WO2016071878A1

WO2016071878A1 - Vanishing cream compositions and uses thereof

Info

Publication number: WO2016071878A1
Application number: PCT/IB2015/058586
Authority: WO
Inventors: Gaurav Kumar; Sarika MULEY
Original assignee: L'oreal
Priority date: 2014-11-07
Filing date: 2015-11-06
Publication date: 2016-05-12
Also published as: CN106999408B; CN106999408A

Abstract

The present invention concerns a composition comprising at least one aqueous phase and at least one oily phase, wherein said composition comprises: - i) at least 4% by weight of solid particles, preferably selected from the group consisting of: solid fatty acid(s), inorganic particles, and mixtures thereof; - ii) from 0.01% to 10% by weight of at least one crosslinked copolymer comprising at least one unit of an unsaturated olefinic carboxylic acid, and at least one unit of a (C_10-C₃₀)alkyl ester of unsaturated carboxylic acid; - iii) from 0.01% to 15% by weight of alkyl phosphate ester salts, wherein the percentages by weight are based on the total weight of the composition.

Description

Vanishing cream compositions and uses thereof [Field of the invention]

The present invention concerns new vanishing cream compositions and uses thereof.

[Background of the Invention]

Vanishing cream compositions are well known cosmetics which provide good sensory and tactile benefits to the skin. Such creams provide a dry, draggy, clean and matte end-feel, which helps overcoming the greasy and shiny appearance of the skin. Vanishing creams spread easily on the skin and are quickly absorbed therein ("quickly vanished"). Such creams counteract skin dryness to alleviate flaking, cracking and roughness.

Traditional vanishing cream formulations comprise high amounts of fatty acid, typically stearic acid. They also comprise salts of fatty acids called "fatty acid soap" which are typically alkali metal salts of the fatty acid, resulting from the in situ partial neutralization of fatty acid with a neutralizing agent (caustic potash or any other base). This partially neutralized composition is having certain pH limitation (generally near 7 or above), which is required for a right balance between fatty acid and salts of fatty acid.

Developments in the cosmetic field aim to incorporate skin benefit actives in vanishing cream compositions, in order to expand its uses. However, the pH limitation of traditional vanishing cream compositions restricts the incorporation of skin benefiting ingredients which are chemically stables at low pH.

A number of attempts were made to prepare stable and efficient low pH vanishing cream compositions which can incorporate such type of ingredients. For example, vanishing cream compositions with relatively low amounts of fatty acid were prepared. However, it was noted that the resulting compositions lack the consumer desired sensory benefits of traditional vanishing cream compositions. Indeed, viscosity and rub-in effect were shown to be affected. Besides, US 6,153,177 discloses vanishing cream compositions having pH above 5, comprising fatty acid and partially neutralized fatty acid, in presence of salts of oc-hydroxy carboxylic acids, for achieving skin lightning benefits through the topical application of the compositions. However, it is well known that the acidic forms of said actives are more potent to penetrate the skin compared to their salts (Percutaneous Penetration Enhancers, CRC press, pp. 407(1995)). WO 01/70187 discloses vanishing creams deprived of neutralized fatty acid, comprising a C₈-C₂2 fatty acid substituted saccharide. These compositions are said to be capable of deliver actives stable at low pH, but failed to realize the complete sensory benefits of tradition vanishing creams, which is believed to be due to improper emulsifier system.

In addition, US 4,536,519 discloses emulsified cosmetic compositions (such as vanishing creams) comprising neutralized product of phosphoric acid ester, a nonionic surfactant with HLB up to 6, an oily substrate and water. Such compositions however lack the sensory characteristics of traditional vanishing creams.

Therefore, there is a need for new stable composition, in particular low pH vanishing cream compositions, which allow the incorporation of a large variety of skin benefiting ingredients stable at low pH, while maintaining in particular the unique sensorial characteristics of traditional fatty acid: soap based vanishing cream compositions.

[Summary of the Invention]

It is an object of the present invention to provide compositions, in particular low pH vanishing cream compositions, which are chemically and physically stable, while providing the sensorial attributes such as of traditional vanishing cream compositions, and which may comprise ingredients stable at low pH.

It is another object of the present invention to provide compositions, in particular low pH vanishing cream compositions, wherein skin benefiting ingredients remain chemically stable in said compositions.

It is another object of the present invention to provide compositions, in particular low pH vanishing cream compositions for incorporation of skin benefiting ingredients, without significantly affecting the end-feel of the compositions on the skin.

[Detailed description of the Invention]

The present invention concerns a composition comprising at least one aqueous phase and at least one oily phase, wherein said composition comprises:

- i) at least 4% by weight of solid particles, preferably selected from the group consisting of: solid fatty acid(s), inorganic particles, and mixtures thereof;

- ii) from 0.01 % to 10% by weight of at least one crosslinked copolymer comprising at least one unit of an unsaturated olefinic carboxylic acid, and at least one unit of a (Ci₀-C₃₀)alkyl ester of unsaturated carboxylic acid; - iii) from 0.01 % to 15% by weight of alkyl phosphate ester salts, wherein the percentages by weight are based on the total weight of the composition. As used herein, the "aqueous phase" is a phase containing at least water.

