WO2020132855A1

WO2020132855A1 - Composition for brightening or whitening keratin materials

Info

Publication number: WO2020132855A1
Application number: PCT/CN2018/123387
Authority: WO
Inventors: Shan Wu
Original assignee: L'oreal
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2020-07-02
Also published as: CN113438938A

Abstract

Provided herein is a composition for brightening or whitening keratin materials in the form of an oil-in-water dispersion, comprising an oily phase dispersed in an aqueous phase, and comprising: (i) at least one skin brightening or whitening active ingredient selected from hydroxylated diphenylmethane derivatives; (ii) at least one oil selected from C4-C24 fatty acid ester of glycerol; and (v) at least one hydrophilic thickening agent selected from copolymer obtained from monomers possessing ethylenic unsaturation and possessing a sulpho group and other monomers possessing ethylenic unsaturation without a sulpho group. It also relates to a cosmetic process for brightening or whitening keratin materials, in particular the human skin.

Description

COMPOSITION FOR BRIGHTENING OR WHITENING KERATIN MATERIALS

TECHNICAL FIELD

The present invention relates to a cosmetic composition. In particular, the present invention relates to a composition for brightening or whitening keratin materials, in particular human skin.

BACKGROUND ART

Human skin colour depends on various factors, and in particular on the seasons of the year, on race and on gender; it is mainly determined by the nature and the concentration of melanin produced by melanocytes. Melanocytes are specialized cells which synthesize melanin by means of specific organelles, melanosomes. In addition, at various times in their life, certain individuals experience the appearance of dark and/or coloured spots on the skin and more especially on the hands, which give the skin heterogeneity.

For various reasons associated in particular with greater comfort of use (softness, emollience and the like) , current compositions for caring for and/or making up keratin materials, in particular the skin, are usually in the form of an emulsion of the oil-in-water (O/W) type consisting of an aqueous dispersing continuous phase and an oily dispersed discontinuous phase, or of an emulsion of the water-in-oil (W/O) type consisting of an oily dispersing continuous phase and an aqueous dispersed discontinuous phase.

O/W emulsions are the ones most sought in the cosmetics field, since they comprise an aqueous phase as the external phase, which gives them, when applied to the skin, a fresher, less greasy and lighter feel than W/O emulsions.

However, due to their natural feature, the conventional oil-in-water emulsions are not totally satisfying, in particular in terms of instant and long-term brightening or whitening of the skin, and meanwhile without impacting the comfort of use.

Efforts have been made to introduce silicone resins, styrene type copolymers in combination with pigments and whitening active agents, into the oil-in-water emulsions. However, the inventors found it difficult to obtain a stable composition with a good brightening or whitening of the skin, i.e., instant and long-term brightening or whitening.

Efforts have also been made to introduce whitening pigments into the oil-in-water emulsions. Unfortunately, such pigments generally negatively impact the stability of the emulsions, thereby somewhat complicating the manufacture of the emulsion.

Therefore, there exists a need for formulating a composition to overcome the difficulties mentioned above.

In particular, there is a need to formulate a composition in the form of an emulsion, comprising an oily phase dispersed in an aqueous phase, with an improved brightening or whitening of keratin materials, and meanwhile maintaining a good comfort of use.

More particularly, there is a need to formulate such a composition which is stable over time.

SUMMARY OF THE INVENTION

The inventors have found that such a need can be achieved by the present invention.

Thus, according to one aspect, the present invention relates to a composition for brightening or whitening keratin materials in the form of an emulsion, comprising an oily phase dispersed in an aqueous phase, and comprising:

(i) at least one white particles;

(ii) at least one non-ionic surfactant selected from oxyalkylenated fatty acid ester of sorbitan;

(iii) at least one hydrophilic thickening polymer selected from copolymers of at least one monomer (a) selected from carboxylic acids possessing α, β-ethylenic unsaturation or their esters with at least one monomer (b) possessing ethylenic unsaturation comprising a hydrophobic group, and polymers comprising at least one monomer possessing a sulpho group and their mixtures;

(iv) at least one skin brightening or whitening active ingredient selected from flavonoids; and

(v) at least one hydrotrope.

The composition according to the present invention is advantageous in several respects.

Firstly, the composition according to the present invention has a brightening or whitening effect to keratin materials, in particular human skin.

In particular, the “brightening and whitening effect” according to the present invention refers to both instant and long-term brightening or whitening of keratin materials.

In addition, the composition of the present invention is stable over time.

An emulsion is stable if no change in its macroscopic or microscopic appearance and in its physicochemical characteristics (drop size, pH, viscosity) is observed after storage at various temperatures (T = 4℃, room temperature, 40℃ and 45℃) for a duration of 2 months.

According to another aspect, the present invention also relates to a cosmetic process for brightening or whitening keratin materials, in particular human skin, comprising the step of applying the composition according to the present invention on the keratin materials.

For the purposes of the present invention, the term “keratin material” is intended to cover human skin, mucous membranes such as the lips, the nails. Human skin, in particular facial skin, is most particularly considered according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

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” ) .

According to one aspect, the present invention relates to a composition for brightening or whitening keratin materials in the form of an emulsion, comprising an oily phase dispersed in an aqueous phase, and comprising:

(i) at least one white particles;

(v) at least one hydrotrope.

White particles

The term "white" is intended to mean particles having the colour white and its derivatives (off-white, alabaster white, etc. ) , as opposed to primary colours and derivatives.

In some embodiment, the white particles used are inorganic particles.

In particular, the white particles have a lightness value L* close to 100 in the CIELab76 system.

Preferably, the white particles is characterized by 0.3μm<D50<40μm.

The volume average size (D50) 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 volume average size (D50) of the particles 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 white particles according to the present invention have a continuous effect, which is controlled by the resolution capacity of the eye. Since said capacity is around 40μm, particles having a volume average size (D50) of less than 40μm, preferably less than 25μm and even better still less than or equal to 6μm are therefore considered. However, it is ensured that particles of which the D50 is greater than 0.3μm and preferentially 0.5μm are taken, so as not to have too great a loss of opacity, which would be extremely detrimental to the desired effect.

Thus, the composition of the present invention preferably comprises at least white particles having a volume size (D50) of less than 40μm, preferably between 0.3 and 25μm and better still between 0.3 and 6μm, or even between 0.5 and 3μm.

These particles may be made of one material or else be composites. For example, these particles may be selected from boron nitride, silica, pearl, mica, synthetic mica, mica based pearl pigment particles, composite particles comprising titanium dioxide and a substrate selected from alumina, silica, barium sulfate, glass, mica and synthetic mica, or mixtures thereof.

According to a preferred embodiment, the particles are boron nitride particles.

According to another embodiment, the particles are composite particles comprising titanium dioxide and an alumina substrate.

According to another embodiment, the particles are composite particles comprising titanium dioxide and a mica substrate.

The white particles are advantageously boron nitride particles, preferentially having a volume average size of from 0.3 to 6μm.

Preferably, the white particles according to the present invention have an average refractive index of between 1.4 and 2.2. This is because, if the particle has a refractive index above 2.2, the opacity of the composition is too high, and if this index is below 1.4, the lightening effect is not sufficient. The average refractive index is defined as being the sum of the refractive indices weighted by the weight content in the particle.

