WO2019228996A1

WO2019228996A1 - Cosmetic composition with visible oil droplets

Info

Publication number: WO2019228996A1
Application number: PCT/EP2019/063674
Authority: WO
Inventors: Rashmi THAKKAR
Original assignee: L'oreal
Priority date: 2018-05-29
Filing date: 2019-05-27
Publication date: 2019-12-05

Abstract

The present invention relates to a cosmetic composition in the form of a stable oil-in-water dispersion, comprising: a) oil droplets comprising at least one oil and at least one pigment; and b) a continuous aqueous phase comprising at least one polymer chosen from a copolymer of ammonium acryloyldimethyltaurate, dimethylacrylamide, lauryl methacrylate and laureth-4 methacrylate, crosslinked with trimethylolpropane triacrylate; dehydroxanthan gum; and copolymers comprising at least one (meth)acrylate monomer and at least one monomer which is an ester of methacrylic acid with an ethoxylated fatty alcohol having a fatty chain of 15 to 30 carbon atoms, wherein said composition is substantially free from any surfactant.

Description

COSMETIC COMPOSITION WITH VISIBLE OIL DROPLETS

The present invention relates to cosmetic compositions that are useful for personal skin care.

The development of formulations dedicated to caring for and/or making up the skin and/or lips, is permanent. Said formulations have to show satisfactory properties in terms of application, such as easy usage, and also in terms of sensory, such as hydration and/or moisturizing feeling after application.

The skin is the protective barrier for the human body. It protects the interior of the body from physical injury (such as trauma) and biological injury (such as bacteria, viruses or fungi). The skin of the human body comprises the dermis and the epidermis. The epidermis is the top most layer of the skin, and its superficial layer is called the stratum corneum.

Cosmetic compositions applied on skin may present different properties.

Two-phase compositions which appeal to consumers on account of their aesthetic nature currently exist on the market, but not in the form of a suspension having visible droplets. The current compositions generally consist of two mutually immiscible phases, which are mixed together extemporaneously by shaking before use.

The desire for light-colored and even-toned skin remains the most important factor driving demand for skin whitening products in the global cosmetics industry. In addition to skin lightening cream and lotion for the face, the retail market is inundated with skin whitening solutions for body, armpits, elbows, arms and feet. Moreover, the conventional fairness products existing in the market mostly contain surfactants. These surfactants can be irritant for certain skins, specifically sensitive ones.

Thus, there is a need for surfactant free cosmetic compositions which may bring an effect of light-colored and even-toned skin.

However, cosmetic suspensions comprising visible oil droplets containing pigments in suspension in a gel or liquid carrier are not available today, as it is difficult to stabilize the droplets in such a formulation. They have a tendency to destabilize the product upon manufacture and on storage over time. Indeed the pigment droplets generally either settle or spurt eventually, thus affecting the aqueous phase; or they coalesce, leading to an unstable and unappealing product. There is thus a need for a cosmetic composition which would be stable, while being not irritant, in the form of a suspension having visible oil droplets containing pigment suspended in carrier. Said composition would be used for caring, protecting and/or making up skin.

The Applicant has now discovered that it is possible to formulate such compositions having the desired properties as described above.

Specifically, the Applicant has discovered that it is possible to formulate compositions for caring for and/or making up of keratin materials, which are stable, non irritant, which confer moisturization, hydration and/or softening after application onto skin, and which confer light-colored and/or even-toned skin. Said compositions comprise visible oil droplets which are homogenously dispersed.

Accordingly, the present invention relates to a composition, preferably a cosmetic composition, in the form of a stable oil-in-water dispersion, comprising:

a) oil droplets comprising at least one oil and at least one pigment; and

b) a continuous aqueous phase comprising at least one polymer chosen from a copolymer of ammonium acryloyldimethyltaurate, dimethylacrylamide, lauryl methacrylate and laureth-4 methacrylate, crosslinked with trimethylolpropane triacrylate; dehydroxanthan gum; and copolymers comprising at least one (meth)acrylate monomer and at least one monomer which is an ester of methacrylic acid with an ethoxylated fatty alcohol having a fatty chain of 15 to 30 carbon atoms,

wherein said composition is substantially free of surfactants.

The composition of the invention has the appearance of a homogenous dispersion of oil droplets, which are visible with the naked eye, in the aqueous phase. As it is stable, it does not need to be shaken before use.

