Cosmetic composition comprising an elastic alginate-based mixture

Abstract

Cosmetic composition comprising an elastic alginate-based mixture. The invention relates to a composition comprising a mixture capable of forming a flexible elastic film comprising at least one polysaccharide selected from: at least one alginate, an alginate derivative, or mixtures thereof; at least one modified polysaccharide; and at least one polyol selected from diols, polyglycerols of the formula H-(O-CH2-CH(OH)-CH2)n-OH, in which n varies from 1 to 10, and mixtures thereof, which provides a tightening effect and deforms elastically to follow the movements and mechanical deformations of the skin surface. The present invention also relates to a method for preparing a cosmetic composition according to the invention, as well as a skincare method comprising a step of applying a cosmetic composition according to the invention to the skin.

Description

Title of the invention: Cosmetic composition comprising an elastic alginate-based mixture technical field

[0001] The present invention relates to the cosmetic field, and more particularly to a cosmetic composition comprising a mixture capable of forming an elastic film, which provides a tightening effect and deforms elastically to follow the movements and mechanical deformations of the skin surface. The present invention also relates to a method for preparing a cosmetic composition according to the invention, as well as a skincare method comprising a step of applying a cosmetic composition according to the invention to the skin.

[0002] Giving cosmetic compositions a smoothing effect is a well-established technique in cosmetology. This can be achieved using active ingredients that penetrate the skin and have a long-lasting effect. Film-forming polymers are also used for a smoothing effect, providing immediate mechanical action on the skin's surface. However, these smoothing materials have some drawbacks. First, once the product is applied to the skin, it is often uncomfortable due to the rigidity of the films formed. This rigidity makes the films difficult to stretch and inelastic, consequently leading to poor durability of the cosmetic compositions, which crack and crumble quickly.

[0003] The Applicant has already described in application WO 2013 / 167835 a cosmetic treatment providing a tightening and smoothing effect comprising a specific elastic complex made up of at least one gelling or thickening starch, at least one polyol, and at least one polymer selected from polyvinyl alcohols, vinylpyrrolidone polymers and copolymers, and latex. However, these compositions have the disadvantage of being too sticky; they also lack adhesion to the skin (peelability problem).

[0004] The inventors have now developed a cosmetic composition comprising a mixture of specific compounds capable of forming an elastic film with an immediate, visible, and lasting smoothing effect. The film thus formed can deform reversibly, so that after deformation, for example after stretching, it returns to the state it had before the application of the mechanical stress provided, for example by deformation of the skin. The film formed by the cosmetic composition comprising said mixture has greater resistance to breakage, which makes it possible to maintain the mechanical properties of the film formed on the skin surface intact. Once incorporated into a cosmetic composition, the mixture capable of forming this The elastic film has a combined tightening and enhanced elastic effect, capable of following the skin's movements without cracking. The resulting effect is comparable to a sheathing effect, as the cosmetic composition of the invention provides elasticity to skin naturally subjected to deformations, such as changes in facial expression or contact with hands or clothing. The inventors have thus succeeded in developing a cosmetic composition capable of combining performance characteristics that are difficult to reconcile: a tightening effect combined with an elastic effect, resolving the tightening / elasticity paradox. The new cosmetic composition is capable of effectively smoothing the skin's surface, notably achieving partial or total erasure of wrinkles, including medium and deep wrinkles.

[0005] The cosmetic composition of the invention exhibits remarkable skin-tightening and elastic properties, which are linked to the simultaneous presence of an alginate, a modified polysaccharide, and a polyol. The resulting cosmetic composition provides a visible and lasting smoothing of the skin's surface with exceptional user comfort. Furthermore, the nature of the ingredients used makes the cosmetic composition of the invention easy to formulate.

[0006] General description of the invention

[0007] The present invention relates first to a cosmetic composition comprising a mixture capable of forming an elastic film comprising: a- at least one alginate, an alginate derivative, or mixtures thereof, b- at least one modified polysaccharide, and c- at least one polyol selected from among the diols, the polyglycerols of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 1 to 10, and their mixtures.

[0008] In the following description, the term "cosmetic composition" refers both to the cosmetic composition according to the invention and to the cosmetic composition used in the process of the invention. In the description, the terms "elastic mixture" and "mixture capable of forming an elastic film" are used interchangeably.

