Chitosan-based composition

Abstract

Chitosan-based composition The present invention relates to a cosmetic composition comprising, in a physiologically acceptable aqueous medium: (a) at least 0.01% by weight relative to the total weight of composition of native chitosan having a molecular weight strictly greater than 3000 Daltons, this quantity being strictly less than 15% by weight, (b) at least one alpha hydroxy acid; (c) from 3 to 50% by weight relative to the total weight of composition of at least one pigmentary coloring matter; and (d) at least one polyol; in which the polyol(s): chitosan weight ratio is between 0.1 and 6. Figure for the abstract: none

Description

Title of the invention: Chitosan-based composition

[0001] The present invention relates to a cosmetic composition comprising, in a physiologically acceptable aqueous medium:

[0002] (a) at least 0.01% by weight relative to the total weight of chitosan composition native having a molecular weight strictly greater than 3000 Daltons, this quantity being strictly less than 15% by weight,

[0003] (b) at least one alpha hydroxy acid;

[0004] (c) from 3 to 50% by weight relative to the total weight of the composition of at least one pigmentary coloring matter; and

[0005] (d) at least one polyol;

[0006] in which the polyol(s): chitosan weight ratio is between 0.1 and 6.

[0007] It also relates to a makeup and / or skin care process and / or of the appendages, in which the composition according to the invention is applied to the skin and / or the appendages.

[0008] There are many cosmetic compositions for which properties of holding the deposited film, after application to keratin materials, are desired. Examples include lipsticks or nail varnishes. In order to obtain such a result, it is possible to combine particular raw materials, in particular film-forming agents. However, the presence of such agents for holding the film on keratin materials can lead to drying compositions.

[0009] Furthermore, we often seek to obtain covering compositions.

[0010] The formulator is therefore looking for raw materials and / or systems making it possible to obtain fluid compositions (i.e. which flow) whose deposit is covering, homogeneous and resistant (i.e. having good hold).

[0011] Furthermore, there is a need for compositions whose makeup properties, in particular hold and coverage, are improved but which also maintain comfort during application.

[0012] Furthermore, the formulation of cosmetic products comprising significant levels of natural or naturally-derived raw materials represents one of the new challenges in meeting consumer expectations. It is therefore desirable that the proposed compositions allow for the retention of a significant level of natural or naturally-derived raw materials.

[0013] The present invention therefore aims to provide a solution to the above problems.

[0014] The aim of the present invention is to provide aqueous cosmetic compositions having improved makeup properties, particularly in terms of coverage. and homogeneity, but also having good hold.

[0015] After application, these compositions leave a covering and homogeneous film-forming deposit, which has good wear resistance. The films formed are adhesive and cohesive, and provide hold and coverage. In particular, they have improved resistance to friction.

[0016] The present invention relates to a cosmetic composition, in particular for makeup and / or care of the skin and / or lips, comprising, in a physiologically acceptable aqueous medium:

[0017] (a) at least 0.01% by weight relative to the total weight of chitosan composition native having a molecular weight strictly greater than 3000 Daltons, this quantity being strictly less than 15% by weight,

[0018] (b) at least one alpha hydroxy acid;

[0019] (c) from 3 to 50% by weight relative to the total weight of the composition of at least one pigment coloring matter;

[0020] (d) at least one polyol; and

[0021] in which the weight ratio of polyol(s): chitosan is between 0.1 and 6.

[0022] By “physiologically acceptable” is meant a medium compatible with keratin materials.

[0023] It also relates to a process for making up and / or caring for the skin and / or the appendages, in which the composition according to the invention is applied to the skin and / or the appendages. Chitosan

[0024] The composition according to the invention comprises at least 0.01% by weight relative to the total weight of the composition of at least one native chitosan having a molecular weight strictly greater than 3000 Daltons (3 kDa).

[0025] The quantity of native chitosan is also strictly less than 15% by weight relative to the total weight of the composition.

[0026] Preferably, the native chitosan has a molecular weight greater than or equal to 10 kDa, preferably greater than or equal to 15 kDa, preferably greater than or equal to 20 kDa. Preferably, the native chitosan has a molecular weight of 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.

