(poly)glycerol, and a polyol

The present invention relates to a composition, especially a cosmetic composition, com- prising hesperetin in the form of a nanoemulsion or a microemulsion.

Hesperetin is an organic compound of the flavanone family, which is a subgroup of the flavonoids. It is found in nature mainly in the form of its heteroside, hesperidin, which is present in fruits of the Citrus genus.

Hesperetin is an advantageous substance as an antioxidant, and for treating the signs of aging of the skin.

However, this compound, which is in solid form at temperature and has a high melting point (220°C), is difficult to dissolve, and especially is sparingly soluble in water and glyc- erol.

Now, it is necessary for this compound to be formulated in a solubilized form, and especially in a high content, especially greater than or equal to 0.30% by weight, in order to fully exploit its activity, and it is also preferable for its solubilization to be maintained over time in order to avoid any recrystallization during the storage of compositions comprising such a compound.

Furthermore, it may be advantageous to formulate this compound in oil-in-water (O/W) emulsions, known in practice in the cosmetic or dermatological field. These emulsions, which are constructed of an oily phase (or a lipophilic phase) dispersed in an aqueous phase, have an outer aqueous phase and are thus products that are more pleasant to use on account of the sensation of freshness that they afford. However, they have the drawback of lacking stability when the amount of oil present is too high. At the present time, for certain applications, it is advantageous to have a large amount of oils, given that oils give the skin a comfortable feel, nourish it and may also remove makeup therefrom when these oils have makeup-removing properties.

Furthermore, it is advantageous to have fine emulsions, i.e. emulsions in which the oily phase is in the form of very small droplets, i.e. droplets less than 4 μηη in size, given that these fine emulsions afford a pleasant cosmetic sensation and are generally more stable than coarse emulsions. These emulsions may be prepared, in particular, via the phase inversion temperature technique (PIT emulsions), in which the mean size of the globules constituting the oily phase is within given limits, namely between 0.1 and 4 μηη (100 to 4000 nm). The principle of phase inversion temperature (PIT) emulsification is, in theoretical terms, known to those skilled in the art; it was described in 1968 by K. Shinoda (J. Chem. Soc. Jpn., 1968, 89, 435). It has been shown that this emulsification technique allows stable, fine emulsions to be obtained (K. Shinoda and H. Saito, J. Colloid Interface Sci., 1969, 30, 258). This technique was applied in cosmetics as early as 1972 by Mitsui et al. ("Application of the phase-inversion-temperature method to the emulsification of cosmetics"; T. Mitsui, Y. Machida and F. Harusawa, American Cosmet. Perfum., 1972, 87, 33).

The principle of this technique is as follows: an O/W emulsion (introduction of the aqueous phase into the oily phase) is prepared at a temperature which should be above the phase inversion temperature of the system, which is the temperature at which the equilibrium between the hydrophilic and lipophilic properties of the emulsifier(s) used is reached; at a higher temperature, i.e. above the phase inversion temperature (>PIT), the emulsion is of water-in-oil type, and, when it cools down, this emulsion inverts at the phase inversion temperature, to become an emulsion of oil-in-water type, passing beforehand through a microemulsion state. This process makes it readily possible to obtain emulsions with a diameter generally less than 4 μηη. The emulsifying surfactants of oil-in-water type conventionally used have an HLB (hydrophilic-lipophilic balance) in the range from 8 to 18. On account of their amphiphilic structure, these emulsifiers are located at the oily phase/aqueous phase interface, and thus stabilize the dispersed oil droplets. However, it is difficult to produce fine O/W emulsions containing a large amount of oily phase, given that such emulsions have a tendency to become destabilized, this destabili- zation leading to coalescence and separation of the aqueous and oily phases with release of oil. In order to improve the stability of these emulsions, the concentration of emulsifiers may be increased; however, a high concentration of emulsifiers may lead to a rough, ad- hesive or tacky feel and to safety concerns with respect to the skin, the eyes and the scalp.

In particular, a fine emulsion such as an O/W nanoemulsion or microemulsion is particularly advantageous in cosmetic products on account of its transparent or slightly translu- cent appearance. For example, JP-A-H09-1 10635 describes a fine emulsion which is formed by using a combination of polyglyceryl fatty acid ester as surfactant and a C10-C22 fatty 2-hydroxy acid. Furthermore, JP-A-H1 1 -71256 describes a fine emulsion which is formed by using a combination of polyglyceryl fatty acid ester and betaine.

However, when certain types of nonionic surfactant are used for preparing fine emulsions, the transparent or slightly translucent appearance of the emulsion and the stability of the emulsion are insufficient. The object of the present invention is, precisely, to propose a novel galenical formulation of hesperetin that can overcome the abovementioned drawbacks, and thus to incorporate this compound in a form that is solubilized and long-lasting, especially when this compound is present in a high content (such as a content greater than or equal to 0.30% by weight relative to the total weight of the composition), and especially in a composition in the form of a nanoemulsion or microemulsion having a transparent or slightly translucent, preferably transparent, appearance. This novel galenical formulation of hesperetin makes it possible especially to improve the efficacy of the active agent for the treatment of keratin materials such as the skin. After extensive studies, the inventors have in particular discovered, unexpectedly, that it is possible to produce such a composition in which hesperetin is solubilized and its recrystal- lization avoided, especially after storage for 2 months at room temperature (25°C), this composition being stable in the form of a nanoemulsion or microemulsion, and especially having the appearance of a transparent or slightly translucent, preferably transparent.

Consequently, the present invention relates to a composition, preferably a cosmetic composition, in the form of a nanoemulsion or microemulsion, comprising:

a) hesperetin;

b) at least one fatty acid ester of (poly)glycerol;

c) at least one polyol;

d) at least one oil;

e) water.

More particularly, the present invention relates to a composition in the form of a nanoemulsion or microemulsion, comprising:

a) hesperetin; b) at least one fatty acid ester of (poly)glycerol formed from at least one acid comprising a saturated linear alkyl chain containing from 12 to 22 carbon atoms and from 1 to 12 glycerol units;

c) at least one polyol;

d) at least one oil;

e) water.

More particularly, the present invention relates to a composition in the form of a nanoemulsion or microemulsion, comprising:

a) hesperetin;

b) at least two fatty acid esters of (poly)glycerol formed from at least one acid comprising a saturated linear alkyl chain containing from 12 to 22 carbon atoms and from 1 to 12 glycerol units different from each other;

c) at least one polyol;

d) at least one oil;

e) water.

Given that the cosmetic composition according to the present invention may have a trans- parent or slightly translucent appearance, the composition may preferably be used for lotions and the like. Furthermore, the cosmetic composition according to the present invention may produce a pleasant texture and afford moisturizing properties and also increased suppleness. Furthermore, if the dispersed phase is an oily phase and comprises one or more lipophilic or even amphiphilic active components, the oily dispersed phase may func- tion as a vehicle for the active substance and accelerate the penetration of the active components into the skin, or may distribute the active components on the skin.

The composition, preferably a cosmetic composition, according to the present invention is described in greater detail hereinbelow.

The composition of the invention may be a cosmetic composition (i.e. intended for cosmetic purposes) or a dermatological composition. Preferentially, according to the invention, the composition is a cosmetic composition and even more preferentially a cosmetic composition for topical application.

The term "cosmetic composition" especially means a substance or a preparation intended to be brought into contact with the various superficial parts of the human body, in particu- lar the epidermis, the bodily-hair and head-hair systems, the nails, the lips and the oral mucous membranes, with a view, exclusively or mainly, to cleansing them, making them more attractive, fragrancing them, modifying their appearance, protecting them, keeping them in good condition, or correcting body odors.

5

The composition according to the invention comprises hesperetin.

Hesperetin is a compound of chemical structure:

I O

Hesperetin is also known as · 3',5,7-trihydroxy-4'-methoxyflavanone, or (S)-2,3-dihydro- 5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl)-4H-1 -benzopyran-4-one (CAS No.: 520-33- 2).

15 Hesperetin is especially available under the trade name Hesperetin Purified® from the company Ferrer Grupo-Exquim (Ferrer), or under the name · FMLT HespeSphere 1.0® from the company Biospectrum, Inc., or under the name · GFX® from the company Industrial Research Limited, or under the name Jeju Citrus Aglyconoid Liposome® from the company.

20

Hesperetin (a) may be present in the composition according to the invention in a content ranging from 0.05% to 5% by weight, preferably ranging from 0.20% to 2% by weight, preferentially ranging from 0.30% to 1 .5% by weight and particularly ranging from 0.40% to 1 % by weight, relative to the total weight of the composition.

25

Preferably, hesperetin (a) is present in the composition according to the invention in a content of greater than or equal to 0.30% by weight, relative to the total weight of the composition, and preferably in a content of greater than or equal to 0.40% by weight, relative to the total weight of the composition, and better still in a content of greater than or 30 equal to 0.50% by weight, relative to the total weight of the composition.

Fatty acid ester(s) of (polv)glycerol (b) The composition according to the present invention comprises at least one fatty acid ester of (poly)glycerol. In one particular embodiment, the composition according to the present invention comprises at least a first fatty acid ester of (poly)glycerol and at least a second fatty acid ester of (poly)glycerol that are different from each other.

The fatty acid esters of glycerol or of polyglycerol used in the context of the present inven- tion are nonionic surfactants that are solid at a temperature of less than or equal to 45°C.

The compositions according to the invention comprise at least one fatty acid ester of glycerol or polyglycerol, which is optionally polyoxyalkylenated. The (poly)glycerol esters according to the invention are glycerol esters (or monoglyceryl esters) or polyglycerol esters (or polyglyceryl esters) such as diglyceryl (or diglycerol) esters.

According to one embodiment, the (poly)glycerol ester according to the invention results from the esterification of at least one saturated or unsaturated fatty acid and of a (poly)glycerol.

In the context of the present invention, the term "(poly)glycerol" denotes glycerol or glyceryl polymers. When it is a polymer, the polyglycerol is generally a linear sequence of 1 to 22 and preferably of 1 to 12 glycerol units.

In the context of the present invention, the term "polyoxyalkylenated (poly)glycerol" corre- sponds to polyoxyalkylenated ethers of glycerol (or of polyglycerol) and preferably polyox- yethylenated (or polyethylene glycol) ethers.

The esters that are more particularly under consideration according to the present invention are esters resulting from the esterification of poly(glycerol) and of C4-C36, preferably C4 to C18 and more particularly C6 to C12, especially C7 to C10, carboxylic acid(s).

In general, they are derived from the esterification of at least one hydroxyl function of a poly(glycerol) with a C4-C36, preferably C4 to C18, and more particularly C6 to C12, especially C7 to C10, carboxylic acid.

According to a particular embodiment, the esters that are suitable for use in the present invention may be derived from the esterification of a poly(glycerol) with one or more iden- tical or different carboxylic acids. It may be a hydroxylated monoester, a hydroxylated diester, a hydroxylated triester, or a mixture thereof. A preferred cosmetic composition according to the invention comprises an ester of (poly)glycerol chosen from the group constituted of glycerol and glycerol polymers.

According to one embodiment, the fatty acid is a linear or branched, saturated or unsatu- rated carboxylic acid, comprising from 4 to 36 carbon atoms, preferably from 4 to 18 carbon atoms, more particularly from 6 to 12 carbon atoms and especially from 7 to 10 carbon atoms.

Preferably, the fatty acid is a saturated monocarboxylic fatty acid comprising from 8 to 18 carbon atoms.

The carboxylic acid may be linear or branched, and saturated or unsaturated.

Advantageously, it is a linear monocarboxylic acid.

As illustrative examples of monocarboxylic acids that are suitable for use in the invention, mention may be made especially of butanoic acid, pentanoic acid, hexanoic acid, hep- tanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, heptadecenoic acid, hexadecanoic acid and pen- tadecanoic acid and octadecanoic acid (stearic acid).

As representative branched acids, mention may be made more particularly of isobutanoic acid, isopentanoic acid, pivalic acid, isohexanoic acid, isoheptanoic acid, isooctanoic acid, dimethyloctanoic acid, isononanoic acid, isodecanoic acid, isoundecanoicacid, isododec- anoic acid, isotridecanoic acid, isotetradecanoic acid, isopentadecanoic acid, isohexadec- anoic acid, 2-ethylhexanoic acid, 2-butyloctanoic acid and 2-hexyldecanoic acid.

Hydroxy acids such as 2-hydroxybutanoic acid, 2-hydropentanoic acid, 2-hydroxyhexanoic acid, 2-hydroxyheptanoic acid, 2-hydroxyoctanoic acid, 2-hydroxynonanoic acid, 2- hydroxydecanoic acid, 2-hydroxyundecanoic acid, 2-hydroxydodecanoic acid, 2- hydroxytridecanoic acid, 2-hydroxytetradecanoic acid and 2-hydroxyhexadecanoic acid are also suitable for use in the present invention.

It is more particularly a non-hydroxylated C7 to C10 acid and more particularly heptanoic acid, caprylic acid and capric acid.

In the context of the present invention, mention may also be made of oxyalkylenated glycerol esters and in particular polyoxyethylenated derivatives of glyceryl esters of fatty acids and hydrogenated derivatives thereof. These oxyalkylenated glycerol esters can be cho- sen, for example, from glyceryl esters of fatty acids which are hydrogenated and oxyethylenated, such as PEG-200 hydrogenated glyceryl palmate, sold under the name Re- woderm Ll-S 80 by the company Goldschmidt; oxyethylenated glyceryl cocoates, such as PEG-7 glyceryl cocoate, sold under the name Tegosoft GC by the company Goldschmidt, and PEG-30 glyceryl cocoate, sold under the name Rewoderm LI-63 by the company Goldschmidt; and mixtures thereof.

Esters chosen from monoglyceryl and/or diglyceryl caprylate, monoglyceryl and/or diglyc- eryl heptanoate, monoglyceryl and/or diglyceryl caprylate, propylene glycol caprylate and propylene glycol heptanoate, and mixtures thereof, are most particularly suitable for use in the invention.

It is more particularly monoglyceryl caprylate (also known as glyceryl caprylate) and mixtures thereof. According to one embodiment, the (poly)glycerol ester according to the invention is chosen from the group constituted of glyceryl caprylate, polyglyceryl-3 caprylate, polyglyceryl- 2 caprate, polyglyceryl-3 caprate, polyglyceryl-4 caprate, glyceryl laurate, polyglyceryl-2 laurate, polyglyceryl-5 laurate, polyglyceryl-10 laurate, glyceryl myristate, glyceryl stea- rate, glyceryl undecylenate, glyceryl caprylate/caprate, PG-4 laurates, PG-5 dilaurate, PG- 5 oleate, PG-5 dioleate, PG-6 tricaprylate, PG-5 myristate, PG-5 trimyristate, PG-5 stea- rate, PG-5 isostearate, PG-5 trioleate, PG-6 caprylate and PG-6 tricaprylate, decaglyceryl monostearate, distearate, tristearate and pentastearate (CTFA names: polyglyceryl-10 stearate, polyglyceryl-10 distearate, polyglyceryl-10 tristearate, polyglyceryl-10 pentastearate), such as the products sold under the respective names Nikkol Decaglyn 1 S, 2 S, 3 S and 5 S by the company Nikko, and diglyceryl monostearate (CTFA name: polyglyceryl-2 stearate), such as the product sold by the company Nikko under the name Nikkol DGMS, and mixtures thereof. According to a particular embodiment, the composition according to the present invention comprises:

- at least a first fatty acid ester of (poly)glycerol formed from at least one acid comprising a saturated linear alkyl chain containing from 12 to 22 carbon atoms and from 1 to 12 glycerol units;

- at least a second fatty acid ester of (poly)glycerol formed from at least one acid comprising a saturated linear alkyl chain containing from 12 to 22 carbon atoms and from 1 to 12 glycerol units.

In a preferred embodiment, the composition according to the invention comprises:

- a first fatty acid ester of (poly)glycerol which is chosen from a fatty acid ester of (poly)glycerol formed from at least one acid comprising a saturated linear alkyl chain containing from 12 to 18 carbon atoms and from 3 to 6 glycerol units, and/or - a second fatty acid ester of (poly)glycerol which is chosen from a fatty acid ester of (poly)glycerol formed from at least one acid comprising a saturated linear alkyl chain containing from 12 to 18 carbon atoms and from 1 to 4 glycerol units. According to a particular embodiment, the composition according to the present invention comprises:

- a first fatty acid ester of (poly)glycerol which is chosen from a fatty acid ester of (poly)glycerol formed from at least one acid comprising an alkyl or alkenyl chain containing from 12 to 20 carbon atoms and from 3 to 6 glycerol units, preferably from 5 to 6 glycerol units, and their mixture, and

- a second fatty acid ester of (poly)glycerol which is chosen from a fatty acid ester of (poly)glycerol formed from at least one acid comprising an alkyl or alkenyl chain containing from 6 to 18 carbon atoms and from 1 to 3 glycerol units, preferably from 2 to 3 glycerol units, and their mixture.

In one particular embodiment of the invention, the composition comprises at least one polyglyceryl fatty acid ester comprises esters of a fatty acid and polyglycerine containing 70 % or more of polyglycerine whose polymerization degree is 4 or more, preferably esters of a fatty acid and polyglycerine containing equal to or more than 30 % of polyglycerine whose polymerization degree is 5.

According to another particular embodiment of the invention,

- a first fatty acid ester of (poly)glycerol have an HLB (Hydrophilic Lipophilic Balance) value of from 10.0 to 13.0; and/or

- a second fatty acid ester of (poly)glycerol have an HLB (Hydrophilic Lipophilic Balance) value of from 8.0 to 10.0.

In more particular embodiment;

- the first fatty acid ester of polyglycerol is chosen from:

-polyglyceryl monolaurate comprising 4 to 6 glycerol units,

-polyglyceryl mono(iso)stearate comprising 4 to 6 glycerol units,

-polyglyceryl monooleate comprising 2 to 6 glycerol units, and

-polyglyceryl dioleate comprising 4 to 6 glycerol units,

- polyglyceryl monomyristate comprising 4 to 6 glycerol units, and their mixtures; and/or - the second fatty acid ester of (poly)glycerol is chosen from:

-polyglyceryl monolaurate comprising 1 to 3 glycerol units, and their mixtures. In a particularly advantageous manner, the composition according to the invention comprises:

- as first fatty acid ester of (poly)glycerol, polyglyceryl-5 laurate, and/or

- as second fatty acid ester of (poly, glycerol, polyglyceryl-2 laurate.

Polyglyceryl-5 laurate or PG-5 laurate is available under the trade name Laurate Sunsoft A-121 E® from the company Taiyo Kagaku.

Polyglyceryl-2 laurate or PG-5 laurate is available under the trade name Sunsoft Q-12D- C® from the company Taiyo Kagaku.

In the compositions according to the invention, the total amount of fatty acid ester(s) of (poly)glycerol (b) may be present in a content of from 0.50% to 20% by weight, preferably from 2% to 15% by weight and more preferably from 6% to 12% by weight, relative to the total weight of the composition.

Polyol (c)

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

According to the invention, the term "polyol" means a hydrocarbon-based chain comprising at least two carbon atoms, preferably from 2 to 50 carbon atoms, preferably from 4 to 20 carbon atoms, preferably containing from 2 to 10 carbon atoms and preferentially con- taining from 2 to 6 carbon atoms, and bearing at least two hydroxyl groups. The polyols used in the present invention may have a weight-average molecular mass of less than or equal to 1000 and preferably between 90 and 500.

The polyol may be a natural or synthetic polyol. The polyol may have a linear, branched or cyclic molecular structure.

The polyol may be chosen from glycerol and derivatives thereof, and glycols and derivatives thereof. The polyol may be chosen from the group constituted of glycerol, diglycerol, polyglycerol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, pen- tylene glycol, hexylene glycol, 1 ,3-propanediol, 1 ,5-pentanediol, polyethylene glycols, especially containing from 5 to 50 ethylene oxide groups, and sugars such as sorbitol, and a mixture thereof. More particularly, the polyol may be chosen from the group constituted of dipropylene glycol and butylene glycol, and a mixture thereof.

Said polyol(s) may be present in a content ranging from 2% to 50% by weight, preferably ranging from 5% to 40% by weight and preferentially ranging from 20% to 30% by weight, relative to the total weight of the composition.

Oil (d)

The cosmetic composition according to the present invention comprises at least one oil (d). According to the present invention, the term "oil" denotes a fatty compound or substance that is in the form of a liquid at room temperature (25°C) and at atmospheric pressure (760 mmHg). As oils, those generally used in cosmetics may be used alone or in combinations thereof. These oils may be volatile or non-volatile, preferably non-volatile.

The oil may be a non-polar oil such as a hydrocarbon oil, a silicone oil or the like; a polar oil such as a plant or animal oil and an ester oil or an ether oil; or a mixture thereof. It is preferable for the oil (d) to be chosen from the group constituted of oils of plant origin, animal oils, synthetic oils, silicone oils and hydrocarbon oils.

As examples of plant oils, mention may be made, for example, of linseed oil, camellia oil, macadamia oil, corn oil, castor oil, olive oil, avocado oil, sasanqua oil, safflower oil, jojoba oil, sunflower oil, almond oil, rapeseed oil, sesame oil, soybean oil, groundnut oil, argan oil and apricot kernel oil, and mixtures thereof.

As examples of animal oils, mention may be made, for example, of squalene and squalane.

As examples of synthetic oils, mention may be made of alkanes such as isododecane and isohexadecane, fatty esters, fatty ethers and artificial C6-C22 acid triglycerides.

The fatty esters are preferably liquid esters of linear or branched, saturated or unsaturated C1 -C26 aliphatic monoacids or polyacids and of linear or branched, saturated or unsaturated C1 -C26 aliphatic monoalcohols or polyalcohols, the total number of carbon atoms in the fatty esters being greater than or equal to 10. Preferably, for the monoalcohol esters, at least one from among the alcohol and the acid is branched.

Among the monoesters of monoacids and of monoalcohols, mention may be made of ethyl palmitate, ethylhexyl palmitate, isopropyl palmitate, dicaprylyl carbonate, alkyl myristates such as isopropyl myristate or ethyl myristate, isocetyl stearate, 2-ethylhexyl isononanoate, isononyl isononanoate, isodecyl neopentanoate and isostearyl neopenta- noate. Esters of C4-C22 dicarboxylic or tricarboxylic acids and of C1 -C22 alcohols and esters of monocarboxylic, dicarboxylic or tricarboxylic acids and of non-saccharide C4-C26 dihy- droxy, trihydroxy, tetrahydroxy or pentahydroxy alcohols may also be used.

Mention may in particular be made of: diethyl sebacate; isopropyllauryl sarcosinate; diiso- propyl sebacate; bis(2-ethylhexyl) sebacate; diisopropyl adipate; di-n-propyl adipate; dioc- tyl adipate; bis(2-ethylhexyl) adipate; diisostearyl adipate; bis(2-ethylhexyl) maleate; triisopropyl citrate; triisocetyl citrate; triisostearyl citrate; glyceryl trilactate; glyceryl trioc- tanoate; trioctyldodecyl citrate; trioleyl citrate; neopentyl glycol diheptanoate; and diethy- lene glycol diisononanoate.

Fatty esters that may be used include sugar esters and diesters of C6-C30 and preferably C12-C22 fatty acids. It is recalled that the term "sugar" means hydrocarbon-based compounds comprising oxygen containing several alcohol functions, with or without aldehyde or ketone functions, and which comprise at least 4 carbon atoms. These sugars may be monosaccharides, oligosaccharides or polysaccharides.

Examples of suitable sugars that may be mentioned include saccharose (or sucrose), glucose, galactose, ribose, fucose, maltose, fructose, mannose, arabinose, xylose and lactose, and derivatives thereof, in particular alkyl derivatives such as methyl derivatives, for example methylglucose.

The sugar esters of fatty acids may be chosen especially from the group comprising the esters or mixtures of esters of sugars described previously and of linear or branched, saturated or unsaturated C6-C30 and preferably C12-C22 fatty acids. If they are unsaturated, these compounds may contain from one to three conjugated or unconjugated double bonds. The esters according to this variant may also be chosen from monoesters, diesters, tri- esters, tetraesters and polyesters, and mixtures thereof.

These esters may be, for example, oleates, laurates, palmitates, myristates, behenates, cocoates, stearates, linoleates, linolenates, caprates and arachidonates, or mixtures thereof such as, in particular, oleopalmitate, oleostearate and palmitostearate mixed esters, and also pentaerythrityl tetraethylhexanoate.

More particularly, use is made of monoesters and diesters and in particular sucrose, glucose or methylglucose monooleates or dioleates, stearates, behenates, oleopalmitates, linoleates, linolenates and oleostearates.

An example that may be mentioned is the product sold under the name Glucate® DO by the company Amerchol, which is a methylglucose dioleate. As preferred examples of fatty esters, mention may be made, for example, of diisopropyl adipate, dioctyl adipate, 2-ethylhexyl hexanoate, ethyl laurate, cetyl octanoate, oc- tyldodecyl octanoate, isodecyl neopentanoate, myristyl propionate, 2-ethylhexyl 2- ethylhexanoate, 2-ethylhexyl octanoate, 2-ethylhexyl caprylate/caprate, methyl palmitate, ethyl palmitate, isopropyl palmitate, ethylhexyl palmitate, isohexyl laurate, hexyl laurate, isocetyl stearate, isopropyl isostearate, isopropyl myristate, isodecyl oleate, glyceryl tris(2- ethylhexanoate), pentaerythrityl tetrakis(2-ethylhexanoate), 2-ethylhexyl succinate and diethyl sebacate, and mixtures thereof.

As examples of artificial triglycerides, mention may be made, for example, of glyceryl trimyristate, glyceryl tripalmitate, glyceryl trilinolenate, glyceryl trilaurate, glyceryl tri- caprate, glyceryl tricaprylate, glyceryl tri(caprate/caprylate) and glyceryl tri(caprate/caprylate/linolenate).

As examples of silicone oils, mention may be made, for example, of linear orga- nopolysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhy- drogenopolysiloxane and the like; cyclic organopolysiloxanes such as octamethylcyclo- tetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane and the like; and mixtures thereof. Preferably, the silicone oil is chosen from liquid polydialkylsiloxanes, in particular liquid polydimethylsiloxanes (PDMS) and liquid polyorganosiloxanes comprising at least one aryl group. These silicone oils may also be organomodified. The organomodified silicones that may be used according to the present invention are silicone oils as defined above comprising in their structure one or more organofunctional groups linked via a hydrocarbon-based group.

Organopolysiloxanes are defined in greater detail in Walter Noll's Chemistry and Technology of Silicones (1968), Academic Press. They may be volatile or non-volatile.

Volatile or non-volatile silicone oils, such as volatile or non-volatile polydimethylsiloxanes (PDMS) containing a linear or cyclic silicone chain, which are liquid or pasty at room temperature, in particular cyclopolydimethylsiloxanes (cyclomethicones) such as cyclohex- asiloxane; polydimethylsiloxanes containing alkyl, alkoxy or phenyl groups that are pendent or at the end of the silicone chain, said groups containing from 2 to 24 carbon atoms; phenyl silicones such as phenyl trimethicones, phenyl dimethicones, phenyltrime- thylsiloxydiphenylsiloxanes, diphenyl dimethicones, diphenylmethyldiphenyltrisiloxanes, 2- phenylethyl trimethylsiloxysilicat.es and polymethylphenylsiloxanes, may be used.

The hydrocarbon-based oils may be chosen from:

- linear or branched, optionally cyclic, C6-C16 lower alkanes. Examples that may be men- tioned include hexane, undecane, dodecane, tridecane, and isoparaffins, for instance iso- hexadecane, isododecane and isodecane; and

linear or branched hydrocarbons containing more than 16 carbon atoms, such as liquid paraffins, a liquid paraffin gel, polydecenes and hydrogenated polyisobutenes such as ParleamD , and squalane.

As preferred examples of hydrocarbon-based oils, mention may be made, for example, of linear or branched hydrocarbons such as a mineral oil (for example liquid paraffin), paraffin, petroleum jelly or petrolatum, naphthalenes and the like; hydrogenated polyisobutene, isoeicosane, and a decene/butene copolymer; and mixtures thereof.

It is also preferable for the oil (e) to be chosen from oils with a molecular weight of less than 600 g/mol.

Preferably, the oil (e) is chosen from fatty esters containing one or more C1 -C12 hydro- carbon-based chains (for example isopropyl myristate, isopropyl palmitate, isononyl isononanoate and ethylhexyl palmitate), hydrocarbon oils (for example isododecane, iso- hexadecane and squalane), oils of branched and/or unsaturated C12-C30 fatty alcohol type such as octyldodecanol or oleyl alcohol, and fatty ethers such as dicaprylyl ether. In a particularly preferred manner, the oil (d) is chosen from ethylhexyl palmitate and iso- propyl myristate. Ethylhexyl palmitate is available under the trade name Palmitate d'ethyl 2 hexyle (DUB PO)® from the company Stearinerie Dubois.

The amount of oil(s) (d) in the cosmetic composition according to the present invention may be present in a content of from 0.50% to 50% by weight, preferably from 1 % to 15% by weight and more preferably from 2% to 5% by weight, relative to the total weight of the composition.

In a particular embodiment, the fatty acid ester(s) of (poly)glycerol (b) and the oil(s) (d) are present in a composition according to the invention, as defined above, in a [total amount of fatty acid ester(s) of (poly)glycerol (b)/oil(s) (d)] mass ratio which ranges from 0.50 to 10, preferably which ranges from 1 to 5. In a particular embodiment, the fatty acid ester(s) of (poly)glycerol (b) and hesperetin (a) are present in a composition according to the invention, as defined above, in a [total amount of fatty acid ester(s) of (poly)glycerol (b)/hesperetin (a)] mass ratio which is at least equal to 2, especially ranging from 2 to 40, preferably ranging from 5 to 20. According to a preferred embodiment, the fatty acid ester(s) of (poly)glycerol (b) in accordance with the invention are, respectively, polyglyceryl-5 laurate and polyglyceryl-2 laurate, and they are present in the composition according to the invention with hesperetin in a [PG-5 + PG-2/hesperetin] mass ratio which is at least equal to 2, especially ranging from 2 to 40 and preferably ranging from 5 to 20.

Water (e)

The cosmetic composition according to the present invention comprises water.

The amount of water (e) is not limited, and may range from 40% to 99% by weight, preferably from 55% to 95% by weight and more preferably from 60% to 90% by weight, relative to the total weight of the composition. The composition according to the present invention may also comprise at least one additional surfactant other than the fatty acid ester(s) of (poly)glycerol (b) as defined above.

The amount of the additional surfactant(s) may be from 0.01 % by weight to 20% by weight, preferably from 0.10% by weight to 10% by weight and more preferably from 1 % by weight to 5% by weight, relative to the total weight of the composition. Thickener

The cosmetic composition according to the present invention may also comprise at least one thickener. The thickener may be chosen from organic and mineral thickeners.

The thickener is preferably chosen from associative thickeners and polysaccharides such as starch and xanthan gum. In the present context, the term "associative thickener" denotes an amphiphilic thickener comprising both hydrophilic and hydrophobic units, for example comprising at least one C8-C30 fatty chain and at least one hydrophilic unit.

The viscosity of the cosmetic composition according to the present invention is not par- ticularly limited. The viscosity may be measured at 25°C with viscometers or rheometers, preferably having cone-plate geometry. Preferably, the viscosity of the cosmetic composition according to the present invention may be, for example, from 1 to 2000 Pa.s and preferably from 1 to 1000 Pa.s at 25°C and 1 s ^' The thickener may be present in an amount in the range from 0.001 % to 10% by weight and preferably from 0.01 % to 10% by weight, for example from 0.1 % to 5% by weight, relative to the total weight of the composition.

[Other components]

The cosmetic composition according to the present invention may also comprise an efficient amount of other components, previously known furthermore in compositions, especially cosmetic compositions, such as various adjuvants, anti-ageing agents, bleaching agents, anti-greasy skin agents, sequestrants such as EDTA and etidronic acid, UV stabilizers, preserving agents, vitamins or provitamins, for example panthenol, opacifiers, fragrances, plant extracts, cationic polymers, etc.

Preparation and properties

The cosmetic composition according to the present invention may be prepared by mixing the essential and optional components above according to a conventional process. The conventional process comprises mixing with a high-pressure homogenizer (a high-energy process). As a variant, the cosmetic composition may be prepared via a low-energy process such as a phase inversion temperature (PIT) process, a phase inversion concentration (PIC), self-emulsification, and the like. Preferably, the cosmetic composition is prepared via a low-energy process.

In a particular embodiment, the mass ratio between the total amount of the fatty acid esters) of (poly)glycerol (b) and the oil (d) in a composition according to the invention as defined above ranges from 0.50 to 10, preferably from 1 to 5.

The cosmetic composition according to the present invention is in the form of a nanoemulsion or microemulsion. The term "microemulsion" may be defined in two ways, i.e. in a broad sense and in a narrower sense. Namely, in one case ("microemulsion in the narrow sense"), the term microemulsion denotes a thermodynamically stable isotropic single liquid phase containing a ternary system having three components comprising an oily component, an aqueous component and a surfactant, and, in the other case ("microemulsion in the broad sense"), among the thermodynamically unstable typical emulsion systems, the term microemulsion also comprises emulsions that have transparent or translucent appearances on account of their smaller particle sizes (Satoshi Tomomasa, et al., Oil Chemistry, vol. 37, No. 1 1 (1988), pp. 48-53). In the present context, the term "microemulsion" denotes a "microemulsion in the narrow sense", i.e. a thermodynamically stable isotropic single liquid phase.

The microemulsion denotes a state of a microemulsion of O/W (oil-in-water) type in which the oil is dissolved by micelles, a microemulsion of W/O (water-in-oil) type in which the water is dissolved by inverse micelles, or a bicontinuous microemulsion in which the number of associations of surfactant molecules tends to infinity such that the aqueous phase and the oily phase both have a continuous structure. The microemulsion may have a dispersed phase with a numerical mean diameter of 100 nm or less, preferably 50 nm or less and more preferably 20 nm or less, measured by laser particle size analysis.

The term "nanoemulsion" presently denotes an emulsion characterized by a dispersed phase with a size of less than 350 nm, the dispersed phase being stabilized by a crown of the nonionic surfactant (b) which may optionally form a liquid crystal phase of lamellar type, at the dispersed phase/continuous phase interface. In the absence of specific opacifies, the transparency of the nanoemulsions is due to the small size of the dispersed phase, this small size being able to be obtained by means of using mechanical energy and in particular a high-pressure homogenizer.

Nanoemulsions may be distinguished from microemulsions by their structure. Specifically, microemulsions are thermodynamically stable dispersions formed, for example, from swollen micelles of nonionic surfactant (b) with the oil (a). Furthermore, microemulsions do not require substantial mechanical energy to be prepared.

The microemulsion may have a dispersed phase with a numerical mean diameter of 300 nm or less, preferably 200 nm or less and more preferably 100 nm or less, measured by laser particle size analysis. The cosmetic composition according to the present invention may be in the form of an O/W nanoemulsion or microemulsion, a W/O nanoemulsion or microemulsion, or a bicontinuous emulsion. It is preferable for the cosmetic composition according to the present invention to be in the form of an O/W nanoemulsion or microemulsion. It is preferable for the cosmetic composition according to the present invention to be in the form of an O/W emulsion.

The mean size of the droplets of the oily phase is measured concentrated by dynamic light scattering (DLS) with a Vasco particle size analyzer.

These measurements are taken on the undiluted emulsion.

The numerical mean size (μηη) of the droplets of oily phase of the composition of the invention is less than 300 nm, preferably from 10 nm to 150 nm and more preferably from 20 nm to 100 nm. The cosmetic composition according to the present invention may have a transparent or slightly translucent appearance, preferably a transparent appearance. The transparency may be measured by measuring the transmission factor with an absorption spectrometer in the visible region (for example, the transparency is measured with a Hach 2100Q portable turbidimeter at 25°C). The portable turbidimeter uses the nephelometric principle for measuring turbidity. The nephelometric turbidity measurement depends on the detection of the light scattered by the particles in suspension in the liquid. The measuring unit is the NTU. A 60 x 25 cm round borosilicate glass tank with a screw stopper is used. The amount of sample required is 15 ml_. The measuring range is 0-1000 NTU. The samples are measured undiluted.

The cosmetic composition according to the present invention may preferably have a tur- bidity of between 1 and 200 NTU and preferably between 5 and 100 NTU.

Process and use

A further subject of the invention is a cosmetic process for treating keratin materials, com- prising the application to the keratin materials, especially the skin, or the oral administration to an individual, of a composition as described previously.

Said cosmetic treatment process is non-therapeutic.

More particularly, a subject of the invention is also a cosmetic treatment process for caring for, making up and/or cleansing keratin materials, especially the skin, comprising the application to said keratin materials, especially the skin, of a composition according to the invention as described previously.

Said cosmetic treatment process for caring for, making up and/or cleansing the skin is non-therapeutic.

More particularly, a subject of the invention is also a cosmetic process for preventing and/or treating the signs of aging of the skin, comprising at least one step of topical application to the keratin materials, such as the skin, of a composition according to the invention as described previously.

The signs of aging of the skin to be prevented and/or treated in the cosmetic process according to the invention may be chosen from wrinkles and fine lines, and/or combating wizened, flaccid and/or thinned skin. A subject of the present invention is also the cosmetic use of a composition according to the invention as defined previously, for caring for, making up and/or cleansing keratin materials.

More particularly, a subject of the invention is the cosmetic use of a composition as de- fined previously for caring for the skin, preferably for preventing and/or treating the signs of aging of the skin.

In another embodiment, the invention relates to a cosmetic treatment process for caring for, making up and/or cleansing keratin materials, especially the skin, comprising the oral administration, to an individual, of a composition as defined previously.

