasting. By "instantly" herein, it means in 5 to 10 minutes after application. By "long lasting", it refers to 24 hours, or 1 day, at least. Different from that anticipated for a product with biological action, the present effect is instantly visible. Favorably, the composition cannot be removed completely from the skin by a normal cleanser or water, which secures the long lasting and durable skin tone modification effect. Further, the appearance of the composition per se is a natural cream without intensive color, which is cherished by consumers, especially those in China.

According to this invention, the oil-in-water composition comprises at least a) water, b) at least one colorant, and c) at least one hydrocarbon-based oil.

According to this invention, the oil-in-water composition has a pH value of less than or equal to 5, preferably less than or equal to 4.5.

According to this invention, the composition comprises water. As the component a), water presents at least 30wt % of the total weight of the composition. Preferably, water presents from 30wt% to 90wt %, more preferably from 40wt % to 85wt %, even more preferably from 50wt% to 80wt %, of the total weight of the composition.

Colorant

The composition of the present invention comprises at least one colorant. The colorant may preferably have a color of red or pink.

The colorants useful in the context of this invention are well known in the art (see for example Green et al, WO 0107009 , incorporated herein by reference, CFTA international Color Handbook, 2 nd ed., Micelle Press, England (1992) and Cosmetic Handbook, US Food and Drug Administration, FDA/IAS Booklet (1992)), and are available commercially from various sources (for example Bayer, Pittsburgh, PA; Ciba-Geigy, Tarrytown, NY; ICI, Bridgewater, NJ; Sandoz, Vienna, Austria; BASF, Mount Olive, NJ; and Hoechst, Frankfurt, Germany).

The colorants may comprise at least one carboxylic or sulfonic acid group. Further, the colorants may be one or more selected from:

i) the organic pigments of xanthene or f uorane colorants;

ii) the organic lakes of xanthene or fluorine colorants; or

iii) a mixture thereof.

Organic pigments that may be mentioned include those with the following denominations: D&C Red No. 21, D&C Red No. 22, D&C Red No.

27, D&C Red No. 28, or a mixture thereof.

D&C Red No. 21 and its lakes, is also known as Solv. Red 43; C.I.45380, and is 2',4',5',7'-tetrabromofiuorescein (CAS Reg. No. 15086-94-9). D&C Red

No. 22 and its lakes, is also known as Red 22 and Acid Red 87; C.I.45380, and is the disodium salt of 2',4',5',7'-tetrabromofluorescein (CAS Reg. No.

17372-87-1). D&C Red No. 27 and its lakes, is also known as Solv. Red 48;

C.I.45410, and is 2',4',5',7'-tetrabromo-4,5,6,7-tetrachlorofluorescein (CAS Reg. No. 13473-26-2). D&C Red No. 28 and its lakes, is also known as Acid

Red 92, Cyanosin; Cyanosine; Eosine bluish; Eosine Blue; Cyanosin B;

Phloxine P; Phloxin B; Eosine I Bluish; C.I. 45410 and is the disodium salt of 2',4',5',7'-tetrabromo-4,5,6,7-tetrachlorofluorescein (CAS Reg. No. 18472-87-2).

The colorant may be an organic lake supported by an organic support such as colophane or aluminum benzoate, for example.

Particular organic lakes that may be mentioned are lakes of the organic pigments identified above, including e.g. those with the following denominations: D&C Red No. 21 Aluminum lake, D&C Red No. 21 Zirconium lake, D&C Red No. 22 Aluminum lake, D&C Red No. 27 Aluminum lake, D&C Red No. 27 Aluminum/Titanium/Zirconium lake, D&C Red No. 27 Barium lake, D&C Red No. 27 Calcium lake, D&C Red No. 27 Zirconium lake, D&C Red No. 28 Aluminum lake, or a mixture thereof.

The chemical materials corresponding to each of the colorants listed above are mentioned in the work entitled "International Cosmetic Ingredient Dictionary and Handbook", 1997 edition, pages 371 to 386 and 524 to 528, published by "The Cosmetic, Toiletry, and Fragrance Association", the contents of which are incorporated herein by reference.

According to this invention, the organic pigment may represent from 0.0005wt % to lwt %, preferably from O.OOlwt % to O.Olwt % of the total weight of the composition.

According to this invention, the organic lake may represent from O.OOlwt

% to 2wt %, preferably from 0.005wt % to lwt %, and more preferably from 0.005wt % to 0.5wt % of the total weight of the composition.

These colorants can be used with one kind or a mixture of two or more kinds in any ratio there between.

Hydrocarbon-based oil

For the purposes of this invention, the term "oil" refers to the liquid state at room temperature and atmospheric pressure. The term "hydrocarbon-based oil" means an oil mainly containing hydrogen and carbon atoms and optionally oxygen, nitrogen, sulfur or phosphorus atoms.

Hydrocarbon-based oil may be a non-volatile oil. The term "non-volatile oil" means an oil that remains on the skin at room temperature and atmospheric pressure for at least several hours and that especially has a vapor pressure of less than 10^" mmHg (0.13 Pa).

According to one embodiment of this invention, as the component c), the hydrocarbon-based oil may be selected from i) a linear or branched, saturated or unsaturated C6-C40 fatty alcohol, ii) a N-acyl amino acid ester, or iii) a mixture thereof.

These hydrocarbon-based oils can be used with one kind or a mixture of two or more kinds in any ratio therebetween.

According to this invention, the hydrocarbon-based oil may represent from O.Olwt % to 60 wt %, preferably from 0.1 wt % to 40 wt %, and more preferably from 0.5wt % to 15wt % of the total weight of the composition. Fatty alcohol

According to this invention, by linear or branched, saturated or unsaturated C6-C40 fatty alcohol, it refers to an alcohol having a linear, branched, saturated or unsaturated C6-C40 hydrocarbon group, or preferably C10-C40 hydrocarbon group, more preferably C10-C34 hydrocarbon group, further preferably C12-C28 hydrocarbon group. The hydrocarbon group may be an alkyl, alkenyl or aralkyl group. The fatty alcohol may have one (as monoalcohol), two, three, four or more hydroxyls. These alcohols can be used with one kind or a mixture of two or more kinds in any ratio therebetween.

By fatty is meant, a water-insoluble organic compound in water at room temperature (25 °C) and atmospheric pressure (760 mmHg), with a solubility of less than 5% and preferably less than 1% and even more preferably less than 0.1%.

As specific examples of these alcohols useful in the context of the present invention, may be mentioned in particular, 2-butyloctanol, 2-hexyldecanol, erucyl alcohol, 2-undecylpentadecanol, linoleyl alcohol, lauryl alcohol, myristic alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, palmityl alcohol, oleyl alcohol, cetyl hard tallow alcohol (a mixture of cetyl alcohol and stearyl alcohol), behenyl alcohol, octyldodecanol, cetearyl alcohol and arachidyl alcohol, preferably octyldodecanol.

As the fatty alcohols useful in the context of the present invention, there may also be mentioned the commercial products NAFOL 18-22, NAFOL 18-22B, NAFOL 18-22 C, NAFOL 20+, NAFOL 20-22, and NACOL 22-98 from the company CONDEA, the commercial product CRODACID PG 3220 from the company CRODA, and the commercial product EDENOR U 122 from the company HENKEL.

According to this invention, the fatty alcohol may represent from 0.0 lwt

% to 60wt %, preferably from O. lwt % to 40wt %, and more preferably from 0.5wt % to 15wt % of the total weight of the composition.