The applicants surprisingly found that compositions of the invention advantageously retain the typical consumer benefits of traditional acid:soap based vanishing cream formulations, even at low pH, such as dry and draggy, non-greasy skin feel with a characteristic non-shiny, matte finish without greasiness, ease of absorption, cool sensation and a matte finish.

The applicants also found that such compositions advantageously allows the incorporation of skin benefiting ingredients, in particular skin benefiting ingredients stable at low pH, without affecting the chemical/physical stability and the desired properties of said compositions.

In particular, the applications found that compositions according to the invention may incorporate skin benefiting ingredient(s), without affecting the end-feel of the compositions on the skin. As used herein, the term "low pH" means an acidic pH as measured by standard pH measurement method, said pH being below 7, preferably below 6.6.

According to one embodiment of the invention, the pH of the composition is from 4 to 6.5, preferably from 4.5 to 6.2. In particular, the pH of the composition is from 5.0. to 6.2, preferably from 5.4 to 6.2.

As used herein, the term "stable at low pH" means that ingredients and formulation comprising them, remain free from any chemical or physical changes such as discoloration, separation..., at low pH. The pH may be measured according to usual method known by the skilled person. Solid particles

In one embodiment, the composition comprises from 4% to 50%, preferably from 8% to 30%, and more preferably from 10% to 20% by weight of solid particles based on the total weight of the composition. In particular, the composition comprises from 10% to 18%, preferably from 10% to 15%, by weight of solid particles based on the total weight of the composition. As used herein, the term "solid" means in the solid state at 25°C, at atmospheric pressure (101325 Pa).

In one embodiment, the solid particles are asymmetric solid particles.

As used herein, the term "asymmetric solid particles" means that the particles have no specific symmetry. For example, these particles can be of round, oval or plate-like type, but without particular symmetry. The solid particles employed in the composition notably impart cream-like viscosity. In case of asymmetric solid particles, the particles deliver high skin frictions.

In one embodiment, the solid particles are plateiike asymmetric particles, such that upon application they align under shear to give perceived dry and draggy feel.

In one embodiment, the average particle size of the solid particles may range from 10^"1 to 10³ micron, preferably from 10^"1 to 10² micron. The particle size may be measured by Dynamic Light Scattering (DLS) or with a good resolution optical microscope.

According to one embodiment of the invention, the solid particles are solid fatty acid(s) having a melting point from 35°C to 100°C, preferably from 40°C to 85°C, more preferably from 50°C to 80°C, and for example from 65°C to 75°C.

As used herein, the term "solid fatty acid" means a fatty acid which is solid at ambient temperature (25°C), with a reversible change of solid/liquid state, having a melting point higher or equal to 35°C, preferably lower than 100°C, notably lower than 85°C.

As used herein, the "melting point" corresponds to the temperature of the most endothermic pic observed in DSC (thermal analysis) such as described in ISO 1 1357-3 norm (1999). The melting point of the solid fatty acid may be measured by traditional method, such as for example with a Differential Scanning Calorimeter (DSC), typically the calorimeter sold under the name MDSC 2920 by TA instruments.

In particular, the solid fatty acid(s) are crystals of fatty acid(s), which are for example a specific type of platelike asymmetric particles.

In one embodiment, the fatty acid comprises a saturated or unsaturated alkyl chain having from 4 to 28 carbon atoms, preferably from 12 to 22 carbon atoms. Preferably, said fatty acid is a linear alkyl chain fatty acid.

In one embodiment, the fatty acid is selected from the group consisting of: stearic acid, palmitic acid, myristic acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid and mixtures thereof. Preferably, in one embodiment, the solid fatty acid is stearic acid, palmitic acid or mixtures thereof.

In a particular embodiment, the composition comprises 1 0% to 1 8% by weight of solid fatty acid(s), based on the total weight of the composition.

According to one embodiment of the invention, the solid particles are inorganic solid particles, notably selected from the group consisting of: talc, mica, clay, and mixtures thereof.

In one embodiment, the inorganic particles are talc.

As used herein, the term "talc" means a mineral composed of hydrated magnesium silicate with the chemical formula H₂Mg3(Si0₃)4 or Mg₃Si₄O₁₀(OH)2.

The talc may be selected from those under the name TALC SG-2000® commercialized by Nippon Talc, LUZENAC PHARMA M® commercialized by LUZENAC, J-68BC commercialized by US Corporation and MICRO ACE-P-3® commercialized by Nippon Talc.

Talc is preferably in the form of particles having a mean particle size comprised from 1 μηι to 1 0 μηι.

In a particular embodiment, the composition comprises from 1 0% to 18% by weight of talc, based on the total weight of the composition.

In one embodiment, the solid particles are in the oily phase. Preferably, when the solid particles are solid fatty acid(s), the solid particles are in the oily phase. Crosslinked copolymer

The composition of the invention comprises at least one crosslinked copolymer comprising at least one unit of an unsaturated olefinic carboxylic acid, and at least one hydrophobic unit of a (C₁₀-C₃₀)alkyl ester of unsaturated carboxylic acid.

In particular, the unsaturated olefinic carboxylic acid unit is a hydrophilic unit.

In particular, the (C₁₀-C₃₀)alkyl ester of unsaturated carboxylic acid unit is a hydrophobic unit.