The composition of the invention is very easy to spread, while bringing a moisturizing feeling after application. The composition of the invention further shows a very good whitening benefit. Said composition is stable, and is processed at room temperature. Finally, said composition is substantially free of surfactants.

By“substantially free of surfactants”, it is meant that the composition of the invention comprises an amount equal to or less than 1.5% by weight, preferably less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.3% by weight, preferably less than 0.1% by weight of the total composition of surfactants. More preferably, the composition of the invention is devoid of any surfactant.

By“stable”, it is meant that the composition of the invention does not show any coalescence of the oil droplets or dephasing (i.e. separation of the aqueous phase from the oil droplets which form a fatty phase), and does not show any pigment spurting, over time, especially during at least 14 days, under a high temperature (50°C).

Other subjects and characteristics, aspects and advantages of the invention will emerge even more clearly on reading the description and the examples that follows.

In that which follows and unless otherwise indicated, the limits of a range of values are included within this range, in particular in the expressions "of between" and "ranging from ... to ...".

Moreover, the expression "at least one" used in the present description is equivalent to the expression "one or more".

Throughout the instant application, the term“comprising” is to be interpreted as encompassing all specifically mentioned features as well optional, additional, unspecified ones. As used herein, the use of the term“comprising” also discloses the embodiment wherein no features other than the specifically mentioned features are present (i.e. “consisting of”).

Continuous aqueous phase

The composition of the invention comprises a continuous aqueous phase, which comprises at least one polymer chosen from a copolymer of ammonium acryloyldimethyltaurate, dimethylacrylamide, lauryl methacrylate and laureth-4 methacrylate, crosslinked with trimethylolpropane triacrylate; dehydroxanthan gum; and copolymers comprising at least one (meth)acrylate monomer and at least one monomer which is an ester of methacrylic acid with an ethoxylated fatty alcohol having a fatty chain of 15 to 30 carbon atoms.

Said aqueous phase is preferably present in an amount ranging from 80% to 99.9% by weight, more preferably from 85% to 98% by weight, and even more preferably from 90% to 95% by weight of the total weight of the composition.

The composition of the invention preferably comprises water. Water is preferably present in the composition of the present invention in an amount ranging from 67% to 99.5% by weight, preferably from 70% to 99.5% by weight, preferably from 75% to 95% by weight, more preferably from 80% to 90% by weight, relative to the total weight of the composition. The aqueous phase may comprise at least one polyol. The polyol may be chosen from polyols having from 2 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, and preferentially having from 2 to 6 carbon atoms, such as glycerol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, caprylylglycol, dipropylene glycol and diethylene glycol. Preferably, the polyol is chosen from glycerol, butylene glycol and pentylene glycol.

The polyol may be present in the composition of the present invention in an amount ranging from 1 % to 30% by weight, preferably from 3% to 20% by weight, more preferably from 4% to 15% by weight, relative to the total weight of the composition.

The aqueous phase may also comprise at least one alcohol. The alcohols may be chosen from alcohols having from 2 to 6 carbon atoms, such as ethanol or butanol. Preferably, the alcohol is ethanol.

The alcohol may be present in the composition of the present invention in an amount ranging from 1% to 20% by weight, preferably from 3% to 50% by weight, more preferably from 4% to 10% by weight, relative to the total weight of the composition.

Polymer

The aqueous phase also comprises at least one polymer chosen from a copolymer of ammonium acryloyldimethyltaurate, dimethylacrylamide, lauryl methacrylate and laureth-4 methacrylate, crosslinked with trimethylolpropane triacrylate; dehydroxanthan gum; and copolymers comprising at least one (meth)acrylate monomer and at least one monomer which is an ester of methacrylic acid with an ethoxylated fatty alcohol having a fatty chain of 15 to 30 carbon atoms.

The copolymer comprising at least one (meth)acrylate monomer and at least one monomer which is an ester of methacrylic acid with an ethoxylated fatty alcohol having a fatty chain of 15 to 30 carbon atoms comprises:

- at least one (meth)acrylate monomer, and

- at least one monomer which is an ester of methacrylic acid with an ethoxylated fatty alcohol having a fatty chain of 15 to 30 carbon atoms.

The (meth)acrylate monomer is chosen from acrylic acid and methacrylic acid. Preferably it is acrylic acid.