N-acyl amino acid ester

According to this invention, the N-acyl amino acid ester is generally of the formula (I).

R₁(CO)N(R₂)CH(R₃)(CH₂)_n(CO)OR₄ (I)

wherein:

n is an integer equal to 0, 1 or 2,

Ri represents a C5 to C₂₁ linear or branched alkyl or alkenyl,

R₂ represents a hydrogen atom or a Ci to C3 linear or branched alkyl,

R3 represents a hydrogen atom, methyl, ethyl, or a C3 to C₄ linear or branched alkyl,

R₄ represents a Ci to C₁₀ linear or branched alkyl or a C₂ to C₁₀ linear or branched alkenyl, or a sterol residue.

According to this invention, preferably, the group Ri(CO)- is an acyl group of an acid selected from the group consisting of capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, linoleic acid, linolenic acid, oleic acid, isostearic acid, 2-ethylhexanoic acid, fatty acids of coconut oil, fatty acids from palm kernel oil. These fatty acids may also have a hydroxyl group. Even more preferably, it will be lauric acid.

According to this invention, the portion -N(R₂)CH(R₃)(CH₂)_n(CO)- of the amino acid ester is preferably selected from the following amino acids: glycine, alanine, valine, leucine, isoleucine, serine, threonine, proline, hydroxyproline, beta-alanine, aminobutyric acid, aminocaproic acid, sarcosine, or N-methyl-beta-alanine. Even more preferably, it will be the sarcosine.

According to this invention, part of the amino acid esters corresponding to the group OR₄ can be obtained from alcohols selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, tert-butanol, isobutanol, 3 -methyl- 1 -butanol, 2 -methyl- 1 -butanol, fusel oil, pentanol, hexanol, cyclohexanol, octanol, 2-ethylhexanol, decanol, lauryl alcohol, myristyl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, jojoba alcohol, 2-hexadecyl alcohol, 2-octyldodecanol alcohol and isostearyl alcohol.

According to this invention, the N-acyl amino acid esters can in particular be obtained from natural sources of amino acids. In this case, amino acids derived from hydrolysis of natural vegetable proteins (oat, wheat, soybean, palm, coconut) and then necessarily lead to amino acid mixtures, which should then be esterified and N-acylated. The preparation of such amino acids is more particularly described in the patent application FR 2 796 550, which is incorporated herein by reference.

According to this invention, the most preferred N-acyl amino acid ester is isopropyl N-lauroylsarcosinate (as shown by Formula (A)), such as the product sold under the name ELDEW SL-205 by the company Ajinomoto.

0 0

CH₃(CH₂)₁₀C NCH₂C OCHCH₃

CH₃ CH

³ Formula (A)

According to this invention, the N-acyl amino acid esters preferably used for this invention and their synthesis are described in Patent Applications EP 1044676 and EP 0928608 by Ajinomoto CO..

According to this invention, the N-acyl amino acid ester may represent from O.Olwt % to 60 wt %, preferably from 0.1 wt % to 40 wt %, and more preferably from 0.5wt % to 15wt % of the total weight of the composition.

According to this invention, the oil-in-water composition may further comprise at least one agent selected from a skin whitening agent, a skin peeling agent and a thickening polymer.

Skin whitening agent

Suitable skin whitening agents include, but are not limited to: phenolic derivatives, such as hydroquinone, hydroquinone monoethyl ether, hydroquinone monobenzyl ether or 4-hydroxyanisole; kojic acid and its derivatives; azelaic acid and its derivatives; linoleic acid; resorcinol and its derivatives such as those described in WO 00/56702, the entire contents of which are incorporated herein by reference; ellagic acid; zinc peroxide; mercury chloride; arbutin and its derivatives such as those described in applications EP 895 779 and EP 524 109, the entire contents of which are incorporated herein by reference; extracts of Emblica officinalis such as those described in U.S. Pat. No. 6,261,605, and in pages 175 and 176 of the 1990 Handbook of Ayurvedic Medicinal Plants by L.D. Kapoor, CRC Press, Inc., the entire contents of which are herein incorporated by reference; aminophenol derivatives such as those described in applications WO 99/10318 and WO 99/32077, the entire contents of which are incorporated herein by reference, and in particular N-cholesteryloxy-carbonyl-para-aminophenol and N-ethyloxycarbonyl-para-aminophenol; dihydroxybenzene derivatives such as those described in WO 00/47045, the entire contents of which are incorporated herein by reference; guaiacol derivatives such as those described in WO 00/47179, the entire contents of which are incorporated herein by reference; 4-(2,3-dihydroxyphenyl)cyclohexanol such as described in WO 00/56279, the entire contents of which are incorporated herein by reference; iminophenol derivatives, in particular those described in application WO 99/22707, the entire contents of which are incorporated herein by reference; L-2-oxothiazolidine-4-carboxylic acid or procysteine, and its salts and esters; and extracts of plants, in particular of liquorice, mulberry and skullcap, phenylethyl resorcinol is preferred for use in the present invention.

The skin whitening agent may preferably be present in an amount of from

O.Olwt % to lOwt %, preferably 0.1 wt % to 5wt %, and more preferably 0.1 wt % to 3wt %, based on the total weight of the composition.

Skin peeling agent

A skin peeling agent may also be used in order to boost the efficiency of the skin whitening agent. Without intending to be bound by theory, it is believed that skin peeling agent stimulates collagen production in the skin, thereby further enhancing the skin whitening effect. Suitable skin peeling agents include, but are not limited to: hydroxy acids and their derivatives, such as ascorbic, citric, lactic, glycolic, malic, tartaric, mandelic, salicylic acid and its derivatives such as 5-(n-octanoyl)salicylic acid (also known as Capryloyl Salicylic Acid under the CTFA designation), examples of which are described in U.S. Pat. No. 4,767,750, the entire contents of which is hereby incorporated by reference; urea; aminosulphonic compounds and in particular

N-(2-hydroxyethyl)piperazine-N'-2-ethanesulphonic acid (HEPES); and derivatives of 2-oxothiazolidine-4-carboxylic acid (procysteine). Particularly preferred skin peeling agent for use in the present invention is salicylic acid.

The skin peeling agent may be present in an amount of from 0.0 lwt % to 50wt %, preferably O. lwt % to 15wt %, and more preferably O. lwt % to 5wt %, based on the total weight of the composition.

Thickening Polymer

The thickening (or gelling) polymer is selected from i) copolymers resulting from the polymerization of at least one monomer (a) selected from carboxylic acids possessing .alpha.,. beta. -ethylenic unsaturation or their esters with at least one monomer (b) possessing ethylenic unsaturation comprising a hydrophobic group, ii) polymers comprising at least one monomer possessing a sulpho group and their mixtures.

This polymer can also exhibit emulsifying properties.

The thickening polymer is preferably anionic.

The thickening polymer according to the invention can represent from O.Olwt % to lOwt %, preferably from 0.05wt % to 5wt %, better still from 0.05wt % to 3wt % and even better still from 0.05wt % to lwt %, with respect to the total weight of the composition.

i) Copolymer of at Least One Monomer (a) Selected from Carboxylic Acids Possessing .alpha.,. beta. -Ethylenic Unsaturation or Their Esters with at Least One Monomer (b) Possessing Ethylenic Unsaturation Comprising a Hydrophobic Group

The term "copolymers" is understood to mean both copolymers obtained from two types of monomers and those obtained from more than two types of monomers, such as terpolymers obtained from three types of monomers.