[0027] Chitosan (or chitosan) is very rare in nature. It is only reported in the exoskeletons of certain insects such as termite queens and in the cell walls of a particular class of fungi, the zygomycetes.

[0028] Chitosan is obtained by deacetylation of chitin. Chitin is a polysaccharide composed of several N-acetyl-D-glucosamine units linked together by a [3 (1,4)] type bond.

[0029] The ideal chemical structure of chitosan is a chain of monomers [3-D-glucosamine linked by a glycosidic bond (1—>4).

[0030] By "chitosan" according to the invention is meant any copolymer formed from constituent units N-acetyl-D-glucosamine and D-glucosamine, the degree of acetylation of which is less than 90%. Chitosan is made up of glucosamine sugar units (deacetylated units) and N-acetyl-D-glucosamine units (acetylated units) linked together by bonds of type [3 (1,4) and constitutes a polymer of the type Poly(N-acetyl-D-glucosamine)-poly(D-glucosamine).

[0031] Preferably, the degree of acetylation of the chitosan is less than or equal to 50%, preferably less than or equal to 35%, preferably less than or equal to 25%, preferably less than or equal to 15%.

[0032] The degree of acetylation is the percentage of acetylated units relative to the number of total units, it can be determined by Fourier transform infrared spectroscopy (FT-IR) or by titration with a strong base.

[0033] The chitosan of the invention is preferably a polysaccharide prepared from a fungal origin. It is in particular extracted and purified from safe and abundant food or biotechnological fungal sources such as Agaricus bisporus or As-pergillus niger.

[0034] The chitosan of the invention is preferably derived from the mycelium of a fungus of the Ascomycete type, and in particular Aspergillus niger and / or a Basi-diomycete fungus, and in particular Lentinula edodes (shiitake) and / or Agaricus bisporus. Preferably the fungus is Aspergillus niger.

[0035] The chitosan may be of GMO origin, but preferably is of non-GMO origin.

[0036] The chitosan according to the invention is native, that is to say that it is not modified. In particular, it does not contain any chemical modification.

[0037] A method for preparing chitosan is that described in application WO03068824.

[0038] Preferably, the chitosan used in the invention is in powder form. It is notably marketed by Kitozyme under the name Kiosmetine or Kionutrime.

[0039] The 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. Alpha hydroxy acid (AHA)

[0040] The composition according to the present invention also comprises (b) at least one alpha hydroxy acid (AHA).

[0041] By alpha hydroxy acid is meant according to the present invention a carboxylic acid having at least one hydroxy function occupying an alpha position on said acid. (carbon adjacent to a carboxylic acid function). This acid may appear in the final composition in the form of a free acid and / or in the form of one of its associated salts (salts with an organic base or an alkali in particular), in particular depending on the final pH imposed on the composition.

[0042] The α-hydroxy acids (alpha hydroxy acids or AHAs) are, for example, chosen 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; mandelic acid; phenyllactic acid; gluconic acid; galacturonic acid; aleuritic acid; ribonic acid; tartronic acid; tartaric acid; malic acid; fumaric acid; their salts and mixtures thereof.

[0043] According to a preferred embodiment, the alpha hydroxy acid (b) is chosen from lactic acid, gluconic acid, citric acid, malic acid, tartaric acid and their salts. More particularly, the alpha hydroxy acid is chosen from lactic acid, citric acid, their salts and their mixtures.

[0044] The alpha hydroxy acid(s) (b) may be present in an amount ranging, for example, from 0.001 to 10% by weight, from 0.005 to 5% by weight and preferably from 0.01 to 2.5% by weight relative to the total weight of the composition. Pigmentary coloring matters

[0045] The composition according to the invention comprises from 3% to 50% by weight relative to the total weight of the composition of at least one pigmentary coloring matter (c). This coloring matter is thus chosen from powdery coloring matters such as mineral pigments, pearlescent agents, organic pigments.

[0046] The term “pigments” means white or colored particles, mineral or organic, insoluble in an aqueous medium, intended to color the composition and / or the resulting deposit.

[0047] The coloring materials may be present in the composition in a content ranging from 3% to 45% by weight, relative to the weight of the composition, preferably from 4% to 30% by weight, preferably from 5% to 20% by weight, preferably from 6% to 15% by weight. Mineral pigments

[0048] According to a particular embodiment, the pigments (c) used according to the invention are chosen from mineral pigments.