The other monomer is an ester between methacrylic acid and an ethoxylated fatty alcohol having a fatty chain of 15 to 30 carbon atoms. The fatty chain of the ethoxylated fatty alcohol is preferably a saturated or unsaturated, linear or grafted, chain comprising from 18 to 28 carbon atoms, preferably from 20 to 25 carbon atoms. Preferably, the ethoxylated fatty alcohol comprises from 5 to 100 ethylene oxide groups (EO), preferably from 10 to 50, preferably from 15 to 30, preferably from 20 to 27.

Preferably, the ethoxylated fatty alcohol comprises a saturated linear chain comprising from 20 to 25 carbon atoms. Preferably, the ethoxylated fatty alcohol comprises from 10 to 50 ethylene oxide groups.

Preferably the ethoxylated fatty alcohol has a saturated linear fatty chain of 22 carbon atom. It corresponds to behenyl alcohol. Preferably behenyl alcohol comprises from 20 to 27 ethylene oxide groups. Preferably it is beheneth-25.

Preferably, the ester of methacrylic acid with an ethoxylated fatty alcohol having a fatty chain of 15 to 30 carbon atoms is beheneth-25 methacrylate.

Preferably, the polymer according to the invention is acrylates/beheneth-25 methacrylate copolymer. Such a copolymer may be sold in a dispersed form in water. For example, it may be sold under the name Novethix L-10 by Lubrizol (dispersion of 30% copolymer in water).

Preferably, according to another embodiment, the polymer according to the invention is a copolymer of ammonium acryloyldimethyltaurate, dimethylacrylamide, lauryl methacrylate and laureth-4 methacrylate, crosslinked with trimethylolpropane triacrylate. Said copolymer is also known under the name AMMONIUM 2-ACRYLAMIDO 2- METHYLPROPANESULFONATE/DIMETHYLACRYLAMIDE/HYDROPHOBIC CHAIN COPOLYMER. It may be sold under the name Sepimax Zen by Seppic (INCI name: polyacrylate crosspolymer-6).

Preferably, according to another embodiment, the polymer according to the invention is dehydroxanthan gum.

The polymer may be present in the composition according to the invention, in active material, in an amount of from 0.1 to 5% by weight, preferably from 0.2 to 3% by weight, preferably from 0.3 to 1% by weight of the composition.

Oil droplets

The composition of the invention further comprises oil droplets a). These droplets correspond to a dispersed fatty phase.

The oil droplets are visible with the naked eye in the composition of the invention. They preferably have a median particle size by volume Dv50 of from 0.1 mm to 10 mm, preferably from 0.5 mm to 5 mm.

The median particle size by volume Dv50 is a parameter for particle size distribution, referring to the maximum particle diameter below which 50% of the sample volume exists (see in A Basic Guide To Particle Characterization, page 10, published by Malvern Instruments Limited in 2012).

The particle size by volume Dv50 of the oil droplets may be measured by static light scattering using a commercial granulometer such as the MasterSizer 3000 machine from Malvern. The data are processed on the basis of the Mie scattering theory. This theory, which is exact for isotropic particles, makes it possible to determine, in the case of non- spherical particles, an "effective" particle diameter. This theory is especially described in the publication by Van de Hulst, H.C., "Light Scattering by Small Particles," Chapters 9 and 10, Wiley, New York, 1957.

The oil droplets are preferably present in an amount of from 0.1 to 20% by weight of the composition, preferably from 0.5 to 15% by weight, preferably from 1 to 10% by weight, more preferably from 2 to 8% by weight.

The oil droplets of the invention comprise at least one oil and at least one pigment.

Preferably, the oil is chosen from hydrocarbon oils and silicone oils, volatile or non volatile.

The term“oil” means a water-immiscible non-aqueous compound that is liquid at room temperature (25°C) and at atmospheric pressure (760 mmHg).

The term“non-volatile oil” means an oil that remains on keratin materials at room temperature and atmospheric pressure for at least several hours and that especially has a vapour pressure of less than 10³ mmHg (0.13 Pa). A non-volatile oil may also be defined as having an evaporation rate such that, under the conditions defined previously, the amount evaporated after 30 minutes is less than 0.07 mg/cm².

These oils may be of plant, mineral or synthetic origin.

Preferably, said oil is chosen from hydrocarbon or silicone oils.