Their chemical structure more particularly comprises at least one hydrophilic unit and at least one hydrophobic unit. The term "hydrophobic group" or "hydrophobic unit" is intended to mean a radical possessing a saturated or unsaturated and linear or branched hydrocarbon chain comprising at least 8 carbon atoms, preferably from 10 to 30 carbon atoms, in particular from 12 to 30 carbon atoms and more preferably from 18 to 30 carbon atoms.

Preferably, the thickening polymers are selected from copolymers resulting from the polymerization:

of at least one monomer of following formula (1):

in which Ri denotes H or CH₃ or C₂H₅, that is to say acrylic acid, methacrylic acid or ethacrylic acid monomers, and

of at least one monomer of unsaturated carboxylic acid (Cio-C3o)alkyl ester type which corresponds to the monomer of following formula (2):

in which R₂ denotes H or CH₃ or C2H5 (that is to say, acrylate, methacrylate or ethacrylate units) and preferably H (acrylate units) or CH₃ (methacrylate units) and R3 denotes a C₁₀-C30 and preferably C₁₂-C₂₂ alkyl radical.

The (C₁₀-C30) alkyl esters of unsaturated carboxylic acids are preferably selected from lauryl acrylate, stearyl acrylate, decyl acrylate, isodecyl acrylate, dodecyl acrylate and the corresponding methacrylates, such as lauryl methacrylate, stearyl methacrylate, decyl methacrylate, isodecyl methacrylate and dodecyl methacrylate, and their mixtures.

According to a preferred embodiment, these thickening polymers are crosslinked.

Use will more particularly be made, among the thickening polymers of this type, of copolymers resulting from the polymerization of a mixture of monomers comprising:

(i) essentially acrylic acid,

(ii) an ester of formula (2) described above in which R₂ denotes H or CH₃ and R3 denotes an alkyl radical having from 12 to 22 carbon atoms,

(iii) and a crosslinking agent which is a well-known copolymerizable polyethylenic unsaturated monomer, such as diallyl phthalate, allyl (meth)acrylate, divinylbenzene, (poly)ethylene glycol dimethacrylate and methylenebisacrylamide.

Use will more particularly be made, among copolymers of this type, of those composed of 95 wt % to 60 wt % of acrylic acid (hydrophilic unit), 4wt % to 40wt % of C10-C30 alkyl acrylate (hydrophobic unit) and Owt % to 6wt % of crosslinking polymerizable monomer or else of those composed of 98wt % to 96wt % of acrylic acid (hydrophilic unit), lwt % to 4wt % of C10-C30 alkyl acrylate (hydrophobic unit) and O. lwt % to 0.6wt % of crosslinking polymerizable monomer, such as those described above.

Preference is very particularly given according to the present invention, among the polymers above, to acrylate/Cio-C3o alkyl acrylate copolymers (INCI name: Acrylates/C 10-30 Alkyl Acrylate Crosspolymer), such as the products sold by Lubrizol under the trade names Pemulen TR1, Pemulen TR2, Carbopol 1382 and Carbopol EDT 2020 and more preferably still Pemulen TR-2.

ii) Polymer Comprising at Least One Monomer Possessing a Sulpho Group

The thickening polymers comprising at least one monomer possessing a sulpho group used in the composition of the invention are soluble or dispersible or swellable in water. The polymers used in accordance with the invention can be homopolymers or copolymers and are capable of being obtained from at least one monomer possessing ethylenic unsaturation and possessing a sulpho group which can be in the free form or in the partially or completely neutralized form. These polymers can optionally comprise at least one hydrophobic group and can then constitute an amphiphilic polymer (or hydrophobic modified polymer). Preferably, the polymers in accordance with the invention can be partially or completely neutralized by an inorganic base (sodium hydroxide, potassium hydroxide, aqueous ammonia) or an organic base, such as mono-, di- or triethanolamine, an aminomethylpropanediol, N-methylglucamine, basic amino acids, such as arginine and lysine, and the mixtures of these compounds. They are generally neutralized. The term "neutralized" is understood to mean, in the present invention, polymers which are completely or virtually completely neutralized, that is to say neutralized to at least 90%.

The polymers used in the composition of the invention generally have a number-average molecular weight ranging from 1000 to 20 000 000 g/mol, preferably from 20 000 to 5 000 000 g/mol and more preferably still from 100 000 to 1 500 000 g/mol.

These polymers according to the invention may or may not be crosslinked.

The monomers possessing a sulpho group of the polymer used in the composition of the invention are selected in particular from vinyl sulphonic acid, styrene sulphonic acid, (meth)acrylamido(Ci-C₂₂)alkylsulphonic acids, N-(Ci-C₂₂)alkyl(meth)acrylamido(Ci-C₂₂)alkylsulphoni- c acids, such as undecylacrylamidomethanesulphonic acid, and also their partially or completely neutralized forms, and their mixtures.

According to a preferred embodiment of the invention, the monomers possessing a sulpho group are selected from (meth) acrylamido (C₁-C₂₂) alkylsulphonic acids, such as, for example, acrylamidomethanesulphonic acid, acrylamidoethanesulphonic acid, acrylamidopropanesulphonic acid, 2-acrylamido-2-methylpropanesulphonic acid,

2-methacrylamido-2-methylpropanesulphonic acid,

2-acrylamido-n-butanesulphonic acid,

2-acrylamido-2,4,4-trimethylpentanesulphonic acid,

2-methacrylamidododecylsulphonic acid, 2-acrylamido-2,6-dimethyl-3-heptanesulphonic acid, and also their partially or completely neutralized forms, and their mixtures.

Use is more particularly made of 2-acrylamido-2-methylpropanesulphonic acid (AMPS) and of its partially or completely neutralized forms.

When the polymers are crosslinked, the crosslinking agents can be selected from the compounds possessing polyolefinic unsaturation commonly used for the crosslinking of polymers obtained by radical polymerization.

Mention may be made, for example, as crosslinking agents, of divinylbenzene, diallyl ether, dipropylene glycol diallyl ether, polyglycol diallyl ethers, triethylene glycol divinyl ether, hydroquinone diallyl ether, ethylene glycol or tetraethylene glycol di(meth)acrylate, trimethylolpropane triacrylate, methylenebisacrylamide, methylenebismethacrylamide, triallylamine, triallyl cyanurate, diallyl maleate, tetraallylethylenediamine, tetraallyloxyethane, trimethylolpropane diallyl ether, allyl (meth)acrylate, allyl ethers of alcohols of the series of the sugars, or other allyl or vinyl ethers of polyfunctional alcohols, and allyl esters of phosphoric and/or vinylphosphonic acid derivatives, or the mixtures of these compounds.

According to a preferred embodiment of the invention, the crosslinking agent is selected from methylenebisacrylamide, allyl methacrylate or trimethylolpropane triacrylate (TMPTA). The degree of crosslinking generally ranges from 0.01 mol % to 10 mol % and more particularly from 0.2 to 2 mol %, with respect to the polymer.

When the polymers used are homopolymers, they comprise only monomers possessing a sulpho group and, if they are crosslinked, one or more crosslinking agents.

