Transparent cosmetic composition with ascorbic acid and specific cationic polymer

Specific cationic polymers and pH control in aqueous cosmetic compositions stabilize ascorbic acid, addressing color and degradation issues, resulting in a stable and transparent cosmetic product.

FR3124388B1Active Publication Date: 2025-11-21LOREAL SA
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Patent Information

Application Number
FR2021006896
Authority / Receiving Office
FR · FR
Patent Type
Patents
Current Assignee / Owner
Filing Date
2021-06-28
Publication Date
2025-11-21
Estimated Expiration
2041-06-28

AI Technical Summary

Technical Problem

Aqueous cosmetic compositions containing ascorbic acid at high concentrations (above 1% by weight) destabilize and change color, leading to unacceptable brown discoloration and degradation, which is not preferred by consumers who seek stable, color-stable, and convenient products.

Method used

Incorporation of specific cationic polymers, such as cationic galactomannan gums and cationic cellulosic polymers with linear fatty chains, along with a pH between 5 and 7, stabilizes ascorbic acid in aqueous solutions, maintaining transparency and preventing chemical degradation.

Benefits of technology

The composition remains transparent and chemically stable, with minimal color change over time and temperature, ensuring a stable and appealing cosmetic product.

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Abstract

Transparent cosmetic composition with ascorbic acid and specific cationic polymer. The present invention relates to a cosmetic composition comprising: - at least 30% by weight of water relative to the total weight of the composition, - at least 5% by weight of ascorbic acid relative to the total weight of the composition, - at least one cationic polymer selected from cationic galactomannan gums and cationic cellulosic polymers modified by groups comprising at least one linear fatty chain, said composition having a pH between 5 and 7, preferably between 5.5 and 6.5. It also relates to a cosmetic process for the treatment of keratinous materials using this composition. Figure for the abstract: none
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Description

Title of the invention: Transparent cosmetic composition with ascorbic acid and specific cationic polymer

[0001] The present invention relates to a transparent aqueous cosmetic composition, comprising ascorbic acid and at least one cationic polymer selected from cationic galactomannan gums and cationic cellulosic polymers modified by groups comprising at least one linear fatty chain.

[0002] In cosmetic applications, it is common to add ascorbic acid (vitamin C) as a skin-regenerating active ingredient by stimulating collagen synthesis, which is responsible for skin firmness, or as a depigmenting agent, since this vitamin reduces the production of melanin, which causes brown spots. Ascorbic acid is also known for its antioxidant properties.

[0003] However, when ascorbic acid is introduced into an aqueous medium (such as emulsions or serums) at high concentrations (i.e., for example, above 1% by weight, preferably above 5% by weight), its formulation becomes difficult to achieve because it destabilizes and changes color drastically. This color change can even result in a brown discoloration, which is unacceptable to the consumer.

[0004] This is why aqueous compositions such as serums or solutions, containing ascorbic acid in powder form for immediate solubilization, are available on the market. The drawback of this type of product is that vitamin C eventually degrades in the aqueous environment. These products thus lose their appeal because consumers, for reasons of convenience, prefer serums that require no prior preparation, guaranteeing color stability and preventing chemical degradation. Consumers also prefer a product in a small volume (for example, 10 ml), allowing for quick application.

[0005] There is therefore a need for an aqueous cosmetic composition comprising ascorbic acid which is stable, i.e. which remains the same color as originally (generally white) and the same texture, and which does not degrade the active ingredient.

[0006] Surprisingly, the Applicant has demonstrated that specific cationic polymers make it possible to limit the degradation of the color of compositions comprising ascorbic acid, over time and temperature, while maintaining the stability of the compositions obtained.

[0007] Thus, the present invention relates to a cosmetic composition comprising:

[0008] - at least 30% by weight of water relative to the total weight of the composition,

[0009] - at least 5% by weight of ascorbic acid relative to the total weight of composition,

[0010] - at least one cationic polymer selected from galactomannan gums cationic and cationic cellulosic polymers modified by groups comprising at least one linear fatty chain,

[0011] said composition having a pH between 5 and 7.

[0012] The invention also relates to a cosmetic process for the care of keratinous materials, preferably the skin, comprising the application to said keratinous materials of a composition according to the invention.