The term “hydrocarbon-based oil” or “hydrocarbon oil” means an oil formed essentially from, or even constituted by, carbon and hydrogen atoms, and optionally O and N atoms, and free of Si and F heteroatoms. Such oil can contain alcohol, ester, ether, carboxylic acid, amine and/or amide groups. The term“silicone oil” means an oil containing at least one silicon atom, especially containing Si-0 groups.

Preferably, the oil is selected from hydrocarbon oils, preferably non-volatile.

The oil can be, for example, present in an amount ranging from 0.1% to 20% by weight, preferably from 0.5% to 10% by weight, more preferably from 1 % to 8% by weight, relative to the total weight of the composition.

Mention may be made, for example, of hydrocarbon-based volatile oils having from 8 to 16 carbon atoms and mixtures thereof and especially branched C8-C16 alkanes such as C8-C16 isoalkanes (also known as isoparaffins), isododecane, isodecane, isohexadecane and, for example, the oils sold under the trade names Isopar or Permethyl, C8-C16 branched esters such as isohexyl neopentanoate and mixtures thereof.

As non-volatile oils, mention may be made of:

- hydrocarbon-based oils of mineral or synthetic origin, such as linear or branched hydrocarbons, for instance liquid paraffin or its derivatives, liquid petroleum jelly, polydecenes, hydrogenated polyisobutene such as Parleam sold by the company Nippon Oil Fats, squalane of synthetic or plant origin;

- hydrocarbon-based oils of plant origin based on triglycerides made up of esters of fatty acids and of glycerol, the fatty acids of which may have varied chain lengths, it being possible for the latter to be linear or branched, and saturated or unsaturated, in particular the triglycerides of a fatty acid containing in particular from 4 to 22 carbon atoms, for instance heptanoic acid triglycerides, octanoic acid triglycerides, capric/caprylic acid triglycerides and caprylic/capric/succinic triglycerides, or else hydroxylated triglycerides, such as sweet almond oil (Prunus amygdalus dulcis oil), orange peel oil (Citrus aurantium dulcis peel oil), calophyllum oil, palm oil, grape seed oil, sesame oil, arara oil, rapeseed oil, sunflower oil, cottonseed oil, apricot oil, castor oil, alfalfa oil, marrow oil, blackcurrant oil, macadamia oil, muscat rose oil, hazelnut oil, coriander oil, avocado oil, jojoba oil, olive oil, cereal (maize, wheat, barley, rye) germ oil, shea butter oil; esters of fatty acids, in particular having from 4 to 28 carbon atoms, preferably from 4 to 22 carbon atoms, and in particular of octanoic acid (or caprylic acid), of heptanoic acid, of lanolic acid, of oleic acid, of lauric acid, of decanoic acid (or capric acid) or of stearic acid, such as propylene glycol dioctanoate, propylene glycol monoisostearate, polyglyceryl-2 diisostearate, neopentyl glycol diheptanoate, coco-caprylate/caprate;

- synthetic esters of formula R1 COOR2 in which R1 represents the residue of a linear or branched higher fatty acid containing from 7 to 40 carbon atoms and R2 represents a branched hydrocarbon-based chain containing from 3 to 40 carbon atoms, for instance purcellin oil (cetostearyl octanoate), isononyl isononanoate, C12 to C15 alcohol benzoate, 2-ethylhexyl palmitate, 2-octyldodecyl stearate, 2-octyldodecyl erucate, isostearyl isostearate, 2-octyldodecyl benzoate, octanoates, decanoates or ricinoleates of alcohols or of polyalcohols, isopropyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, diisopropyl adipate, 2-ethylhexyl palmitate, 2-hexyldecyl laurate, 2-octyldecyl palmitate, 2-octyldodecyl myristate, 2-diethylhexyl succinate, diisostearyl malate, isodecyl neopentanoate, hydroxylated esters such as isostearyl lactate, octyl hydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate, triisocetyl citrate, glyceryl or diglyceryl triisostearate; diethylene glycol diisononanoate; pentaerythritol esters; esters of aromatic acids and of alcohols containing from 4 to 22 carbon atoms, in particular tridecyl trimellitate;

- C8-C26 higher fatty acids such as myristic acid, oleic acid, linoleic acid, linolenic acid or isostearic acid;