The preferred AMPS homopolymers are generally wherein they comprise, distributed randomly:

a) from 90 wt % to 99.9wt % of units of following general formula (II):

in which X denotes a proton, an alkali metal cation, an alkaline earth metal cation or the ammonium ion, it being possible for at most 10 mol % of the cations X⁺ to be protons H⁺;

b) from 0.0 lwt % to lOwt % of crosslinking units originating from at least one monomer having at least two olefinic double bonds; the proportions by weight being defined with respect to the total weight of the polymer.

The homopolymers according to the invention which are more particularly preferred comprise from 98wt % to 99.5wt % of units of formula (II) and from 0.2wt % to 2wt % of crosslinking units.

Mention may in particular be made, as polymers of this type, of the crosslinked and neutralized homopolymer of

2-acrylamido-2-methylpropanesulphonic acid sold by Clariant under the trade name Hostacerin® AMPS (CTFA name: ammonium polyacryldimethyltauramide).

The polymer can also be an amphiphilic homopolymer (or hydrophobic modified homopolymer) selected from random amphiphilic AMPS polymers modified by reaction with a mono(C6-C22 n-alkyl)amine or a di(C6-C22 n-alkyl)-amine, such as those described in the document WO-A-00/31154, which are grafted homopolymers.

When the polymers used are copolymers, they are capable of being obtained from monomers possessing ethylenic unsaturation and possessing a sulpho group and from other monomers possessing ethylenic unsaturation, that is to say from monomers possessing ethylenic unsaturation without a sulpho group.

The monomers possessing ethylenic unsaturation and possessing a sulpho group are selected from those described above.

The monomers possessing ethylenic unsaturation without a sulpho group can be selected from hydrophilic monomers possessing ethylenic unsaturation, hydrophobic monomers possessing ethylenic unsaturation and their mixtures. When the polymer comprises hydrophobic monomers, it constitutes an amphiphilic polymer (also known as hydrophobic modified polymer).

The hydrophilic monomers possessing ethylenic unsaturation can be selected, for example, from (meth)acrylic acids, their alkyl derivatives substituted at the .beta, position or their esters obtained with monoalcohols or mono- or polyalkylene glycols, (meth)acrylamides, vinylpyrrolidone, vinylformamide, maleic anhydride, itaconic acid, maleic acid or the mixtures of these compounds.

When the polymer of the composition according to the invention is a copolymer capable of being obtained from monomers possessing ethylenic unsaturation and possessing a sulpho group and from hydrophilic monomers possessing ethylenic unsaturation, it can be selected in particular from (1) crosslinked anionic copolymers of acrylamide or methacrylamide and of 2-acrylamido-2-methylpropanesulphonic acid, in particular those which are provided in the form of a W/O emulsion, such as those sold under the name of Sepigel 305 by Seppic (CTFA name: Polyacrylamide/C13-14 Isoparaffin/Laureth-7) or under the name of Simulgel 600 by Seppic (CTFA name: Acrylamide/S odium acryloyldimethyltaurate copolymer/Isohexadecane/Polysorbate 80), (2) copolymers of (meth)acrylic acid or of (meth)acrylate and of 2-acrylamido-2-methylpropanesulphonic acid, in particular those which are provided in the form of a W/O emulsion, such as those sold under the name of Simulgel NS by Seppic (sodium 2-acrylamido-2-methylpropanesulphonate/hydroxyethyl acrylate copolymer as a 40% inverse emulsion in Polysorbate 60 and squalane) (CTFA name: hydroxy ethyl acrylate/sodium acryloyldimethyltaurate copolymer/squalane/polysorbate 60) or under the name of Simulgel EG by Seppic (acrylic acid/2-acrylamido-2-methylpropanesulphonic acid in the form of a sodium salt copolymer as a 45% inverse emulsion in isohexadecane/water) (CTFA name: Sodium Aery late/Sodium Acryloyldimethyltaurate Copolymer/Isohexadecane/Polysorbate 80), and (3) copolymers of 2-acrylamido-2-methylpropanesulphonic acid and of vinylpyrrolidone or of vinylformamide, such as the products sold under the Aristoflex AVC names by Clariant.

When the monomers possessing a sulpho group are copolymerized with hydrophobic monomers possessing ethylenic unsaturation and comprising a hydrophobic chain, also known as fatty chain (C6-C50 chain), the polymer obtained is amphiphilic, that is to say that it comprises both a hydrophilic part and a hydrophobic part. Such polymers are also known as hydrophobic modified polymers.

These hydrophobic modified polymers can additionally comprise one or more monomers comprising neither a sulpho group nor a fatty chain, such as (meth)acrylic acids, their alkyl derivatives substituted at the .beta, position or their esters obtained with monoalcohols or mono- or polyalkylene glycols, (meth)acrylamides, vinylpyrrolidone, vinylformamide, maleic anhydride, itaconic acid, maleic acid or the mixtures of these compounds.

Use may in particular be made, as hydrophobic modified polymers, of those capable of being obtained from 2-acrylamido-2-methylpropanesulphonic acid (AMPS) and from at least one hydrophobic monomer possessing ethylenic unsaturation and comprising at least one group having from 6 to 50 carbon atoms, more preferably from 6 to 22 carbon atoms, more preferably still from 6 to 18 carbon atoms and more particularly from 12 to 18 carbon atoms.

These polymers are described in particular in the documents EP-A-750899, U.S. Pat. No. 5,089,578 and WO-A-2002/43689 and in the following publications by Yotaro Morishima:

"Self-assembling amphiphilic polyelectrolytes and their nanostructures—Chinese Journal of Polymer Science", Vol. 18, No. 40 (2000), 323-336;

"Micelle formation of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulphonate and a non-ionic surfactant macromonomer in water as studied by fluorescence and dynamic light scattering", Macromolecules 2000, Vol. 33, No. 10, 3694-3704;

"Solution properties of micelle networks formed by non-ionic moieties covalently bound to a polyelectrolyte: salt effects on rheological behaviour", Langmuir, 2000, Vol. 16, No. 12, 5324-5332;

"Stimuli responsive amphiphilic copolymers of sodium

2-(acrylamido)-2-methylpropanesulphonate and associative macromonomers", Polym. Preprint, Div. Polym. Chem., 1999, 40(2), 220-221. The hydrophobic monomers of these specific polymers are preferably selected from acrylates, alkyl acrylates, acrylamides or alkylacrylamides of following formula (III):

in which Ri and R3, which are identical or different, denote a hydrogen atom or a substantially linear or branched C₁-C6 alkyl radical (preferably a methyl radical); Y denotes O or NH; R₂ denotes a hydrocarbon radical comprising from 6 to 50 carbon atoms, more preferably from 6 to 22 carbon atoms, more preferably still from 6 to 18 carbon atoms and more particularly from 12 to 18 carbon atoms; and x denotes a number of moles of alkylene oxide and varies from 0 to 100.

The R₂ radical is preferably selected from substantially linear C6-C18 alkyl radicals (for example n-hexyl, n-octyl, n-decyl, n-hexadecyl, n-dodecyl or lauryl, or n-octadecyl or stearyl) or branched or cyclic C6-C18 alkyl radicals (for example cyclododecane (C₁₂) or adamantane (C₁₀)); perfluorinated C6-C18 alkyl radicals (for example the group of formula -(CH₂)₂(CF₂)₉CF₃); the cholesteryl radical (C27) or a cholesterol ester residue, such as the cholesteryl oxyhexanoate group; or polycyclic aromatic groups, such as naphthalene or pyrene. Preference is more particularly given, among these radicals, to substantially linear alkyl radicals and more particularly to the n-dodecyl, n-hexadecyl or n-octadecyl radical, and to their mixtures.

