Compositions containing chitosan

Abstract

The present invention relates to a composition comprising, in a physiologically acceptable aqueous medium: (a) natural chitosan having a molecular weight strictly greater than 3000 daltons and present in an amount of at least 0.01% by weight, based on the total weight of the composition, said amount being strictly less than 15% by weight; (b) at least one alpha hydroxy acid; (c) 3 to 50% by weight of at least one pigment coloring material, based on the total weight of the composition; and (d) at least one polyol; Including, The cosmetic composition relates to a composition in which the weight ratio between polyol and chitosan is between 0.1 and 6.

Description

[Technical Field]

[0001] The present invention relates to a composition comprising, in a physiologically acceptable aqueous medium: (a) natural chitosan having a molecular weight strictly greater than 3000 daltons and present in an amount of at least 0.01% by weight, based on the total weight of the composition, said amount being strictly less than 15% by weight; (b) at least one alpha hydroxy acid; (c) 3 to 50% by weight of at least one pigment coloring material, based on the total weight of the composition; and (d) at least one polyol; Including, The cosmetic composition relates to a composition in which the weight ratio between polyol and chitosan is between 0.1 and 6.

[0002] The present invention also relates to a method for making up and / or treating the skin and / or keratinous appendages, wherein a composition according to the invention is applied to the skin and / or keratinous appendages. [Background technology]

[0003] Many cosmetic compositions require that the film deposited on the keratinous material should be well-lasting after application. For example, lipstick or nail polish may be mentioned. To achieve such a result, it is possible to combine certain raw materials, in particular film-forming agents. However, the presence of such agents that make the film well-lasting on the keratinous material may cause the composition to dry out.

[0004] Furthermore, it is often desirable to have a composition that coats well.

[0005] For this reason, formulators are seeking raw materials and / or systems that allow them to obtain fluid compositions (i.e., ones that flow) whose deposits provide good coverage, are homogeneous and strong (i.e., last well).

[0006] Furthermore, there is a need for compositions that have improved cosmetic properties, particularly wear and coverage, yet remain comfortable during application.

[0007] Furthermore, formulating cosmetic compositions containing a high proportion of natural or naturally occurring raw materials is one of the new challenges to meet consumer expectations, and it is therefore desirable that the proposed compositions make it possible to maintain a high proportion of natural or naturally occurring raw materials. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] WO03068824 [Patent Document 2] French Patent No. 2679771 [Patent Document 3] EP1184426 [Non-patent literature]

[0009] [Non-Patent Document 1] Van de Hulst, H.C., Light Scattering by Small Particles, Chapters 9 and 10, Wiley, New York, 1957 Summary of the Invention [Problem to be solved by the invention]

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a solution to the above-mentioned problems.

[0011] The object of the present invention is to propose an aqueous cosmetic composition having improved cosmetic properties, in particular covering power and uniformity, and good long-lasting properties.

[0012] After application, these compositions leave a homogeneous film-forming deposit that coats well and has good resistance to abrasion. The films formed are adhesive and cohesive, and coat and last well. Specifically, they have improved resistance to abrasion. [Means for solving the problem]

[0013] The present invention relates to a cosmetic composition, in particular for the makeup and / or treatment of the skin and / or lips, which comprises, in a physiologically acceptable aqueous medium: (a) natural chitosan having a molecular weight strictly greater than 3000 daltons and present in an amount of at least 0.01% by weight, based on the total weight of the composition, said amount being strictly less than 15% by weight; (b) at least one alpha hydroxy acid; (c) 3 to 50% by weight of at least one pigment coloring material, based on the total weight of the composition; (d) at least one polyol Including, The cosmetic composition relates to a composition in which the weight ratio between polyol and chitosan is between 0.1 and 6. DETAILED DESCRIPTION OF THE INVENTION

[0014] "Physiologically acceptable" refers to a medium that is compatible with keratin materials.

[0015] Another object of the present invention is a method for making up and / or caring for the skin and / or keratinous appendages, in which a composition according to the invention is applied to the skin and / or keratinous appendages.

[0016] Preferably, the composition according to the present invention is substantially free of (meth)acrylic polymers. Preferably, the composition according to the present invention is substantially free of silicones.

[0017] By "substantially free of (meth)acrylic polymer" is meant that the composition comprises less than 1% by weight, preferably less than 0.5% by weight, preferably less than 0.3% by weight, preferably 0.1% by weight of (meth)acrylic polymer, based on the total weight of the composition. Preferably, the composition is completely free of (meth)acrylic polymer. By (meth)acrylic polymer is meant a polymer comprising at least one acrylic acid monomer or at least one methacrylic acid monomer.