- C8-C26 higher fatty alcohols such as oleyl alcohol, linoleyl alcohol, linolenyl alcohol, isostearyl alcohol or octyldodecanol;

- synthetic ethers containing at least 7 carbon atoms;

- silicone oils such as linear polydimethylsiloxanes (PDMSs) that are liquid at ambient temperature, and that are optionally phenylated, such as phenyltrimethicones, phenyltrimethylsiloxydiphenylsiloxanes, diphenyl dimethicones, diphenylmethyl- diphenyltrisiloxanes, liquid 2-phenylethyltrimethyl-siloxysilicates, optionally substituted with aliphatic and/or aromatic groups, for instance alkyl, alkoxy or phenyl groups, which are pendent and/or at the end of a silicone chain, these groups containing from 2 to 24 carbon atoms, and optionally fluorinated, or with functional groups such as hydroxyl, thiol and/or amine groups; polysiloxanes modified with fatty acids or fatty alcohols or polyoxyalkylenes, such as dimethicone copolyols or alkyl methicone copolyols; liquid fluorosilicones;

- and mixtures thereof.

Preferably, the oil is a hydrocarbon-based oil, preferably non-volatile. Preferably it is chosen form hydrocarbon-based oils of plant origin, such as sweet almond oil (Prunus amygdalus dulcis oil), orange peel oil (Citrus aurantium dulcis peel oil), calophyllum oil, palm oil, grape seed oil, sesame oil, arara oil, rapeseed oil, sunflower oil, cottonseed oil, apricot oil, castor oil, alfalfa oil, marrow oil, blackcurrant oil, macadamia oil, muscat rose oil, hazelnut oil, coriander oil, avocado oil, jojoba oil, olive oil, cereal (maize, wheat, barley, rye) germ oil, shea butter oil and their mixtures. The oil droplets also comprise at least one pigment. Preferably the pigment is chosen from hydrophobic pigments and hydrophobically modified (i.e. with a hydrophobic surface treatment) pigments. For the purposes of the present invention, the hydrophobic pigments have a solubility in water of less than 0.01% by weight, for example, less than 0.0001 % by weight at 20°C.

The hydrophobic pigment may be an inorganic pigment, in a preferred embodiment. As used herein, the term "inorganic pigment" means any pigment that satisfies the definition in Ullmann's encyclopedia in the chapter on inorganic pigments. Preferably, the inorganic pigments comprise at least one inorganic material. Non-limiting examples of inorganic pigments that are useful in the present invention include metal oxides, in particular, transition metal oxides, such as zirconium oxides, cerium oxides, iron oxides, chromium oxides, manganese violet, ultramarine blue, chromium hydrate, ferric blue, and titanium dioxide. The following inorganic pigments may also be used: Ta₂0₅, Ti₃0₅, T1203, TiO, and Zr0₂ as a mixture with Ti0₂, Zr0₂, Nb₂0₅, Ce0₂, and ZnS.

The pigment may also be a nacreous pigment such as a white nacreous pigment, for example, mica coated with titanium or with bismuth oxychloride, a colored nacreous pigment such as mica coated with titanium and with iron oxides, mica coated with titanium and, for example, with ferric blue or chromium oxide, mica coated with titanium and with an organic pigment as defined above, and also a nacreous pigment based on bismuth oxychloride. Examples of such pigments may include the Cellini pigments sold by Engelhard (Mica-Ti0₂-Iake), Prestige sold by Eckart (Mica- Ti0₂), and Colorona sold by Merck (Mica-Ti0_2.Fe₂0₃).

In addition to nacres on a mica support, multilayer pigments based on synthetic substrates such as alumina, silica, calcium sodium borosilicate, calcium aluminium borosilicates, and aluminum, may be useful in accordance with the present disclosure.

According to the present invention, the pigment may be surface treated. The surface treatment can be performed by any conventional process. It results preferably in a hydrophobic coating. For the purposes of the present invention, the surface treatment is such that a surface-treated pigment conserves its intrinsic pretreatment pigmenting properties.