[0013] Preferably, the composition according to the invention is an aqueous solution, more preferably an aqueous solution with a slightly gel-like appearance. Preferably, the composition according to the invention is monophasic. This composition may be called a "serum." By "serum," we mean a composition with a fluid texture, a slightly gel-like appearance, and which flows easily, and is preferably concentrated in ascorbic acid (i.e., preferably at least 5% by weight of ascorbic acid).

[0014] Preferably, the composition according to the invention is substantially free of surfactants. By "substantially free of surfactants," it is understood that the composition according to the invention has a surfactant content of less than or equal to 2% by weight, relative to the total weight of the composition, preferably less than or equal to 1% by weight. The surfactants may preferably be peptizers, the concentration of which is between 0.1 and 2% by weight; they allow the solubilization of a small amount of oil(s) or lipophilic compounds or perfume(s) (i.e., a concentration of perfume(s) or oil(s) or lipophilic compound(s) between 0.05% and 2%). Aqueous phase

[0015] The composition according to the invention comprises water, which constitutes the aqueous phase.

[0016] The water used may be sterile demineralized water and / or floral water such as rose water, cornflower water, chamomile water or linden water, and / or natural thermal or mineral water.

[0017] The composition preferably comprises at least 30% by weight of water relative to the total weight of the composition.

[0018] The composition preferably comprises from 30% to 93% by weight of water relative to the total weight of the composition, more preferably from 50% to 90%, and even more preferably from 55% to 70%.

[0019] The aqueous phase may also include at least one organic solvent soluble in water, at 25°C.

[0020] Preferably, the water-soluble organic solvent is chosen from alcohols, polyols and their mixtures.

[0021] Among alcohols, we can mention alcohols in CrCl₂, more preferably in CrCl₂, such as ethanol, isopropanol, propanol and butanol.

[0022] The polyol is preferably chosen from polyols having from 2 to 20 carbon atoms, more preferably from 2 to 6 carbon atoms, such as glycerol, diglycerol, propylene glycol, isoprene glycol, dipropylene glycol, butylene glycol, hexylene glycol, 1,3-propanediol, pentylene glycol, polyethylene glycols having from 2 to 200 ethylene oxide motifs and their mixtures.

[0023] Preferably, the water-soluble organic solvent is chosen from polyols, preferably glycerol and / or hexylene glycol and / or pentylene glycol.

[0024] Preferably, the composition comprises from 1% to 25% by weight of water-soluble organic solvent, relative to the total weight of the composition, more preferably from 2% to 30% by weight, even more preferably from 5% to 20% by weight. Ascorbic acid

[0025] Ascorbic acid, as defined in the invention, preferably corresponds to L-ascorbic acid, or vitamin C. Its structure is as follows: (I)

[0026] [Chem.l]

[0027] The composition comprises at least 5% by weight of ascorbic acid relative to the total weight of the composition, more preferably at least 7% by weight.

[0028] Preferably, the composition comprises 5% to 30% by weight of ascorbic acid, relative to the total weight of the composition, more preferably 7% to 20% by weight.

[0029] As shown in the examples, surprisingly, the compositions according to the invention are perfectly transparent, include in particular 10% or 15% by weight of ascorbic acid, and exhibit good chemical stability and acceptable color change after 2 months at 45°C for 0.5% polyquaternium-67 and 2% cationic guar. This color change is acceptable because, rated on a color scale from 0 (white, very light) to 9 (black, very dark), the compositions according to the invention have a score of 4, and this score is lower than the reference composition comprising 10% by weight of ascorbic acid in water (rated 4.5, therefore greater than 4).

[0030] Cationic polymer selected from cationic galactomannan gums and cationic cellulosic polymers modified by groups comprising at least one linear fatty chain

[0031] The cationic polymer according to the invention is chosen from cationic galactomannan gums (cationic guars) and cationic cellulosic polymers modified by groups comprising at least one linear fatty chain (preferably polyquaternium-67).

[0032] Indeed, as shown in examples, these polymers are more favorable to the cosmetic appeal and stability of compositions.

[0033] The cationic polymer according to the invention may be a cationic galactomannan gum (cationic guar). "Cationic galactomannan gum" means any galactomannan gum containing cationic groups and / or groups that can be ionized into cationic groups.