As examples of composite particles, mention may, for example, be made of platelets of mica (60%) covered with TiO ₂ (40%) , with an average refractive index of 1.9 (0.6x1.5+0.4x2.5) ; inclusions of titanium oxide (40%) in a matrix of alumina (60%) , with an average refractive index of 1.96 (0.6x1.6+0.4x2.5) .

The following is a table of the refractive indices used:

Mica	1.4-1.7
Bismuth oxychloride	2.15
Fe ₃O ₄	2.4
TiO ₂ (anatase)	2.5
TiO ₂ (rutile)	2.7
Boronnitride	1.74
Alumina (amorphous)	1.6

Table1: Example of the refractive index of various materials

By way of example of particles, mention may be made of boron nitride particles, such as PUHP1030L from Saint Gobain Ceramics and UHP-1010 from Carborundum.

According to one particularly preferred embodiment, use will be made of boron nitride particles having a volume average size D50 of less than 6μm, such as the boron nitride particles sold under the name PUHP1030L by Saint Gobain Ceramics, having a volume average size of 3μm.

preferably, the white particles are present in an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 0.5 wt. %to 5 wt. %, more preferably from 1 wt. %to 3 wt. %, relative to the total weight of the composition.

Non-ionic surfactant

The composition according to the present invention comprises at least one non-ionic surfactant selected from oxyalkylenated fatty acid ester of sorbitan.

Surfactants of this type that may be mentioned more particularly include:

oxyethylenated fatty acid esters of sorbitan such as (INCI name) Polysorbate 20, Polysorbate 65, Polysorbate 80, Polysorbate 85, PEG-5 sorbitan isostearate, PEG-20 sorbitan triisostearate, PEG-20 sorbitan isostearate, PEG-40 sorbitan septaoleate, PEG-20 sorbitan tetraoleate and PEG-20 sorbitan trioleate.

Mentions may be made of polysorbate 20, such as those sold by the company Croda under the tradename Tween ^TM 20-LQ- (AP) ,

The non-ionic surfactant is present in an amount effective to improve the dispersion of the white particles in the composition according to the present invention.

The weight ratio of the non-ionic surfactant to the white particles ranges from 1: 100 to 1: 10, preferably from 1: 20 to 1: 10.

preferably, the non-ionic surfactant is present in an amount ranging from 0.05 wt. %to 3 wt. %, preferably from 0.05 wt. %to 1 wt. %and more preferably from 0.1 wt. %to 0.5 wt. %, relative to the total weight of the composition.

Hydrophilic thickening Polymer

The hydrophilic thickening polymer is selected from copolymers of at least one monomer (a) selected from carboxylic acids possessing α, β-ethylenic unsaturation or their esters with at least one monomer (b) possessing ethylenic unsaturation comprising a hydrophobic group, and polymers comprising at least one monomer possessing a sulpho group and their mixtures.

The hydrophilic thickening polymers can also exhibit emulsifying properties.

The hydrophilic thickening polymer is preferably anionic.

i) Copolymer of at least one monomer (a) selected from carboxylic ccids possessing α, β- 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 hydrophilic thickening polymers are selected from copolymers of: at least one monomer of following formula (1) :

in which R ₁ denotes H or CH ₃ or C ₂H ₅, that is to say acrylic acid, methacrylic acid or ethacrylic acid monomers, and

at least one monomer of unsaturated carboxylic acid (C ₁₀-C ₃₀) alkyl ester type which corresponds to the monomer of following formula (2) :

in which R ₂ denotes H or CH ₃ or C ₂H ₅ (that is to say, acrylate, methacrylate or ethacrylate units) and preferably H (acrylate units) or CH ₃ (methacrylate units) and R ₃ denotes a C ₁₀-C ₃₀ and preferably C ₁₂-C ₂₂ alkyl radical.

The (C ₁₀-C ₃₀) 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 hydrophilic thickening polymers are crosslinked.

Use will more particularly be made, among the hydrophilic 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 R ₂ denotes H or CH ₃ and R ₃ denotes an alkyl radical having from 12 to 22 carbon atoms, and

(iii) 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 95wt%to 60wt%of acrylic acid (hydrophilic unit) , 4wt%to 40wt%of C ₁₀-C ₃₀ alkyl acrylate (hydrophobic unit) and 0wt%to 6wt%of crosslinking polymerizable monomer or else of those composed of 98wt%to 96wt%of acrylic acid (hydrophilic unit) , 1wt%to 4wt%of C ₁₀-C ₃₀ alkyl acrylate (hydrophobic unit) and 0.1wt%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/C ₁₀-C ₃₀ alkyl acrylate copolymers (INCI name: Acrylates/C10-30 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 hydrophilic thickening polymers comprising at least one monomer possessing a sulpho group used in the composition of the present invention are soluble or dispersible or swellable in water. The polymers used in accordance with the present 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 a polymer (or hydrophobic modified polymer) .

Preferably, the polymers in accordance with the present 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 present 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 present 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 vinylsulphonic acid, styrenesulphonic acid, (meth) acrylamido (C ₁-C ₂₂) alkylsulphonic acids, N- (C ₁-C ₂₂) alkyl (meth) acrylamido (C ₁-C ₂₂) alkylsulphonic 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 (C ₁-C ₂₂) 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

homopolymers are generally wherein they comprise, distributed randomly:

a) from 90wt%to 99.9wt%of units of following formula (3) :

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 0.01wt%to 10wt%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

(CTFA name: ammonium polyacryldimethyltauramide) .

The polymer can also be an amphiphilic homopolymer (or hydrophobic modified homopolymer) selected from random amphiphilic

polymers modified by reaction with a mono (C ₆-C ₂₂ n-alkyl) amine or a di (C ₆-C ₂₂ 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 theβposition 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 hydrophilic thickening polymer used in 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 ^TM by Seppic (CTFA name: Polyacrylamide/C13-14 Isoparaffin/Laureth-7) or under the name of Simulgel ^TM 600 by Seppic (CTFA name: Acrylamide/Sodium 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 ^TM NS by Seppic (sodium 2-acrylamido-2-methylpropanesulphonate/hydroxyethyl acrylate copolymer as a 40%inverse emulsion in Polysorbate 60 and squalane) (CTFA name: hydroxyethyl acrylate/sodium acryloyldimethyltaurate copolymer/squalane/polysorbate 60) or under the name of Simulgel ^TM 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 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.

In a preferred embodiment, the hydrophilic thickening polymer used is selected from acrylates/C10-30 alkyl acrylate crosspolymer and crosslinked anionic copolymers of acrylamide or methacrylamide and of 2-acrylamido-2-methylpropanesulphonic acid.

Preferably, the hydrophilic thickening plymer is present in amount ranging from 0.1 wt. %to 5 wt. %, preferably from 0.2 wt. %to 5 wt. %, and more preferably from 0.5 wt. %to 3 wt. %, relative to the total weight of the composition.

The inventors surprisedly found that the white particles can be easily dispersed in the composition according to the present invention with the aid of the non-ionic surfactant selected from oxyalkylenated fatty acid ester of sorbitan and the hydrophilic thickening polymer. No pigment aggregation and agglomeration was observed in the composition according to the present invention.