Thus, such crosslinked copolymer may comprise at least one hydrophilic unit of the olefinic unsaturated carboxylic acid type and at least one hydrophobic unit of (Ci₀- C₃₀)alkyl ester of unsaturated carboxylic acid type.

As used herein, "at least one crosslinked copolymer" means one crosslinked copolymer or a mixture of copolymers. In one embodiment, said copolymer is a block copolymer.

As used herein, the term (Ci₀-C₃₀)alkyl means an alkyl group, linear or branched, comprising from 10 to 30 carbon atoms. In one embodiment, the molecular weight of the above-mentioned copolymer is of at least 50 kD.

In one embodiment, the above-mentioned crosslinked copolymer are chosen from those comprising:

- at least one unit derived from olefinic unsaturated carboxylic acid monomers of formula (I):

H₉C= C— C— OH _m

2 I I I ^w

Ri O

wherein is selected from the group consisting of :H, CH₃, and C₂H₅, (which corresponds respectively to acrylic acid, methacrylic acid and ethacrylic acid units), and

at least one unit derived from (C₁₀-C₃₀)alkyl esters of unsaturated carboxylic acid monomers of formula (II):

H C= C— COR. _(m

2 I I I ^{3 w}

R₂ O

wherein R₂ is selected from the group consisting of: H, CH₃, and C₂H₅ (which corresponds respectively to acrylate, methacrylate and ethacrylate units), and

R₃ is a saturated or unsaturated, branched or unbranched (Ci₀-C₃₀)alkyl group.

As used herein, the term "at least one unit derived from olefinic unsaturated carboxylic acid monomers of formula (I)" means that said unit is formed from the monomers of formula (I), for example by polymerization of the monomers of formula (I).

In one embodiment, for example, R₂ is chosen from H (acrylate units) and CH₃ (methacrylate units) and R₃ is chosen from (C₁₂-C₂₂)alkyl groups.

(C₁₀-C₃₀)alkyl esters of unsaturated carboxylic acids in accordance with the invention include for example lauryl acrylate, stearyl acrylate, decyl acrylate, isodecyl acrylate, dodecyl acrylate, lauryl methacrylate, stearyl methacrylate, decyl methacrylate, isodecyl methacrylate, and dodecyl methacrylate. Crosslinked copolymer of this type are for example described and prepared according to U.S. Pat. Nos. 3,915,921 and 4,509,949, the disclosures of which are incorporated by reference herein.

In one embodiment, the crosslinked copolymer that can be used include those formed from a mixture of monomers comprising :

• (a) acrylic acid,

• (b) at least one ester of formula (I I) described above wherein R₂ is chosen from H and CH₃, and R₃ is chosen from alkyl groups comprising from 12 to 22 carbon atoms, and

· (c) at least one crosslinking agent chosen from copolymerizable polyethylenic unsaturated monomers such as diallyl phthalate, allyl (meth)acrylate, divinylbenzene, (poly)ethylene glycol dimethacrylate and methylenebisacrylamide.

In one embodiment, the crosslinked copolymers of the invention that can be used include (% being given with respect to the total weight of the respective copolymers):

- copolymers comprising from 95% to 60% by weight of acrylic acid (hydrophilic unit), from 4% to 40% by weight of C₁₀-C₃₀ alkyl acrylate (hydrophobic unit), and from 0% to 6% by weight of crosslinking polymerizable monomer, and

- copolymers comprising from 98% to 96% by weight of acrylic acid (hydrophilic unit), from 1 % to 4% by weight of C₁₀-C₃₀ alkyl acrylate (hydrophobic unit) and from 0.1 % to 0.6% by weight of crosslinking polymerizable monomer such as those described above.

Among the above crosslinked copolymers, the products sold by the company Lubrizol under the trade names PEMULEN TR1 ®, PEMULEN TR2®, and CARBOPOL 1382® can be used.

Preferably, the crosslinked copolymer used in the present invention is PEMULEN TR2®, which is a acrylates/Ci₀-C₃₀ alkyl acrylate crosspolymer.

In one embodiment, the composition of the invention comprises from 0.05% to 5% by weight, preferably from 0.1 % to 1 % by weight, more preferably from 0.1 % to 0.5% by weight of the above-mentioned crosslinked copolymer, based on the total weight of the composition. In particular, the composition comprises from 0.1 % to 0.15% by weight of above-mentioned crosslinked copolymer, based on the total weight of the composition. In one embodiment, the crosslinked copolymer is used as an emulsifier of the composition.

Alkyl phosphate ester salts

According to the invention, the composition comprises from 0.01 % to 15% by weight of at least one alkyl phosphate ester salt, based on the total weight of the composition.

In one embodiment, the alkyl phosphate ester is used as a co-emulsifier of the composition.

In one embodiment, the alkyl phosphate ester is a dialkyl phosphate ester or a monoalkyl phosphate ester. Preferably, the alkyl phosphate ester is a monoalkylphosphate ester.

As used herein, the term "monoalkyl" means that the phosphate element is linked to only one alkyl chain.

As used herein, the term "dialkyl" means that the phosphate element is linked to two alkyl chains.