[0018] "Substantially free of silicone" means that the composition contains less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.3% by weight, preferably 0.1% by weight of silicone based on the total weight of the composition.Preferably, the composition does not contain any silicone.Silicone refers to any silicone compound.

[0019] Chitosan The composition according to the invention comprises at least 0.01% relative to the total mass of the composition of at least one natural chitosan having a molecular weight strictly greater than 3000 Daltons (3 kDa, 1 Da=1 g / mol).

[0020] The amount of natural chitosan is also strictly less than 15% by weight relative to the total weight of the composition.

[0021] Preferably, the natural chitosan has a molecular weight of 10 kDa or more, preferably 15 kDa or more, preferably 20 kDa or more. Preferably, the natural chitosan has a molecular weight between 10 kDa and 2 MDa, preferably between 15 kDa and 1.5 MDa, preferably between 20 kDa and 300 kDa, preferably between 20 kDa and 150 kDa.

[0022] Chitosan (or chitosane) is very widespread in nature: it has only been reported in the exoskeletons of certain insects, such as termite queens, and in the cell walls of a specific class of fungi, Zygomycetes.

[0023] Chitosan is obtained by deacetylation of chitin, a polysaccharide composed of several N-acetyl-D-glucosamine units linked together by β-type bonds (1,4).

[0024] The ideal chemical structure of chitosan is a chain of β-D-glucosamine monomers linked by glycosidic bonds (1→4).

[0025] "Chitosan" according to the present invention refers to any copolymer formed by N-acetyl-D-glucosamine and D-glucosamine building blocks, the degree of acetylation of which is less than 90%. Chitosan consists of glucosamine sugar units (deacetylated units) and N-acetyl-D-glucosamine units (acetylated units) linked together by β-type (1,4) bonds, forming a polymer of the poly(N-acetyl-D-glucosamine)-poly(D-glucosamine) type.

[0026] Preferably, the degree of acetylation of the chitosan is 50% or less, preferably 35% or less, preferably 25% or less, preferably 15% or less.

[0027] The degree of acetylation is the percentage of acetylated units relative to the total number of units and can be determined by Fourier transform infrared (FTIR) spectroscopy or strong base titration.

[0028] The chitosan of the present invention is preferably a polysaccharide prepared from a fungal source, in particular, chitosan extracted and purified from safe and abundant edible or biotechnological fungal sources, such as mushroom (Agaricus bisporus) or Aspergillus niger.

[0029] The chitosan of the present invention is preferably derived from the mycelium of a fungus of the ascomycete type, in particular Aspergillus niger and / or a fungus of the Basidiomycete type, in particular Lentinula edodes and / or a mushroom. Preferably, the fungus is Aspergillus niger.

[0030] The chitosan may be of GMO origin, but is preferably of non-GMO origin.

[0031] The chitosan according to the invention is natural, i.e. unmodified, in particular it does not contain any chemical modification.

[0032] One method for preparing chitosan is that described in application WO03068824.

[0033] The chitosan used in the present invention is preferably in the form of a powder, in particular that sold under the name Kiosmetine or Kionutrime by the company Kitozyme.

[0034] Chitosan is preferably present in an amount ranging from 0.01% to 14% by weight, preferably from 0.1% to 14% by weight, preferably from 0.1% to 12% by weight, preferably from 0.2% to 7% by weight, preferably from 0.25% to 5% by weight relative to the total weight of the composition.

[0035] Alpha Hydroxy Acids (AHAs) Compositions according to the present invention also include (b) at least one alpha hydroxy acid (AHA).

[0036] By alpha hydroxy acid is meant, according to the invention, a carboxylic acid having at least one hydroxy functional group occupying the alpha position of said acid (the carbon adjacent to the carboxylic acid functional group), which may be present in the final composition in the form of the free acid and / or in the form of one of its associated salts (in particular with an organic base or alkali), in particular according to the final pH to be imposed on the composition.

[0037] The α-hydroxy acid (alpha hydroxy acid or AHA) may be selected from, for example, lactic acid, citric acid, methyllactic acid, glucuronic acid, glycolic acid, pyruvic acid, 2-hydroxybutanoic acid, 2-hydroxypentanoic acid, 2-hydroxyhexanoic acid, 2-hydroxyheptanoic acid, 2-hydroxyoctanoic acid, 2-hydroxynonanoic acid, 2-hydroxydecanoic acid, 2-hydroxyundecanoic acid, 2-hydroxydodecanoic acid, 2-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 2-hydroxyoctadecanoic acid, 2-hydroxytetracosanoic acid, 2-hydroxyeicosanoic acid; mandelic acid; phenyllactic acid; gluconic acid; galacturonic acid; aleuritic acid; ribonic acid; tartronic acid; tartaric acid; malic acid; fumaric acid; salts and mixtures thereof.