The hydrophobic coating may be formed by treating the pigment with a hydrophobic treating agent. The hydrophobic treating agent can be chosen from silicones, such as methicones, dimethicones or perfluoroalkylsilanes; fatty acids, such as stearic acid; metal soaps, such as aluminum dimyristate or the aluminum salt of hydrogenated tallow glutamate, perfluoroalkyl phosphates, perfluoroalkylsilanes, perfluoroalkylsilazanes, poly(hexafluoropropylene oxides), polyorganosiloxanes comprising perfluoroalkyl or perfluoropolyether groups, and amino acids; N-acylated amino acids or their salts; lecithin, isopropyl triisostearyl titanate, and their mixtures. As the pigments, Ti02 particles coated with at least one hydrophobic coating are preferable. Among the coated Ti02 particles, mention may be made of:

- those coated with polydimethylsiloxane (CARDRE ULTRAFINE TITANIUM DIOXIDE AS provided by the company CARDRE);

- those coated with polymethylhydrogenosiloxane (untreated titanium oxide coated with polymethylhydrogenosiloxane sold under the trade name Cosmetic White S A-C47-051 - 10 by the company MYOSH I) ;

- those coated with perfluoropolymethyl isopropyl ether (CARDRE MICA FHC 70173 OR 70170 CARDRE UF TI02 FHC provided by the company CARDRE);

- those coated with silica (SPHERJTITAN AB provided by the company CATALYSTS & CHEMICALS;

- those coated with teflon (CS- 13997 TEFLON COATED TITANIUM DIOXIDE provided by the company CLARK COLORS); and

- those coated with polyester (EXPERIMENTAL DESOTO BEADS provided by the company DESOTO).

According to one embodiment of the present invention, the pigment may be surface treated, preferably partially treated, with at least one amphiphilic agent.

The amphiphilic agent can provide pigments with both hydrophilic and hydrophobic properties. Preferably, the pigments have an amphiphilic surface. The amphiphilic agent may comprise at least one compound chosen from, for example, amino acids; waxes, for example, carnauba wax and beeswax; fatty acids, fatty alcohols and derivatives thereof, such as stearic acid, hydroxystearic acid, stearyl alcohol, hydroxystearyl alcohol, lauric acid, and derivatives thereof; anionic surfactants; lecithins; sodium, potassium, magnesium, iron, titanium, zinc, or aluminum salts of fatty acids, for example, aluminum stearate or laurate; metal alkoxides; polysaccharides, for example, chitosan, cellulose, and derivatives thereof; polyethylenes; (meth)acrylic polymers, for example, polymethyl methacrylates; polymers and copolymers containing acrylate units; proteins; and alkanolamines.

The surface-treated pigments may be prepared according to surface-treatment techniques that are well known to those skilled in the art, or may be commercially available in the required form. Preferably, the surface-treated pigments are coated with an organic layer. The organic layer may be deposited on the pigments by evaporation of a solvent, chemical reaction between the molecules in the amphiphilic agents, or creation of a covalent bond between the molecules in the amphiphilic agents and the pigments. The surface treatment may thus be performed, for example, by chemical reaction of the amphiphilic agent with the surface of the pigments and creation of a covalent bond between the amphiphilic agent and the pigments.

Pigments to which the amphiphilic agents covalently or ionically bond are preferably used.

The amphiphilic agents may represent from 0.1% to 50% by weight, preferably from 0.5% to 30% by weight, and more preferably 1% to 10% by weight, relative to the total weight of the surface-treated pigments. It is preferable that the amphiphilic agent comprises at least one hydrophobicized amino acid.

The hydrophobicized amino acid may be a glutamic acid derivative or a condensate of at least one glutamic acid derivative and an amino acid.

The glutamic acid derivative may be N-acylated glutamic acid or a salt thereof. As the salt, mention may be made of metal salts, ammonium salts, and onium salts of an organic alkanolamine. As the metal, Na, K, Ba, Zn, Ca, Mg, Fe, Zr, Co, Al, and Ti may be used. As the organic alkanolamine, monoethanolamine, diethanolamine, 2-amino-2- methylpropanol, 2-amino-2-methyl-1 ,3-propanediol, and triisopropanolamine may be used. The acyl group bound to the nitrogen atom of the glutamic acid may be derived from a saturated or unsaturated fatty acid having 8 to 22 carbon atoms, such as capric acid, lauric acid, myristic acid, isomyristic acid, palmitic acid, isopalmitic acid, stearic acid, isostearic acid, arachic acid, undecylenic acid, oleic acid, myristic acid, elaidic acid, linolic acid, linoleic acid, arachidonic acid, palm oil fatty acid, beef tallow fatty acid, and resin acid (abietic acid).