[0049] By "mineral pigment" is meant any pigment that meets the definition of the Ullmann encyclopedia in the inorganic pigment chapter. Among the mineral pigments useful in the present invention, mention may be made of zirconium or cerium oxides, as well as zinc, iron (black, yellow or red) or chromium oxides, manganese violet, ultramarine blue, chromium hydrate and ferric blue, titanium dioxide, metal powders such as aluminum powder and copper powder. The following mineral pigments may also be used: Ta2O5, Ti3O5, Ti2O3, TiO, ZrO2 in mixture with TiO2, ZrO2, Nb2O5, CeO2, ZnS.

[0050] The size of the pigment useful in the context of the present invention is generally greater than 100 nm and can range up to 10 qm, preferably from 200 nm to 5 qm, and more preferably from 300 nm to 1 qm. According to a particular form of the invention, the pigments have a size characterized by a D

[50] greater than 100 nm and can range up to 10 qm, preferably from 200 nm to 5 qm, and more preferably from 300 nm to 1 qm. The sizes are measured by static light scattering using a commercial granulometer of the MasterSizer 3000® type from Malvem, making it possible to understand the particle size distribution of all the particles over a wide range which can range from 0.01 qm to 1000 qm. The data are processed on the basis of the classical Mie scattering theory. This theory is most suitable for size distributions ranging from submicron to multi-micron, it allows determining an “effective” particle diameter.This theory is notably described in the work of Van de Hulst, HC, "Light Scattering by Small Particles", Chapters 9 and 10, Wiley, New York, 1957. D

[50] represents the maximum size that 50% by volume of the particles has.

[0051] In the context of the present invention, the mineral pigments are more particularly iron oxide and / or titanium dioxide.

[0052] As mineral pigments which can be used in the invention, mention may also be made of nacres.

[0053] By "mother-of-pearl" is meant colored particles of any shape, iridescent or not, in particular, produced by certain molluscs in their shell or synthesized and which present a color effect by optical interference.

[0054] The nacres may be chosen from pearlescent pigments, such as titanium mica coated with iron oxide, titanium mica coated with bismuth oxychloride, titanium mica coated with chromium oxide, titanium mica coated with an organic dye, as well as pearlescent pigments based on bismuth oxychloride. They may also be mica particles on the surface of which are superimposed at least two successive layers of metal oxides and / or organic coloring materials. Mention may also be made, as an example of nacres, of mica natural coated with titanium oxide, iron oxide, natural pigment or bismuth oxychloride. Mother-of-pearl can more specifically have a yellow, pink, red, bronze, orange, brown, gold and / or coppery color or reflection.

[0055] Among the pigments which can be used according to the invention, mention may also be made of those with an optical effect different from a simple conventional tint effect, that is to say unified and stabilized as produced by conventional coloring materials, such as, for example, monochromatic pigments. For the purposes of the invention, "stabilized" means devoid of any effect of color variability with the viewing angle or in response to a change in temperature. For example, this material may be chosen from particles with a metallic sheen, goniochromatic coloring agents, diffracting pigments, thermochromic agents, optical brightening agents, as well as fibers, in particular interference fibers. Of course, these different materials may be combined so as to provide the simultaneous manifestation of two effects, or even a new effect in accordance with the invention.

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

[0057] According to another embodiment of the invention, the pigmentary coloring matter (c) is an organic, synthetic, natural or naturally occurring pigment.

[0058] By "organic pigment" is meant any pigment which meets the definition of the Ullmann encyclopedia in the organic pigment chapter. The organic pigment may in particular be chosen from nitroso, nitro, azo, xanthene, quinoline, anthraquinone, phthalocyanine, metal complex type compounds, isoindolinone, isoindoline, quinacridone, perinone, perylene, diketopyrrolopyrrole, thioindigo, dioxazine, triphenylmethane, quinophthalone.