[0009] The elastic blend of the cosmetic composition of the invention comprises an α-alginate, also called a contractile film-forming polymer, which provides an immediate smoothing / tightening (lifting) effect. This contractile effect occurs upon drying, as hydrogen bonds form between the polymer chains to create contraction.

[0010] A polymer is said to be film-forming within the meaning of the invention if, after evaporation of the volatile substances present in the medium, a continuous and homogeneous film is observed to form. Intermolecular bonds, responsible for the mechanical properties, then form between the polymer chains and with other components such as the plasticizers to create a film that does not penetrate the skin and provides resistance to water and sebum, non-transfer, etc.

[0011] The alginate of the invention can be selected from sodium alginate (INCI name: ALGIN), potassium alginate (INCI name: POTASSIUM ALGINATE), ammonium alginate (INCI name: AMMONIUM ALGINATE), sodium alginate sulfate (INCI name: SODIUM ALGINATE SULFATE), propylene glycol alginate (INCI name: PROPYLENE GLYCOL ALGINATE), triethanolamine alginate (INCI name: TEA-ALGINATE), and mixtures thereof. Advantageously, the alginate of the invention is sodium alginate (INCI name: ALGIN), for example, marketed under the reference GELCARIN® FF 46 by IFF.

[0012] According to one embodiment, the cosmetic composition of the invention comprises from 0.1 to 15%, preferably from 0.1 to 10%, and more preferably from 0.5 to 5%, by weight of alginate a- relative to the total weight of said cosmetic composition.

[0013] The elastic mixture of the cosmetic composition of the invention also comprises a modified β-polysaccharide, also called an elastic film-forming polymer, which provides an elastic (comfortable) effect to the composition. The modified β-polysaccharide of the invention has the advantage of providing, when mixed with the other ingredients, a dry, elastic film that is transparent and remains transparent after undergoing mechanical deformation (stretching). In particular, the film formed on the skin retains its transparency under the effect of multiple mechanical stresses, so that it does not, over time, alter the color of the cosmetic composition deposited on the skin into which the mixture has been incorporated.

[0014] The modified β- polysaccharide, distinct from α- alginate, is advantageously a modified starch. The modified starches of the invention are obtained from native starches that have been modified chemically and / or physically and / or enzymatically to improve their elastic properties. The native starches can be derived from a wide variety of sources, such as, for example, starches from maize, wheat, rice, buckwheat, barley, oats, millet, rye, sorghum, cassava, potato, sweet potato, tapioca, banana, plantain, malanga, taro, chestnut, beans, peas, and preferably native starches from maize, wheat, rice, cassava, potato, tapioca, and peas.

[0015] The modified starches used in the context of the invention have the advantage of providing, when mixed with the other components of the invention, elastic dry films that are transparent and remain transparent after stretching when prepared in the form of thin films (typically less than one millimeter thick). Indeed, it is particularly advantageous in the context of the present invention that the film formed on the skin by application of the cosmetic composition of the invention retains its transparency under the effect of multiple mechanical stresses, and does not alter the color of the deposit on the skin over time.

[0016] The modified b- polysaccharide advantageously has a weight-average molecular weight greater than 106 g.mol1, and preferably from 106 to 109 g.mol1. The weight-average molecular weight can be determined by HPSEC-MALLS (high-performance size exclusion chromatography coupled online with multi-angle laser light scattering detection).

[0017] Among the preferred modified starches, alkylated starches, hydroxyalkylated starches, acetylated starches, and mixtures thereof, and more preferably hydroxyalkylated starches, may be mentioned.

[0018] The modified β- polysaccharide is advantageously selected from among hydroxyalkylated starches. In a preferred embodiment, the modified β- polysaccharide is hydroxypropyl starch, which may have the INCI name: HYDROXYPROPYL STARCH, such as the product Beauté By Roquette® ST 720 marketed by the company ROQUETTE.

[0019] In a particularly preferred embodiment, the modified b- polysaccharide is a hydroxyalkylated starch, and even more preferably a hydroxypropyl starch, having a weight-average molecular weight greater than 106 g.mol1, and advantageously from 106 to 109 g.mol1. The weight-average molecular weight can be determined by HPSEC-MALLS.