In one embodiment, the monoalkyl phosphate ester salt possesses the following formula (III):

O

I I

R; -O-A- -Ρ-ΟΧ

I

OX

wherein:

R₄ represents a linear or branched, saturated or unsaturated, alkyl group comprising from 4 to 24 carbon atoms, preferably from 12 to 22 carbon atoms, more preferably from 16 to 18 carbon atoms;

A represents an alkylene group comprising from 2 to 10 carbon atoms;

n represents an integer comprised from 0 to 20, preferably n is 0;

X represents alkali metals, such as potassium, lithium and sodium.

In one embodiment, the dialkyl phosphate ester salt is a dicetyl phosphate salt, such as a potassium dicetyl phosphate.

In another embodiment, the monoalkyl phosphate ester salt is a potassium cetyl phosphate, for example commercialized under the trade names Amphisol® K (Roche), Amphisol® A (Roche), Arlatone® MAP (Uniqema), Crodafos® MCA (Croda). In one embodiment, the total content of alkyi phosphate(s) ester salt, or in one embodiment the total content of monoalkyi phosphate(s) ester salt, in the composition is from 0.1 % to 10% by weight, preferably from 0.5% to 5% by weight, and more preferably from 1 % by weight to 2% by weight, based on the total weight of the composition.

In one embodiment, in the compositions of the invention, the ratio R, wherein:

R = alkyl phosphate ester salts / crosslinked copolymer

alkyl phosphate ester salts and crosslinked copolymer being as defined above, ranges from 20 : 1 to 10 : 0.1 , preferably from 10 : 1 to 10:1 .

In one embodiment, in the compositions of the invention, the ratio R, wherein:

R = monoalkyi phosphate ester salts / crosslinked copolymer monoalkyi phosphate ester salts and crosslinked copolymer being as defined above, ranges from 20 : 1 to 10 : 0.1 , preferably from 10 : 1 to 10:1 .

In one embodiment, the composition of the invention comprises:

- i) from 10% to 20% by weight of solid particles, preferably solid fatty acid(s) or talc, based on the total weight of the composition;

- ii) from 0.05% to 2% by weight at least one crosslinked comprising at least one unit of an unsaturated olefinic carboxylic acid, and at least one unit of a (Ci₀-C₃₀) alkyl ester of unsaturated carboxylic acid,

- iii) from 0.2% to 2% by weight of monoalkyi phosphate ester salts, based on the total weight of the composition.

In one embodiment, the composition of the present invention comprises:

- i) from 12% to 15% by weight of solid stearic acid or talc, based on the total weight of the composition;

- ii) from 0.05% to 1 % by weight of at least one crosslinked as defined above, based on the total weight of the composition;

- iii) from 0.2% to 2% by weight of potassium cetyl phosphate, based on the total weight of the composition.

Physiologically acceptable medium

In addition to the compounds indicated above, a composition according to the invention may include a physiologically acceptable medium. The term "physiologically acceptable medium" is intended to denote a medium that non-toxic and is particularly capable of being applied to the skin or the lips.

The physiologically acceptable medium is generally suitable for the nature of the support to which the composition should be applied, and also for the way in which the composition should be packaged.

The composition of the invention comprises an aqueous phase. Such aqueous phase may in particular comprise water and optionally hydrophilic solvents such as monoalcohols comprising from 1 to 8 carbon atoms (in particular ethanol, isopropanol, propanol, butanol), polyols (in particular propylene glycol, butylene glycol), and polyethylene glycols (in particular PEG-8, dipropylene glycol) and mixtures thereof.

The composition of the present invention typically comprises water in amounts ranging from about 5% to 95%, preferably from about 30% to about 90%, and more preferably from about 50% to about 85% by weight based on the total weight of the composition.

The composition of the invention comprises an oily phase, said oily phase usually comprises at least one oil.

For example, as oils which can be used in the composition of the invention, mention may be made of:

- hydrocarbon oils of animal origin, such as perhydrosqualene;

- hydrocarbon oils of plant origin, such as liquid triglycerides of fatty acids containing from 4 to 10 carbon atoms, for instance heptanoic or octanoic acid triglycerides, or alternatively, for example, sunflower oil, corn oil, soybean oil, marrow oil, grapeseed oil, sesame seed oil, hazelnut oil, apricot oil, macadamia oil, arara oil, castor oil, avocado oil, caprylic/capric acid triglycerides, for instance those sold by Stearineries Dubois or those sold under the names Miglyol 810, 812 and 818 by Dynamit Nobel, jojoba oil and shea butter oil;

- synthetic esters and ethers, especially of fatty acids, for instance the oils of formulae R1 COOR2 and R10R2 in which R1 represents a fatty acid residue containing from 8 to 29 carbon atoms and R2 represents a branched or unbranched hydrocarbon-based chain containing from 3 to 30 carbon atoms, for instance purcellin oil, isononyl isononanoate, isopropyl myristate, 2- ethylhexyl palmitate, 2-octyldodecyl stearate, 2-octyldodecyl erucate or isostearyl isostearate; hydroxylated esters, for instance isostearyl lactate, octyl hydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate or triisocetyl citrate; fatty alcohol heptanoates, octanoates or decanoates; polyol esters, for instance propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; and pentaerythritol esters, for instance pentaerythrityl tetraisostearate;