According to a particularly preferred form of the invention, the monomer of formula (III) comprises at least one alkylene oxide unit (x.gtoreq. l) and preferably several alkylene oxide units (x>l) constituting a poly oxyalkylene chain. The polyoxyalkylene chain is preferably composed of ethylene oxide units and/or of propylene oxide units and more particularly still is composed of ethylene oxide units. The number of oxyalkylene units (or number of moles of alkylene oxide) generally varies from 3 to 100, more preferably from 3 to 50 and more preferably still from 7 to 25. Mention may be made, among these polymers, of:

crosslinked or non-crosslinked and neutralized or non-neutralized copolymers comprising from 15wt % to 60wt % of AMPS units and from 40wt % to 85wt % of (C8-Ci6)alkyl(meth)acrylamide units or of

(meth)acrylate units, with respect to the polymer, such as those described in the document EP-A-750 899;

terpolymers comprising from 10 mol % to 90 mol % of acrylamide units, from 0.1 mol % to 10 mol % of AMPS units and from 5 mol % to 80 mol % of n-(C6-Cioalkylacrylamide units, with respect to the polymer, such as those described in the document U.S. Pat. No. 5,089,578;

non-crosslinked copolymers of partially or completely neutralized AMPS and of n-dodecyl, n-hexadecyl or n-octadecyl methacrylate, such as those described in the abovementioned papers by Morishima;

crosslinked or non-crosslinked copolymers of partially or completely neutralized AMPS and of n-dodecylmethacrylamide, such as those described in the abovementioned papers by Morishima.

Mention may more particularly be made, as hydrophobic modified polymers, of the copolymers composed (i) of 2-acrylamido-2-methylpropanesulphonic acid (AMPS) units of formula (II) indicated above, in which X' is a proton, an alkali metal cation, an alkaline earth metal cation or the ammonium ion, and (ii) of units of following formula (IV):

in which x denotes an integer varying from 3 to 100, preferably from 3 to 50 and more preferably from 7 to 25; Ri has the same meaning as that indicated above in the formula (III) and R₄ denotes a linear or branched alkyl radical comprising from 6 to 22 carbon atoms and preferably from 10 to 22 carbon atoms. The hydrophobic modified polymers of this type are in particular those described in the above-mentioned papers by Morishima, for which x=25, Ri denotes methyl and R₄ represents n-dodecyl, or those described in the document WO-A-02/43689, for which x=8 or 25, Ri denotes methyl and R₄ represents n-hexadecyl (Ci6), n-octadecyl (Cis) or n-dodecyl (C₁₂), or their mixtures. The polymers for which X⁺ denotes sodium or ammonium are more particularly preferred.

The preferred hydrophobic modified polymers which can be used in the composition in accordance with the invention can be obtained according to conventional radical polymerization processes in the presence of one or more initiators, such as, for example, azobisisobutyronitrile (AIBN), azobisdimethylvaleronitrile, 2,2'-azobis[2-amidinopropane] hydrochloride (ABAH), organic peroxides, such as dilauryl peroxide, benzoyl peroxide, tert-butyl hydroperoxide, and the like, inorganic peroxide compounds, such as potassium persulphate or ammonium persulphate, or H202, optionally in the presence of reducing agents.

These hydrophobic modified polymers can be obtained in particular by radical polymerization in a tert-butanol medium, from which they precipitate. It is possible, using polymerization by precipitation from tert-butanol, to obtain a distribution in the size of the particles of the polymer which is particularly favourable to the uses thereof.

The reaction can be carried out at a temperature of between 0 and 150. degree. C, preferably between 10 and 100. degree. C, either at atmospheric pressure or under reduced pressure. It can also be carried out under an inert atmosphere and preferably under nitrogen.

These preferred hydrophobic modified polymers are in particular those described in the document EP-1 069 142 and especially those obtained by polymerization of 2-acrylamido-2-methylpropanesulphonic acid (AMPS) or one of its sodium or ammonium salts with an ester of (meth)acrylic acid and of a C₁₀-C18 alcohol oxyethylenated with 8 mol of ethylene oxide

(Genapol.RTM. C-080 from Clariant),

of a C₁₁ oxo alcohol oxyethylenated with 8 mol of ethylene oxide (Genapol.RTM. UD-080 from Clariant),

of a On oxo alcohol oxyethylenated with 7 mol of ethylene oxide (Genapol.RTM. UD-070 from Clariant),

of a C12-C14 alcohol oxyethylenated with 7 mol of ethylene oxide (Genapol.RTM. LA-070 from Clariant),

of a C12-C14 alcohol oxyethylenated with 9 mol of ethylene oxide (Genapol.RTM. LA-090 from Clariant),

of a C12-C14 alcohol oxyethylenated with 11 mol of ethylene oxide (Genapol.RTM. LA- 110 from Clariant),

of a C16-C18 alcohol oxyethylenated with 8 mol of ethylene oxide

(Genapol.RTM. T-080 from Clariant),

of a C16-C18 alcohol oxyethylenated with 15 mol of ethylene oxide (Genapol.RTM. T-150 from Clariant),

of a C16-C18 alcohol oxyethylenated with 11 mol of ethylene oxide (Genapol.RTM. T- 110 from Clariant),

of a C16-C18 alcohol oxyethylenated with 20 mol of ethylene oxide (Genapol.RTM. T-200 from Clariant),

of a C16-C18 alcohol oxyethylenated with 25 mol of ethylene oxide (Genapol.RTM. T-250 from Clariant),

of a C18-C22 alcohol oxyethylenated with 25 mol of ethylene oxide and/or of an iso-Ci6-Ci8 alcohol oxyethylenated with 25 mol of ethylene oxide. The mol % concentration of the units of formula (II) and of the units of formula (IV) in the polymers according to the invention varies according to the cosmetic application desired and the rheological properties desired for the formulation. It can vary between 0.1 mol % and 99.9 mol %.

Preferably, for the most hydrophobic polymers, the molar proportion of units of formula (II) or (IV) varies from 50.1 to 99.9%, more particularly from 70 to 95% and more particularly still from 80 to 90%.

Preferably, for the polymers which are not very hydrophobic, the molar proportion of units of formula (II) or (IV) varies from 0.1 to 50%, more particularly from 5 to 25% and more particularly still from 10 to 20%.

The distribution of the monomers in the polymers of the invention can be, for example, alternating, block (including multiblock) or random.

Mention may in particular be made, as hydrophobic modified polymers of this type, of the copolymer of AMPS and of ethoxylated C12-C14 alkyl methacrylate (noncrosslinked copolymer obtained from Genapol LA-070 and from AMPS) (CTFA name: Ammonium Acryloyldimethyltaurate/Laureth-7 Methacrylate Copolymer) sold under the name Aristoflex LNC by Clariant, and the copolymer of AMPS and of ethoxylated (25 EO) stearyl methacrylate (copolymer crosslinked with trimethylolpropane triacrylate obtained from Genapol T-250 and from AMPS) (CTFA name: Ammonium Acryloyldimethyltaurate/Steareth-Methacrylate Crosspolymer) sold under the name Aristoflex HMS by Clariant.

Preferably, the polymer possessing a sulpho group is selected from AMPS copolymers, preferably selected from copolymers of (meth)acrylic acid or of (meth)acrylate and of 2-acrylamido-2-methylpropanesulphonic acid, in particular copolymers of alkyl aery late and of AMPS, preferably copolymers of hydroxyalkyl acrylate and of AMPS.