[0020] The modified b- polysaccharide preferably represents 0.5 to 15%, preferably 0.5 to 10%, and more preferably 1 to 8%, by weight relative to the total weight of the cosmetic composition.

[0021] The elastic mixture of the cosmetic composition of the invention also comprises a c- polyol, which aids in the dispersion and plasticizes the polymers present in the cosmetic composition. Thus, the c- polyol acts as a plasticizer by providing mobility between the polymer chains, making them more elastic and flexible.

[0022] The c- polyol of the invention is selected from diols, polyglycerols of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 1 to 10, and preferably from 1 to 6, and their mixtures.

[0023] According to another embodiment, the c- polyol is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 1 to 10, and preferably from 1 to 6, and their mixtures.

[0024] According to an advantageous embodiment, the c- polyol is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 1 (INCI name: GLYCERIN), n = 3 (INCI name: POLYGLYCERIN-3) or n = 6 (INCI name: POLYGLYCERIN-6), and more advantageously a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 1 (INCI name: GLYCERIN) or n = 3 (INCI name: POLYGLYCERIN-3). POLYGLYCERIN-3 (PGL-S MB) and POLYGLYCERIN-6 (POLYGLYCERIN 500 MB) are marketed, for example, by the company SAKAMOTO YAKUHIN KOGYO.

[0025] According to one embodiment, the c- polyol is a diol selected from C2-C12 aliphatic or aromatic, linear or branched diols, preferably propane-1,2-diol, propane-1,3-diol, butane-1,2-diol, butane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol, and mixtures thereof, and more preferably propane-1,3-diol.

[0026] The c- polyol preferably represents 1 to 20%, preferably 3 to 15%, and more preferably 5 to 10%, by weight relative to the total weight of the cosmetic composition.

[0027] In one embodiment, the cosmetic composition of the invention comprises: a- from 0.1 to 15%, preferably from 0.1 to 10%, and more preferably from 0.5 to 5%, by weight of alginate a-, b- from 0.5 to 15%, preferably from 0.5 to 10%, and more preferably from 1 to 8%, by weight of modified polysaccharide b-, and c- from 1 to 20%, preferably from 3 to 15%, and more preferably from 5 to 10%, by weight of polyol c- selected from diols, polyglycerols of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 1 to 10, and mixtures thereof, relative to the total weight of the cosmetic composition.

[0028] The quantities of each of the components a-, b-, and c- are preferably chosen so that the cosmetic composition provides a pleasant feel without being too sticky, while ensuring good adhesion to the skin. Thus, the proportions of each of the components a-, b-, and c- are adjusted to satisfy the desired compromise between stickiness and adhesion properties. Depending on the formula, for example, if it is a foundation or a serum, a compromise will be sought between adherence to the skin and the viscoelasticity of the composition. For example, if the formula contains powders, the quantity of polyol to be introduced will be greater in order to maintain a certain degree of plasticity and elasticity.

[0029] The mass ratio of polyol c- / (alginate a- + modified polysaccharide b-) is preferably between 20 / 80 and 80 / 20, and preferably from 40 / 60 to 60 / 40.

[0030] According to a particularly advantageous embodiment, the cosmetic composition of the invention comprises a film-forming mixture comprising: a- at least one alginate selected from sodium alginate (INCI name: ALGIN), b- at least one modified polysaccharide selected from hydroxypropyl starch (INCI name: HYDROXYPROPYL STARCH), and c- at least one polyol selected from a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 1 and / or 3.

[0031] In an advantageous embodiment, the cosmetic composition of the invention contains from 0.5 to 50%, preferably from 1 to 30%, and more preferably from 5 to 25%, by weight relative to the total weight of the cosmetic composition, of a mixture capable of forming an elastic film consisting of α-alginate, β-modified polysaccharide, and δ-polyol, as defined above. The mixture of α-alginate, β-modified polysaccharide, and δ-polyol, as defined above, is also referred to as the active ingredient mixture.

[0032] The cosmetic composition of the invention may further comprise an aqueous phase, which may include water. Preferably, the composition comprises from 40 to 99%, preferably from 50 to 90%, and more preferably from 60 to 70%, by weight of water, relative to the total weight of the cosmetic composition.