[0034] Galactomannans are polysaccharides composed primarily of galactose and mannose units, in which the mannose units are linked by a 1,4-glycosidic bond and the galactose branching occurs by means of a 1,6-bridge to the mannose units. Each ring of galactose or mannose units (or sugar units) bears three free hydroxyl groups available for the chemical reaction. Galactomannans are generally found in the endosperm of legume seeds such as guar or carob.

[0035] The preferred cationic groups are chosen from those comprising primary, secondary, tertiary and / or quaternary amine groups.

[0036] The cationic galactomannan gums used generally have an average molecular mass by weight of between 500 and approximately 5x106, and preferably between approximately 103 and 3x106.

[0037] The cationic galactomannan gums usable according to the present invention are, for example, gums comprising trialkyl (Ci-C4)ammonium cationic groups. Preferably, 2% to 30% by number of the hydroxyl functions of these gums bear trialkylammonium cationic groups.

[0038] Among these trialkylammonium groups, trimethylammonium and triethylammonium groups can be mentioned in particular.

[0039] Even more preferably, these groups represent from 5% to 20% by weight of the total weight of the modified galactomannan gum.

[0040] According to the invention, the cationic galactomannan gum is preferably a guar gum comprising hydroxypropyl trialkylammonium groups, more preferably a guar gum comprising hydroxypropyl groups trimethylammonium, that is to say a guar gum modified for example by 2,3-epoxypropyl trimethylammonium chloride.

[0041] These galactomannan gums, in particular guar gums modified by cationic groups, are products already known in themselves and are described, for example, in US patents 3,589,578 and 4,031,307. Such products are also sold, in particular, under the trade names Jaguar EXCEL, Jaguar C13 S, Jaguar C 15, Jaguar C 17 and Jaguar C162 (Guar Hydroxypropyltrimonium Chloride) by Rhodia, under the name Amilan® Guar (Guar Hydroxypropyltrimonium Chloride) by Degussa, and under the name N-Hance® 3000 (Guar Hydroxypropyltrimonium Chloride) by Aqualon.

[0042] The cationic polymer according to the invention can alternatively be a cationic cellulosic polymer modified by groups comprising at least one linear fatty chain. For the purposes of the present invention, a "cationic cellulosic polymer" means any non-siliconized cellulosic polymer (not containing silicon atoms) containing cationic groups and / or groups ionizable into cationic groups, and preferably not containing anionic groups and / or groups ionizable into anionic groups.

[0043] By "cellulosic" polymer, according to the invention, any polysaccharide compound having in its structure at least 20 chains of glucose residues joined by [3-1,4] bonds. The cellulosic polymer may be associative, that is to say, have in its structure at least one C8-C30 fatty chain.

[0044] The cationic cellulosic polymers that may be used preferably have a weight average molar mass (Mw) between approximately 5000 and 5.106, preferably between approximately 103 and 3.106.

[0045] Among cationic celluloses, cellulose ethers comprising quaternary ammonium groups modified by groups comprising at least one linear fatty chain may be mentioned in particular.

[0046] Among quatemized celluloses, particular mention may be made of quatemized celluloses modified by groups comprising at least one linear fatty chain, such as linear alkyl, linear or branched arylalkyl, linear alkylaryl, preferably linear alkyl groups, these groups comprising at least 8 carbon atoms, in particular from 8 to 30 carbon atoms, better from 10 to 24, or even from 10 to 14, carbon atoms; or mixtures thereof.

[0047] Preferably, one can mention quaternized hydroxyethylcelluloses modified by groups comprising at least one linear fatty chain, such as linear alkyl, linear arylalkyl, linear alkylaryl groups, preferably linear alkyl, these groups comprising at least 8 carbon atoms, in particular 8 to 30 carbon atoms, better 10 to 24, or even 10 to 14, carbon atoms; or mixtures thereof.