The condensate of at least one glutamic acid derivative and an amino acid may be a condensate of N-acylated glutamic acid and an amino acid such as lysine, or a salt thereof. As the salt, mention may be made of metal salts, ammonium salts and onium salts of an organic alkanolamine as mentioned above.

Sodium salt is preferable. The acyl group bound to the nitrogen atom of the glutamic acid may be derived from a saturated or unsaturated fatty acid having 8 to 22 carbon atoms as mentioned above.

The amphiphilic surface treatments of the pigments may be chosen from the following treatments:

- a PEG-silicone treatment, for instance, the AQ surface treatment sold by LOW;

- a lauroyllysine treatment, for instance, the LL surface treatment sold by LOW; - a lauroyllysine dimethicone treatment, for instance, the LL/SI surface treatment sold by LOW;

- a disodium stearoyl glutamate treatment, for instance, the NAI surface treatment sold by Miyoshi;

- a dimethicone/disodium stearoyl glutamate treatment, for instance, the SA/NAI surface treatment sold by Miyoshi;

- a microcrystalline cellulose and carboxymethylcellulose treatment, for instance, the AC surface treatment sold by Daito;

- an acrylate copolymer treatment, for instance, the APD surface treatment sold by Daito;

- a sodium dilauramidoglutamide lysine treatment, for instance, the ASL treatment sold by Daito; and

- a sodium lauramidoglutamide lysine/isopropyl titanium triisostearate treatment, for instance, the ASL treatment sold by Daito.

Preferably the amphiphilic surface treatment is a disodium stearoyl glutamate treatment.

The amphiphilic agent can be bound to pigments ionically with a metal salt or hydroxide. The metal may be selected from Mg, Al, Ca and Zn.

Aluminum hydroxide or magnesium chloride may be used. A treatment by disodium stearoylglutamate (and) aluminum hydroxide is more preferable.

It is preferable that pigments are inorganic and selected from metal oxides, more preferably aluminum or transition metal oxides, these compounds being eventually surface treated. Preferably the pigment is titanium dioxide treated by disodium stearoylglutamate (and) aluminum hydroxide.

The amount of pigment may be from 0.1 to 5% by weight, preferably from 0.5 to 4% by weight, and more preferably from 0.5 to 3% by weight, relative to the total weight of the composition.

According to a particularly preferred embodiment, the present invention relates to a cosmetic composition in form of a stable oil-in-water dispersion, comprising:

a) from 2 to 8% by weight of the composition of oil droplets; and

b) from 90 to 98% by weight of continuous aqueous phase, which comprises from 0.3 to 1% by weight of polymer.

Additional ingredients

The composition of the invention may comprise at least one additive, such as fragrances, preservatives, active agents, vitamins, pH regulators and/or fillers. 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 desired cosmetic properties and stability properties for these compositions are not affected by the additives.

The filler may be organic or mineral. Among the mineral fillers that can be used in the compositions according to the invention, mention may be made of talc, mica, silica, kaolin or bentone. Among the organic fillers, mention may be made of polyamide powders (Nylon® Orgasol from Atochem), polyalanine and polyethylene powders, polytetrafluoroethylene (Teflon®) powders, lauroyllysine, tetrafluoroethylene polymer powders, hollow polymer microspheres, such as Expancel (Nobel Industrie), metal soaps derived from organic carboxylic acids containing from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example zinc stearate, magnesium stearate or lithium stearate, zinc laurate or magnesium myristate.

The active agent may be chosen from UV screening agents, humectants, moisturizers and emollients.

Notably, a humectant may be present.

Methods and use

According to an embodiment, the present invention relates to a non-therapeutic method for treating a keratin material, comprising the step of applying the composition of the present invention to the keratin material.

Preferably the present invention relates to a method for caring for the skin, comprising the step of applying the composition of the present invention to the skin.

According to another embodiment, the invention relates to the use of a composition of the present invention for moisturizing a keratin material, especially the skin.

The present invention also relates to a process for preparing a composition of the invention, comprising the steps of:

i) mixing at least one oil with at least one pigment, in order to obtain an oil phase; ii) mixing the polymer with water, in order to obtain an aqueous phase; and iii) dispersing the oil phase obtained in step i) into the aqueous phase obtained in ii), in order to obtain an oil-in-water dispersion.