[0059] The organic pigment(s) (c) may be chosen, for example, from carmine, carbon black, aniline black, melanin, azo yellow, quinacridone, phthalocyanine blue, sorghum red, the blue pigments codified in the Color Index under the references CI 42090, 69800, 69825, 73000, 74100, 74160, the yellow pigments codified in the Color Index under the references CI 11680, 11710, 15985, 19140, 20040, 21100, 21108, 47000, 47005, the green pigments codified in the Color Index under the references CI 61565, 61570, 74260, the orange pigments codified in the Color Index under the references CI 11725, 15510, 45370, 71105, the red pigments codified in the Color Index under the references 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 derivatives,phenolics as described in patent FR 2 679 771.,

[0060] The pigments may also be in the form of composite pigments as described in patent EP 1 184 426. These composite pigments may be composed in particular of particles comprising an inorganic core covered at least partially with an organic pigment and at least one binder ensuring the fixing of the organic pigments on the core.

[0061] The pigment can also be a lake.

[0062] By lake is meant insolubilized dyes adsorbed on insoluble particles, the whole thus obtained remaining insoluble during use.

[0063] The inorganic substrates on which the dyes are adsorbed are, for example, alumina, silica, calcium and sodium borosilicate or calcium and aluminum borosilicate, and aluminum.

[0064] Among the organic dyes, we can cite cochineal carmine. Other products known under the following names include: 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). Examples of lacquers include the product known as D&C Red 7 (CI 15850:1). Polyols

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

[0066] The term "polyol" herein refers to an alcohol having two or more hydroxy groups and does not include a saccharide or a derivative thereof. The derivative of a saccharide includes a sugar alcohol obtained by reducing one or more carbonyl groups of a saccharide, as well as a saccharide or a sugar alcohol in which the hydrogen atom(s) in one or more hydroxy groups thereof has been replaced by 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) may be a C2-24 polyol, preferably a C2-9 polyol, comprising at least 2 hydroxy groups, and preferably 2 to 5 hydroxy groups.

[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) may be chosen from glycerins and their derivatives, as well as glycols and their derivatives. The polyol may be chosen 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 glycol, in particular having from 5 to 50 ethylene oxide groups and mixtures thereof; more particularly chosen from glycerin, propylene glycol, dipropylene glycol, butylene glycol and mixtures thereof.

[0070] It is preferable that the polyol (d) is 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, relative to the total weight of the composition, preferably ranging from 0.05% to 30% by weight, preferably ranging from 0.08% to 20% by weight, preferably ranging 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% and preferably ranging from 0.2% to 2% by weight.

[0072] Preferably, when the chitosan content in the composition is greater than or equal to 2% by weight relative to the total weight of the composition, the polyol (d) is present in a content 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 the polyol(s) and the chitosan (i.e. polyol(s): chitosan weight ratio) is between 0.1 and 6. Preferably, it 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. Physiologically acceptable aqueous medium

[0074] The composition according to the invention comprises a physiologically acceptable aqueous medium. Said medium comprises water.

[0075] The water used may be sterile demineralized water and / or a floral water such as rose water, cornflower water, chamomile water or linden water, and / or a natural thermal or mineral water.

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

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

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

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

[0080] Preferably, the non-ionic surfactant is chosen from fatty acid and polyglycerol esters and sugar esters. pH of the composition

[0081] The composition according to the invention has a pH 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 invention comprises at least one base.

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

[0084] The base can be chosen from mineral bases such as, for example, alkali metal hydroxides, sodium hydroxide, potassium hydroxide.

[0085] Preferably, the base of the composition is an alkali metal hydroxide, preferably sodium hydroxide or potassium hydroxide. Indeed, these bases are more advantageous than nitrogenous bases, such as triethanolamine, in terms of color stabilization (i.e. less yellowing).

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

[0087] The composition in accordance with the invention can be obtained in a conventional manner by a person skilled in the art.

[0088] The following examples will allow a better understanding of the invention, without however being limiting in nature. The raw materials are named by their chemical or INCI name. The quantities indicated are in % by weight of raw materials relative to the total weight of the composition (% w / w), unless otherwise stated. Examples

[0089] Preparation of the compositions according to the invention and of the comparative compositions

[0090] In the following examples, each formula was prepared according to the protocol described below:

[0091] Under mechanical stirring with minimal vortex and at room temperature, - Disperse the chitosan and water under mechanical vortexing with minimal vortexing - Add the appropriate amount of acid to solubilize the chitosan and form a more viscous solution. - Add the pigments, then the polyols, then the surfactants (if present?) - The mixture can then be passed to the three-cylinder if necessary

[0092] Chitosan is considered solubilized when the solution loses transparency. For this we measures the transmittance of the composition using the Turbiscan lab and Turbisoft lab software.

[0093] Example 1: Evaluations of the effects of different ingredients

[0094] Formulas Fl to Fil are prepared according to the above protocol.

[0095] Test protocol for the filmable and peelable appearance of formulas after deposition

[0096] In an aluminum capsule 9.5 cm in diameter, place 10g of solution and spread it evenly over the entire surface. The deposit is left to dry for 24 hours at 32°C on a hot plate. The sample is then initially assessed by touch. If the sample is liquid and sticks to the finger, it is considered that the sample is not filmable. If the sample is filmable, a second assessment is carried out by peeling the sample from the aluminum capsule using a spatula. If the experimenter succeeds, the deposit is said to be filmable.

[0097] The results are described below in Table 1.

[0098] The appearance is said to be compliant if the appearance of the preparation is fluid and can flow. The appearance will be non-compliant if the formulation is solid, or in the form of a gum, or unable to flow.

[0099] Sensoriality is defined by spreading with the finger on a square of skin on the arm measuring 2.54 cm on each side. If the spreading is not fluid and clearly reveals sensations of irregularities such as lumpy texture or brittle solidity, we will say that the sensoriality is non-compliant. If the spreading is fluid, we will say that the sensoriality is compliant.

[0100] In the table OK = compliant, NO = non-compliant, F5 and F6 = Intermediate).

[0101] Homogeneity is described on the visual aspect of the preceding film. If it has visible thickness inhomogeneities, the film will be said to be inhomogeneous. If the film is visually of constant thickness, the film will be said to be homogeneous.

[0102] [Tables 1] Formula Chitosan (%. w / W) AL (%. W / W) Gly (%. w / W) Appearance of the composition (bulk) Filmifiable Filmable Sensoriality Homogeneity of the film on the skin Fl 0.1 0.05 CONFORM OK NO OK homogeneous F2 0.5 0.25 CONFORM OK OK OK homogeneous F3 10 5 CONFORM OK OK OK homogeneous F4 15 7.5 NON CONFORM Solid elastic OK OK NO because solid Inhomogeneous F5 14 7 CONFORM OK OK Disintegrates with difficulty but ok Inhomogeneous F6 13 6.5 CONFORM OK OK Disintegrates with difficulty but ok Inhomogeneous F7 12 6 CONFORM OK OK OK homogeneous F8 5 2.5 20 CONFORM OK OK OK Homogeneous F9 5 2.5 30 COMPLIANT OK NO OK Inhomogeneous F10 5 2.5 40 COMPLIANT NO NO OK Inhomogeneous Wire 5 2.5 50 COMPLIANT NO NO NO because solid Inhomogeneous

[0103] In the table above and the following

[0104] AL = lactic acid

[0105] Gly = Glycerin

[0106] Formulas Fl and F2: The minimum dose of chitosan to form a film detectable by this test is 0.1%. The quantity of 0.5% makes it possible to obtain a film that can be peeled off.

[0107] Formula F4: Chitosan must in all cases be present in a quantity strictly less than 15% by weight, because the formula is then no longer applicable and the appearance of the composition (bulk) is no longer fluid.

[0108] Formulas F8 to F10: the polyol: chitosan weight ratio is ideally less than or equal to 6 (F9), because beyond this the deposits are no longer homogeneous (F10 and Fl 1), preferably equal to 4 to obtain a very homogeneous film (F8). The inhomogeneity comes from the inability to work / mix / apply the formed material.

[0109] Example 2: Protocol for evaluating changes in the mechanical properties of films for improved comfort

[0110] Formulas C1 to C6, A1 and A2 are prepared.

[0111] In a 9.5 cm diameter aluminum capsule, place 10 g of solution and spread it evenly over the entire surface. The deposit is left to dry for 24 hours at 32°C on a heating plate.

[0112] - Cut out 3 test pieces measuring L 20 x 1 6 mm using a cookie cutter.

[0113] - Measure the thickness of the test pieces using a Palmer micrometer.

[0114] - Place the test piece in the jaws of the Stable Micro TA.XT Plus Texturometer Systems and using the Exponent software, start the measurement to obtain the force (g) and the breaking length (mm).

[0115] TA Setting: speed 0.1 or 0.3 mm / s

[0116] [Math.l] => % deformation = elongation / initial size *100 = (breaking length - initial size) / initial size *100 => stress = force (N) / area (m) =JMÇâ (9) * 9 forgerfthickness

[0117] [Tables2] Formula Chitosan (100 kDa) (%. w / w) AL (%. w / w) Glycerin (%. w / w) % Average Elongation at Break Error on Elongation % Average Stress at Break Error on Stress Cl 5 2.5 0 4.8 0.9 46 7.5 C2 5 2.5 0.1 4.3 1.5 34.8 11.4 C3 5 2.5 0.5 8.0 0.4 18.5 10.7 C4 5 2.5 1 50.0 25.6 16.4 4.6 C5 5 2.5 5 593.2 59.8 1.5 0.2 C6 5 2.5 20 723.3 85.6 0.1 0.0

[0118] These results make it possible to set the minimum dose of glycols compared to chitosan with regard to the technical problem of comfort. Having a softer film, therefore one which has a longer elongation at break, improves comfort at deposition.

[0119] Without glycerin, the chitosan film remains rigid and uncomfortable on the skin (Cl).

[0120] The evolution of the film rigidity is evaluated with the above measurements and shows that from a polyol:chitosan weight ratio equal to 1:10 (C3) the softening effects are perceptible. This softening is essential for comfort. Formula Chitosan (100 kDa) (%. w / W) AL (% • W / W) Glycerin (%. w / W) Red pigment (%. w / W) % Average elongation at break Error on elongation% Average stress at break Error on stress Al* 5 2.5 15 1.3 0.1 18.2 1.2 A2 5 2.5 10 15 208.5 7.7 1.0 0.1

[0121] Formula Al is comparative (marked by a star), while formula A2 is according to the invention.

[0122] [Table 9]

[0123] Example A2 shows the impact of the polyol on the flexibility of the film in the presence of pigment.

[0124] Example 3: Protocol for evaluating dry friction resistance

[0125] Certain compositions are evaluated for their resistance to friction, by colorimetric measurements on dry film before and after abrasion, test protocol for which is detailed below.

[0126] 3.1. Protocol for spreading compositions into a film

[0127] The products are spread on a spreading bench (Elcometer 4340 Applicator) allowing its speed and the distance over which it is spread to be adjusted. The bench is equipped with a suction system connected to a pump so that the support where the spreading is done does not move. Contrast cards with a black background and an unvarnished white background are used (1 byko-chart, uncoated N2A, code 2831). The spreading thickness is adjustable thanks to the square spreader placed on the support so as to spread by leveling when the platform is started. Each slice of the spreader allows spreading with a different thickness ranging from 25qm to 200qm. The chosen thickness is 50 μm in order to get closer to an in vivo film thickness. A weight of 960 g is added on top of the spreader during spreading. The spreading speed is set to lin / sec, or 2.54cm / s. The films are dried for 24 hours at room temperature and humidity (RH) (50% RH).

[0128] [Tables3] Formula Chitosan (100 kDa) AL (% w / w) Glycerin (% w / w) Native pigments (% w / w) Wet Comparative composition 0.1 0.08 0 15 No, therefore inhomogeneity Composition according to the invention 0.1 0.08 1 15 Yes

[0129] The results are shown in Table 3. Some compositions cannot be spread to perform the following contrast ratio (CR) tests; they are said to dewet. This dewetting leads to deposit inhomogeneities. These formulas therefore do not meet the criteria for solving the technical problem of homogeneity and coverage because of their dewetting.

[0130] On the contrary, the composition according to the invention has good wettability.

[0131] 32. Contrast ratio measurement protocol for objectification of coverage

[0132] Color measurement is performed using a Konica Minolta CM-700d spectrophotometer. Contact measurement ensures the absence of light pollution.

[0133] Selected settings: Aperture 8 mm; Uncertainty: 0.04; SCI / SCE measurement; Geometry d / 8°.