Use may in particular be made of those which are provided in the form of a W/O emulsion, such as those sold under the name of Simulgel NS by Seppic (sodium 2-acrylamido-2-methylpropanesulphonate/hydroxyethyl acrylate copolymer as a 40% inverse emulsion in Polysorbate 60 and squalane) (CTFA name: Hydroxy ethyl Acrylate/Sodium Acryloyldimethyltaurate Copolymer/Squalane/Polysorbate 60) or Simulgel FS by Seppic (sodium 2-acrylamido-2-methylpropanesulphonate/hydroxyethyl acrylate copolymer as a 40% inverse emulsion in Polysorbate 60 and isohexadecane) (CTFA name: Hydroxy ethyl Acrylate/Sodium Acryloyldimethyltaurate

Copolymer/Isohexadecane/Polysorbate 60) or those sold under the name of Simulgel EG by Seppic (acrylic acid/2-acrylamido-2-methylpropanesulphonic acid in the form of a sodium salt copolymer as a 45% inverse emulsion in isohexadecane/ water) (CTFA name: Sodium Acrylate/Sodium Acryloydimethyltaurate Copolymer/Isohexadecane/Polysorbate 80).

According to this invention, the oil-in-water composition may further comprise an additional additive normally used in the relevant field, such as antioxidants, preservatives, neutralizing agents, fragrances, emollients, structuring agents or cosmetic active agents. These additives may represent from 0.000 lwt % to 50wt % and, for example, from lwt % to 50wt % and even better from lwt % to 20 wt % of the total weight of the composition.

According to this invention, as the cosmetic active agent, there may be mentioned vitamins A, E, C, B3, F, provitamins such as D-panthenol, soothing active agents such as a-bisabolol, Aloe vera, allantoin, plant extracts or essential oils, protective or restructuring agents such as ceramides, freshening active agents such as menthol and its derivatives, moisturizers (e.g. glycerin or arginin PCA), anti-wrinkle active agents, essential fatty acids, sunscreens, and mixtures thereof. Of course, persons skilled in the art will be careful to choose the possible additional additives and/or their quantity such that the advantageous properties of the composition according to this invention are not, or not substantially, impaired by the envisaged addition.

According to this invention, of course, the oil-in- water composition should be physiologically acceptable (in particular cosmetically acceptable), that is to say nontoxic and capable of being applied to the skin. The expression "cosmetically acceptable" herein is understood to mean having a pleasant feel, appearance and/or odor, applicable for several days and for several months.

According to this invention, the oil-in- water composition may be semi- to non-transparent. As used herein, the term "semi- to non-transparent" means that the composition has a percent transmittance of less than 95%, alternatively less than 80%, alternatively less than 60%, alternatively less than 50%, alternatively less than 30%, alternatively less than 10%, for visible light at a wavelength of 400 nm, with water being 100%, at a sample thickness of 10mm.

According to this invention, the oil-in-water composition may be provided in the form of cream, essence, water, lotion or gel, preferably in the form of face skincare cream. Due to its skin tone modification effect or purpose, the oil-in-water composition of this invention will not be identified as products for hands or lips. Further, the composition per se appears as pale colored and much more like a natural product, which is much more attractive to consumers as compared with e.g. a make up product.

According to this invention, the oil-in-water composition is able to modify the skin tone, especially the face skin tone, into a pinkish color to achieve a "healthy glow" effect immediately after applied to the skin, especially the face skin. The "healthy glow" effect is achieved in a natural way without a makeup appearance, which represents a much more cherished product character by consumers, especially in China. Moreover, the composition of the present invention provides to the skin, particularly the face skin, a long lasting skin tone modification effect, for example 24 hours skin tone modification effect.

In this context, this invention further provides a method for instantly and lastingly modifying the skin tone into a pinkish color, which comprises applying to the skin the oil-in-water composition of this invention. The modification is instantly visible, which means, 5 to 10 minutes after application and maintained in a long period of time, such as 24 hours or 1 day at least, the skin color is changed to a healthy glow look. Moreover, the pinkish color is more intensive (but acceptable) than that of the composition per se, which necessarily makes each application of the composition a magic and pleasant experience for the consumer. While not willing to be bound by any theory, it is believed that after application of the composition, the colorant develops a more intensive (pinkish) color when contacting the skin, which in general, has a greater pH value (about 5.0 to 7.0) than that of the composition. Further, the modification is also long lasting, i.e. being effective at least for a whole day. Thanks to this, consumers do not have to redress any more. Still, the present composition exhibits excellent water fastness, and cannot be removed completely from the skin by a normal cleanser or water (e.g. sweat), which secures a long-lasting and durable modification effect, avoiding an embarrassing mistiness.

According to a preferable embodiment of this invention, the oil-in-water composition is a skincare composition, especially a face skincare composition.

According to an embodiment of this invention, further provided is a combination of the component a), the component b) and the component c) as described above. The combination can be used to prepare the oil-in-water composition of this invention, especially the skincare composition.

According to this invention, the oil-in-water composition may be prepared by known methods which are generally used in the cosmetic field. Specifically, there may be mentioned a method comprising at least the following steps 1) to 3).

Step 1): a step of mixing the component b) with the component c), as described above, to obtain an oil phase.

According to this invention, in Step 1), the oil phase comprises at least the components b) and c). Nevertheless, if needed, it is acceptable for the oil phase to further comprise the skin whitening agent and/or the additional additive normally used in the relevant field as identified above, preferably that of oil-soluble type.

According to this invention, Step 1) may be conducted at any acceptable temperature, e.g. the room temperature. Further, in Step 1), the component b), the component c), and if any, the skin whitening agent and/or the additional additive, may be used respectively in an amount as identified above, and are then mixed together till homogenous, to obtain the oil phase.

Step 2): a step of dispersing the oil phase into an aqueous phase.

According to this invention, in Step 2), the aqueous phase comprises at least water. Obviously, if needed, it is acceptable for the aqueous phase to further comprise the skin peeling agent, the thickening polymer, and/or the additional additive normally used in the relevant field as identified above, preferably that of water-soluble type.

According to this invention, Step 2) may be conducted at any acceptable temperature, e.g. the room temperature or under heat to facilitate mixing or to improve dispersion. Further, in Step 2), water, and if any, the skin peeling agent, the thickening polymer, and/or the additional additive, may be used respectively in an amount as identified above, nevertheless, it is noted that water, the skin peeling agent, the thickening polymer, and/or the additional additive may be also added in other steps (e.g. in the aforesaid Step 1 and/or in the following Step 3 or separate additional steps). In view of this, in the context of this specification, the amount of water, that of the skin peeling agent, that of the thickening polymer, and that of the additional additive (if any) to be added to Step 2) may be not as herein defined. In fact, any suitable amount can be used herein with the only proviso that upon completion of the method, the final oil-in-water composition comprises water, the skin peeling agent, the thickening polymer, and the additional additive in a total amount respectively as identified above.

Step 3): a step of adjusting the pH value of the resultant till less than or equal to 5, preferably less than or equal to 4.5.