Skin brightening or whitening active ingredient

The composition according to the present invention comprises at least one skin brightening or whitening active ingredient selected from flavonoids.

Flavonoids

Flavonoids are a specific group of polyphenols, and are the most plentiful group of polyphenol compounds, making up about two-thirds of the total phenols in consumed feed. Flavonoids are further categorized, according to chemical structure, into chalcones, flavones, flavanones, flavanols, flavonols, dihydroflavonols, isoflavonoids, neoflavonoids, catechins, anthocyanidins, and tannins. Over 4,000 flavonoids have been identified, many of which occur in fruits, vegetables and beverages (tea, coffee, beer, wine and fruit drinks) . The flavonoids have been reported to have antiviral, anti-allergic, antiplatelet, anti-inflammatory, antitumor and antioxidant activities. Flavonoids protect lipids and vital cell components from damaging oxidative stress by efficiently scavenging free radicals.

Preferably, the flavonoid used is flavone.

Baicalin, a component of Chinese medicinal herb Huang-chin, is a flavone, a type of flavonoid. It is a potent antioxidant that demonstrates potent effects against oxidative stress diseases, inflammation, allergy, cancer, bacterial infections, etc.

Baicalin is found in several species in the genus Scutellaria, including Scutellaria baicalensis and Scutellaria lateriflora. There are 10 mg/g baicalin in Scutellaria galericulata leaves. It is also present in the bark isolate of the Oroxylum indicum tree.

In one embodiment according to the present invention, baicalin is used in the form of scutellaria baiclensis root extract.

Preferably, the flavonoid is present in an amount ranging from 0.01 wt. %to 2 wt. %, preferably from 0.1 wt. %to 1 wt. %, more preferably from 0.1 wt. %to 0.5 wt. %, relative to the total weight of the composition.

Hydroxylated diphenylmethane derivatives

According to a preferred embodiment according to the present invention, the composition further comprises at least one hydroxylated diphenylmethane derivative as skin brightening or whitening active ingredient.

The hydroxylated diphenylmethane derivative that can be used in the composition of the present invention is preferably selected from those of formula (4) below:

in which:

R ₁ is selected from a hydrogen atom, a methyl group, a saturated or unsaturated, linear or branched hydrocarbon chain containing from 2 to 4 carbon atoms, an–OH group and a halogen,

R ₂ is selected from a hydrogen atom, a methyl group, and a saturated or unsaturated, linear or branched hydrocarbon chain containing from 2 to 5 carbon atoms,

R ₃ is selected from a methyl group or a saturated or unsaturated, linear or branched hydrocarbon chain containing from 2 to 5 carbon atoms,

R ₄ and R ₅ are, independently of one another, selected from a hydrogen atom, a methyl group, a saturated or unsaturated, linear or branched hydrocarbon chain containing from 2 to 5 carbon atoms, an–OH group or a halogen.

The–OH, R ₁, R ₄ and R ₅ groups may be in the ortho-, meta-or para-position with respect to the bond formed with the carbon linking the two aromatic nuclei to one another.

According to one preferred embodiment of the present invention, use is made of a compound of formula (4) in which:

- R ₁, R ₂, R ₄ and R ₅ denote a hydrogen atom;

- R ₃ is a methyl group;

- the–OH groups are in the ortho-and para-position with respect to the bond formed with the carbon linking the two aromatic nuclei to one another.

This compound corresponds to formula (5) below:

known as 4- (1-phenylethyl) -1, 3-benzenediol or 4- (1-phenylethyl) -1, 3-dihydroxybenzene or otherwise known as phenylethyl resorcinol or phenylethylbenzenediol or styryl resorcinol. This compound has a CAS number 85-27-8. Such a compound is sold under the name Symwhite

or Bio 377 by the company Symrise.

If presents, the hydroxylated diphenylmethane derivative is present in amount ranging from 0.1 wt. %to 2 wt. %, preferably from 0.1 wt. %to 1 wt. %, more preferably from 0.1 wt. %to 0.5 wt. %, relative to the total weight of the composition.

Hydrotrope

The composition according to the present invention comprises at least one hydrotrope.

A single type of hydrotrope may be used, but two or more different types of hydrotrope may be used in combination.

Hydrotropes may be a diverse class of compounds characterized by an amphiphilic molecular structure and ability to dramatically increase the solubility of poorly soluble organic molecules in water. Many hydrotropes have aromatic structure with an ionic moiety, while some of them are linear alkyl chains, as listed in the table below. Although hydrotropes noticeably resemble surfactants and have the ability to reduce surface tension, their small hydrophobic units and relatively shorter alkyl chain distinguish them as a separate class of amphiphiles.

Common hydrotropic molecules include: sodium 1, 3-benzenedisulfonate, sodium benzoate, sodium 4-pyridinecarboxylate, sodium salicylate, sodium benzene sulfonate, caffeine, sodium p-toluene sulfonate, sodium butyl monoglycolsulfate, 4-aminobenzoic acid HCl, sodium cumene sulfonate, N, N-diethylnicotinamide, N-picolylnicotinamide, N-allylnicotinamide, 2-methacryloyloxyethyl phosphorylcholine, resorcinol, butylurea, pyrogallol, N-picolylacetamide 3.5, procaine HCl, proline HCl, nicotinamide, pyridine, 3-picolylamine, sodium ibuprofen, sodium xylenesulfonate, ethyl carbamate, pyridoxal hydrochloride, sodium benzoate, 2-pyrrolidone, ethylurea, N, N-dimethylacetamide, N-methylacetamide, and isoniazid. Hydrotropes can be found in Lee J. et al., “Hydrotropic Solubilization of Paclitaxel: Analysis of Chemical Structures for Hydrotropic Property” , Pharmaceutical Research, Vol. 20, No. 7, 2003; and Hodgon T. K., Kaler E.W., “Hydrotropic Solutions” , Current Opinion in Colloid and Interface Science, 12, 121-128, 2007.

Cosmetically acceptable hydrotropes are preferable hydrotropes that can be used in cosmetic compositions. While hydrotropes represent a broad class of molecules used in various fields, cosmetic applications will be limited due to safety and tolerance restrictions. Preferred hydrotropes in cosmetics are listed as below:

The suitability of a hydrotrope for use in cosmetic compositions can be determined using tests known in the art for determining effects of compounds on skin, and bioavailability methods.

An advantage of using hydrotropes is, once a stable solution is obtained, further dilution doesn’ t influence the stability of the solution. This is very different from organic solvents that are commonly used to increase the water solubility of actives. Typically, an aqueous dilution of organic solvents with pre-dissolved actives results in crystallization or precipitation.

The hydrotrope may have a logP being from-0.7 to 6, preferably from-0.7 to 1.0, preferably from-0.5 to 0.7 for non-ionic hydrotropes, and preferably from-0.7 to 5.5 for ionic hydrotropes (e.g. acidic hydrotropes) .

Formulator will adjust pH in order to reach the best state of transparency with hydrotropes.

A logP value is a value for the base-ten logarithm of the apparent octan-1-ol/water partition coefficient. The logp values are known and are determined by a standard test which determines the concentration of the (c) compound in octan-1-ol and water. The log P may be calculated according to the method described in the article by Meylan and Howard: Atom/Fragment contribution method for estimating octanol-water partition coefficients, J. Pharm. Sci., 84: 83-92, 1995. This value may also be calculated using numerous commercially available software packages, which determine the log P as a function of the structure of a molecule. By way of example, mention may be made of the Epiwin software from the United States Environmental Agency.