The present invention is now illustrated by the following examples, which are not limitative. Examples

Example 1 : preparation of a composition according to the invention and evaluation of stability over time

Table 1 below illustrates the different compositions which are prepared. The percentages are indicated in weight by total weight of composition (wt %).

Compositions F1 , F3 and F5 are according to the invention, whereas compositions F2 and F4 are comparative.

Composition F1 was prepared as follows:

1 ) Phase A: In main vessel, acrylates/beheneth-25 methacrylate copolymer is added to water under stirring for 10 minutes, followed by addition of preservative, glycerin, methyl guceth-20 and orange 4. It is mixed well under stirring for 15 minutes;

2) Phase A is neutralized by addition of sodium hydroxide, and is mixed under stirring for 20 minutes to obtain a clear gel;

3) Phase B: In a side mixer, sweet almond oil, tocopherol and orange peel oil are mixed under stirring for 5 minutes. Titanium dioxide is uniformly dispersed in this mixture using a homogenizer for 5 minutes;

4) Phase B is then added to Phase A under slow stirring and mixed using a propeller for 5 minutes at 200/300 rpm to obtain a uniform suspension. Composition F1 is thus obtained.

Comparative formulas F2 to F5 are prepared using the same process, by replacing acrylates/behenteh-25 methacrylate by xanthan gum, polyacrylate crosspolymer-6, xanthan gum (and) ceratonia siliqua (carob) gum or dehydroxanthan gum, respectively.

After preparation, each composition is observed visually, and stability is evaluated by placing each composition at 50°C for 14 days.

The results are as shown in Table 2 below:

Conclusion:

Results of Table 2 indicate that formulations F1 , F3 and F5 are the single formulations which give stable gels with visible droplets which are uniform in size and show good sensorial.

Formula F1 was tested on voluntary women, and was shown to bring skin lightening and instant skin whitening. It was also evaluated as moisturizing.

Example 2: formulations F6 and F7 according to the invention

Table 3 below illustrates the different compositions F6 and F7 of the invention, which are prepared. The percentages are indicated in weight by total weight of composition (wt %).

Claims

1. A cosmetic composition in the form of a stable oil-in-water dispersion, comprising:

a) oil droplets comprising at least one oil and at least one pigment; and

wherein said composition is substantially free of surfactants.

2. The composition according to claim 1 , wherein the fatty chain is a saturated or unsaturated, linear or grafted, chain comprising from 18 to 28 carbon atoms, preferably from 20 to 25 carbon atoms.

3. The composition according to claim 1 or 2, wherein the ethoxylated fatty alcohol comprises from 5 to 100 ethylene oxide groups, preferably from 10 to 50, preferably from 15 to 30, preferably from 20 to 27.

4. The composition according to any one of claims 1 to 3, wherein the ethoxylated fatty alcohol comprises a saturated linear chain comprising from 20 to 25 carbon atoms, and from 10 to 50 ethylene oxide groups.

5. The composition according to any one of claims 1 to 4, wherein it comprises an amount equal to or less than 1.5% by weight of the composition of surfactant, preferably less than 1% by weight, preferably less than 0.5% by weight, preferably less than 0.3% by weight, preferably less than 0.1% by weight, more preferably is devoid of any surfactant.

6. The composition according to any one of claims 1 to 5, wherein the oil droplets a) have a median particle size by volume Dv50 from 0.1 mm to 10 mm, preferably from 0.5 mm to 5 mm.

7. The composition according to any one of claims 1 to 6, wherein the oil is chosen from hydrocarbon oils and silicone oils, volatile or non-volatile.

8. The composition according to any one of claims 1 to 7, wherein the pigment is chosen from hydrophobic pigments and hydrophobically modified pigments, preferably from inorganic pigments which are surface treated with at least one amphiphilic agent.

9. The composition according to any one of claims 1 to 8, wherein the oil droplets a) are present in an amount of from 0,1 to 20% by weight of the composition, preferably from 0,5 to 15% by weight, preferably from 1 to 10% by weight.

10. The composition according to any one of claims 1 to 9, wherein it comprises:

a) from 2 to 8% by weight of the composition of oil droplets; and

1 1. A method for caring for the skin, comprising the application to the skin of the composition of any one of claims 1 to 10.

12. A process for preparing a composition of any one of claims 1 to 10, comprising the steps of: