The present invention relates to an aqueous transparent cosmetic composition, comprising at least 5% by weight of ascorbic acid and/or one of the derivatives thereof, at least 3.5% by weight of a glycol comprising 5 to 7 carbon atoms and at least one cationic polymer chosen from cationic cellulose polymers modified by groups including at least one linear fatty chain.

In cosmetic applications, it is routine to add ascorbic acid (vitamin C) as a skin regenerating agent thanks to stimulation of collagen synthesis responsible for skin firmness, or as a depigmenting agent, as this vitamin lowers the production of melanin responsible for brown spots. Ascorbic acid is also known for the antioxidant properties thereof.

However, when ascorbic acid or one of the derivatives thereof is introduced into an aqueous medium at high levels (i.e., for example greater than 1% by weight, preferably greater than 5% by weight), the formulation thereof is difficult to carry out, as it destabilizes and changes color dramatically.

For this reason, serum or solution type aqueous compositions, which comprise ascorbic acid in the form of powder to be solubilized extemporaneously, are found on the market. The drawback of this type of products is that vitamin C eventually degrades in the aqueous medium. These products thus lose their appeal as consumers prefer, for practical reasons, serums with no prior handling, with the guarantee of color stability and with no chemical degradation.

Therefore there is a need for stable aqueous compositions comprising ascorbic acid. It is possible to gel the aqueous phase of such compositions by means of a specific cationic polymer, preferably polyquaternium-67. This polymer has the triple advantage of adding viscosity to the medium and leaving a soft film on the skin and reducing the degradation of the color of ascorbic acid over time.

However, these serum or gelled solution type aqueous compositions have nevertheless the drawback of forming, when spread on the skin, a non-homogeneous deposit, which whitens during shearing, and which is not satisfactory for the consumer. Such whitening is referred to as "soaping" in the present application.

There is therefore a need for an aqueous cosmetic composition comprising ascorbic acid and/or one of the derivatives thereof, which is stable, i.e., which stays the same color as originally (generally white) and the same texture, which does not degrade the active agent, and which does not exhibit soaping when applied.

Surprisingly, the Applicant demonstrated that associating a specific cationic polymer with hexylene glycol and/or pentylene glycol at a content of at least 3.5% by weight with respect to the total composition weight, makes it possible to obtain compositions comprising at least 5% by weight of ascorbic acid and/or one of the derivatives thereof, which are stable, and which do not exhibit soaping when applied.

Thus, the present invention relates to a cosmetic composition comprising, in a physiologically acceptable aqueous medium:

- at least 5% by weight of ascorbic acid or one of the derivatives thereof,

- at least 3.5% by weight with respect to the total weight of the composition of at least one glycol comprising 5 to 7 carbon atoms,

- at least one cationic polymer chosen from cationic cellulose polymers modified by groups including at least one linear fatty chain, the percentages being by weight with respect to the total composition weight.

Preferably, the composition has a pH between 5 and 7.

The invention also relates to a cosmetic method for the care of keratin materials, preferably the skin, comprising the application of a composition according to the invention on said keratin materials.

The term "physiologically acceptable medium" denotes a medium comprising water and compatible with the skin, mucosa and/or appendages.

Preferably, the composition according to the invention is an aqueous solution, more preferably an aqueous solution of slightly gelled appearance. Preferably, the composition according to the invention is single-phase. This composition can be referred to as "serum". The term "serum" denotes a composition of fluid texture, of slightly gelled appearance, that is flowing, and preferably concentrated with ascorbic acid (i.e., at least 5% by weight of ascorbic acid).

Preferably, the composition according to the invention is substantially free from lipophilic phase. The term "substantially free from lipophilic phase" denotes that the composition according to the invention has a lipophilic phase content less than or equal to 2% by weight, with respect to the total weight of the composition, preferably less than or equal to 1% by weight, preferably less than or equal to 0.5% by weight. Preferably, the composition according to the invention is totally free from lipophilic phase.

The term "lipophilic phase" denotes a phase comprising at least one lipophilic compound chosen from oils and perfumes.

Preferably, the composition according to the invention is substantially free from surfactants. The term "substantially free from surfactants" denotes that the composition according to the invention has a surfactant content less than or equal to 2% by weight, with respect to the total weight of the composition, preferably less than or equal to 1% by weight.

The surfactants can preferably be peptizing agents, the concentration of which is between 0.1 and 2% by weight, which enable the solubilization of a small quantity of oils, lipophilic compounds or perfume (i.e., perfume or oil concentration between 0.05% and 2% by weight).

Preferably, the composition according to this invention is transparent.

The term transparent composition according to the present invention denotes a composition with a turbidity value of less than 200 NTU, preferably less than 150 NTU, preferably less than 100 NTU. Preferably, the turbidity of the compositions is equal to at least 1 NTU. NTUs (nephelometric turbidity units) are units for measurement of the turbidity of a composition. The turbidity measurement is made, for example, with a model 21 OOP turbidity meter made by the Hach Company, the tubes used for the measurement being references AR397A cat 24347-06. The measurements are made at ambient temperature (from 20°C to 25°C).

Preferably, the composition is transparent and has a turbidity value between 1 and 200 NTU, preferably between 1 and 150 NTU, and preferably less than 100 NTU.

The composition according to the invention comprises a physiologically acceptable aqueous medium. Said phase comprises water. The water used can be sterile demineralized water and/or floral water such as rose water, cornflower water, chamomile water or linden water, and/or a spring or natural mineral water.

The composition preferably comprises at least 30% by weight of water with respect to the total weight of the composition, preferably at least 40% by weight.

The composition preferably comprises from 30% to 93% by weight of water with respect to the total weight of the composition, more preferably from 50% to 90%, even more preferably from 55% to 70%.

The aqueous phase can also comprise at least one water-soluble organic solvent, at 25°C.

Preferably, the water-soluble organic solvent is chosen from alcohols, certain polyols and mixtures thereof.

Among the alcohols, mention can be made of C1-C10, more preferably C1-C5, alcohols, such as ethanol, isopropanol, propanol and butanol.

The polyol is, preferably chosen from polyols having 2 to 20 carbon atoms, preferably 2 to 5 carbon atoms, such as glycerol, diglycerol, propylene glycol, isoprene glycol, dipropylene glycol, butylene glycol, 1 ,3-propanediol, pentylene glycol, polyethyleneglycols having 2 to 200 ethylene oxide units and mixtures thereof.

Preferably, the water-soluble organic solvent is a polyol such as glycerol.

Preferably, the composition comprises from 1% to 25% by weight of water-soluble organic solvent, with respect to the total weight of the composition, more preferably from 2% to 30% by weight, even more preferably from 5% to 20% by weight.

Glycol comprising 5 to 7 carbon atoms The composition according to the invention also comprises at least 3.5% by weight in relation to the total weight of the composition of at least one glycol comprising 5 to 7 carbon atoms.

The term glycol comprising 5 to 7 carbon atoms denotes a diol comprising a C5 to C7 carbon chain, devoid of ether function, and wherein the two hydroxyl groups are carried by different carbon atoms. The C5 to C7 carbon chain can be linear or branched. Preferably, the glycol comprising 5 to 7 carbon atoms is hexylene glycol, also referred to as 2-methyl-2,4-pentanediol, or pentylene glycol (also referred to as pentane-1 ,2-diol). 2-methyl-2,4-pentanediol is different from 1 ,2-hexylene glycol by the location of the hydroxyl groups and by the carbon chain: the hydroxylated groups are positioned at 2 and 4 on the branched carbon chain for 2-methyl-2,4-pentanediol (hexylene glycol), while 1 ,2-hexylene glycol contains hydroxylated groups at 1 and 2 on the linear carbon chain.

The glycol comprising 5 to 7 carbon atoms is present in the physiologically acceptable aqueous medium.

The composition comprises at least 3.5% by weight of glycol comprising 5 to 7 carbon atoms with respect to the total weight of the composition. Preferably, it comprises from 4% to 15% by weight of glycol comprising 5 to 7 carbon atoms, more preferably from 5% to 10% by weight.

Ascorbic acid or derivatives thereof

The composition according to the invention also comprises ascorbic acid or one of the derivatives thereof.

The ascorbic acid according to the invention corresponds preferably to L-ascorbic acid, or vitamin C. Its structure is as in formula (I):

[Chem 1]

The term "ascorbic acid derivative" preferably denotes a compound chosen from 5,6-di-O- dimethylsilylascorbate (particularly sold by Exsymol under the reference PRO-AA), DL- alpha-tocopheryl-DL-ascorbyl-phosphate potassium salt also referred to as Potassium Ascorbyl Tocopheryl Phosphate (sold by Senju Pharmaceutical under the reference SEPIVITAL EPC), magnesium ascorbyl phosphate, sodium ascorbyl phosphate (sold by Roche under the reference Stay-C 50), disodium ascorbyl sulfate, sulfinyl-L-ascorbic acid, glucopyranosyl-L-ascorbic acid and ascorbyl glucoside.

The term "ascorbyl glucoside" denotes the condensation product of glucose, in D form, i.e., in the form of a or b glucopyrannose or a or b furanose, or in L form, with ascorbic acid, preferably in L form. Preferably, the ascorbyl glucoside is L-ascorbic acid 2-O-a-D- glucopyranoside, particularly available from HAYASHIBARA.

Preferably, the composition according to the invention comprises ascorbic acid, preferably L-ascorbic acid.

The composition comprises at least 5% by weight of ascorbic acid or one of the derivatives thereof with respect to the total weight of the composition, preferably at least 8% by weight, more preferably at least 10% by weight.

Preferably, the composition comprises from 5% to 25% by weight of ascorbic acid or one of the derivatives thereof, with respect to the total weight of the composition, more preferably from 5% to 20% by weight, even more preferably from 9% to 17% by weight.

Cationic polymer chosen from cationic cellulose polymers modified by oroups including at least one linear fattv chain The cationic polymer according to the invention is chosen from cationic cellulose polymers modified by groups including at least one linear fatty chain, preferably polyquaternium-67.

The cationic polymer according to the invention is a cationic cellulose polymer modified by groups including at least one linear fatty chain. According to the present invention, a "cationic cellulose polymer" denotes any non-siliconized (comprising no silicon atoms) cellulose polymer containing cationic groups and/or groups ionizable into cationic groups, and preferably not containing anionic groups and/or groups ionizable into anionic groups. The term "cellulose" polymer denotes according to the invention any polysaccharide compound having in the structure thereof at least 20 glucose residue chains joined by b-1 ,4 bonds. The cellulose polymer can be associative, i.e., having the structure thereof at least one C8-C30 fatty chain.

The cationic cellulose polymers suitable for use preferably have a weight-average molecular weight (Mw) between about 5000 and 5.10 ⁶ , preferably between about 10 ³ and 3.10 ⁶ . Among the cationic celluloses, mention can more particularly be made of cellulose ethers including quaternary ammonium groups modified by groups including at least one linear fatty chain.

Among the quaternary celluloses, mention can be made in particular of quaternized celluloses modified by groups including at least one linear fatty chain, such as linear alkyl, linear or branched arylalkyl, linear alkylaryl, preferably linear alkyl, groups, these groups including at least 8 carbon atoms, particularly 8 to 30 carbon atoms, more preferably 10 to 24, or 10 to 14, carbon atoms; or mixtures thereof.

Preferably, mention can be made of quaternized hydroxyethylcelluloses modified by groups including at least one linear fatty chain, such as linear alkyl, linear arylalkyl, linear alkylaryl, preferably linear alkyl, groups, these groups including at least 8 carbon atoms, particularly 8 to 30 carbon atoms, more preferably 10 to 24, or 10 to 14, carbon atoms; or mixtures thereof.