- straight or branched hydrocarbons of inorganic or synthetic origin, such as volatile or non-volatile liquid paraffins, and derivatives thereof, petroleum jelly, polydecenes, and hydrogenated polyisobutene such as Parleam oil;

- fatty alcohols having from 8 to 26 carbon atoms, such as cetyl alcohol, stearyl alcohol and their mixture (cetearyl alcohol), octyldodecanol, 2- butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol or linoleyl alcohol;

- partially hydrocarbon-based and/or silicone-based fluoro oils, for instance those described in document JP-A-2-295 912;

silicone oils, for instance volatile or non-volatile polymethylsiloxanes (PDMSs) with a straight or cyclic silicone chain, which are liquid or pasty at room temperature, especially cyclopolydimethylsiloxanes (cyclomethicones) such as cyclohexasiloxane; polydimethylsiloxanes containing alkyl, alkoxy or phenyl groups, which are pendent or at the end of a silicone chain, these groups containing from 2 to 24 carbon atoms; phenyl silicones, for instance phenyl trimethicones, phenyl dimethicones, phenyltrimethylsiloxydiphenylsiloxanes, diphenyl dimethicones, diphenylmethyldiphenyltrisiloxanes or 2-phenylethyl trimethylsiloxy silicates, and polymethylphenylsiloxanes; and

mixtures thereof.

In the list of the above-mentioned oils, the term "hydrocarbon oil" is understood to mean any oil predominantly containing carbon and hydrogen atoms, and optionally ester, ether, fluoro, carboxylic acid and/or alcohol groups.

In one embodiment, the composition of the invention is an oil-in-water emulsion (O/W).

As used herein, the term "emulsion" means a composition containing at least one aqueous phase and at least one oily phase of which at least one of the phases is dispersed in the other phase, with or without emu!sifier. In one embodiment, the emulsion is a simple emulsion, i.e., the composition contains only one aqueous phase and one oily phase.

In another embodiment, the emulsion is a multiple emulsion, for example a double emulsion.

The proportion of the oily phase of the emulsion may range from 0.5% to 80% by weight, preferably from 1 % to 50% by weight relative to the total weight of the composition.

The emulsions generally contain at least one emulsifier for example selected from the group consisting of: amphoteric, anionic, cationic or non-ionic emulsifiers, used alone or as a mixture, and optionally a co-emulsifier.

In the present invention, these emulsifiers are different from the crosslinked copolymer of the invention, and are called "additional emulsifiers". The emulsifier and the additional emulsifiers are generally present in the composition in a total proportion ranging from 0.3% to 30% by weight and preferably from 0.5% to 20% by weight relative to the total weight of the composition.

For W/O emulsions, examples of emulsifiers that may be mentioned include dimethicone copolyols, such as the mixture of cyclomethicone and dimethicone copolyol sold under the name DC 5225 C by Dow Corning, and alkyl dimethicone copolyols such as the lauryl methicone copolyol sold under the name Dow Corning 5200 Formulation Aid by Dow Corning, and the cetyl dimethicone copolyol sold under the name Abil EM 90® by Goldschmidt. A crosslinked elastomeric solid organopolysiloxane containing at least one oxyalkylenated group, such as those obtained according to the procedure of Examples 3, 4 and 8 of document US-A-5 412 004 and of the examples of document US-A-5 81 1 487, especially the product of Example 3 (synthesis example) of patent US-A-5 412 004, such as the product sold under the reference KSG 21 by Shin-Etsu, may also be used as surfactant for W/O emulsions.

For O/W emulsions, examples of emulsifiers that may be mentioned include non- ionic emulsifiers such as oxyalkylenated (more particularly polyoxyethylenated) fatty acid esters of glycerol; oxyalkylenated fatty acid esters of sorbitan; oxyalkylenated (oxyethylenated and/or oxypropylenated) fatty acid esters; oxyalkylenated (oxyethylenated and/or oxypropylenated) fatty alcohol ethers; sugar esters such as sucrose stearate; and mixtures thereof, such as the mixture of glyceryl stearate and PEG-40 stearate.

Additives such as benefit agents

The composition according to the invention may also further comprise any additive normally used in the field under consideration, for example selected from anionic, cationic, amphoteric or nonionic surfactants, silicone surfactants, gums, resins, dispersants, semicrystalline polymers, thickeners, antioxidants, fillers, coloring materials, essential oils, preservatives, fragrances, neutralizing agents, antiseptics, anti-UV protective agents, skin benefiting ingredients, such as: vitamins, skin lightening agents, hydrating agents, emollients or collagen-protecting agents, and mixtures thereof.

A person skilled in the art can adjust the type and amount of additives present in the compositions according to the invention by means of routine operations, so that the cosmetic properties and the stability properties desired for these compositions are not affected by the additives.

As used herein, the term "skin benefiting ingredient" also refers to "skin benefiting agent", "cosmetic active agent" or "cosmetic active ingredient".

For example, preservatives may be incorporated into the compositions of the present invention to protect against the growth of potentially harmful microorganisms.