According to this invention, in Step 3), any pH adjusting agent can be used, e.g. an alkali metal hydroxide, e.g. NaOH or KOH, or an acidifying agent, e.g. HC1, H₂SO₄ or citric acid. The pH adjusting agent may be used in the form of an aqueous solution. There is no specific limitation as to the amount of the pH adjusting agent to be used, as long as the resultant could be adjusted to have a pH value of less than or equal to 5. Herein, by "resultant", it refers to the resultant obtained from Step 2), or if needed, the resultant obtained from any separate additional step after Step 2) (specifically defined as below), or even the final oil-in-water composition.

According to this invention, following Step 3) and/or Step 2), if needed, there may exist one or more separate additional steps of introducing the skin peeling agent, the thickening polymer, and/or the additional additive normally used in the relevant field as identified above into the resultant obtained from the preceding step. These separate additional steps can be conducted in a normal way without any specific limitation thereto.

According to this invention, upon completion of the method, the thus prepared oil-in-water composition may exhibit a pH value of less than or equal to 5, preferably less than or equal to 4.5.

Examples

The present invention is further illustrated by using the following examples, but not limiting to same.

Formulae I to IV

The following procedure was followed to prepare Formula I to Formula IV (according to this invention) in line with the corresponding compositions given in Table 1-1 to Table 1- 4.

At 75°C, the phase A constituents were solubilized by using a homogenizer to obtain a phase A. Separately, the phase B constituents were mixed together till homogenous at room temperature to obtain a phase B. Then, the phase B was introduced into the phase A under stirring with cooling, to obtain a mixture. Upon completion of this introduction, at 60°C, the phase C constituents were introduced into the mixture under stirring with cooling. The stirring continued till a homogenous bulk was obtained. Then, if applicable, at 30°C, the phase D constituents were slowly added to the homogenous bulk under stirring.

Tables 1-1 : the composition of Formula I

Tables 1-2: the composition of Formula II

Tables 1-3: the composition of Formula III

Tables 1-4: the composition of Formula IV

Comparative Formulae 1 to 4

The preparation was similar to Formula IV, with the exception that D&C

Red No. 28 Lake in an amount of 0.04wt % was replaced by D&C Red No. 33 (UNICERT RED K7057-J, from SENSIENT) in an amount of 0.0001 wt % (to obtain Comparative Formula 1), or D&C Red No. 28 Lake in an amount of 0.04wt % was replaced by D&C Red No. 33 (UNICERT RED K7057-J, from SENSIENT) in an amount of 0.04wt % (to obtain Comparative Formula 2), or octyldodecanol (EUTANOL G, from COGNIS (BASF)) in an amount of 3.00wt % was replaced by caprylic/capric triglyceride (TRIGLYCERIDES C8C10 70/30 (DUB MCT 7030), from STEARINERIE DUBOIS) in an amount of 3.00wt % (to obtain Comparative Formula 3), or water (as the phase A constituent in an amount of 75.96wt %) was reduced in amount to 25 wt %, while remaining D&C Red No. 28 Lake at 0.04wt % (to obtain Comparative Formula 4).

Evaluation

The appearance, instant skin tone modification effect, long lasting skin tone modification effect, and sensory of each of the Formulae I to IV and the Comparative Formulae 1 to 4 was evaluated using instruments and a panel of 10 women models with yellow skin tone.

Appearance

The appearance of each formula (per se) was observed by the 10 models with naked eyes, and a score was given to the formula by the models (3 : very natural and pleasant appearance, 2: natural and pleasant appearance, 1 : poor and unacceptable appearance, with synthetic or make up product feeling).

Instant Skin Tone Modification Effect and Long Lasting Skin Tone

Modification Effect

The instant and the long lasting skin tone modification effects of each formula were evaluated using a colorimetric measurement of the skin before and after application of the formula by measuring the means for the panel of 10 women models, H* (hue, the angle/direction in the 360 degree range), respectively. For each of the 10 women models, an image was taken using a Chromasphere with a definition of 410 x 410 pixels. The results were expressed in the following manner: the color was quantified by the H* (hue, the angle/direction in the 360 degree range), analyzed by the camera. The instant effect and the long lasting effect were evaluated by the variation of H* 10 minutes and 24 hours after application (H*(T_imm) and H*(T₂4h), respectively). More specifically, the measurements of the instant and the long lasting skin tone modification effects were carried out and the measurements (H*(T_imm), H*(T₂4h) and H*(T₀)) were made at the following points of time:

To = measurement (H*(T₀)) on naked skin free of the formula, before application of the formula;

T_imm ⁼ measurement (H*(T_imm)) 10 minutes after application and left drying of the formula;

T24h ⁼ measurement (H*(T₂4h)) 24 hours after application of the formula, wherein the area of the skin was prohibited from washing.

The measurements were performed on a panel of 10 women models who were kept in an air-conditioned (21 °C +/- 2°C) waiting room for 10 mins before the beginning of the test. They removed their makeup and an image of one of their cheeks was acquired using the Chromasphere with a definition of 410 x 410 pixels. This image made it possible to measure the color at T₀ before applying the formula, corresponding to H*(T₀). Approximately 300 mg of the Formulae I to IV, and the Comparative Formulae 1 to 4 were then weighed out into a watch glass and were applied with the bare fingers, respectively, to the half of the face on which the measurement was carried out at To.

The women models then returned to the air-conditioned room. An image of the cheek after application was acquired using the Chromasphere after 10 minutes. This image made it possible to measure the color immediately after wearing the formula, corresponding to H*(T_imm).

On the next day, the women models returned to the air-conditioned room. The cheek wherein the formula was applied on was prohibited from washing during the past 24 hours. The women models waited for 30 mins in the air-conditioned room, and at 24 hours after application, an image of the cheek after application was acquired using the Chromasphere. This image made it possible to measure the color 24 hours after wearing the formula, corresponding to H*(T₂4h).

The results were expressed by calculating the percent difference A_imm (A_imm ⁼|(H*(T_imm)-H*(To))/H*(T₀)|), which measures the instant skin tone modification effect, and the percent difference Ai_ong (Ai_ong ⁼|(H*(T24h)-H*(T_imm))/H*(T_imm)|) measures the long lasting skin tone modification effect. Statistically, regarding the incertitude of the values, the confidence level is a=0.05.

The instant skin tone modification effect was scored as follows.

1 : poor instant effect, with a A_imm of less than 0.3% or more than 10% in value;

2: natural instant effect, with a A_imm of from 0.3% to 2% or from 5% to 10% in value;

3 : very natural instant effect, with a A_imm of more than 2% but less than

5% in value.

The long lasting skin tone modification effect was scored as follows. 1 : no long lasting effect, with a Ai_ong of less than 0.3% or more than 10% in value;

2: long lasting effect, with a Ai_ong of from 0.3% to 2% or from 7% to

10% ;

3 : very good long lasting effect, with a Ai_ong of more than 2% but less than 5% in value.

Sensory

The sensory of each formula was evaluated by the 10 women models, and a score was given to the formula (3 : very good hydration and comfortable sensory, 2: good hydration and comfortable sensory, 1 : poor and unacceptable greasy feeling).

The results were listed in Table 2.