Preferably, mention can be made of hydroxyethy lcel I u loses of formula (lb):

[Chem 2] wherein:

- R represents an ammonium group RaRbRcN+-, Q- wherein Ra, Rb, Rc, identical or different represent a hydrogen atom or linear, C1-C30, alkyl, preferably an alkyl and Q- represents an anionic counterion such as a halide such as chloride or bromide;

- R’ represents an ammonium group R’aR’bR’cN+-, Q’- wherein R’a, R’b, R’c, identical or different represent a hydrogen atom or linear, C1-C30, alkyl, preferably an alkyl and Q’- represents an anionic counterion such as a halide such as chloride or bromide; preferably an alkyl; it being understood that at least one of the radicals Ra, Rb, Rc, R’a, R’b, R’c represents a linear, C8-C30, alkyl;

- n, x and y, identical or different, represent an integer between 1 and 10000. Preferably, in formula (lb), at least one of the radicals Ra, Rb, Rc, R’a, R’b, R’c represents a linear C8-C30 alkyl; preferably C10-C24, or C10-C14; mention can particularly be made of the dodecyl radical (C12). Preferably, the or the other radicals represent a linear C1-C4 alkyl, particularly methyl.

Preferably, in formula (lb), only one of the radicals Ra, Rb, Rc, R’a, R’b, R’c represents a linear, C8-C30 alkyl; preferably C10-C24, or C10-C14; mention can particularly be made of the dodecyl radical (C12). Preferably, all the other radicals represent a linear C1-C4 alkyl, particularly methyl. More preferably, R can be a group chosen from -N ⁺ (CH ₃ )3, Q’ and -N ⁺ (Ci2H ₂ 5)(CH ₃ )2, Q’ , preferably a group -N ⁺ (CH ₃ ) ₃ , Q’\

More preferably, R’ can be a group -N ⁺ (Ci2H25)(CH ₃ )2, Q’\

The nitrogen percentage can vary from 0.1 to 10% by weight with respect to the total polymer weight, preferably from 0.2 to 5% by weight and more preferably from 0.5 to 3% by weight.

Mention can particularly be made of polymers having the INCI names:

- Polyquaternium-24, such as the product QUATRISOFT LM 200®, marketed by AMERCHOL/DOW CHEMICAL;

- PG-Hydroxyethylcellulose Cocodimonium Chloride, such as the product CRODACEL QM®;

- PG-Hydroxyethylcellulose Lauryldimonium Chloride (C12 alkyl), such as the product CRODACEL QL® and

- PG-Hydroxyethylcellulose Stearyldimonium Chloride (C18 alkyl) such as the product CRODACEL QS®, marketed by CRODA.

Mention can also be made of hydroxyethylcelluloses of formula (lb) wherein R represents trimethylammonium halide and R’ represents dimethyldodecylammonium halide, preferably R represents trimethylammonium chloride CI-,(CH3)3N+- and R’ represents dimethyldodecylammonium chloride CI-,(CH3)2(C12H25)N+- . This type of polymer is known under the INCI name Polyquaternium-67; as commercial products, mention can be made of SOFTCAT POLYMER SL® polymers such as SL-100, SL-60, SL-30, SL-5 and SX- 1300X from AMERCHOL/DOW CHEMICAL.

More particularly, the cationic cellulose polymer is chosen from hydroxyethyl celluloses having reacted with a trimethyl ammonium epoxide and a lauryl dimethyl ammonium epoxide (INCI name POLYQUATERNIUM-67).

It is preferably marketed under the name Softcat Polymer SL-100 or Softcat Polymer SX- 1300X by Amerchol.

Preferably, the composition comprises from 0.05% to 5% by weight of cationic polymer, with respect to the total weight of the composition, more preferably from 0.3% to 3% by weight, even more preferably from 0.4% to 2% by weight. pH of the composition The pH of the composition according to the invention is preferably 5.0 to 7.0. Advantageously, the pH of the composition is between 5.5 and 6.5.