[0038] According to a preferred embodiment, the alpha hydroxy acid (b) is selected from lactic acid, gluconic acid, citric acid, malic acid, tartaric acid, and salts thereof. More specifically, the alpha hydroxy acid is selected from lactic acid, citric acid, and salts and mixtures thereof.

[0039] The alpha hydroxy acid(s) (b) may be present in an amount ranging, for example, from 0.001% to 10%, from 0.005% to 5%, preferably from 0.01% to 2.5% by weight relative to the total weight of the composition.

[0040] pigment colorant The composition according to the invention comprises from 3% to 50% by weight of at least one pigment dye (c), relative to the total weight of the composition, said dye being therefore chosen from powder dyes, such as inorganic pigments, pearlescent agents and organic pigments.

[0041] The term "pigments" should be understood to mean white or colored, inorganic or organic particles that are insoluble in aqueous solutions and that are intended to color and / or consequently deposit the composition.

[0042] A pigment colorant is a compound that has a color index (CI).

[0043] The term "pigments" should be understood to mean white or colored, inorganic or organic particles that are insoluble in aqueous media and that are intended to color and / or consequently adhere to the composition.

[0044] Preferably, the pigment dyes of the present invention have a refractive index of at least 1.9 at 25°C.

[0045] The refractive index of the pigment dyes of the invention is preferably comprised between 1.9 and 4. In particular, the pigment dyes are different from the fillers; preferably, the pigment dyes are different from the talc.

[0046] The dye may be present in the composition in a content ranging from 3% to 45% by weight, preferably from 4% to 30% by weight, preferably from 5% to 20% by weight, preferably from 6% to 15% by weight, relative to the weight of the composition.

[0047] inorganic pigments According to one particular embodiment, the pigment (c) used according to the invention is chosen from inorganic pigments.

[0048] By "inorganic pigment" is meant any pigment that meets the definition in the chapter on inorganic pigments in Ullmann's Encyclopedia. Among the inorganic pigments useful in the present invention, mention may be made of zirconium oxide or cerium oxide, as well as zinc oxide, iron oxide (black, yellow, or red) or chromium oxide, manganese violet, ultramarine blue, chromium hydrate, and iron blue, titanium dioxide, and metal powders such as aluminum powder and copper powder. The following inorganic pigments may also be used: TiO2, ZrO2, Nb2O5, CeO2, Ta2O5 in a mixture with ZnS, Ti3O5, Ti2O3, TiO, ZrO2.

[0049] The size of pigments useful in the context of the present invention is generally greater than 100 nm and can range up to 10 μm, preferably 200 nm to 5 μm, and more preferentially 300 nm to 1 μm. According to a specific embodiment of the present invention, the pigments have a size characterized by a D50 greater than 100 nm and can range up to 10 μm, preferably 200 nm to 5 μm, and more preferably 300 nm to 1 μm. This size is measured by static light scattering using a commercially available Malvern Master Sizer 3000® particle size analyzer, which allows for the determination of the full granulometric distribution of particles over a wide range that can extend from 0.01 μm to 1000 μm. The data are processed based on classical Mie scattering theory, which is best suited to particle size distributions in the submicron to several micron range and allows for the determination of the "effective" diameter of the particles. This theory is described in particular in Van de Hulst, HC, in the book "Light Scattering by Small Particles", Chapters 9 and 10, Wiley, New York, 1957. D50 represents the largest size possessed by 50% of the particles by volume.

[0050] In the context of the present invention, inorganic pigments are more particularly iron oxide and / or titanium dioxide.

[0051] Inorganic pigments that may be used in the present invention may also include pearlescent agents.

[0052] The term "pearlescent agent" should be understood to mean iridescent or non-iridescent colored particles of any shape, which are produced in particular by certain mollusks in their shells or synthesized, and which produce a color effect by optical interference.

[0053] The pearlescent agent can be selected from pearlescent pigments such as titanium dioxide-coated mica, titanium dioxide-coated mica, titanium dioxide-coated mica, titanium dioxide-coated mica, and titanium dioxide-coated mica with organic dyes, as well as bismuth oxychloride-based pearlescent pigments. The pearlescent agent can also include mica particles having at least two successive layers of metal oxides and / or organic dyes laminated on their surfaces. Examples of pearlescent agents include natural mica coated with titanium dioxide, iron oxide, natural pigments, or bismuth oxychloride. More specifically, the pearlescent agent can have a yellow, pink, red, bronze, orange, brown, and / or copper color or luster.