[0033] According to one embodiment of the invention, the cosmetic composition may further comprise at least one cosmetic active ingredient. The cosmetic active ingredient may, in particular, advantageously be chosen from among a moisturizing agent, an anti-wrinkle agent, an antioxidant, a free radical scavenging agent, an agent that repairs the destructive effects of ultraviolet rays, or a slimming agent such as caffeine. Preferably, the cosmetic active ingredient is chosen from among hyaluronic acids, such as sodium hyaluronate. The invention thus relates, according to one of its aspects, to a cosmetic composition containing water and at least one cosmetic active ingredient in a proportion ranging from 0.01 to 5% by weight, relative to the total weight of the cosmetic composition.

[0034] The cosmetic composition of the invention may further include a gelling agent. Suitable gelling agents include natural or synthetic polysaccharides, preferably chosen from xanthan gum (such as Rhodicare® XC or T sold by Solvay Novecare or Keltrol® CG LAXT sold by CP Keltro), agar-agar (such as Ina Agar CS 83 sold by Iwase Cosfa), gellan gum (such as Kelcogel® CG-LA sold by Azelis), carrageenans (such as Satiagum™ VPC 430 sold by Cargill Beauty), cellulose and its derivatives such as hydroxyethylcellulose (such as Klucel® GF and Natrosol® 250 HHX, sold by Ashland) and hydroxypropylcellulose, corn starch, cellulose carboxymethyl ethers (such as Blanose™ 7H3SF sold by Ashland), and copolymers based on bis-decyltetradeceth-20 ether (such as Adeka Nol GT-700 sold by Adeka), polysaccharide alcaligens (such as Alcasealan sold by Iwase Cosfa),Sclerotium gum (INCI name: Sclerotium Gum) (such as Amigel® sold by Alban Muller International (Croda)), and mixtures thereof. Synthetic polymers, preferably chosen from among, may also be advantageously mentioned. l’ammonium acryloyldimethyltaurate / VP copolymer (Aristoflex® AVC de Clariant International Ltd.), l’acrylate / C10-30 alkyl acrylate crosspolymer (Carbopol® Ultrez 21) ou le Polyacrylate Crosspolymer-6 (tel que SEPIMAX ZEN™ vendu par SEPPIC).The gelling agent is particularly advantageous when chosen from among xanthan gum (such as Rhodicare® XC or T sold by Solvay Novecare or Keltrol® CG LAXT sold by CP Keltro), gellan gum (such as Kelcogel® CG-LA sold by Azelis), hydroxyethylcellulose (such as Klucel® GF and Natrosol® 250 HHX sold by Ashland), alkaligene polysaccharides (such as Alcasealan sold by Iwase Cosfa), sclerotium gum (INCI name: Sclerotium Gum) (such as Amigel® sold by Alban Muller International (Croda)), acrylate / C 10-30 alkyl acrylate crosspolymer (Carbopol® Ultrez 21), polyacrylate crosspolymer-6 (such as SEPIMAX ZEN™ sold by SEPPIC), and ammonium. acryloyldimethyltaurate / VP copolymer (Aristoflex® AVC of Clariant International Ltd.), and their mixtures.

[0035] The cosmetic composition of the invention may further include one or more cosmetic excipients such as opacifying agents, perfumes, reflective agents, coalescing agents, preservatives such as chlorphenesin (INCI name: CHLORPHENESIN), UVA and UVB ultraviolet protection agents, in particular filters, organic pigments and nano-pigments, such as zinc, iron and titanium oxides.

[0036] The cosmetic composition of the invention may be in the form of a gel, a lotion, a serum, a suspension, an oil-in-water emulsion, a water-in-oil emulsion, or a mask, and preferably in the form of a serum or an oil-in-water emulsion.

[0037] Another object of the invention relates to a method for preparing a cosmetic composition according to the invention, as described above.

[0038] The process for preparing the cosmetic composition of the invention comprises the following steps: (i) preparation of a mixture capable of forming an elastic film by dissolving in water: - at least one α-alginate or one of its derivatives, - at least one modified β- polysaccharide, and - at least one c- polyol selected from diols, polyglycerols of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 1 to 10, and their mixtures, and (ii) dispersion of the mixture obtained in step (i) in an aqueous phase possibly including cosmetic actives and / or excipients.