[0048] Preferably, hydroxyethylcelluloses of formula (Ib) may be cited:

[0049] [Chem.2]

[0050] in which:

[0051] - R represents an ammonium group RaRbRcN-i--, Q- in which Ra, Rb, Rc, identical or different represent a hydrogen atom or a linear alkyl, in C1-C30, preferably an alkyl and Q- represents an anionic counterion such as a halide like a chloride or bromide;

[0052] - R' represents an ammonium group R'aR'bR'cN-i—, Q'- in which R'a, R'b, R'c, identical or different, represent a hydrogen atom or a linear alkyl, in C1-C30, and Q'- represents an anionic counterion such as a halide like a chloride or bromide; preferably an alkyl;

[0053] 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;

[0054] - n, x and y, identical or different, represent an integer between 1 and 10000.

[0055] Preferably, in formula (Ib), at least one of the radicals Ra, Rb, Rc, R'a, R'b, R'c represents a linear alkyl group in the C8-C30 range; better still in the C10-C24 range, or even in the C10-C14 range; the dodecyl radical (C12) is a particularly good example. Preferably, the other radical(s) represent a linear alkyl group in the C1-C4 range, especially a methyl group.

[0056] Preferably, in formula (Ib), only one of the radicals Ra, Rb, Rc, R'a, R'b, R'c represents a linear alkyl group in the C8-C30 range; better still, in the C10-C24 range, or even in the C10-C14 range; the dodecyl radical (Cl2) is a particularly good example. Preferably, all the other radicals represent a linear alkyl group in the C1-C4 range, especially a methyl group.

[0057] Even better, R can be a group chosen from -N+(CH3)3, Q' and -N+(Ci2H25) (CH3)2, Q', preferably a group -N+(CH3)3, Q'.

[0058] Even better, R' can be a group -N+(Ci2H25)(CH3)2, Q'.

[0059] The percentage of nitrogen can vary from 0.1 to 10% by weight relative to the total weight of polymer, preferably from 0.2 to 5% by weight and better from 0.5 to 3% by weight.

[0060] Examples include polymers with the following INCI names:

[0061] - Polyquatemium-24, such as the QUATRISOFT LM 200® product, marketed by the company AMERCHOL / DOW CHEMICAL;

[0062] - PG-Hydroxyethylcellulose Cocodimonium Chloride, such as the product CRODACEL QM®;

[0063] - PG-Hydroxyethylcellulose Lauryldimonium Chloride (C12 alkyl), such as CRODACEL QL® product and

[0064] - PG-Hydroxyethylcellulose Stearyldimonium Chloride (Cl8 alkyl) such as CRODACEL QS® product, marketed by the company CRODA.

[0065] Other examples include hydroxyethylcelluloses of formula (Ib) in which R represents trimethylammonium halide and R' represents dimethyldodecylammonium halide, preferably R representing trimethylammonium chloride C1-,(CH3)3N+- and R' representing dimethyldodecylammonium chloride C1-,(CH3)2(C12H25)N+-. This type of polymer is known by the INCI name Polyquaternium-67; commercial products include SOFTCAT POLYMER SL® polymers such as SL-100, SL-60, SL-30, SL-5 and SX-1300X from AMERCHOL / DOW CHEMICAL.

[0066] More particularly, the cationic cellulosic polymer is chosen from hydroxyethyl celluloses that have reacted with a trimethyl ammonium epoxide and a lauryl dimethyl ammonium epoxide (INCI name POLYQUATERNIUM-67).

[0067] It is preferably marketed under the name Softcat Polymer SL-100 or Softcat Polymer SX-1300X by Amerchol.

[0068] Preferably, the cationic polymer is selected from guar gums comprising trialkylammonium cationic groups and quaternized hydroxyethylcelluloses modified by groups having at least one linear fatty chain; preferably from guar gums modified by a salt of 2,3-epoxypropyl trimethylammonium and hydroxyethylcelluloses of formula (Ib) in which R represents trimethylammonium halide and R' represents dimethyldodecylammonium halide

[0069] [Chem.2] —$ LI— U—Ç- ~t~ (!&| * 4 A * ><: ] >y

[0070] and preferably among Guar Hydroxypropyl Tri-Methyl Ammonium chloride and hydroxyethyl celluloses having reacted with a trimethyl ammonium epoxide and a lauryl dimethyl ammonium epoxide (INCI name polyquaternium-67).