Preferably, the cosmetic composition according to the invention comprises at least one base.

The base is particularly used to increase the final pH of the composition to between 5.0 and 7.0, preferably between 5.5 and 6.5.

The base can be chosen from mineral bases such as for example alkaline metal hydroxides, sodium hydroxide, potassium hydroxide.

Preferably, the base of the composition is an alkaline metal hydroxide, preferably sodium hydroxide or potassium hydroxide. Indeed, these bases are more advantageous than nitrogenous bases, such as triethanolamine, on color stabilization (i.e., less yellowing).

Preferably, the base of the composition according to the invention is present in a base:ascorbic acid weight ratio ranging from 0.22 to 0.30.

The composition can also comprise one or more additive(s) conventionally used in cosmetic compositions such as for example active agents, sequestering agents, additional glycols different from the glycols comprising 5 to 7 carbon atoms cited above, preservatives or perfumes.

Preferably, among the usable active agents, adenosine, salicylic acid, glycolic acid, niacinamide (Vitamin B3), tocopherol or perfumes are preferred.

The composition according to the invention can comprise at least one sequestering agent. Among the preferred sequestering agents, mention can be made of ethylene diamine disuccinic acid. Ethylene diamine disuccinic acid is a compound of formula (II):

[Chem 3] Preferably, the ethylene diamine disuccinic salt is chosen from alkaline metal salts, such as potassium salts and sodium salts, ammonium salts, and amine salts. The alkaline metal salts of ethylene diamine acid are more particularly preferred.

Preferably, the ethylene diamine disuccinic acid salt used according to the invention is trisodium ethylene diamine disuccinate.

Such a compound is for example that marketed under the name Natrlquest® E30 by Innospec Active Chemicals, or that marketed under the name Octaquest E30 ^® by Octel Performance Chemicals.

Preferably, the composition according to the invention comprises from 0.01% to 2.5% by weight, preferably from 0.05% to 1 .5% by weight, more preferably from 0.07% to 0.3% by weight of ethylene diamine disuccinic acid salt, with respect to the total weight of the composition.

It is understood that the ethylene diamine disuccinic acid salt corresponds to the active substance, also referred to as dry matter, content of ethylene diamine disuccinic acid salt introduced into the composition.

According to a specific embodiment, the ethylene diamine disuccinic acid salt can be introduced into the composition dissolved in water, particularly at a content ranging from 25% to 50% by weight, preferably from 35% to 40% by weight in water.

Such a compound is for example that marketed under the name Natrlquest® E30 by Innospec Active Chemicals, at 37% by weight in water.

Preferably, the composition according to the invention comprises at least one additional glycol different from the glycols comprising 5 to 7 carbon atoms cited above. Preferably, such a glycol is a glycol comprising 8 carbon atoms, preferably caprylyl glycol.

The composition according to the invention preferably comprises at least caprylyl glycol. Indeed, the presence of caprylyl glycol, coupled with the presence of at least 3.5% by weight of hexylene glycol, favors obtaining transparent compositions.

Preferably, the composition according to the invention comprises from 0.1% to 2% by weight, preferably from 0.5% to 1 .5% by weight, more preferably from 0.7% to 1 % by weight of glycol comprising 8 carbon atoms with respect to the total weight of the composition.

Preferably, the composition according to the invention comprises at least one preservative. Among the preferred preservatives, mention can be made of hydroxyacetophenone, phenoxyethanol and mixtures thereof.

Preferably, the composition according to the invention comprises from 0.1% to 2% by weight, preferably from 0.5% to 1 .5% by weight, more preferably from 0.7% to 1 % by weight of preservative(s) with respect to the total weight of the composition.

Finally, the invention also relates to a cosmetic method for cleansing keratin materials, preferably the skin, comprising the application of a composition according to the invention.