[0134] The color measurements on the two backgrounds (black background FN and white background FB) make it possible to characterize the coverage of a foundation by calculating the “contrast ratio”, (CR%), i.e. YFN / YFB x 100, where YFN and YFB are respectively the luminance values ​​measured on a black background and the white background, the latter being higher the more covering the foundation is.

[0135] - Quantity of pigments

[0136] Formula F12 is according to the invention while formulas F13 to F16 are comparative.

[0137] [Tables4] Formula Chitosan (100 kDa) AL (% w / P) Glycerin e (% w / w) Native pigments (% w / w) TA (PG10L) CR F12 (invention) 1 0.5 1 3 0.1 52 ±2 50pm F13 1 0.5 1 2.5 0.1 44 ±1 50pm F14 1 0.5 1 2 0.1 43 ±1 50pm F15 1 0.5 1 1.5 0.1 35 ±2 50pm F16 1 0.5 1 1 0.1 19 ±1 50pm

[0138] TA (PG10L) = surfactant (PG10 laurate)

[0139] In order to achieve a minimum coverage set at 50%, it is necessary to have a minimum of 3% pigments.

[0140] - Nature of chitosan

[0141] Formulas F19 to F20 are according to the invention while formulas F17 and F18 are comparative.

[0142] [Tables5] Formula Chitosan (% w / w) Molecular weight (Da) AL (% W / W) Glycerin (% w / w) Native pigments (% w / w) TA CR 0 F17 0 5 15 1 84 ±4 F18 5% < 3kDa 5 15 1 89 ±1 F19 (invention) 5% 20kDa 2.5 5 15 1 95 ±1 F20 (invention) 5% 100kDa 2.5 5 15 1 103 ±3

[0143] TA = surfactant (PG10 laurate)

[0144] Formulas F19 to F20 are the only ones significantly different from F17 (reference without chitosan) with regard to coverage in the deposit. 3.3. Friction resistance test protocol

[0145] The friction resistance test is carried out by colorimetric measurements on dry film before and after abrasion. The abrasion is carried out by fixing a strip of tissue (Chicopee^ Veraclean^ Polish Plus) on the spreader edge at 25 pm. The weight of 960 g is added over the spreader during abrasion. The bench speed is set at 2.54 cm / s.

[0146] The measurement of the color before and after abrasion is done with the same spectrophotometric method as explained previously.

[0147] In order to evaluate the resistance to friction, the "Contrast Ratio" respectively before friction (CR Dry Deposition, %) and after abrasion (CR Rub Dry Deposition, %) are measured. The loss [(CR Rub Dry Deposition - CR Dry Deposition] / CR Dry Deposition] *100, in percentage, quantifies the loss of coverage and indicates the resistance of the film to friction: the lower this loss, the more resistant the film is to friction.

[0148] Each CR value therefore represents an average of 6 measurements.

[0149] - Choice of chitosan type

[0150] [Tableauxô] Formula % Loss CR F17 23.8 ± 2 F18 26.3 ± 1 F19 0±1 F20 -0.3 ± 1

[0151] Formulas F19 to F20 are the only ones that do not lose coverage.

[0152] -Quantity of chitosan

[0153] Formula F27 is according to the invention while formulas F22 to F26 are comparative.

[0154] [Tables?] Formula Chitosan (100 kDa) (% w / w) AL (% w / w) Glycerin e (% w / w) Native Pigments TA % Loss CR F17 0 5 15 1 23.8 ± 2 F22 0 0 15 0.1 21.9 ± 1 F23 0.001 0.0008 15 0.1 24.6 ± 2 F24 0.005 0.004 15 0.1 23.9 ± 1 F25 0.01 0.008 15 0.1 5.6 ±1 F26 5 4 15 0.1 0.8 ±1 F27 (invention) 5 2.5 5 15 1 -0.3 ± 1

[0155] Comparative formulas F17 and F22 show that the presence of glycerin does not impact coverage.

[0156] Comparison of formulas F23-F26 (comparative) and F27 (invention) shows that chitosan impacts coverage. 3.4. Oily friction resistance test

[0157] The test consists of spreading 15 pL of formula on a 4 cm diameter disc on the forearm and letting the deposit dry for 20 minutes. In parallel, 100 pL of oil (5022 caprylic / capric triglyceride) is placed on a strip of tissue handkerchief (Chicopee^ Veraclean^ Polish Plus). Then the handkerchief is rubbed with an axial force of 200-300 grams and the stain on the handkerchief is evaluated.