Suitable traditional preservatives include alkyl esters of para-hydroxybenzoic acid. Other preservatives which have more recently come into use include hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Cosmetic chemists are familiar with appropriate preservatives and routinely choose them to satisfy the preservative challenge test and to provide product stability. Particularly preferred preservatives are disodium and tetrasodium EDTA, phenoxyethanol, methyl paraben, butyl paraben, propyl paraben, imidazolidinyl urea (commercially available as Germall 1 157), sodium dehydroacetate and benzyl alcohol.

The preservatives are preferably employed in amounts ranging from 0.01 % to about 2% by weight of the composition.

A wide variety of organic sunscreen agents may be suitable for use in combination with the essential ingredients of this invention. Suitable UV-A / UV-B sunscreen agents include, 2- hydroxy-4-methoxybenzophenone, octyldimethyl p-aminobenzoic acid, digalloyltrioleate, 2,2-dihydroxy-4-methoxybenzophenone, ethyl-4-(bis(hydroxypropyl)) aminobenzoate, 2-ethylhexyl-2-cyano-3,3-diphenyl-2propenoate (octocrylene), 2- ethylhexylsalicylate, glyceryl p-aminobenzoate, 3,3,5-trimethylcyclohexylsalicylate, methylanthranilate, p-dimethyl- aminobenzoic acid or aminobenzoate, 2-ethylhexyl-p- dimethyl-amino-benzoate, 2-phenylbenzimidazole-5-sulfonic acid, 2-(p- dimethylaminophenyl)-5-sulfonic-benzoxazoic acid, 2-ethylhexyl-p-methoxycinnamate, butylmethoxy-dibenzoylmethane, 2-hydroxy-4-methoxybenzophenone, octyldimethyl-p- aminobenzoic acid and mixtures thereof. The most suitable organic sunscreens are 2- ethylhexyl-2-cyano-3,3-diphenyl-2propenoate (octocrylene) and butylmethoxy- dibenzoylmethane.

A safe and effective amount of UV sunscreen may be used in the compositions useful in the subject invention. The composition preferably comprises from about 0.1 % to about 10%, more preferably from about 0.5 % to about 5% by weight of at least one sunscreen agent based on the total weight of the composition.

The composition of the invention may comprise from 0.01 % to 10%, preferably from 0.1 % to 5%, and more preferably from 0.2% to 1 % by weight of at least one skin benefiting ingredient, based on the total weight of the composition.

As skin benefiting ingredient, mention may be made of skin lightening agent, which may be selected from niacin, alkali or alkaline earth metal salts of lactic acid and/or acyloxyl lactylate, retinol and derivatives, hydroquinone and derivatives (e.g. arbutin), kojic acid, dicarboxylic acids (e.g. azelaic acid, sebacic acid), represented by the formula HOOC-(C_xH_y)-COOH where x ranges from 4 to 20 and y ranges from 6 to 40, ascorbic acid and derivatives thereof, and diols such as 4-(1 -phenylethyl)benzene-1 ,3-diol.

Preferably, the skin lightening agent is 4-(1 -phenylethyl)benzene-1 ,3-diol, for example commercialized under the trade name Symwhite 377® by the company Symrise.

As skin benefiting ingredient, mention may also be made of vitamins, such as vitamin A (retinol), vitamin E (tocopherol), vitamin B5 (panthenol), vitamin B3 (niacinamide), and their derivatives (such as esters), and their mixtures thereof. As used herein, the term "surfactant" means a detergent and differs from an emulsifier according to the value of the HLB (Hydrophi!ic Lipophilic Balance), the HLB being the ratio between the hydrophilic part and the lipophilic part in a molecule.

The term HLB is well known by the skilled person and is described for example in "The HLB system. A time-saving guide to Emulsifier Selection" (published by ICi Americas !nc ; 1984). For emulsifiers, HLB is typically comprised from 3 to 8 for preparing water-in- oil emulsions, and is typically comprised from 8 to 18 for preparing oil-in-water emulsions, whereas surfactants typically have a HLB higher than 20.

In a particular embodiment of the invention, the applicants have nevertheless surprisingly discovered that the use of emulsifiers with a HLB ranging from 2 to 8 in a composition according to the invention, and more particularly in a composition under the form of an oil-in-water emulsion according to the invention, provides an improved sensoriality and/or consistency to the resulting cream.

In a particular embodiment, emulsifiers having a HLB ranging from 2 to 8 for use in the present invention are, for instance selected among Propylene Glycol Isostearate (HLB = 2.5), Glycol Stearate (HLB = 2.9), Sorbitan Sesquioleate (HLB = 3.7), Glyceryl Stearate (HLB = 3.8), Lecithin (HLB = 4), Sorbitan Oleate (HLB = 4.3), Sorbitan Monostearate NF (HLB = 4.7), Sorbitan Stearate (HLB = 4.7), Sorbitan Isostearate (HLB = 4.7), Steareth-2 (HLB = 4.9), Oleth-2 (HLB = 4.9), Glyceryl Laurate (HLB = 5.2), Ceteth-2 (HLB = 5.3), PEG-30 Dipolyhydroxystearate (HLB = 5.5), Glyceryl Stearate SE (HLB = 5.8), Sorbitan Stearate (and) Sucrose Cocoate (HLB = 6), PEG-4 Dilaurate (HLB = 6), Methyl Glucose Sesquistearate (HLB = 6.6), Lecithin, and PEG-8 Dioleate (HLB = 8), or mixtures thereof.