[0039] The components alginate a-, polysaccharide b- and polyol c-, implemented in the process of preparing the cosmetic composition of the invention are as defined above.

[0040] Advantageously, step (i) is carried out, under stirring, at a temperature ranging from 50 to 120°C, and preferably from 70 to 100°C, for a period ranging from 5 minutes to 1 hour, and preferably for about 30 minutes. The mixture obtained at the end of step (i) is then cooled to room temperature (20°C).

[0041] In step (i), the elastic mixture can be prepared by first dissolving the c- polyol in water. The a- alginate is then dissolved or dispersed in the water-c- polyol mixture, possibly with the addition of heat and stirring. Once the a- alginate has dissolved or dispersed, the b- modified polysaccharide is then added, with heat added to thoroughly homogenize the different components. Advantageously, the a- alginate and the b- modified polysaccharide are added successively, with stirring, at a temperature ranging from 50 to 120°C, and preferably from 70 to 100°C, for a period ranging from 5 minutes to 1 hour, and preferably for about 30 minutes. The mixture obtained at the end of step (i) is then cooled to room temperature (20°C).

[0042] In step (ii), the mixture prepared in step (i) is added to an aqueous phase comprising cosmetic actives and / or other cosmetic excipients.

[0043] According to another embodiment, the cosmetic composition of the invention is prepared by successively adding each of the components alginate a-, modified polysaccharide b-, and polyol c-, directly into the aqueous phase of the cosmetic composition, without prior mixing. Advantageously, the components alginate a-, modified polysaccharide b-, and polyol c- are added successively, with stirring, at a temperature ranging from 50 to 120°C, and preferably from 70 to 100°C, for a period ranging from 5 minutes to 1 hour, and preferably for approximately 30 minutes. The mixture obtained at the end of step (i) is then cooled to room temperature (20°C).

[0044] In the particular case of an emulsion, the components alginate a-, modified polysaccharide b-, and polyol c-, are added to the aqueous dispersing phase before dispersion of the oily phase.

[0045] Finally, a last object of the invention relates to a skin care process comprising a step of applying a cosmetic composition as defined according to the invention, on at least one part of the body and / or face, for a firming and smoothing effect.

[0046] In one embodiment, the application step on at least one part of the body and / or face is carried out on at least one area of ​​skin, in particular the face and / or décolleté, showing signs of aging or fatigue such as a loss of firmness, loss of elasticity, or sagging skin, to obtain an effect chosen from a smoothing effect, a tightening effect, a skin-bouncing effect, or a combination of one of these effects.

[0047] The cosmetic composition, when applied directly to the skin, forms a film after application and gradual evaporation of the water in the composition. This film exhibits elastic mechanical properties and a texture particularly well-suited to makeup application. Furthermore, this type of texture possesses properties that are useful both aesthetically and in terms of user comfort, especially near highly mobile areas such as the eyes and lips. The elastic properties of the cosmetic composition of the invention are particularly useful for application to areas of the body subject to significant movement, such as the skin of the face.

[0048] The skin care process may include the topical application to the affected areas of skin of an effective amount of a cosmetic composition according to the invention as defined above, to obtain a second-skin sensation.

[0049] In addition to the foregoing provisions, the invention also includes other provisions which will become apparent from the following supplementary description, which relates to the preparation of cosmetic compositions according to the invention and comparative cosmetic compositions.

[0050] Examples:

[0051] In the following examples, and unless otherwise indicated, all percentages are given as mass percentages, ingredients are designated by their INCI name, and the temperature is given in degrees Celsius.

[0052] Method for characterizing the smoothing effect:

[0053] The test consists of evaluating and comparing the smoothing and tightening effect on the area at the corner of the eye called "crow's feet" after 4 hours on a panel of four volunteers.

[0054] The elastic mixture was applied to the crow's foot and then left to dry for 15 minutes. Visual observations were made immediately after drying and after 4 hours.

[0055] Evaluation criteria:

[0056] +++ means that the product has a very significant smoothing / tightening effect on crow's feet,

[0057] ++ means that the product has a significant smoothing / tightening effect on crow's feet,

[0058] + means that the product has a slightly visible smoothing effect on crow's feet, and

[0059] x means that the product has no smoothing effect.