In another embodiment, the invention also relates to the cosmetic use as defined previously, in which the combination of hesperetin and of at least one organic solvent as defined previously, or the composition comprising it, is used in a food supplement. According to the invention, the term "keratin materials" means the skin, of the body, face and/or area around the eyes, the lips, the nails, mucous membranes, the eyelashes, the eyebrows, bodily hair, the scalp and/or head hair, or any other area of bodily skin. More particularly, the keratin materials according to the invention are the scalp, the hair and/or the skin.

Preferably, the keratin materials according to the invention are the scalp and/or the hair. Preferably, the keratin material according to the invention is the skin.

The term "skin" means all of the skin of the body, and preferably the skin of the face, neckline, neck, arms and forearms, or even more preferably still the skin of the face, in particular of the forehead, nose, cheeks, chin and area around the eyes.

As specified hereinbelow, hesperetin is advantageously present in the compositions in accordance with the invention in a dissolved form.

By way of example, the composition according to the invention may be intended to be administered topically, i.e. by application to the surface of the keratin material under con- sideration, such as the skin under consideration.

The cosmetic composition according to the present invention may be used for a non- therapeutic process, such as a cosmetic process, for treating the skin, the hair, mucous membranes, the nails, the eyelashes, the eyelids and/or the scalp, by application to the skin, the hair, mucous membranes, the nails, the eyelashes, the eyelids or the scalp.

The present invention also relates to a use of the cosmetic composition according to the present invention, in its native form or in care products and/or washing products and/or makeup products and/or makeup-removing products for bodily and/or facial skin and/or mucous membranes and/or the scalp and/or the hair and/or the nails and/or the eyelashes and/or the eyelids. The care product may be a lotion, a cream, a hair tonic, a hair conditioner, a sunscreen, and the like. The cleansing product may be a shampoo, a facial cleanser, a hand cleanser, and the like. The makeup product may be a foundation, a mascara, a lipstick, a lip gloss, a face powder, an eyeshadow, a nail varnish, and the like. The makeup-removing product may be a makeup-cleansing product, and the like.

The expressions "between... and..." and "ranging from... to..." or "at least..." or "at least..." should be understood as being inclusive of limits, unless otherwise specified.

The present invention is described in greater detail by means of examples, which should not, however, be considered as limiting the scope of the present invention.

The compounds are indicated by their chemical name or their INCI name.

The amounts of the ingredients are expressed as weight percentages.

Example 1 :

Evaluation of the stability and transparency of compositions 1 and 3 according to the invention and of Comparative Example 2

Protocol for evaluating the transparency:

The transparency is measured using a Hach 2100Q portable turbidimeter at 25°C. A 60 x 25 cm round borosilicate glass tank with a screw stopper is used. The amount of sample required is 15 ml_. The measuring range is 0-1000 NTU. The samples are measured undiluted.

The higher the mean turbidity value (NTU), the more turbid and the less transparent the composition.

Protocol for evaluating the stability:

The stability of the preparation obtained is evaluated at time T = 0 and also after 2 months (T = 2 months) stored at a temperature of 45°C by macroscopic monitoring with the eye (observation of cloudiness or a deposit, if any), and by observation with a microscope under polarized light (presence or absence of crystals).

The following compositions according to Examples 1 and 3 and Comparative Example 2, described below, were prepared by mixing the components described in Table 1 as fol- lows:

(1 ) mixing ethylhexyl palmitate and polyglyceryl-5 laurate and polyglyceryl-2 laurate to form an oily phase;

(2) heating the oily phase to about 60°C;

(3) adding water to the oily phase with stirring to obtain an oil-in-water microemulsion;

(4) mixing hesperetin and the polyols (dipropylene glycol and butylene glycol), followed by adding the solution to the microemulsion;

(5) adding the preserving agents and ethanol. The numerical values for the amounts of the components described in Table 1 are all based on weight percentages of starting materials relative to the total weight of the composition. Table 1:

g The macroscopic appearance, the turbidity and the stability of the oil-in-water C7W emulsions obtained according to compositions 1 and 3 in accordance with the invention and Comparative Example 2 are described in Table 2 below.

It was thus observed that Comparative Example 2, which is a composition in the form of an oil-in-water emulsion comprising 0.5% of hesperetin and especially not comprising any fatty acid ester of (poly)glycerol, is not stable, and has an opaque appearance with substantial precipitation and a high mean turbidity.

As clearly indicated by the above results, it was observed that compositions 1 and 3 according to the invention, in the form of an oil-in-water nanoemulsion or microemulsion and comprising at least one fatty acid ester of (poly)glycerol, have better transparency and are stable for 2 months at 45°C, and in particular no crystallization of the hesperetin is observed. Example 2: Cosmetic composition according to the invention

A facial care lotion (oil-in-water emulsion) having the following composition was prepared:

Preparation process:

(1 ) ethylhexyl palmitate, polyglyceryl-5 laurate and polyglyceryl-2 laurate were mixed to form an oily phase A;

(2) the oily phase A was heated to about 60°C;

(3) water B was added to the oily phase A with stirring to obtain an oil-in-water microemul- sion;

(4) hesperetin and the polyols (dipropylene glycol and butylene glycol) were mixed, fol- lowed by adding the solution C to the microemulsion; (5) phase D (preserving agents and ethanol) was added.

The composition is single-phase and clear, and remains stable and homogeneous after storage for 2 months at 45°C.

This composition may be applied regularly to facial skin in order to attenuate the signs of aging of the skin.