HLB of the surfactants) which may be used in the compositions of the invention, may be determined by the GRIFFIN method or by the DAVIES method.

The preferred surfactants are selected from anionic, amphoteric, non-ionic and/or cationic surfactants, and any of their mixtures.

The composition of the invention may comprise from 0.0% to 1 .0% by weight of surfactant(s), preferably from 0.0% to 0.5% by weight, and more preferably from 0.0% to 0.1 % by weight, base on the total weight of the composition.

In one embodiment, the composition comprises less than 1 .0% by weight of surfactant(s), preferably less than 0.5%, and more preferably less than 0.1 %, based on the total weight of the composition.

Preferably, the composition does not comprise surfactant.

In one embodiment, the composition is a sulfate surfactants free composition. Preferably, the composition does not comprise a sulfate surfactant.

As used herein, the term "free" means that the composition does not comprise or comprises at most 1 % by weight of a compound based on the total weight of the composition.

Uses - Industrial applications

In one embodiment, the composition of the invention is a cosmetic composition, preferably a vanishing cream composition. The present invention also concerns the use of the composition as defined above as a vanishing cream.

The present invention also concerns the use of the composition as defined above for the stabilization of at least one skin benefiting ingredient.

The present invention also concerns a method of skin care comprising applying to the skin a composition as defined above.

The present invention is further described by way of the following non-limiting examples.

Examples

In all the following examples, the provided % is % by weight based on the total weight of the composition.

Example 1 : Composition 1 - Low pH vanishing cream composition

qs : quantity sufficient to 100% Method of preparation:

1. Phase A was heated up to 75°C and mixed well.

2. Phase A1 was slowly added to phase A with stirring. The mixture was stirred until Pemulen-TR2® solubilized well in phase A.

3. Phase A2 was added to main phase A. Temperature was maintained at 75°C.

4. Phase B was melted at 75°C. Phase B was then slowly added to phase A while mixing. Temperature was maintained at 75°C.

5. Phase B1 was mixed well at 70°C till dissolution and added to phase A at 60°C.

6. The mixture was allowed to cool slowly, with continuous mixing. Phase C was added at 50°C and mixed well

7. Phase D was added at 45°C with continuous mixing.

8. The resulting composition is allowed to cool down to room temperature.

The composition is an oil-in-water emulsion.

pH of composition 1 : 5.7-6.2

Example 2: Composition 2 - Low pH vanishing cream composition

qs : quantity sufficient to 100% Method of preparation:

1 . Phase A was heated up to 75°C and mixed well.

3. Phase A2 was added to main phase A. Temperature was maintained at 75°C.

6. Phase C was then added to main phase A while mixing at 60°C.

7. The mixture was then allowed to cool slowly, with continuous mixing.

Phase D was added at 50°C and mixed well.

8. Phase E was added at 45°C with continuous mixing.

9. The resulting composition is allowed to cool down to room temperature.

The composition is an oil-in-water emulsion. pH of composition 2: 5.4 - 5.8

The composition 2 was applied to the skin of a panel of volunteers. The sensory evaluation indicates that the composition provides identical sensorial benefits than typical vanishing cream, such as desirable creamy texture characteristics upon application onto skin, ease of absorption, dry feel, clean and matte end-feel, which helps overcoming the greasy and shiny appearance of the skin.

Example 3: Composition 3 - Low pH vanishing cream composition

qs: quantity sufficient to 100%

Method of preparation:

1 . Phase A was heated up to 75°C and mixed well.

3. Phase A2 was added to main phase A. Temperature was maintained at 75°C.

6. Phase C was then added to main phase A while mixing at 60°C.

7. The mixture was then allowed to cool slowly, with continuous mixing.

Phase D was added at 50°C and mixed well.

8. The resulting composition is allowed to cool down to room temperature.

The composition is an oil-in-water emulsion. pH of composition 3: 4.9-5.4 The composition 3 was applied to the skin of a panel of volunteers. The sensory evaluation indicates that the composition provides characteristic vanishing cream sensorials, with improved consistency of the cream.

Example 4: Composition 4 - Traditional vanishing cream composition

(Comparative example)

qs: quantity sufficient to 100%

Method of preparation:

1 . Phase A was heated up to 75°C and mixed well.

2. Phase B was melted at 75°C and was slowly added to phase A while mixing.

The mass was mixed at 75°C for 15-20 minutes.

3. Phase B1 was mixed and melted at 70°C. Phase B1 was then added to the mixture of step 2, at 60°C.

4. Phase C was then added at 50°C.

5. Phase D was added at 45°C.

6. The resulting composition is allowed to cool down to room temperature. The composition is an oil-in-water composition.

The pH of composition 4: 7.00 - 7.25 (pH was measured by standard method).

The composition 4 was applied to the skin of a panel of volunteers. The sensory evaluation indicates that this composition provides sensorial benefits typically obtained with such type of traditional acid/soap vanishing cream.

Example 5 : Assessment of the compositions' stability

The stability of the acidic active (Phenylethyl resorcinol, Symwhite) was assessed for the composition 1 , composition 2 (examples 1 and 2) and the control composition 4 of example 4. The results are provided in the following table:

It was shown that the control composition 4 (example 4) being a traditional vanishing cream is not stable in presence of the acidic skin benefiting ingredient such as for example Phenylethyl resorcinol (Symwhite 377). More particularly, this is considered to be due to the instability of the acidic skin benefiting ingredient in said control composition, wherein the pH is equal to or higher than 7.