[0060] Example 1:

[0061] Two compositions according to the invention (compositions 1 and 2) were prepared and compared to two comparative compositions (compositions 3 and 4) corresponding to the following formulas:

[0062] [Tables 1] Ingredients (chemical names or INCI) Phases Quantity (% by weight) Composition 1 according to invention Composition 2 according to invention Comparative Composition 3 Comparative Composition 4 PURIFIED WATER Al QSP 100.00 QSP 100.00 QSP 100.00 QSP 100.00 CHLORPHENES IN Al 0.27 0.27 0.27 0.27 POLYGLYCERIN -3 (PGL-S) Al 9.00 - - - VEGETABLE GLYCEROL Al - 9.00 9.00 - RENEX™ PEG 6000 Al - - 9.00 ALGIN A2 3.00 3.00 3.00 3.00 TAPIOCA NATURAL A3 - - 6.00 - HYDROXYPROPYL STARCH A3 6.00 6.00 - 6.00

[0063] The ingredients of phase A1 were weighed into a beaker and then mixed using a deflocculating turbine in a water bath at 85°C. Phase A2 was weighed, added to phase A1, and mixed for 30 minutes at 600 rpm. Phase A3 was weighed, added to phase A1, and mixed at 600 rpm for 30 minutes. The mixture was removed from the water bath and cooled to room temperature.

[0064] The smoothing effect of these four compositions has been characterized. The results obtained are summarized in the following Table 2:

[0065] [Tables2] Immediate smoothing effect (at 15 min) Smoothing effect (4h) Composition 1 of the invention +++ +++ Composition 2 of the invention ++ +++ Composition 3 (comparative): +++ No smoothing effect. Composition 4 (comparative): + No smoothing effect.

[0066] Compositions 1 and 2 of the invention, comprising an alginate, a modified polysaccharide, and respectively as a polyol of POLYGLYCERIN-3 (PGL-S) or VEGETABLE GLYCEROL, exhibit a very good immediate and long-term (4-hour) smoothing effect. Composition 1 based on POLYGLYCERIN-3 (PGL-S) even exhibits an improved smoothing effect compared to composition 2 based on VEGETABLE GLYCEROL.

[0067] On the contrary, comparative composition 3 combining an alginate, an unmodified polysaccharide (TAPIOCA NATURAL), and a polyol, presents an immediate smoothing effect but which does not last over time.

[0068] Similarly, comparative composition 4, combining an alginate, a modified polysaccharide, and polyethylene glycol (PEG 6000), exhibits a slight immediate smoothing effect that does not last over time. The film becomes rigid and brittle.

[0069] Example 2: Anti-wrinkle serum according to the invention

[0070] An anti-wrinkle serum according to the invention corresponding to the composition of Table 3 below has been prepared.

[0071] [Tables3] Ingredients (chemical names or INCI) Phases Quantities (% by weight) PURIFIED WATER A QSP 100.0 HYDROXYPROPYL STARCH A 1.5 ALGIN A 1.0 DIGLYCERIN A 1.5 VEGETABLE GLYCEROL A 6.0 POLYGLYCERIN-3 (PGL-S) A 0.5 ACRYLATES / C10-30 ALKYL ACR YLATE CROSSPOLYMER A 0.3 AMMONIUM ACRYLOYLDIMETH YLTAURATE / VP COPOLYMER A 0.3 CHLORPHENESIN A 0.3 HYDROXYACETOPHENONE A 0.2 PURIFIED WATER B 0.5 SODIUM HYDROXIDE B <0.1 TRISODIUM ETHYLENEDIAMINE DISUCCINATE B <0.1 PURIFIED WATER C 1.1 TRISODIUM CITRATE C 0.1 CITRIC ACID C <0.1

[0072] The ingredients of phase A were weighed successively into a beaker, then mixed using a deflocculating turbine in a water bath at 85°C. Once the mixture was homogeneous, it was removed from the water bath. The ingredients of phase B were weighed and then added to phase A at 70°C. The ingredients of phase C were weighed and then added to the previous phase at 50°C. The mixture was then blended until it reached room temperature.

Claims

Demands

1. Cosmetic composition characterized in that it comprises a mixture capable of forming an elastic film comprising: a- at least one alginate, an alginate derivative, or mixtures thereof, b- at least one modified polysaccharide, and c- at least one polyol selected from diols, polyglycerols of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 1 to 10, and mixtures thereof.