The values may especially be calculated using the ACD (Advanced Chemistry Development) Solaris software V4.67; they may also be obtained from Exploring QSAR: hydrophobic, electronic and steric constants (ACS professional reference book, 1995) . There is also an Internet site which provides estimated values (address: http: //esc. syrres. com/interkow/kowdemo. htm) .

It is preferable that the hydrotrope be selected from the group consisting of oxothiazolidinecarboxylic acid, Vitamin B3 and derivatives thereof, preferably niacinamide, xanthine bases, preferably caffeine, camphor benzalkonium methosulfate, ellagic acid, hydroxyphenoxy propionic acid, diethyllutidinate, terephthalylidene dicamphor sulfonic acid, ferulic acid, salicylic acid, phloretine, acetyl trifluoromethylphenyl valylglycine, resveratrol, 4-butylresorcinol, apigenin, phenylethyl resorcinol, prasterone, benzophenone-3, butyl methoxydibenzoylmethane, capryloyl salicylic acid, ethylhexyl salicylate, and jasmonic acid derivatives, preferably sodium tetrahydrojasmonate. Vitamin B3 and derivatives thereof, xanthine bases such as caffeine, and jasmonic acid derivatives, which are described below in more detailed manner, are more preferable.

(Vitamin B3 and Derivatives Thereof)

Vitamin B3, also called vitamin PP, is a compound of the following formula (6) :

in which R may be-CONH ₂ (niacinamide) , -COOH (nicotinic acid or niacin) , or CH ₂OH (nicotinyl alcohol) , -CO-NH-CH ₂-COOH (nicotinuric acid) or-CO-NH-OH (niconityl hydroxamic acid) .

Niacinamide is preferable.

Vitamin B3 derivatives that may be mentioned include, for example, nicotinic acid esters such as tocopherol nicotinate, amides derived from niacinamide by substitution of the hydrogen groups of-CONH ₂, products from reaction with carboxylic acids and amino acids, esters of nicotinyl alcohol and of carboxylic acids such as acetic acid, salicyclic acid, glycolid acid or palmitic acid.

Mention may also be made of the following derivatives: 2-chloronicotinamide, 6-methylnicotinamide, 6-aminonicotinamide, N-methylnicotinamide, N, N-dimethylnicotinamide, N- (hydroxymethyl) nicotinamide, quinolinic acid imide, nicotinanilide, N-benzylnicotinamide, N-ethylnicotinamide, nifenazone, nicotinaldehyde, isonicotinic acid, methylisonicotinic acid, thionicotinamide, nialamide, 2-mercaptonicotinic acid, nicomol and niaprazine, methyl nicotinate and sodium nicotinate.

Other vitamin B3 derivatives that may also be mentioned include its inorganic salts, such as chlorides, bromides, iodides or carbonates, and its organic salts, such as the salts obtained by reaction with carboxylic acids, such as acetate, salicylate, glycolate, lactate, malate, citrate, mandelate, tartrate, etc.

It is preferable that the Vitamin B3 or a derivative thereof has a log P being from-0.7 to 6, preferably from-0.6 to 5, more preferably-0.5 to 4.

(Xanthine Base)

Among the xanthine bases which may be used according to the present invention, mention may be made of: caffeine, theophylline, theobromine, acefylline, xanthinol nicotinate, diniprophylline, diprophylline, etamiphylline and its derivatives, etophylline, proxyphylline, pentophylline, propentophylline, pyridophylline, and bamiphylline, without this list being limiting.

It is preferable that the xanthine base be selected from the group consisting of caffeine, theophylline, theobromine, acefylline and mixtures thereof. These xanthine bases are known as inhibitors of phosphodiesterase, which is the enzyme responsible for the degradation of cAMP. By increasing the intracellular content of cAMP, these xanthine bases promote lipolytic activity and thus constitute first-rate slimming active agents.

As examples of plant extracts containing xanthine bases, mention may be made in particular of extracts of tea, of coffee, of guarana, of Paraguay tea, and of cola, without this list being limiting.

It is preferable that the xanthine base has a log P being from-0.7 to 6, preferably from-0.6 to 5, more preferably-0.5 to 4, and even more preferably from-0.3 to 2.

(Jasmonic Acid Derivative)

The jasmonic acid derivative is a compound selected from those corresponding to the following formula (7) :

in which: R ₁ represents a COOR ₃ radical, R ₃ denoting a hydrogen atom or a C ₁-C ₄ alkyl radical optionally substituted by one or more hydroxyl groups; R ₂ represents a hydrocarbon radical which is saturated or unsaturated, which is linear and which has from 1 to 18 carbon atoms or which is branched or cyclic and which has from 3 to 18 carbon atoms; and their optical isomers, and corresponding salts.

Preferably, R ₁ denotes a radical selected from-COOH, -COOMe (Me: methyl group) , -COO-CH ₂-CH ₃, -COO-CH _2--CH (OH) -CH ₂OH, -COOCH ₂-CH ₂-CH ₂OH or-COOCH ₂-CH (OH) -CH ₃. Preferably R ₁ denotes a-COOH radical.

Preferably, R ₂ denotes a saturated or unsaturated linear hydrocarbon radical preferably having from 2 to carbon atoms. In particular, R ₂ can be a pentyl, pentenyl, hexyl or heptyl radical.

According to one embodiment, the compound offormula (I) is selected from 3-hydroxy-2- [ (2Z) -2-pentenyl] cyclopentaneacetic acid or 3-hydroxy-2-pentylcyclopentaneacetic acid and is preferably 3-hydroxy-2-pentylcyclopentaneacetic acid.

The salts of the compounds which can be used according to the present invention are chosen in particular from alkali metal salts, for example sodium or potassium salts; alkaline earth metal salts, for example calcium, magnesium or strontium salts; metal salts, for example zinc, aluminum, manganese or copper salts; salts of ammonium offormula NH ₄ ⁺; quaternary ammonium salts; organic amine salts, such as, for example, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, 2-hydroxyethylamine, bis (2-hydroxyethyl) amine or tris (2-hydroxyethyl) amine salts; or lysine or arginine salts. Use is preferably made of salts selected from sodium, potassium, calcium, magnesium, strontium, copper, manganese or zinc salts.

It is preferable to use the following compound as the jasmonic acid derivative (Mexoryl SBO) .

It is preferable that the jasmonic acid derivative has a log P being from-0.7 to 6, preferably from-0.6 to 5, more preferably-0.5 to 4.

Preferably, the hydrotrope is present in an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 0.5 wt. %to 8 wt. %, more preferably from 1 wt. %to 5 wt. %, relative to the total weight of the composition.

Organopolysiloxane elastomer

In some embodiment, the composition according to the present invention may further comprises at least one organopolysiloxane elastomer (also named silicone elastomer) to further improve the sensation.

The organopolysiloxane elastomer might be an emulsifying elastomer or a non-emulsifying elastomer.

In a preferred embodiment, the organopolysiloxane elastomer is an organopolysiloxane elastomer not containing a hydrophilic chain, such as polyoxyalkylene or polyglycerolated units, which is also known under the name of non-emulsifying elastomer.

In one embodiment, the organopolysiloxane elastomer not containing a hydrophilic chain, or non-emulsifying silicone elastomer, can be defined as being an elastomeric crossbonded organopolysiloxane that may be obtained by crosslinking addition reaction of diorganopolysiloxane containing at least one hydrogen bonded to silicon and of diorganopolysiloxane containing ethylenically unsaturated groups bonded to silicon, especially in the presence of a platinum catalyst; or by dehydrogenation crosslinking coupling reaction between a diorganopolysiloxane with hydroxyl end groups and a diorganopolysiloxane containing at least one hydrogen bonded to silicon, especially in the presence of an organotin compound; or by crosslinking coupling reaction of a diorganopolysiloxane with hydroxyl end groups and of a hydrolysable organopolysilane; or by thermal crosslinking of organopolysiloxane, especially in the presence of an organoperoxide catalyst; or by crosslinking of organopolysiloxane via high-energy radiation such as gamma rays, ultraviolet rays or an electron beam.

Preferably, the elastomeric crossbonded organopolysiloxane is obtained by crosslinking addition reaction (A2) of diorganopolysiloxane containing at least two hydrogens each bonded to a silicon, and (B2) of diorganopolysiloxane containing at least two ethylenically unsaturated groups bonded to silicon, especially in the presence (C2) of a platinum catalyst, as described, for example, in patent application EP-A-295 886.

In particular, the organopolysiloxane may be obtained by reaction of dimethylpolysiloxane with dimethylvinylsiloxy end groups and of methylhydrogenopolysiloxane with trimethylsiloxy end groups, in the presence of a platinum catalyst.

Compound (A2) is the base reagent for the formation of elastomeric organopolysiloxane, and the crosslinking is performed by addition reaction of compound (A2) with compound (B2) in the presence of the catalyst (C2) .

Compound (A2) is advantageously a diorganopolysiloxane containing at least two lower (for example C ₂-C ₄) alkenyl groups; the lower alkenyl group may be selected from vinyl, allyl and propenyl groups. These lower alkenyl groups may be located in any position on the organopolysiloxane molecule, but are preferably located at the ends of the organopolysiloxane molecule. The organopolysiloxane (A2) may have a branched-chain, linear-chain, cyclic or network structure, but the linear-chain structure is preferred. Compound (A2) may have a viscosity ranging from the liquid state to the gum state. Preferably, compound (A2) has a viscosity of at least 100 centistokes at 25℃.

The organopolysiloxanes (A2) may be selected from methylvinylsiloxanes, methylvinylsiloxane-dimethylsiloxane copolymers, dimethylpolysiloxanes with dimethylvinylsiloxy end groups, dimethylsiloxane-methylphenylsiloxane copolymers with dimethylvinylsiloxy end groups, dimethylsiloxane-diphenylsiloxane-methylvinylsiloxane copolymers with dimethyl-vinylsiloxy end groups, dimethylsiloxane-methylvinylsiloxane copolymers with trimethylsiloxy end groups, dimethylsiloxane-methylphenylsiloxane-methylvinylsiloxane copolymers with trimethylsiloxy end groups, methyl (3, 3, 3-trifluoropropyl) polysiloxanes with dimethylvinylsiloxy end groups, and dimethylsiloxane-methyl (3, 3, 3-trifluoropropyl) siloxane copolymers with dimethylvinylsiloxy end groups.

Compound (B2) is in particular an organopolysiloxane containing at least two hydrogens bonded to silicon in each molecule and is thus the crosslinking agent for compound (A2) .

Advantageously, the sum of the number of ethylenic groups per molecule of compound (A2) and the number of hydrogen atoms bonded to silicon per molecule of compound (B2) is at least 4.

Compound (B2) may be in any molecular structure, especially of linear-chain or branched-chain structure, or cyclic structure.

Compound (B2) may have a viscosity at 25℃ ranging from 1 to 50 000 centistokes, especially in order to have good miscibility with compound (A) .

It is advantageous for compound (B2) to be added in an amount such that the molecular ratio between the total amount of hydrogen atoms bonded to silicon in compound (B2) and the total amount of all of the ethylenically unsaturated groups in compound (A2) is within the range from 1/1 to 20/1.

Compound (B2) may be selected from methylhydrogenopolysiloxanes with trimethylsiloxy end groups, dimethylsiloxane-methylhydrogenosiloxane copolymers with trimethylsiloxy end groups, and dimethylsiloxane-methylhydrogenosiloxane cyclic copolymers.

Compound (C2) is the crosslinking reaction catalyst, and is especially chloroplatinic acid, chloroplatinic acid-olefin complexes, chloroplatinic acid-alkenylsiloxane complexes, chloroplatinic acid-diketone complexes, platinum black and platinum on a support.

The catalyst (C2) is preferably added in from 0.1 to 1000 parts by weight, better still from 1 to 100 parts by weight, as clean platinum metal per 1000 parts by weight of the total amount of compounds (A2) and (B2) .

Other organic groups may be bonded to silicon in the organopolysiloxanes (A2) and (B2) described above, for instance alkyl groups such as methyl, ethyl, propyl, butyl or octyl; substituted alkyl groups such as 2-phenylethyl, 2-phenylpropyl or 3, 3, 3-trifluoropropyl; aryl groups such as phenyl, tolyl or xylyl; substituted aryl groups such as phenylethyl; and substituted monovalent hydrocarbon-based groups such as an epoxy group, acarboxylate ester group or a mercapto group.

According to one preferred embodiment, the organopolysiloxane elastomer is mixed with at least one hydrocarbon-based oil and/or one silicone oil to form a gel. In these gels, the non-emulsifying organopolysiloxane elastomer is particularly in the form of non-spherical particles.

In a preferred embodiment, the silicone oil mixed with the organopolysiloxane elastomer to form a gel is a linear silicone oil (dimethylsiloxane) with molecular weight ranging from 1 to 350cst at 25℃, in particular 2 to 100cst and preferably 2 to 10cst. The silicone oil viscosity might be measured according to ASTM D-445 norm.

As examples of organopolysiloxane elastomer mixed with linear silicone oil, used in the present invention, mention may be made of the following references:

- DIMETHICONE/VINYL DIMETHICONE CROSSPOLYMER (and) DIMETHICONE, such as the commercial references 《KSG-6》 and 《KSG-16》 sold by Shin Etsu;

- DIMETHICONE (and) DIMETHICONE CROSSPOLYMER, such as the comercial reference 《DC9041》 sold by Dow Corning.

In a preferred embodiment, the composition comprises at least a non-emulsifying organopolysiloxane elastomer in a form of a gel wherein the organopolysiloxane elastomer is mixed with a linear silicone oil having a viscosity ranging from 1 to 100cst at 25℃, in particular 1 to 10cst at 25℃, in particular the one having INCI Name DIMETHICONE/VINYL DIMETHICONE CROSSPOLYMER (and) DIMETHICONE, such as the commercial references 《KSG-6》 and 《KSG-16》 sold by Shin Etsu, preferably KSG-16.

In another embodiment, the organopolysiloxane elastomer is an emulsifying elastomer.

Emulsifying silicone elastomer is understood as meaning a silicone elastomer comprising at least one hydrophilic chain.

The emulsifying silicone elastomer can be selected from amongst the elastomers of polyoxyalkylenated or polyglycerolated silicone.

The polyoxyalkylenated silicone elastomer is a crosslinked organopolysiloxane which can be obtained by crosslinking addition reaction of diorganopolysiloxane containing at least one hydrogen linked to the silicon and one polyoxyalkylene having at least two ethylenically unsaturated groups.

The polyoxyalkylenated elastomers are especially described in the patents US5236986, US5412004, US5837793 and US5811487, the content of which is incorporated by reference.

As a polyoxyalkylenated silicone elastomer, it is possible to use those marketed under the names "KSG-21" , "KSG-20" , "KSG-30" , "KSG-210" , "KSG-310" , "KSG-320" , "KSG-330" , "KSG-340" , "X-226146" by Shin Etsu, and "DC9010" , "DC9011" by Dow Corning.

The polyglycerolated silicone elastomer is a crosslinked organopolysiloxane elastomer which can be obtained by crosslinking addition reaction of diorganopolysiloxane containing at least one hydrogen linked to the silicon and of polyglycerolated compounds having ethylenically unsaturated groups, especially in the presence of platinum catalyst.

Such polyglycerolated elastomers are especially described in the patent application WO2004/024798.

As polyglycerolated silicone elastomers, it is possible to use those sold under the names "KSG-710" , "KSG-810" , "KSG-820" , "KSG-830" , "KSG-840" by Shin Etsu.

In a preferred embodiment, the organopolysiloxane elastomer is a non-emulsifying elastomer, i.e. an organopolysiloxane elastomers not containing a hydrophilic chain.

The non-emulsifying elastomers that may be used include those sold under the names KSG-6,KSG-15, KSG-16, KSG-18, KSG-41, KSG-42, KSG-43 and KSG-44 by the company Shin-Etsu, DC9040, DC9041, DC9509, DC9505 and DC9506 by the company Dow Corning, Gransil by the company Grant Industries, and SFE 839 by the company General Electric.

The non-emulsifying elastomer that may more particularly be used include those sold under the names KSG-6, KSG-15, KSG-16, KSG-18, KSG-41, KSG-42, KSG-43 and KSG-44 by the company Shin-Etsu, more particularly those sold under the names KSG-15 and KSG-16, and preferentially the one sold under the name KSG-16.

KSG-16 is a gel composed of 24%of dimethicone/vinyl dimethicone crosspolymer, and of 76%of dimethicone.

KSG-15 is a gel composed of 6%of dimethicone/vinyl dimethicone crosspolymer, and of 94%of cyclodimethicone.

In a preferred embodiment, the organopolysiloxane elastomer has INCI name dimethicone/vinyl dimethicone crosspolymer.

The organopolysiloxane elastomer is present in an amount effective to maintain the dispersion of the white particles in the composition according to the present invention.

If present, the organopolysiloxane elastomer, in particular a non-emulsifying organopolysiloxane elastomer, alone or as a mixture, is present in an amount ranging from 0.1 wt. %to 5 wt. %, preferably from 0.5 wt. %to 3 wt. %, and more preferably from 1.0 wt. %to 2.5 wt. %, relative to the total weight of the composition.

Aqueous phase

The composition of the present invention comprises at least one continuous aqueous phase.

The aqueous phase of the composition according to the present invention comprises water and optionally one or more water-miscible or at least partially water-miscible compounds, for instance C ₂ to C ₈ lower polyols or monoalcohols, such as ethanol and isopropanol.

The term “polyol” should be understood as meaning any organic molecule comprising at least two free hydroxyl groups. Examples of polyols that may be mentioned include glycols, for instance butylene glycol, propylene glycol, and isoprene glycol, caprylyl glycol, glycerol (i.e. glycerin) and polyethylene glycols.

The aqueous phase may also comprise any common water-soluble or water-dispersible additive as mentioned below.

The aqueous phase may represent in amount ranging from 30 wt. %to 99 wt. %, preferably from 30 wt. %to 95 wt. %, more preferablyfrom 60 wt. %to 90 wt. %, relative to the total weight of the composition.

Oily phase

The composition of the present invention comprises at least one oily phase, dispersed in the aqueous phase as described above.

The nature of the oily phase of the composition according to the present invention is not critical.

In particular, the oily phase comprises at least one oil.

The term oil refers to any fatty body in liquid form at room temperature (20-25℃) and atmospheric pressure. These oils may be of animal, plant, mineral or synthetic origin.

The oils may be volatile or non-volatile.

The term "volatile oil" refers to any non-aqueous medium capable of evaporating from the skin or lips, in less than one hour, at room temperature (20-25℃) and atmospheric pressure (760 mmHg) . The volatile oil is a volatile cosmetic oil, liquid at room temperature. More specifically, a volatile oil has an evaporation rate of between 0.01 and 200mg/cm ²/min, inclusive.

The term "non-volatile oil" is intended to mean an oil remaining on keratin materials at ambient temperature and atmospheric pressure. More specifically, anon-volatile oil has an evaporation rate strictly below 0.01 mg/cm ²/min.

To measure this evaporation rate, 15g of oil or a mixture of oils to be tested are introduced into a crystallizer, 7cm in diameter, placed on a scale located in a large 0.3m ³ chamber temperature-controlled at a temperature of 25℃, and humidity-controlled with a relative humidity of 50%. The liquid is left to evaporate freely, without stirring, by providing ventilation with a fan (PAPST-MOTOREN, reference 8550 N, rotating at 2700 rpm) positioned vertically above the crystallizer containing the solvent, with the blades directed toward the crystallizer and at a distance of 20cm from the base of the crystallizer. The mass of oil remaining in the crystallizer is measured at regular intervals. The evaporation rates are expressed in mg of oil evaporated per surface area unit (cm ²) and per time unit (minute) .

The oil that is suitable for the present invention are not limited, it may be hydrocarbon-based, silicone-based or fluorine-based.

According to the present invention, the term "silicone oil" refers to an oil including at least one silicon atom, and in particular at least on Si-O group.

The term "fluorine oil" refers to an oil including at least one fluorine atom.

The term "hydrocarbon oil" refers to an oil containing primarily hydrogen and carbon atoms.

The oils may optionally include oxygen, nitrogen, sulfur and/or phosphorus atoms, for example, in the form of hydroxyl or acid radicals.

The oily phase may present in amount ranging from 0.5 wt. %to 70 wt. %, preferably from 0.5 wt. %to 50 wt. %and more preferably from 0.5 wt. %to 20 wt. %, relative to the total weight of the composition.

As indicated above, this amount of oily phase does not comprise the amount of emulsifier.

Additives

In a known manner, the composition of the present invention may also contain one or more additives that are common in cosmetics or dermatology.

Examples of adjuvants that may be mentioned include emulsifiers, gelling agents, active agents, preserving agents, antioxidants, fragrances, sunscreens (=UV-screening agents) , additional dyestuffs, basic agents (triethanolamine, diethanolamine or sodium hydroxide) or acidic agents (citric acid) , and also lipid vesicles or any other type of vector (nanocapsules, microcapsules, etc. ) , and mixtures thereof.

These additives are used in the usual proportions in the cosmetics field, for example from 0.01%to 30%of the total weight of the composition, and, depending on their nature, they are introduced into the aqueous phase of the composition or into the oily phase, or alternatively into vesicles or any other type ofvector.

These additives and the concentrations thereof must be such that they do not modify the desired properties for the composition of the present invention.

According to a preferred embodiment, the present invention relates to a composition for brightening or whitening keratin materials in the form of an emulsion, comprising an oily phase dispersed in an aqueous phase, and comprising, relative to the total weight of the composition:

(i) from 1 wt. %to 3 wt. %of at least one white particles selected from the group consisting of boron nitride, silica, pearl, mica, synthetic mica, mica based pearl pigment particles, composite particles comprising titanium dioxide and a substrate selected from alumina, silica, barium sulfate, glass, mica and synthetic mica, or mixtures thereof;

(ii) from 0.1 wt. %to 0.5 wt. %of at least one non-ionic surfactant selected from selected from Polysorbate 20, Polysorbate 80, Polysorbate 65, Polysorbate 85, PEG-5 sorbitan isostearate, PEG-20 sorbitan triisostearate, PEG-20 sorbitan isostearate, PEG-40 sorbitan septaoleate, PEG-20 sorbitan tetraoleate and PEG-20 sorbitan trioleate;

(iii) from 0.5 wt. %to 3 wt. %of at least one hydrophilic thickening polymer selected from acrylates/C10-30 alkyl acrylate crosspolymer and crosslinked anionic copolymers of acrylamide or methacrylamide and of 2-acrylamido-2-methylpropanesulphonic acid;

(iv) as skin brightening or whitening active ingredients:

from 0.1 wt. %to 0.5 wt. %of at least one flavone; and

from 0.1 wt. %to 0.5wt. %of at least one hydroxylated diphenylmethane derivatives selected from those of formula (4) below:

in which:

- R ₁, R ₂, R ₄ and R ₅ denote a hydrogen atom;

- R ₃ is a methyl group;

- the–OH groups are in the ortho-and para-position with respect to the bond formed with the carbon linking the two aromatic nuclei to one another; and

(v) from 1 wt. %to 5wt. %of at least one hydrotrope oxothiazolidinecarboxylic acid, Vitamin B3 and derivatives thereof, preferably niacinamide, xanthine bases, preferably caffeine, camphor benzalkonium methosulfate, ellagic acid, hydroxyphenoxy propionic acid, diethyllutidinate, terephthalylidene dicamphor sulfonic acid, ferulic acid, salicylic acid, phloretine, acetyl trifluoromethylphenyl valylglycine, resveratrol, 4-butylresorcinol, apigenin, phenylethyl resorcinol, prasterone, benzophenone-3, butyl methoxydibenzoylmethane, capryloyl salicylic acid, ethylhexyl salicylate, and jasmonic acid derivatives, preferably sodium tetrahydrojasmonate.

Preferably the composition of the present invention is in the form of oil-in-water emulsion, for example in the form of a lotion, cream, gel or liquid foundation and they are prepared according to the conventional methods in the cosmetic field.

Method and use

The composition according to the present invention is intended for topical application and can especially constitute a composition intended for brightening or whitening keratin materials, and especially human skin.

Thus, in another aspect, the present invention relates to a cosmetic process for brightening or whitening keratin materials, in particular skin, comprising the step of applying the composition as defined above to the keratin materials.

The present invention is illustrated in greater detail by the examples described below, which are given as non-limiting illustrations.

The percentages are weight percentages by active ingredient, or active matters.

In the examples that follow, the weight percentages are indicated relative to the total weight of the composition.

Examples

Example 1: Preparation of the invention and comparative formulas

Invention formulas (inv. ) 1-3 and comparative formulas (comp. ) 1-3 were prepared:

Note: the amount of SCUTELLARIA BAICALENSIS ROOT EXTRACT is calculated by weight of baicalin.

Preparation process:

1. preparing water phase: adding hydrotrope ingredient (NIACINAMIDE and/or CAFFEINE) into water, stirring till complete dissolution, then adding in SCUTELLARIA BAICALENSIS ROOT EXTRACT to water, stirring till complete dissolution, then add other water phase ingredients one by one, stirring at 500 rpm;

2. adding hydrophilic thickening polymer (ACRYLAMIDE/SODIUM ACRYLOYLDIMETHYLTAURATE COPOLYMER and/or ACRYLATES/C10-30 ALKYL ACRYLATE) into water phase to get gelled aqueous phase;

3. preparing oil phsae: adding active ingredients (PHENYLETHYL RESORCINOL) into oil, heating to 60℃ to dissolve active ingredients;

4. adding oil phase to gel phase with fast stirring at 1000 rpm for 10 minutes;

5. preparing a mixture of tween-20 and BN in water: adding BN and Tween 20 into small amount of water, then stirring in low speed to get harmonious suspension;

6. adding the mixture of tween-20 and BN in water, mix well (if need, add other charge or pearl) .

Example 2: Evaluation of the invention and comparative formulas

The stability of compositions according to invention formulas and comparative formula prepared in Example 1 were measured.

The following two tests are carried out to observe the stability of the compositions according to the invention formulas and comparative formulas:

1. Accelerate Stability Test: transportation test, shake the compositions in two directions, 1h/each direction.

2. Long-term aging test: put the compositions in different temperature for 2 months.

The stability tests of the compositions according to invention formulas and comparative formulas at 40℃, 45℃, and 65℃ for two months were conducted using Binder oven (USA) , by leaving the compositions according to invention formulas and comparative formulas in the oven for 2 months.

The stability tests at 4℃ were conducted for two months using Zhongke Meiling refrigerator (YC-260L, China) , by leaving the compositions according to invention formulas and comparative formulas in the refrigerator for 2 months.

The light stability tests for 24 hours were conducted using ATLAC (AMETEK Measurement and Calibration Technologies) .

Lastly, the freezing-thaw stability tests were conducted for 10 cycles using Binder over (USA) . In each cycle, the temperature will be changed gradually from 20℃ to-20℃ in 24 hours.

The results of the stability of the compositions according to invention formulas and comparative formula were listed below.

The results show that the compositions according to invention formulas 1-3 are stable at different temperatures.