On the contrary, the compositions of the invention (compositions 1 and 2) having low pH, in particular pH below 7, comprising the acidic skin benefiting ingredient (Symwhite) are chemically and physically stable. Example 6: Composition 5 (Comparative example of composition 1)

qs: quantity sufficient to 100%

Method of preparation:

1 . Phase A was heated up to 75°C and mixed well.

3. Phase A2 was added to main phase A. Temperature was maintained at 75°C.

6. The mixture was allowed to cool slowly, with continuous mixing. Phase C was added at 50°C and mixed well.

7. Phase D was added at 45°C with continuous mixing.

8. The resulting composition is allowed to cool down to room temperature.

The composition is an oil-in-water emulsion. pH of the composition 5: 6.85-6.96

Assessment of the compositions' stability of composition 1 (example 1 ), and composition 5 (example 6):

The composition 1 and composition 5 were applied on the skin of female volunteers.

80% of the total volunteers found that composition 1 provides better vanishing cream benefits than composition 5, such as quick absorption, dry-draggy and matte end-feel, which helps overcoming the greasy and shiny appearance of the skin.

Example 7: Composition 6 - Vanishing cream with asymmetric solid particles (Talc)

qs : quantity sufficient to 100% pH of the above composition 6

Method of preparation:

1 . Phase A was heated up to 75°C.

2. Phase A1 added to main phase A slowly while mixing. A1 was missed well till complete dispersion. The medium was mixed at 75°C.

3. Phase A2 was then added to main phase A and mixed well

4. Phase B was added in main phase.

5. The constituents of phase C were mixed and were melted at 70°C, then complete mass was added to the mixture of main phase.

6. Phase D was added at 45°C.

7. The resulting composition was allowed to cool down to room temperature. The composition is an oil-in-water emulsion.

The composition 6 was applied on the skin of female volunteers. The sensory evaluation indicates that the composition provides identical sensorial benefits than typical vanishing cream, such as desirable creamy texture characteristics upon application onto skin, ease of absorption, dry feel, clean and matte end-feel, which helps overcoming the greasy and shiny appearance of the skin.

Claims

1 . Composition comprising at least one aqueous phase and at least one oily phase, wherein said composition comprises:

- ii) from 0.01 % to 10% by weight of at least one crosslinked copolymer comprising at least one unit of an unsaturated olefinic carboxylic acid, and at least one unit of a (C₁₀-C₃₀)alkyl ester of unsaturated carboxylic acid;

- iii) from 0.01 % to 15% by weight of alkyl phosphate ester salts, wherein the percentages by weight are based on the total weight of the composition.

2. Composition according to claim 1 , having a pH comprised from 4 to 6.5, preferably from 4.5 to 6.2.

3. Composition according to any one of claim 1 or 2, wherein the solid particles are solid fatty acid(s), wherein the fatty acid is selected from the group consisting of: stearic acid, palmitic acid, myristic acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid and mixtures thereof.

4. Composition according to any one of claim 1 or 2, wherein the solid particles are inorganic solid particles selected from the group consisting of: talc, mica, clay, and mixtures thereof.

5. Composition according to any one of claims 1 to 4, wherein the alkyl phosphate ester salt is a monoalkyl phosphate ester salt, in particular potassium cetyl phosphate.

6. Composition according to any one of claims 1 to 5, wherein the at least one crosslinked copolymer comprises:

- at least one unit derived from olefinic unsaturated carboxylic acid monomers of formula (I) :

H C= C— C— OH _m

Ri O wherein R is selected from the group consisting of :H, CH₃, and C₂H₅, and

- at least one unit derived from (Ci₀-C₃₀)alkyl esters of unsaturated carboxylic acid monomers of formula (I I) :

H₂C= C- COR₃ (Π)

R₂ O

wherein R₂ is selected from the group consisting of: H, CH₃, and C₂H_5, and R₃ is a saturated or unsaturated, branched or unbranched (C₁₀-C₃₀)alkyl group.

7. Composition according to any one of claims 1 to 6, comprising from 0.5% to 5% by weight, preferably from 0.1 % to 1 % by weight of the crosslinked copolymer.

8. Composition according to any one of claims 1 to 7 comprising:

- i) from 10% to 20% by weight of solid particles, preferably solid fatty acid(s) or talc;

- ii) from 0.05% to 2% by weight of at least one crosslinked copolymer;

- iii) from 0.2% to 2% by weight of alkyl phosphate ester salts, wherein the percentages by weight are based on the total weight of the composition.

9. Composition according to anyone of claims 1 to 8, wherein the composition is an oil-in-water emulsion.

10. Composition according to anyone of claims 1 to 9, wherein the composition further comprises an emulsifier with a HLB ranging from 2 to 8.

1 1 . Composition according to any one of claims 1 to 1 0, wherein the composition is a cosmetic composition, preferably a vanishing cream composition.

12. A method of skin care comprising applying to the skin a composition according to any one of claims 1 to 1 1 .