[0054] Among the pigments that can be used according to the invention, mention may also be made of those which have simple conventional hue effects, i.e. uniform and stable effects of the kind produced by conventional dyes, e.g. optical effects which differ from those of monochrome pigments.

[0055] For the purposes of the present invention, "stable" means that there is no effect of color variation depending on the viewing angle or in response to temperature changes. For example, the material can be selected from particles with a metallic luster, goniochromatic colorants, diffractive pigments, thermochromatic agents, optical brighteners, and also fibers, especially those of the interference type. Naturally, these various materials can be combined to produce the simultaneous appearance of two effects, or even the novel effect according to the invention.

[0056] According to one particular embodiment, the composition according to the invention comprises at least one uncoated pigment.

[0057] organic pigments According to another embodiment of the present invention, the pigment colorant (c) is an organic, synthetic or natural pigment, or of natural origin.

[0058] "Organic pigment" means any pigment that meets the definition in the chapter on organic pigments of Ullmann's Encyclopedia. The organic pigment may be chosen in particular from nitroso, nitro, azo, xanthene, quinoline, anthraquinone and phthalocyanine compounds, compounds of the metal complex type, isoindolinone, isoindoline, quinacridone, perinone, perylene, diketopyrrolopyrrole, thioindigo, dioxazine, triphenylmethane and quinophthalone compounds.

[0059] The organic pigment(s) (c) may be, for example, carmine, carbon black, aniline black, melanin, azo yellow, quinacridone, phthalocyanine blue, sorghum red, blue pigments codified in the Color Index with the reference numbers CI 42090, 69800, 69825, 73000, 74100, 74160, yellow pigments codified in the Color Index with the reference numbers CI 11680, 11710, 15985, 19140, 20040, 21100, 21108, 47000, 47005, green pigments codified in the Color Index with the reference numbers CI 61565, 61570, 74260, The pigments may be selected from the orange pigments organized in the Colour Index under the reference numbers CI 11725, 15510, 45370, 71105, the red pigments organized in the Colour Index under the reference numbers CI 12085, 12120, 12370, 12420, 12490, 14700, 15525, 15580, 15620, 15630, 15800, 15850, 15865, 15880, 17200, 26100, 45380, 45410, 58000, 73360, 73915, 75470, and the pigments obtained by oxidative polymerization of indole or phenol derivatives as described in French Patent No. 2 679 771.

[0060] The pigments may also be in the form of composite pigments, such as those described in EP 1 184 426. These composite pigments may in particular consist of particles comprising an inorganic core at least partially coated with an organic pigment and at least one binder for fixing the organic pigment to the core.

[0061] The pigment may also be a lacquer.

[0062] The term "lacquer" refers to an insolubilized pigment that is adsorbed onto an insoluble particle, the aggregate thus obtained remaining insoluble during use.

[0063] Inorganic substrates for adsorbing dyes include, for example, alumina, silica, calcium sodium borosilicate or calcium aluminum borosilicate, and aluminum.

[0064] Among the organic dyes, mention may be made of cochineal carmine. Mention may also be made of products known by the following names: D&C Red 21 (CI 45 380), D&C Orange 5 (CI 45 370), D&C Red 27 (CI 45 410), D&C Orange 10 (CI 45 425), D&C Red 3 (CI 45 430), D&C Red 4 (CI 15). 510), D&C Red 33(CI 17 200), D&C Yellow 5(CI 19 140), D&C Yellow 6(CI 15 985), D&C Green(CI 61 570), D&C Yellow 1 O(CI 77 002), D&C Green 3(CI 42 053), D&C Blue 1(CI 42 090). An example of a lacquer is the product known as D&C Red 7 (CI 15 850:1).

[0065] polyol The composition according to the present invention also includes (d) at least one polyol.

[0066] The term "polyol" as used herein refers to an alcohol having two or more hydroxy groups and does not include sugars or their derivatives. Sugar derivatives include sugar alcohols obtained by reducing one or more carbonyl groups of a sugar, and sugars or sugar alcohols in which one or more hydrogen atoms in one or more hydroxy groups have been replaced with at least one substituent, such as an alkyl group, a hydroxyalkyl group, an alkoxy group, an acyl group, or a carbonyl group.

[0067] The polyol (d) is a C hydroxyl group containing at least two hydroxyl groups, preferably 2 to 5 hydroxyl groups. 2~24 Polyol, preferably C 2~9 It may also be a polyol.

[0068] The polyol (d) may be a natural or synthetic polyol. The polyol may have a linear, branched or cyclic molecular structure.