[0071] The total active matter content of the cationic polymer(s) present in the composition according to the invention is preferably from 0.05 to 5% by weight, preferably from 0.3 to 3% by weight, and more preferably from 0.4 to 2% by weight relative to the total weight of the composition. pH of the composition

[0072] The composition according to the invention has a pH of 5.0 to 7.0. Advantageously, the pH of the composition is between 5.5 and 6.5.

[0073] Such a pH effectively limits the degradation of the color of ascorbic acid, and thus limits the transformation of a colorless composition into one that turns yellow to brown over time. When the pH is below 5, the composition turns brown, and, rated on a color scale from 0 (white, very light) to 9 (black, very dark), it has a score above 8.

[0074] Preferably, the cosmetic composition according to the invention comprises at least one base.

[0075] The base is notably used to increase the final pH of the composition between 5.0 and 7.0, preferably between 5.5 and 6.5.

[0076] The base can be chosen from mineral bases such as, for example, alkali metal hydroxides, sodium hydroxide or potassium hydroxide.

[0077] Preferably, the base of the composition is an alkali metal hydroxide, preferably sodium hydroxide or potassium hydroxide, preferably sodium hydroxide. Indeed, these bases are more advantageous than nitrogenous bases, such as triethanolamine, with regard to color stabilization (i.e., less yellowing).

[0078] Preferably, the base of the composition according to the invention is present in a weight ratio base:ascorbic acid ranging from 0.22 to 0.30.

[0079] The composition may also include one or more additive(s) commonly used in cosmetic compositions such as active ingredients, sequestrants, glycols, preservatives or perfumes.

[0080] Preferably, among the usable active ingredients, adenosine, salicylic acid, glycolic acid, niacinamide (Vitamin B3), tocopherol or perfumes are preferred.

[0081] The composition according to the invention may include at least one sequestrant.

[0082] Among the preferred sequestrants, we can mention the salts of ethylenediaminedisuccinic acid.

[0083] Ethylenediaminedisuccinic acid is a compound of formula (II):

[0084] [Chem.3] CK ht 'r? HO. . y YN' ■•••••" OH s H O., ¼. n HO O (II)

[0085] Preferably, the salt of ethylenediaminedisuccinic acid is chosen from alkali metal salts, such as potassium and sodium salts, ammonium salts, and amine salts. Alkali metal salts of ethylenediaminedisuccinic acid are particularly preferred.

[0086] Preferably, the salt of ethylenediaminedisuccinic acid used according to the invention is trisodium ethylenediaminedisuccinate.

[0087] Such a compound is, for example, that marketed under the name Natrlquest® E30 by the company Innospec Active Chemicals, or that marketed under the name Octaquest E30® by the company Octel Performance Chemicals.

[0088] 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 ethylenediaminedisuccinic acid salt, relative to the total weight of the composition.

[0089] It is understood that the salt content of ethylenediaminedisuccinic acid corresponds to the content of active matter, also called dry matter, of salt of ethylenediaminedisuccinic acid introduced into the composition.

[0090] According to a particular embodiment, the salt of ethylenediaminedisuccinic acid can be introduced into the composition dissolved in water, in particular in a content ranging from 25% to 50% by weight, preferably from 35% to 40% by weight in water.

[0091] Such a compound is for example that marketed under the name Natrlquest® E30 by the company Innospec Active Chemicals, at 37% by weight in water.

[0092] The composition according to the invention may comprise at least one glycol, preferably caprylyl glycol.

[0093] Preferably, the composition according to the invention comprises from 0.1% to 2% by weight, preferably from 0.2% to 1.5% by weight of glycol(s) relative to the total weight of the composition.

[0094] The composition according to the invention may include at least one preservative.

[0095] Among the preferred preservatives, we can mention hydroxyacetophenone, phenoxyethanol and their mixtures.

[0096] Preferably, the composition according to the invention comprises 0.1% to 2% by weight, preferably 0.5% to 1.5% by weight, more preferably 0.7% to 1% by weight of preservative(s) relative to the total weight of the composition.

[0097] Preferably, the composition of the present invention is transparent.

[0098] For the purposes of this invention, a transparent composition is defined as a composition having a turbidity value of less than 200 NTU, preferably less than 150 NTU, and preferably less than 100 NTU. Preferably, the turbidity of the compositions is at least equal to 1 NTU.