2. Composition according to claim 1, characterized in alginate a- is sodium alginate (INCI name: ALGIN).

3. Composition according to claim 1 or claim 2, characterized in that the modified polysaccharide b- is a modified starch, selected from alkylated starches, hydroxyalkylated starches, acetylated starches, and mixtures thereof, and preferably hydroxyalkylated starches.

4. Composition according to claim 3, characterized in that the modified b- polysaccharide is hydroxypropyl starch (HYDROXYPROPYL STARCH).

5. Composition according to claim 4, characterized in that the hydroxypropyl starch (INCI name: HYDROXYPROPYL STARCH) has a weight average molecular weight greater than 106 g.mol1, and preferably from 106 to 109 g.mol1.

6. Composition according to any one of claims 1 to 5, characterized in that the c- polyol is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 1 to 10, and preferably from 1 to 6.

7. Composition according to claim 6, characterized in that the polyol c- is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 1, n = 3 or n = 6, and preferably a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 1 or n = 3.

8. Composition according to any one of claims 1 to 5, characterized in that the c- polyol is a diol selected from the C2-C12 aliphatic or aromatic, linear or branched diols, preferably propane-1,2-diol, propane-1,3-diol, butane-1,2-diol, butane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol, and mixtures thereof, and more preferably propane-1,3-diol.

9. Composition according to any one of claims 1 to 8, characterized in that it comprises a mixture capable of forming a film comprising: a- at least one alginate selected from sodium alginate (INCI name: ALGIN), b- at least one modified polysaccharide selected from hydroxypropyl starch (INCI name: HYDROXYPROPYL STARCH), and c- at least one polyol selected from a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 1 and / or 3.

10. Composition according to any one of claims 1 to 9, characterized in that it comprises from 0.1 to 15%, preferably from 0.1 to 10%, and more preferably from 0.5 to 5%, by weight of an alginate α- relative to the total weight of the cosmetic composition.

11. Composition according to any one of claims 1 to 10, characterized in that it comprises from 0.5 to 15%, preferably from 0.5 to 10%, and more preferably from 1 to 8%, by weight of b-modified polysaccharide relative to the total weight of the cosmetic composition.

12. Composition according to any one of claims 1 to 11, characterized in that it comprises from 1 to 20%, preferably from 3 to 15%, and more preferably from 5 to 10%, by weight of a c- polyol relative to the total weight of the cosmetic composition.

13. Composition according to any one of claims 1 to 12, characterized in that the weight ratio of polyol c- / (alginate a- + modified polysaccharide b-) varies from 20 / 80 to 80 / 20, and preferably from 40 / 60 to 60 / 40.

14. Composition according to any one of claims 1 to 13 characterized in that the mixture of alginate a-, modified polysaccharide b- and polyol c- represents from 0.5 to 50%, preferably from 1 to 30%, and more preferably from 5 to 25%, by weight relative to the total weight of the cosmetic composition.

15. Composition according to any one of claims 1 to 14 characterized in that it is in the form of a gel, lotion, serum, suspension, oil-in-water emulsion, or mask, and preferably in the form of a serum or an oil-in-water emulsion.

16. A method for preparing a cosmetic composition according to any one of claims 1 to 15, characterized in that it comprises the following steps: (i) preparing a mixture capable of forming a film by dissolving in water: - at least one alginate a- or one of its derivatives, - at least one modified polysaccharide b-, and - at least one polyol c- selected from diols, polyglycerols of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 1 to 10, and mixtures thereof, and (ii) dispersion of the mixture obtained in step (i) in an aqueous phase possibly including cosmetic actives and / or excipients.

17. A skin care method characterized in that it comprises a step of applying a composition as defined according to any one of claims 1 to 15, to at least one part of the body and / or face.

18. A method according to claim 17, characterized in that the application step on at least one part of the body and / or face is carried out on at least one area of ​​skin, in particular of the face and / or décolleté, showing signs of aging or fatigue such as loss of firmness, loss of elasticity, or sagging skin, to obtain an effect selected from a smoothing effect, a tightening effect, a skin-bouncing effect, or a combination of one of these effects.