Concrete, yet non-limiting, examples, illustrating the invention, will now be provided.

EXAMPLES

Unless stated otherwise, the pressure in the examples is atmospheric pressure. Unless specified otherwise, the percentages are expressed by weight in relation to the total weight of the composition (% w/w).

Example 1 : Compositions according to the invention

Formulas A and B according to the invention are prepared below according to the following protocol:

In a first beaker (phase A):

1. Introduce water (T>60°C) and add the ingredients of phase Ain the following order: glycerin, caprylyl glycol, trisodium ethylene diamine disuccinate, hexylene glycol or pentylene glycol at 60°C;

2. Once everything has dissolved and there are no more crystals, allow to cool.

In a second beaker (phase B):

1 . Introduce water at ambient temperature and add ascorbic acid;

2. Adjust the pH to 5.8 with sodium hydroxide;

3. Add polyquaternium-67 with moderate, lengthy stirring to ensure effective deployment of the polymer.

Mix the two beakers (pour phase A into phase B) and make up to the QS with water if required. [Table 1]

Example 2: Influence of different ingredients on soaping of aqueous formulas comprisina at 10% ascorbic acid and 0.5% polvauaternium-67

The following comparative compositions are prepared with the following protocol:

Formulas A and B according to the invention are prepared below according to the following protocol: In a first beaker (phase A):

1. Introduce water (T>60°C) and add the ingredients of phase Ain the following order: glycerin, caprylyl glycol, trisodium ethylene diamine disuccinate, hexylene glycol or pentylene glycol at 60°C;

2. Once everything has dissolved and there are no more crystals, allow to cool.

In a second beaker (phase B):

1 . Introduce water at ambient temperature and add ascorbic acid;

2. Adjust the pH to 5.8 with sodium hydroxide; 3. Add polyquaternium-67 with moderate, lengthy stirring to ensure effective deployment of the polymer.

Mix the two beakers and make up to the QS with water if required.

The appearance of the compositions is evaluated with the naked eye.

The effect on soaping was evaluated as follows:

The test was performed blind on 6 people. Soaping was evaluated by applying one drop of product on the hand and shearing quickly with the other hand until the product has penetrated.

Finally, the stability of the compositions was evaluated up to 2 months at 45°C. Comparative examples C1 to C4- effect of oils [Table 2]

Adding isopropyl myristate makes it possible to eliminate soaping, but the formulas are unstable. Comparative examples C5 to C8- effect of silicone compounds

[Table 3]

Adding silicone compounds, soluble in the composition, does not eliminate soaping. Comparative examples C9 to C11 - effect of Nad or glycerol

[Table 4]

Adding NaCI or glycerin does not reduce soaping.

Comparative examples C12 to C14- effect of ethanol

[Table 5]

Adding ethanol does not reduce soaping. Comparative example C15- effect of methyl gluceth-20

[Table 6]

Adding methyl gluceth-20 does not eliminate soaping.

Comparative examples C16 to C19- effect of oolvols

[Table 7]

[Table 8]

Adding propylene glycol, dipropylene glycol or butylene glycol does not reduce soaping.

Examples according to the invention ( C and D) and comparative example C20 effect of hexylene glycol

[Table 9]

Hexylene glycol has the advantage of reducing soaping, or eliminating soaping, at a concentration greater than or equal to 3.5% by weight in the formula. Examples according to the invention (A and B) and comparative examples C12 and C21 - effect of hexylene alvcol

[Table 10] Surprisingly, only hexylene glycol, at a concentration greater than or equal to 3.5% by weight in the formula, has not only the advantage of reducing or even eliminating soaping, but also of solubilizing caprylyl glycol to promote serum transparency.

Example E according to the invention and comparative example C22 - effect of pentylene glycol

[Table 11]

Surprisingly, pentylene glycol, at a concentration greater than or equal to 3.5% by weight in the formula, has not only the advantage of reducing or even eliminating soaping, but also of solubilizing caprylyl glycol to promote serum transparency.