[0099] NTUs (nephelometric turbidity units) are the units of measurement for the turbidity of a composition. Turbidity measurement is carried out, for example, with a Hach Company model 2100P turbidimeter, the tubes used for the measurement being referenced AR397A cat 24347-06. The measurements are carried out at room temperature (from 20°C to 25°C).

[0100] Preferably, the composition is transparent and has a turbidity value between 1 and 200 NTU, preferably between 1 and 150 NTU, preferably less than 100 NTU.

[0101] Finally, the invention also relates to a cosmetic process for the care of keratinous materials, preferably the skin, comprising the application to said keratinous materials of a composition according to the invention.

[0102] Concrete, but by no means limiting, examples illustrating the invention will now be given. EXAMPLES

[0103] In the examples, pressure is atmospheric pressure unless otherwise stated. Unless otherwise stated, percentages are expressed as a percentage of the total weight of composition (% w / w).

[0104] Example 1: Influence of cationic polymers on the color stabilization of an aqueous solution comprising 10% by weight of vitamin C Comparative examples

[0105] 1 / with polyquaternium-6 (MERQUAT 100 POLYMER from Nalco; poly chloride dimethyl diallyl ammonium in water at 40% unstabilized):

[0106] Aqueous solutions are prepared comprising 10% by weight of vitamin C, from 1% to 40% by weight of polyquatemium-6, and having a pH of 6, the pH having been adjusted by sodium hydroxide (NaOH).

[0107] A stability test of the solutions is carried out for 15 days, 1 month and 2 months at 45°C.

[0108] The results show that increasing the concentration of polyquaternium-6 has the opposite effect to what was expected; that is, there is a degradation of the color, which becomes increasingly darker. The higher the concentration of polyquaternium-6, the more visible the color degradation (darker).

[0109] 2 / with Cassia Hydroxypropyltrimonium Chloride (Ashland's ClearHance C):

[0110] Aqueous solutions are prepared comprising 10% by weight of vitamin C, 0.5% to 4% by weight of Cassia Hydroxypropyltrimonium Chloride, and having a pH of 6, the pH having been adjusted by sodium hydroxide (NaOH).

[0111] A stability test of the solutions is carried out for at least 1 month either at room temperature or at 45°C.

[0112] The results show that increasing the concentration of Cassia Hydroxypropyltrimonium Chloride goes against the expected effect, i.e. there is a degradation of the color which becomes increasingly darker.

[0113] 3 / with the polysaccharide N-acetyl-D-glucosamine (KIONUTRIME CSG of Kitozyme):

[0114] Aqueous solutions are prepared comprising 10% by weight of vitamin C, 0.25% to 4% by weight of N-acetyl-D-glucosamine polysaccharide, and having a pH of 6, the pH having been adjusted by sodium hydroxide (NaOH).

[0115] A stability test of the solutions is carried out for 1 month at 45°C.

[0116] The results show that increasing the concentration of the polysaccharide N-acetyl-D-glucosamine goes against the expected effect, i.e. there is a degradation of the color which becomes increasingly darker.

[0117] 4 / with cationic starch (starch hydroxypropyltrimonium chloride, PENCARE DP 1015® marketed by INGREDION):

[0118] Aqueous solutions are prepared comprising 10% by weight of vitamin C, 0.5% to 4% by weight (0.5%; 1%; 2%; 4%) of cationic starch, and having a pH of 6, the pH having been adjusted by sodium hydroxide (NaOH).

[0119] A stability test of the solutions is carried out for 2 months at 45°C.

[0120] The results show that there is a dose-response effect of starch concentration cationic on color stability compared to the polymer-free reference. However, the resulting formula is cloudy and does not solve the problem of the invention, which is to obtain a transparent serum. Examples according to the invention

[0121] 1 / with cationic galactomannan gum (Hydroxypropyl Tri- Guar Chloride Methyl Ammonium, hydroxypropyl guar hydroxypropyl trimonium chloride, Jaguar C 162 SGI from Rhodia):

[0122] Aqueous solutions are prepared comprising 10% by weight of vitamin C, 0.5% to 4% by weight (0.5%; 1%; 2%; 4%) of cationic guar, and having a pH of 6, the pH having been adjusted by sodium hydroxide (NaOH).