Table 2

*due to its poor instant skin tone modification effect, long lasting effect is not necessary to conduct;

**due to its poor sensory (too greasy), it is not possible to keep the skin un- washed for 24 hours.

It was observed that, comparing to the Comparative Formulae 1 to 4, the Formulae I to IV of the present invention have a very natural and pleasant appearance, providing to the skin very good instant and long lasting skin tone modification effect, meanwhile possessing very good and pleasant sensory.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

CLAIMS We claim:

1. An oil-in- water composition, comprising

a) water, representing at least 30wt % of the total weight of the composition;

b) at least one colorant selected from i) the organic pigments of xanthene or fluorane colorants; ii) the organic lakes of xanthene or fluorine colorants, or iii) a mixture thereof; and

c) at least one hydrocarbon-based oil selected from:

i) a linear or branched, saturated or unsaturated C6-C40 fatty alcohol, ii) a N-acyl amino acid ester of the formula (I):

R₁(CO)N(R₂)CH(R₃)(CH₂)_n(CO)OR₄ (I)

wherein:

n is an integer of 0, 1 or 2,

Ri represents a C5 to C21 linear or branched alkyl or alkenyl,

R2 represents a hydrogen atom or a Ci to C3 linear or branched alkyl, R3 represents a hydrogen atom, methyl, ethyl, or a C3 to C₄ linear or branched alkyl,

R₄ represents a Ci to C10 linear or branched alkyl or a C2 to C10 linear or branched alkenyl, or a sterol residue,

or iii) a mixture thereof;

wherein the composition has a pH value of less than or equal to 5.

2. The composition according to claim 1, characterized in that water represents from 30wt% to 90wt %, preferably from 40wt % to 85wt %, and more preferably from 50wt % to 80wt % of the total weight of the composition.

3. The composition according to any one of the preceding claim 1 or 2, characterized in that the colorant is selected from D&C Red No. 21, D&C Red No. 22, D&C Red No. 27, D&C Red No. 28, a lake thereof, or a mixture thereof, and more preferably one or more selected from D&C Red No. 27, D&C Red No. 28, a lake thereof or a mixture thereof.

4. The composition according to any one of the preceding claims 1 to 3, characterized in that the organic pigment represents from 0.0005 wt % to lwt %, preferably from 0.00 lwt % to 0.0 lwt % of the total weight of the composition, while the organic lake represents from 0.00 lwt % to 2wt %, preferably from 0.005wt % to lwt %, and more preferably from 0.005wt % to 0.5wt % of the total weight of the composition.

5. The composition according to any one of the preceding claims 1 to 4, characterized in that the linear or branched, saturated or unsaturated C6-C40 fatty alcohol is selected from a linear or branched, saturated or unsaturated Cio-40 fatty alcohol, a linear or branched, saturated or unsaturated Cio-34 fatty alcohol, and a linear or branched, saturated or unsaturated C₁₂-28 fatty alcohol, preferably a linear or branched, saturated or unsaturated C ₁₂-28 fatty monoalcohol, especially octyldodecanol.

6. The composition according to any one of the preceding claims 1 to 5, characterized in that in the N-acyl amino acid ester, the group Ri(CO)- is an acyl group of an acid selected from capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, linoleic acid, linolenic acid, oleic acid, isostearic acid, 2-ethylhexanoic acid, fatty acids of coconut oil and fatty acids from palm kernel oil, optionally having a hydroxyl group, preferably lauric acid, while the portion -N(R₂)CH(R₃)(CH₂)n(CO)- is selected from glycine, alanine, valine, leucine, isoleucine, serine, threonine, proline, hydroxyproline, beta-alanine, aminobutyric acid, aminocaproic acid, sarcosine, and N-methyl-beta-alanine, preferably sarcosine, the N-acyl amino acid ester most preferably being isopropyl N-lauroyl sarcosinate.

7. The composition according to any one of the preceding claims 1 to 6, characterized in that the hydrocarbon-based oil represents from 0.0 lwt % to 60wt %, preferably from O. lwt % to 40wt %, and more preferably from 0.5wt % to 15wt % of the total weight of the composition.

8. The composition according to any one of the preceding claims 1 to 7, characterized in that it has a pH value of less than or equal to 4.5.

9. The composition according to any one of the preceding claims 1 to 8, further comprising at least one agent selected from a skin whitening agent, a skin peeling agent and a thickening polymer.

10. The composition according to any one of the preceding claims 1 to 9, characterized in that it is provided in the form of cream, essence, water, lotion or gel, preferably in the form of face skincare cream.

11. An oil-in- water skincare composition comprising:

a) water, representing at least 30wt % of the total weight of the composition;

b) at least one colorant selected from i) the organic pigments of xanthene or f uorane colorants; ii) the organic lakes of xanthene or fluorine colorants, or iii) a mixture thereof, wherein the organic pigment represents from 0.0005wt % to lwt %, preferably from 0.00 lwt % to 0.0 lwt %, while the organic lake represents from O.OOlwt % to 2wt %, preferably from 0.005wt % to lwt %, and more preferably from 0.005wt % to 0.5wt % of the total weight of the composition; and

c) at least one hydrocarbon-based oil, representing from 0.0 lwt % to

60wt %, preferably from O. lwt % to 40wt %, and more preferably from 0.5wt % to 15wt % of the total weight of the composition, and selected from:

R₁(CO)N(R₂)CH(R₃)(CH₂)_n(CO)OR₄ (I)

wherein:

n is an integer of 0, 1 or 2,

Ri represents a C5 to C₂₁ linear or branched alkyl or alkenyl,

R₂ represents a hydrogen atom or a Ci to C3 linear or branched alkyl, R₃ represents a hydrogen atom, methyl, ethyl, or a C3 to C₄ linear or branched alkyl,

R₄ represents a Ci to C₁₀ linear or branched alkyl or a C₂ to C₁₀ linear or branched alkenyl, or a sterol residue,

or iii) a mixture thereof;

wherein the composition has a pH value of less than or equal to 5.

12. A method for instantly and lastingly modifying the skin tone into a pinkish color, comprising applying to the skin the composition according to any one of the preceding claims 1 to 11.

13. A method for preparing the composition according to any one of the preceding claims 1 to 11, comprising the steps of:

1) mixing at least one colorant selected from i) the organic pigments of xanthene or fluorane colorants; ii) the organic lakes of xanthene or fluorine colorants, or iii) a mixture thereof with at least one hydrocarbon-based oil, to obtain an oil phase,

2) dispersing the oil phase into an aqueous phase comprising water, and

3) adjusting the pH value of the resultant till less than or equal to 5, wherein the hydrocarbon-based oil is selected from:

R₁(CO)N(R₂)CH(R₃)(CH₂)_n(CO)OR₄ (I)

wherein:

n is an integer of 0, 1 or 2,

Ri represents a C5 to C₂₁ linear or branched alkyl or alkenyl,

R₂ represents a hydrogen atom or a Ci to C3 linear or branched alkyl, R3 represents a hydrogen atom, methyl, ethyl, or a C3 to C₄ linear or branched alkyl,

or iii) a mixture thereof.

14. Use of the combination of a) water; b) at least one colorant selected from i) the organic pigments of xanthene or fluorane colorants; ii) the organic lakes of xanthene or fluorine colorants, or iii) a mixture thereof and c) at least one hydrocarbon-based oil, for producing a skincare composition, especially a skincare composition for instantly and lastingly modifying the skin tone into a pinkish color,

wherein the hydrocarbon-based oil is selected from:

R₁(CO)N(R₂)CH(R₃)(CH₂)_n(CO)OR₄ (I) wherein:

n is an integer of 0, 1 or 2,

Ri represents a C5 to C21 linear or branched alkyl or alkenyl,

R2 represents a hydrogen atom or a Ci to C3 linear or branched alkyl, R₃ represents a hydrogen atom, methyl, ethyl, or a C3 to C₄ linear or branched alkyl,

or iii) a mixture thereof.