[0158] [Tables8] Chitosan test (100 kDa) (% w / w) AL (% w / w) Native pigments (% w / w) TA (PG10L) Dipropylene glycol Oil resistance rating Comparative composition 0 15 1 12 1 / 5 Composition according to the invention 3 1.5 15 1 12 3 / 5

[0159] The positive terminal having a score of 5 / 5 corresponds to the unstained cloth, while if the cloth is completely stained a score of 1 / 5 will be given.

[0160] Under these conditions the composition according to the invention performs in such a way as to obtain a score of 3 / 5.

[0161] We see that chitosan improves the resistance of deposits to oily friction.

Claims

Claims

1. Cosmetic composition comprising, in a physiologically acceptable aqueous medium: - (a) at least 0.01% by weight relative to the total weight of the composition of native chitosan having a molecular weight strictly greater than 3000 Daltons (1 Da = 1 g / mol), this quantity being strictly less than 15% by weight, - (b) at least one alpha hydroxy acid; - (c) from 5 to 20% by weight relative to the total weight of the composition of at least one pigmentary coloring matter; - (d) at least one polyol; - in which the weight ratio polyol(s): chitosan is between 0.1 and 6.

2. Composition according to claim 1, characterized in that it comprises 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 native chitosan composition.

3. Composition according to one of the preceding claims, characterized in that the native chitosan (a) has a molecular weight greater than or equal to 10 kDa, preferably greater than or equal to 15 kDa, preferably greater than or equal to 20 kDa, 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 less than or equal to 50%, preferably less than or equal to 35%, preferably less than or equal to 25%, preferably less than or equal to 15%.

4. Composition according to one of the preceding claims, characterized in that the chitosan (a) is extracted and purified from food or biotechnological fungal sources such as Agaricus bisporus or As-pergillus niger, preferably from Aspergillus niger.

5. Composition according to one of the preceding claims, characterized in that the alpha hydroxy acid (b) is chosen from lactic acid, citric acid, methyllactic acid, glucuronic acid, glycolic acid, pyruvic acid, 2-hydroxy-butanoic 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; their salts and mixtures; more particularly, the alpha hydroxy acid is chosen from lactic acid, citric acid, their salts and their mixtures.

6. Composition according to one of the preceding claims, 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. Composition according to one of the preceding claims, characterized in that the coloring matter (c) is chosen from powdery coloring matters such as mineral pigments, pearlescent agents, organic pigments; preferably, the mineral pigments are iron oxide and / or titanium dioxide.

8. Composition according to one of the preceding claims, characterized in that the polyol (d) is chosen from glycerin, diglycerin, polyglycerin, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, pentylene glycol, hexylene glycol, 1,3-propanediol, 1,4-butanediol, 11,5-pentanediol, polyethylene glycols comprising 5 to 50 ethylene oxide groups and mixtures thereof; more particularly chosen from glycerin, propylene glycol, dipropylene glycol, butylene glycol and mixtures thereof.

9. Composition according to one of the preceding claims, characterized in that the polyol (d) is present in a content ranging from 0.01% to 50% by weight, relative to the total weight of the composition, preferably ranging from 0.05% to 30% by weight, preferably ranging from 0.08% to 20% by weight, preferably ranging 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% and preferably ranging from 0.2% at 2% by weight.

10. Composition according to one of the preceding claims, characterized in that the weight ratio polyol(s): 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. Composition according to one of the preceding claims, characterized in that it comprises at least 30% by weight of water relative to the total weight of the composition, preferably at least 40% by weight, preferably from 30% to 95% by weight of water relative to the total weight of the composition, more preferably from 40% to 90%, even more preferably from 45% to 85%, and optionally may comprise at least one non-ionic surfactant preferably chosen from fatty acid and polyglycerol esters, sugar esters, poloxamers, polysorbates and mixtures thereof.

12. Composition according to one of the preceding claims, characterized in that it has a pH 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. Method for making up and / or caring for the skin and / or the appendages, in which the composition according to one of the preceding claims is applied to the skin and / or the appendages.