[0069] The polyol (d) can be selected from glycerin and its derivatives, and glycol and its derivatives. The polyol can be selected from the group consisting of glycerin, diglycerin, polyglycerin, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, pentylene glycol, hexylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and polyethylene glycols, particularly those having 5 to 50 ethylene oxide groups, and mixtures thereof, more specifically glycerin, propylene glycol, dipropylene glycol, butylene glycol, hexylene glycol, and mixtures thereof.

[0070] The polyol (d) is preferably glycerin.

[0071] The polyol (d) may be present in the composition according to the invention in a content ranging from 0.01% to 50% by weight, preferably from 0.05% to 30% by weight, preferably from 0.08% to 20% by weight, preferably from 0.1% to 15% by weight, preferably from 0.1% to 12% by weight, preferably from 0.1% to 10% by weight, preferably from 0.2% to 8% by weight, preferably from 0.2% to 5% by weight, preferably from 0.2% to 3% by weight and preferentially from 0.2% to 2% by weight, relative to the total weight of the composition.

[0072] Preferentially, when the proportion of chitosan in the composition is equal to or greater than 2% by weight relative to the total weight of the composition, polyol (d) is present in a proportion ranging from 0.5% to 15% by weight, preferably from 1% to 12% by weight, preferably from 3% to 10%.

[0073] According to the invention, the weight ratio between polyol and chitosan (i.e. the weight ratio of polyol to chitosan) is between 0.1 and 6. Preferably, the weight ratio is between 0.1 and 5, preferably between 0.2 and 5, preferably between 0.2 and 4.5, preferably between 0.5 and 2.

[0074] a physiologically acceptable aqueous medium The composition according to the present invention comprises a physiologically acceptable aqueous medium, said medium comprising water.

[0075] 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 spring or natural mineral water.

[0076] The composition preferably comprises at least 5% by weight, preferably at least 10% by weight, preferably at least 20% by weight, preferably at least 30% by weight, preferably at least 40% by weight of water relative to the total weight of the composition.

[0077] The composition preferably comprises from 5% to 95% by weight of water relative to the total weight of the composition, more preferentially from 10% to 85%, even more preferentially from 20% to 80%, even more preferentially from 25% to 70%, even more preferentially from 28% to 60%, even more preferentially from 30% to 50%.

[0078] The aqueous phase may also include at least one non-ionic surfactant.

[0079] Preferably, in this case, the non-ionic surfactant can be chosen from the non-ionic surfactants known from the prior art, in particular from esters of fatty acids and polyglycerols, sugar esters, poloxamers, polysorbates and mixtures thereof.

[0080] The non-ionic surfactants are preferably chosen from esters of fatty acids and polyglycerols, and sugar esters.

[0081] pH of the composition The composition according to the invention has a pH of less than or equal to 7, preferably less than or equal to 6.5, preferably less than or equal to 6.3. Advantageously, the pH of the composition is between 3 and 6.3, preferably between 4 and 6.3.

[0082] Preferably, the cosmetic composition according to the present invention comprises at least one base.

[0083] The base is particularly used to adjust the final pH of the composition to between 3 and 6.3.

[0084] The base may be selected from inorganic bases such as alkali metal hydroxides, sodium hydroxide, potassium hydroxide, and the like.

[0085] Preferably, the base of the composition is an alkali metal hydroxide, preferably sodium hydroxide or potassium hydroxide, because these bases provide color stabilization advantages (i.e., less yellowing) than nitrogen-containing bases such as triethanolamine.

[0086] The compositions according to the invention may comprise at least one base in an active substance content ranging from 0.5% to 10% by weight, in particular from 1% to 5% by weight, preferably from 1% to 4% by weight, relative to the total weight of the composition.

[0087] The compositions according to the invention can be obtained conventionally by those skilled in the art.

[0088] The following examples make it possible to better understand the invention, but are not limiting. Raw materials are referred to by their chemical or INCI names. The amounts given are in weight percent (w / w%) of the raw material relative to the total weight of the composition, unless otherwise specified. [Example]

[0089] Preparation of compositions according to the invention and comparative compositions In the following examples, each formulation was prepared according to the procedure described below: At room temperature T° under mechanical agitation with minimal vortex: - Disperse the chitosan and water under mechanical agitation with minimal vortexing; - Adding an appropriate amount of acid to solubilize the chitosan and form a more viscous solution; - adding the pigment, then the polyol, then the surfactant (if present); - If necessary, the mixture may then be passed through a triple roll mill.

[0090] Chitosan is considered to be solubilized when the solution loses transparency. For this purpose, the transmittance of the composition is measured by Turbiscan LAB and Turbisoft LAB software.

[0091] Example 1 Evaluation of the effects of various ingredients Formulations F1 to F11 are prepared according to the procedure above.