Claims

A composition for brightening or whitening keratin materials in the form of an emulsion, comprising an oily phase dispersed in an aqueous phase, and comprising:

(i) at least one white particles;

(ii) at least one non-ionic surfactant selected from oxyalkylenated fatty acid ester of sorbitan;

(iii) at least one hydrophilic thickening polymer selected from copolymers of at least one monomer (a) selected from carboxylic acids possessing α, β-ethylenic unsaturation or their esters with at least one monomer (b) possessing ethylenic unsaturation comprising a hydrophobic group, and polymers comprising at least one monomer possessing a sulpho group and their mixtures;

(iv) at least one skin brightening or whitening active ingredient selected from flavonoids; and

(v) at least one hydrotrope.
Composition of claim 1, wherein the white particles are selected from boron nitride, silica, pearl, mica, synthetic mica, mica based pearl pigment particles, composite particles comprising titanium dioxide and a substrate selected from alumina, silica, barium sulfate, glass, mica and synthetic mica, or mixtures thereof.
Composition of claim 1 or 2, wherein the white particles are present in the composition in an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 0.5 wt. %to 5 wt. %, more preferably from 1 wt. %to 3 wt. %, relative to the total weight of the composition.
Composition of any one of claims 1 to 3, wherein the non-ionic surfactant is selected from Polysorbate 20, Polysorbate 65, Polysorbate 80, Polysorbate 85, PEG-5 sorbitan isostearate, PEG-20 sorbitan triisostearate, PEG-20 sorbitan isostearate, PEG-40 sorbitan septaoleate, PEG-20 sorbitan tetraoleate and PEG-20 sorbitan trioleate.
Composition of any one of claims 1 to 4, wherein the non-ionic surfactant is present in an amount ranging from 0.05 wt. %to 3 wt. %, preferably from 0.05 wt. %to 1 wt. %and more preferably from 0.1 wt. %to 0.5 wt. %, relative to the total weight of the composition.
Composition of any one of claims 1 to 5, wherein the hydrophilic thickening polymer is selected from

copolymers of:

at least one monomer of following formula (1) :

in which R ₁ denotes H or CH ₃ or C ₂H ₅, that is to say acrylic acid, methacrylic acid or ethacrylic acid monomers, and

at least one monomer of unsaturated carboxylic acid (C ₁₀-C ₃₀) alkyl ester type which corresponds to the monomer of following formula (2) :

in which R ₂ denotes H or CH ₃ or C ₂H ₅ (that is to say, acrylate, methacrylate or ethacrylate units) and preferably H (acrylate units) or CH ₃ (methacrylate units) and R ₃ denotes a C ₁₀-C ₃₀ and preferably C ₁₂-C ₂₂ alkyl radical, and

polymers comprising a monomer selected from (meth) acrylamido (C ₁-C ₂₂) alkylsulphonic acids, and also their partially or completely neutralized forms.
Composition according to any one of claims 1 to 6, wherein the hydrophilic thickening polymer is present in an amount ranging from 0.1 wt. %to 5 wt. %, preferably from 0.2 wt. %to 5 wt. %, and more preferably from 0.5 wt. %to 3 wt. %, relative to the total weight of the composition.
Composition according to any one of claims 1 to 7, wherein the flavonoid is selected from chalcones, flavones, flavanones, flavanols, flavonols, dihydroflavonols, isoflavonoids, neoflavonoids, catechins, anthocyanidins, and tannins.
Composition according to any one of claims 1 to 8, wherein the flavonoid is present in an amount ranging from 0.01 wt. %to 2 wt. %, preferably from 0.1 wt. %to 1 wt. %, more preferably from 0.1 wt. %to 0.5 wt. %, relative to the total weight of the composition.
Composition according to any one of claims 1 to 9, wherein the hydrotrope is selected from the group consisting of oxothiazolidinecarboxylic acid, Vitamin B3 and derivatives thereof, preferably niacinamide, xanthine bases, preferably caffeine, camphor benzalkonium methosulfate, ellagic acid, hydroxyphenoxy propionic acid, diethyllutidinate, terephthalylidene dicamphor sulfonic acid, ferulic acid, salicylic acid, phloretine, acetyl trifluoromethylphenyl valylglycine, resveratrol, apigenin, prasterone, benzophenone-3, butyl methoxydibenzoylmethane, capryloyl salicylic acid, ethylhexyl salicylate, and jasmonic acid derivatives, preferably sodium tetrahydrojasmonate.
The composition according to any one of claims 1 to 10, wherein the hydrotrope is present in an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 0.5 wt. %to 8 wt. %, more preferably from 1 wt. %to 5 wt. %, relative to the total weight of the composition.
The composition according to any one of claims 1 to 11 further comprising, as skin brightening or whitening ingredient, ahydroxylated diphenylmethane derivative selected from those of formula (4) below:

in which:

R ₁ is selected from a hydrogen atom, a methyl group, a saturated or unsaturated, linear or branched hydrocarbon chain containing from 2 to 4 carbon atoms, an–OH group and a halogen,

R ₂ is selected from a hydrogen atom, a methyl group, and a saturated or unsaturated, linear or branched hydrocarbon chain containing from 2 to 5 carbon atoms,

R ₃ is selected from a methyl group or a saturated or unsaturated, linear or branched hydrocarbon chain containing from 2 to 5 carbon atoms,

R ₄ and R ₅ are, independently of one another, selected from a hydrogen atom, a methyl group, a saturated or unsaturated, linear or branched hydrocarbon chain containing from 2 to 5 carbon atoms, an–OH group or a halogen.
A composition for brightening or whitening keratin materials in the form of an emulsion, comprising an oily phase dispersed in an aqueous phase, and comprising, relative to the total weight of the composition:

(i) from 1 wt. %to 3 wt. %of at least one white particles selected from the group consisting of boron nitride, silica, pearl, mica, synthetic mica, mica based pearl pigment particles, composite particles comprising titanium dioxide and a substrate selected from alumina, silica, barium sulfate, glass, mica and synthetic mica, or mixtures thereof;

(ii) from 0.1 wt. %to 0.5 wt. %of at least one non-ionic surfactant selected from selected from Polysorbate 20, Polysorbate 80, Polysorbate 65, Polysorbate 85, PEG-5 sorbitan isostearate, PEG-20 sorbitan triisostearate, PEG-20 sorbitan isostearate, PEG-40 sorbitan septaoleate, PEG-20 sorbitan tetraoleate and PEG-20 sorbitan trioleate;

(iii) from 0.5 wt. %to 3 wt. %of at least one hydrophilic thickening polymer selected from acrylates/C10-30 alkyl acrylate crosspolymer and crosslinked anionic copolymers of acrylamide or methacrylamide and of 2-acrylamido-2-methylpropanesulphonic acid;

(iv) as skin brightening or whitening active ingredients:

from 0.1 wt. %to 0.5 wt. %of at least one flavone; and

from 0.1 wt. %to 0.5 wt. %of at least one hydroxylated diphenylmethane derivatives selected from those of formula (4) below:

in which:

-R ₁, R ₂, R ₄ and R ₅ denote a hydrogen atom;

-R ₃ is a methyl group;

-the–OH groups are in the ortho-and para-position with respect to the bond formed with the carbon linking the two aromatic nuclei to one another; and

(v) from 1 wt. %to 5wt. %of at least one hydrotrope oxothiazolidinecarboxylic acid, Vitamin B3 and derivatives thereof, preferably niacinamide, xanthine bases, preferably caffeine, camphor benzalkonium methosulfate, ellagic acid, hydroxyphenoxy propionic acid, diethyllutidinate, terephthalylidene dicamphor sulfonic acid, ferulic acid, salicylic acid, phloretine, acetyl trifluoromethylphenyl valylglycine, resveratrol, 4-butylresorcinol, apigenin, phenylethyl resorcinol, prasterone, benzophenone-3, butyl methoxydibenzoylmethane, capryloyl salicylic acid, ethylhexyl salicylate, and jasmonic acid derivatives, preferably sodium tetrahydrojasmonate.
A cosmetic process for brightening or whitening keratin materials, in particular human skin, comprising the step of applying the composition of any one of claims 1 to 13 on the keratin materials.