[0123] A stability test of the solutions is carried out for 2 months at 4°C, or 2 months at room temperature, or 2 months at 45°C.

[0124] The solutions obtained are all stable.

[0125] The solution comprising 2% cationic guar, after storage for 2 months at 45°C, shows an acceptable loss of vitamin C.

[0126] The results show that there is a dose-response effect of the concentration of cationic guar on color stability compared to the reference without cationic guar. The preferred concentration is between 0.5% and 4%.

[0127] 2 / with polyquaternium-67 (Amerchol's Softcat Polymer SL-100):

[0128] Aqueous solutions are prepared comprising 10% by weight of vitamin C, 0.5% to 4% by weight (0.5%; 1%; 2%; 4%) of polyquaternium-67, and having a pH of 6, the pH having been adjusted by sodium hydroxide (NaOH).

[0129] A stability test of the solutions is carried out for 2 months at 4°C, or 2 months at room temperature, or 2 months at 45°C.

[0130] The solutions obtained are all stable, showing an acceptable loss of vitamin C.

[0131] The results show that there is a dose-response effect of the polyquaternium-67 concentration on color stability compared to the polymer-free reference. The preferred concentration is between 0.5% and 4%. CONCLUSION

[0132] The condition of a pH of 6 is not sufficient to stabilize the color of an aqueous solution of vitamin C.

[0133] Not all cationic polymers are effective in this functionality.

[0134] The association of sodium hydroxide or potassium hydroxide with a cationic polymer such as cationic galactomannan gums or specific cationic celluloses (polyquaternium-67) makes it possible to stabilize the color of vitamin C solutions.

[0135] Only cationic galactomannan gums and specific cationic celluloses make it possible to combine color stabilization and the obtaining of a perfectly transparent serum. Example 2: Compositions according to the invention

[0136] Formulas A to D are prepared according to the invention below according to the following protocol:

[0137] 1- Disperse the cationic polymer (hydroxypropyl guar hydroxypropyl chloride) trimmonium or polyquaternium-67) in a little water until a translucent and homogeneous gelled water appearance is obtained (without grains)

[0138] 2- Add the ascorbic acid and water; the mixture then becomes perfectly transparent and colorless;

[0139] 3- Adjust the pH to 6 with NaOH. A perfectly gelled solution is obtained transparent.

[0140] [Tables 1] Ingredients (% w / w) Formula A Formula B Formula C Formula D Sodium Hydroxide (NaOH) Qs pH6 Qs pH6 Qs pH6 Qs pH6 Ascorbic Acid 10 10 10 10 Guar Chloride Hydroxypropyl Tri-Methyl Ammonium (Jaguar C 162 SGI from Rhodia) 1 2 Polyquaterium-67 (Softcat Polymer SL-100 from Amerchol) - - 0.5 1 Water Qsp 100 Qsp 100 Qsp 100 Qsp 100 Example 3: Compositions according to the invention

[0141] Formulas E and F are prepared according to the invention below according to the following protocol:

[0142] In a first beaker (phase A): 1. Introduce water (T>60°C) and add the ingredients of phase A# in the following order: glycerin, caprylyl glycol, preservative(s), trisodium ethylenediamine dissuccinate, hexylene glycol and adenosine at 60°C; 1. Once everything has dissolved and there are no more crystals, let it cool.

[0143] In a second beaker (phase B)#: 1. Introduce water at room temperature and add ascorbic acid; 1. Adjust the pH to 5.8 with sodium hydroxide; 1. Add Polyquaternium-67 with medium and long stirring to ensure efficient polymer deployment.

[0144]

[0145] Mix the two beakers and make the QS in water if necessary.