[0092] Procedure for testing the film-forming and release aspects of formulations after deposition 10 g of the solution is deposited on an aluminum capsule with a diameter of 9.5 cm and spread evenly over the entire surface. The deposit is allowed to dry on a hot plate at 32°C for 24 hours. The sample is then evaluated for feel at first touch. If the sample remains liquid and sticks to the finger, it is considered to be incapable of forming a film. If the sample is able to form a film, a second evaluation consists of peeling the sample from the aluminum capsule with a spatula. If the experimenter is able to peel it off, the deposit can be said to be releasable.

[0093] The results are shown in table 1.

[0094] The appearance of the preparation is considered to meet the specification if it is fluid and flowable. The appearance is considered to be out of specification if the formulation is solid or in the shape of a gum or is not flowable.

[0095] Sensory characteristics are defined by spreading the product with a finger on a 2.54 cm square on the skin of the arm. If the spread is not fluid and produces a distinctly bumpy texture or brittle solid-type irregular sensation, the sensory characteristics are considered to be out of specification. If the spread is fluid, the sensory characteristics are considered to be within specification.

[0096] In the table, OK = meets specifications, NO = out of specifications, F5 and F6 = intermediate.

[0097] Homogeneity is described with respect to the visual aspects of the film as described above. A film is said to be non-homogeneous if its thickness contains visible non-homogeneities. A film is said to be homogeneous if it has a visually constant thickness.

[0098] [Table 1]

[0099] Formulations F1 and F2: The minimum dose for chitosan to form a film detectable by this test is 0.1%. An amount of 0.5% makes it possible to obtain a peelable film.

[0100] Formulation F4: Chitosan must in all cases be present in an amount strictly less than 15% by weight, since then the formulation would not be applicable and the appearance (bulk) of the composition would not be fluid.

[0101] Formulations F8-F10: The mass ratio between polyol and chitosan is ideally equal to or less than 6 (F9), since above this the deposit is not homogeneous (F10 and F11), and preferentially 4, which results in a very homogeneous film (F8). The non-homogeneity is due to the inability to work / mix / apply the formed material.

[0102] Example 2 Procedures for evaluating modifications to membrane mechanical properties to improve comfort Formulations C1-C6, A1 and A2 are prepared.

[0103] 10 g of the solution is applied to an aluminum capsule with a diameter of 9.5 cm, and the applied solution is spread evenly over the entire surface. The applied solution is dried on a hot plate at 32°C for 24 hours. - Using a punching die, cut three test pieces measuring 20 mm long and 6 mm wide. - The thickness of the test specimen is measured by a Palmer micrometer. - Place the specimen in the jaws of a Stable Micro Systems TA.XT Plus texturometer and start the measurement using the Exponent software to obtain the strength (g) and length at break (mm). TA setting: Speed ​​0.1 or 0.3 mm / sec → Deformation % = Elongation / Original size * 100 = (elongation at break - original size) / original size * 100 → Stress = Strength (N) / Surface (m) = Strength (g) * g / Width * Thickness

[0104] [Table 2]

[0105] These results make it possible to determine the minimum dosage of glycol relative to chitosan with regard to the technical issue of comfort: the softer the film, and therefore the longer the elongation at break, the better the comfort during application.

[0106] Without glycerin, the chitosan film remains hard and uncomfortable on the skin (C1).

[0107] The change in the stiffness of the membrane was evaluated using the above measurements and, with a mass ratio of polyol to chitosan equal to 1:10 (C3), a softening effect was discernible, which is essential for comfort.

[0108] Formulation A1 is for comparison (indicated by an asterisk) and formulation A2 is according to the invention.

[0109] [Table 3]

[0110] Example A2 shows the effect of polyol on film flexibility in the presence of pigment.

[0111] Formulations B, C and E according to the invention are prepared.

[0112] The mechanical properties are measured as indicated above.

[0113] [Table 4]

[0114] [Table 5]

[0115] Examples B, C, and E demonstrate the effect of polyols on film flexibility in the presence of pigments. Additionally, Example K demonstrates that citric acid (AHA) can be used in place of lactic acid.

[0116] Example 3 Procedure for assessing dry rub resistance Some compositions are evaluated for their resistance to abrasion by colorimetric measurements on dried films before and after rubbing, the test procedure being detailed below.

[0117] 3.1 Procedure for spreading the composition onto the film The product is spread on an applicator table (Elcometer 4340 Applicator) with adjustable spreading speed and distance. The table is equipped with a suction system connected to a pump to prevent movement of the substrate on which the coating is applied. A contrast chart with a matte black background and a white background is used (1 Byco Chart, Uncoated N2A, Code 2831). Spreading thickness can be adjusted by placing a square spreader on the substrate and flattening it as the platform begins to rise. Each end of the spreader allows for different spreading thicknesses, ranging from 25 μm to 200 μm. A thickness of 50 μm is chosen to approximate the in vivo film thickness. A 960 g weight is applied to the top of the spreader during spreading. The spreading speed is adjusted to 1 inch / second, or 2.54 cm / second. The film is allowed to dry for 24 hours at room temperature and humidity (50% RH).

[0118] [Table 6]

[0119] The results are shown in Table 3. Some compositions cannot be spread to perform the subsequent contrast ratio (CR) test and are said to be repellent. This repellency causes non-uniformity in the deposit. Therefore, due to their repellency, these formulations do not meet the criteria for solving the technical problems of uniformity and coverage.

[0120] On the other hand, the composition according to the present invention has good wetting properties.

[0121] 3.2 Contrast ratio measurement procedure for objectifying coverage Color is measured with a Konica Minolta CM-700d spectrophotometer. Contact measurements ensure the elimination of light pollution.

[0122] Selected settings: aperture 8 mm, uncertainty 0.04, SCI / SCE measurement, geometric condition d / 8°.

[0123] The measurement of the color on two backgrounds (black background BB and white background WB) makes it possible to characterize the coverage of the cosmetic foundation by calculating the contrast ratio (CR%), i.e. YBB / YWB x 100, where YBB and YWB are the luminance values ​​measured on a black background and a white background, respectively, and the higher this is, the better the coverage of the cosmetic foundation.

[0124] - Amount of pigment Formulation F12 is in accordance with the invention, while formulations F13 to F16 are comparative.

[0125] [Table 7]

[0126] To achieve a fixed minimum coverage of 50%, one needs to have a minimum of 3% pigment.

[0127] - Properties of chitosan Formulations F19-F20 are in accordance with the invention, while formulations F17-F18 are comparative.

[0128] [Table 8]

[0129] In terms of coverage in the deposit, only formulations F19-F20 are significantly different from F17 (reference without chitosan).

[0130] 3.3 Procedure for testing resistance to friction The rub resistance test is performed by colorimetric measurement on the dry film before and after rubbing. The rub is performed by attaching a piece of fabric handkerchief (Chicopee® Veraclean™ Polish Plus) to the end 25 μm of the spreader. A 960 g weight is added to the top of the spreader during the rub. The bench speed is set at 2.54 cm / sec.

[0131] Pre- and post-rubbing color measurements are taken using the same spectrophotometric method as described above.

[0132] To assess resistance to abrasion, the contrast ratio is measured before (CR dry adhesion, %) and after rubbing (CR rub adhesion dry, %). The percentage loss [(CR rub adhesion dry - CR adhesion dry] / CR adhesion dry] * 100 quantifies the loss of coverage and indicates the resistance of the film to abrasion: the lower this loss, the more resistant the film is to abrasion.

[0133] Therefore, each CR value represents the average of six measurements.

[0134] - Select the type of chitosan

[0135] [Table 9]

[0136] Formulations F19-F20 are the only ones that do not lose coverage.

[0137] - Amount of chitosan Formulation F27 is in accordance with the invention, while formulations F22-F26 are comparative.

[0138] [Table 10]

[0139] Comparative formulations F17 and F22 show that the presence of glycerin has no effect on coverage.

[0140] A comparison of formulations F23-F26 (comparative) and F27 (invention) shows that chitosan influences coverage.

[0141] 3.4 Oily friction resistance test The test consisted of spreading 15 μL of the formulation onto a 4 cm diameter disk on the forearm and allowing the deposit to dry for 20 minutes. In parallel, 100 μL of oil (caprylic / capric triglyceride 5022) was applied to a piece of fabric handkerchief (Chicopee® Veraclean™ Polish Plus). The handkerchief was then rubbed using an axial force of 200-300 grams and the staining on the handkerchief was evaluated.

[0142] [Table 11]

[0143] A positive limit with a rating of 5 / 5 corresponds to a spotless fabric, whereas if the fabric is completely stained the rating is 1 / 5.

[0144] Under these conditions, the composition according to the invention performs to a rating of 3 / 5.

[0145] Chitosan is found to improve the resistance of the deposit to oily rubs.

Claims

1. In a physiologically acceptable aqueous medium, (a) natural chitosan having a molecular weight strictly greater than 3000 daltons and representing at least 0.01% by weight, based on the total weight of the composition, said amount being strictly less than 15% by weight; (b) at least one alpha hydroxy acid; (c) from 3 to 50% by weight of at least one pigment coloring material relative to the total weight of the composition; (d) at least one polyol Including, A cosmetic composition in which the weight ratio between polyol and chitosan is between 0.1 and 6.

2. 2. The composition according to claim 1, characterized in that it contains from 0.01% to 14% by weight, preferably from 0.1% to 14% by weight, preferably from 0.1% to 12% by weight, preferably from 0.2% to 7% by weight, preferably from 0.25% to 5% by weight of natural chitosan relative to the total weight of the composition.

3. 3. Composition according to claim 1 or 2, characterized in that the natural chitosan (a) has a molecular weight of 10 kDa or more, preferably 15 kDa or more, preferably 20 kDa or more, preferably between 10 kDa and 2 MDa, preferably between 15 kDa and 1.5 MDa, preferably between 20 kDa and 300 kDa, preferably between 20 kDa and 150 kDa, and / or the degree of acetylation of the chitosan is 50% or less, preferably 35% or less, preferably 25% or less, preferably 15% or less.

4. 4. Composition according to any one of claims 1 to 3, characterized in that the chitosan (a) is extracted and purified from an edible or biotechnological fungal source, such as mushroom or Aspergillus niger, preferably Aspergillus niger.

5. 5. Composition according to any one of claims 1 to 4, characterized in that the alpha-hydroxy acid (b) is selected from lactic acid, citric acid, methyllactic acid, glucuronic acid, glycolic acid, pyruvic acid, 2-hydroxybutanoic acid, 2-hydroxypentanoic acid, 2-hydroxyhexanoic acid, 2-hydroxyheptanoic acid, 2-hydroxyoctanoic acid, 2-hydroxynonanoic acid, 2-hydroxydecanoic acid, 2-hydroxyundecanoic acid, 2-hydroxydodecanoic acid, 2-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 2-hydroxyoctadecanoic acid, 2-hydroxytetracosanoic acid, 2-hydroxyeicosanoic acid; gluconic acid; mandelic acid; phenyllactic acid; gluconic acid; galacturonic acid; aleuritic acid; ribonic acid; tartronic acid; tartaric acid; malic acid; fumaric acid; salts and mixtures thereof, more particularly the alpha hydroxy acid is selected from lactic acid, citric acid and salts and mixtures thereof.

6. 6. Composition according to any one of claims 1 to 5, characterized in that the alpha hydroxy acid (b) is present in an amount ranging from 0.001% to 10% by weight, from 0.005% to 5% by weight, preferably from 0.01% to 2.5% by weight relative to the total weight of the composition.

7. 7. Composition according to any one of claims 1 to 6, characterized in that the pigment (c) is selected from powder pigments, such as inorganic pigments, pearlescent agents and organic pigments, the inorganic pigments being preferably iron oxide and / or titanium dioxide.

8. 8. Composition according to any one of claims 1 to 7, characterized in that the polyol (d) is selected from glycerin, diglycerin, polyglycerin, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, pentylene glycol, hexylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, polyethylene glycols having 5 to 50 ethylene oxide groups, and mixtures thereof, more particularly selected from glycerin, propylene glycol, dipropylene glycol, butylene glycol, hexylene glycol, and mixtures thereof.

9. 9. Composition according to any one of claims 1 to 8, characterized in that the polyol (d) is present in a content ranging from 0.01% to 50% by weight, preferably from 0.05% to 30% by weight, preferably from 0.08% to 20% by weight, preferably from 0.1% to 15% by weight, preferably from 0.1% to 12% by weight, preferably from 0.1% to 10% by weight, preferably from 0.2% to 8% by weight, preferably from 0.2% to 5% by weight, preferably from 0.2% to 3% by weight and preferentially from 0.2% to 2% by weight relative to the total weight of the composition.

10. 10. Composition according to any one of claims 1 to 9, characterized in that the weight ratio between polyol and chitosan is between 0.1 and 5, preferably between 0.2 and 5, preferably between 0.2 and 4.5, preferably between 0.5 and 2.

11. 11. Composition according to any one of claims 1 to 10, characterized in that it comprises at least 30% by weight, preferably at least 40% by weight, of water relative to the total weight of the composition, preferably between 30% and 95% by weight, more preferentially between 40% and 90%, even more preferentially between 45% and 85% by weight, of water relative to the total weight of the composition, and optionally at least one non-ionic surfactant, preferably chosen from esters of fatty acids and of polyglycerol, sugar esters, poloxamers, polysorbates and mixtures thereof.

12. 12. Composition according to any one of claims 1 to 11, characterized in that it has a pH of less than or equal to 7, preferably less than or equal to 6.5, preferably less than or equal to 6.3, advantageously between 3 and 6.3, preferably between 4 and 6.

3.

13. A method for making up and / or caring for the skin and / or keratinous appendages, in which a composition according to any one of claims 1 to 12 is applied to the skin and / or keratinous appendages.

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