[0146] [Tables2] Ingredients (% w / w) Formula E Formula F Phase Hexylene glycol 5 5 A Sodium hydroxide (caustic soda) 3.33 3.33 B Ascorbic acid 15 15 B Glycerin 7 7 A Caprylyl glycol Qs Qs A Preservative(s) Qs Qs A Adenosine - 0.04 A Polyquatemium-67 (Softcat Polymer SL-100 from Amerchol) 0.5 0.5 B Trisodium ethylenediamine disuccinate (Natrlquest® E30 from Innospec Active Chemicals, at 37% wt. in water) 0.2 (*0.074 wt. in water) 0.2 (*0.074 wt. in water) A Water Qsp 100 Qsp 100 A

[0147] ma: active ingredient

[0148] The compositions according to the invention have the following properties:

[0149] - Maintaining transparency at 1 (scale of 1 to 3: 1 being transparent, 2 translucent, 3, opaque) over time and temperature (after 2 months at 4°C, room temperature and 45°C);

[0150] - No or slight acceptable gaseous release, i.e., CO2 release due to the degradation of ascorbic acid over time and temperature (after 2 months at 4°C, room temperature and 45°C);

[0151] - No crystals were observed macroscopically and microscopically during the time and temperature (after 2 months at 4°C, room temperature and 45°C); and

[0152] - Physico-chemical stability over time and temperature (after 2 months at 4°C, room temperature and 45°C).

Claims

Demands

1. Cosmetic composition comprising: - 50 to 90% by weight of water relative to the total weight of composition, - at least 5% by weight of ascorbic acid relative to the total weight of composition, - at least one cationic polymer selected from cationic galactomannan gums and cationic cellulosic polymers modified by groups comprising at least one linear fatty chain, said composition having a pH between 5 and 7.

2. Composition according to claim 1, characterized in that it comprises from 55% to 70%.

3. Composition according to claim 1 or 2, characterized in that it comprises at least one water-soluble organic solvent at 25°C, selected from alcohols, polyols and mixtures thereof; preferably selected from alcohols in the form of Ci-CiO, more preferably in Cr C5, such as ethanol, isopropanol, propanol and butanol, and polyols having from 2 to 20 carbon atoms, more preferably from 2 to 6 carbon atoms, such as glycerol, diglycerol, propylene glycol, isoprene glycol, dipropylene glycol, butylene glycol, hexylene glycol, 1,3-propanediol, pentylene glycol, polyethylene glycols having from 2 to 200 ethylene oxide units and mixtures thereof.

4. Composition according to any one of claims 1 to 3, characterized in that it comprises at least 7% by weight of ascorbic acid relative to the total weight of the composition, preferably the composition comprises from 5% to 30% by weight of ascorbic acid, relative to the total weight of the composition, more preferably from 7% to 20% by weight.

5. Composition according to any one of claims 1 to 4, characterized in that the cationic polymer is selected from guar gums comprising trialkylammonium cationic groups and quaternized hydroxyethylcelluloses modified by groups comprising at least one linear fatty chain; preferably from guar gums modified by a salt of 2,3-epoxypropyl trimethylammonium and hydroxyethylcelluloses of formula (Ib) in which R represents trimethylammonium halide and R' represents dimethyldodecylammonium halide [Chem.2] OH «. । ' R ~ * OH \ 1 H s Q—(ŒÆH.O1H-C.....0—Ç-fH HH) ' Æ A 1 h. HH and preferably among Guar Chloride Hydroxypropyl Tri-Methyl Ammonium and hydroxyethyl celluloses having reacted with a trimethyl ammonium epoxide and a lauryl dimethyl ammonium epoxide (INCI name polyquatemium-67).

6. Composition according to any one of claims 1 to 5, characterized in that it comprises from 0.05% to 5% by weight of cationic polymer active material, relative 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.

7. Composition according to any one of claims 1 to 6, characterized in that the pH of the composition is between 5.5 and 6.

5.

8. Composition according to any one of claims 1 to 7, characterized in that it comprises at least one base, preferably the base of the composition is an alkali metal hydroxide, preferably sodium hydroxide or potassium hydroxide, and more preferably sodium hydroxide.

9. Composition according to any one of claims 1 to 8, characterized in that it comprises at least one additive selected from actives, sequestrants, glycols, preservatives and perfumes, preferably it comprises at least one sequestrant selected from salts of ethylenediaminedisuccinic acid and / or at least one glycol which is preferably caprylyl glycol and / or at least one preservative, preferably selected from hydroxyacetophenone, phenoxyethanol and mixtures thereof.

10. 18 Composition according to any one of claims 1 to 9, characterized in that it is transparent.

11. A cosmetic process for the care of keratinous materials, preferably the skin, comprising the application to said keratinous materials of a composition according to any one of claims 1 to 10.