Cosmetic composition comprising an elastic mixture based on tapioca starch

Abstract

The invention relates to a composition comprising a mixture which is capable of forming a flexible elastic film and comprises at least one natural starch selected from tapioca starch, derivatives thereof and mixtures thereof, at least one modified polysaccharide and at least one polyol. The composition provides a tightening effect and deforms elastically in order to follow the movements and the mechanical deformations of the surface of the skin. The present invention also relates to a method for preparing a cosmetic composition according to the invention, and to a skin care method comprising a step of applying a cosmetic composition according to the invention to the skin.

Description

Description Title of the invention: Cosmetic composition comprising an elastic mixture based on tapioca starch 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 surface of the skin. The present invention also relates to a process for preparing a cosmetic composition according to the invention, as well as a skin care process comprising a step of applying a cosmetic composition according to the invention to the skin.

[0002] Giving a smoothing effect to cosmetic compositions is a technique mastered in cosmetology. For this, we can use active ingredients, which penetrate the skin, and which will have a lasting effect over the long term. Film-forming polymers are also used for a smoothing effect, and their instantaneous mechanical actions on the surface of the skin. These smoothing materials, however, have certain drawbacks. First of all, once the product is applied to the skin, it is often uncomfortable due to the rigidity of the films formed. This rigidity of the films makes them poorly stretchable and inelastic, and consequently leads to poor durability of 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 consisting of at least one gelling or thickening starch, at least one polyol and at least one polymer chosen from polyvinyl alcohols, vinylpyrrolidone polymers and copolymers and latexes. These 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 having an immediate, visible and lasting smoothing effect. The film thus formed can deform reversibly, so that it resumes after deformation, for example after stretching, 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 intact the mechanical properties of the film formed on the surface of the skin. Once incorporated into a cosmetic composition, the mixture capable of forming this elastic film has an improved combined tensing and elastic effect, capable of following the movements of the skin without cracking.The effect obtained is comparable to a sheathing effect, the cosmetic composition of the invention providing elasticity to the skin naturally stressed by deformations, such as changes in facial expression or contact with the hands or clothing. The inventors have thus succeeded in developing a cosmetic composition capable of combining performances that are difficult to combine, namely a tightening effect combined with an elastic effect, which resolves the tightening / elasticity paradox. The new cosmetic composition is capable of acting effectively to smooth the surface of the skin, in particular obtaining a partial or total erasure of wrinkles, including medium and deep wrinkles.

[0005] The cosmetic composition of the invention has remarkable properties of tightening and elastic effect on the skin, properties which are linked to the simultaneous presence of a natural tapioca starch, a modified polysaccharide, and a polyol. The cosmetic composition thus obtained allows a visible and lasting smoothing of the surface of the skin with very great comfort of use. In addition, the nature of the ingredients used makes the cosmetic composition of the invention easily formulable. General description of the invention

[0006] The present invention relates firstly to a cosmetic composition which comprises a mixture capable of forming an elastic film comprising: a- at least one natural starch selected from tapioca starch (INCI name: TAPIOCA STARCH), its derivatives, and their mixtures, b- at least one modified polysaccharide, and c- at least one polyol.

[0007] Natural starch a- and modified polysaccharide b- are two different components of the cosmetic composition of the invention. They are both present, independently, in the composition.

[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, we speak indifferently of an elastic mixture or of a mixture capable of forming an elastic film.

[0009] A polymer is said to be film-forming within the meaning of the invention if, after evaporation of the volatile materials present in the medium, the formation of a continuous and homogeneous film is observed. Intermolecular bonds, responsible for the mechanical properties, are then formed between the polymer chains and with other components such as plasticizers to create a film that does not penetrate the skin and provides resistance to water and sebum, non-transfer, etc.

[0010] The elastic blend of the cosmetic composition of the invention comprises a natural starch a-, also called a contractile film-forming polymer, which provides an immediate smoothing / tightening (lifting) effect. This contractile effect occurs at the time of drying, with hydrogen bonds forming between the polymer chains to create a contraction.

[0011] The natural starch a- of the invention is advantageously tapioca starch (INCI name: TAPIOCA STARCH). As tapioca starch, it is possible to use, for example, that marketed under the reference TAPIOCA NATURAL by the company AGRANA. Among the tapioca starch derivatives, mention may be made of tapioca starch tapioca polymethylsilisesquioxane or tapioca starch modified with propylene oxide.

[0012] According to one embodiment, the cosmetic composition of the invention comprises from 0.1 to 15%, preferably from 0.5 to 10%, and more preferably from 1 to 5%, by weight of natural starch a- relative to the total weight of said cosmetic composition.

[0013] The elastic mixture of the cosmetic composition of the invention also comprises a b-modified polysaccharide, also called an elastic film-forming polymer, which provides an elastic effect (comfort) to the composition. The b-modified polysaccharide of the invention has the advantage of providing, when mixed with the other ingredients, an elastic dry film which is transparent and which 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 disturb over time the color of the deposit on the skin of the cosmetic composition into which the mixture has been introduced.

[0014] The modified polysaccharide b- different from the natural starch a- is advantageously a modified starch. The modified starches of the invention are obtained from native starches which have been modified chemically and / or physically and / or enzymatically, to improve their elastic properties. The native starches can come from a wide variety of sources, such as, for example, starches of corn, wheat, rice, buckwheat, barley, oats, millet, rye, sorghum, cassava, potato, sweet potato, tapioca, banana, plantain, malanga, tara, chestnut, beans, peas, and preferably native starches of corn, wheat, rice, cassava, potato, tapioca, 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 which are transparent and which remain transparent after stretching(s) when they are prepared in the form of thin films (typically with thicknesses of less than one millimeter). 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 disturb the color of the deposit on the skin over time.

[0016] The modified polysaccharide b- advantageously has a weight-average molecular weight greater than 10 6 g. mol' 1 (i.e. 1,000,000 g. mol' 1 ), preferably at least 10 7 g. mol 1 (i.e. 10,000,000 g. mol' 1), and more preferably at least 10 8 g. mol' 1 (i.e. 100,000,000 g. mol' 1 ). In a preferred embodiment, the modified polysaccharide b- has a weight average molecular weight ranging from 10 6 at 10 9 g. mol" 1 , preferably 10 7 at 10 9 g. mol -1 , and more preferably 10 8 at 10 9 g. mol' 1 . 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, mention may be made of alkylated starches, hydroxyalkylated starches, acetylated starches, and mixtures thereof, and more preferably hydroxyalkylated starches.

[0018] The b-modified polysaccharide is advantageously selected from hydroxyalkylated starches. In a preferred embodiment, the b-modified polysaccharide is hydroxypropylated starch which may have the INCI name: HYDROXYPROPYL STARCH, such as the Beauté By Roquette® ST 730 product marketed by the company ROQUETTE.

[0019] In a particularly preferred embodiment, the modified polysaccharide b- is a hydroxyalkylated starch, and even more preferably a hydroxypropylated starch, having a weight average molecular weight greater than 10 6 g. mol 1 , and advantageously 10 5 at 10 9 g. mol' 1 . The weight average molecular weight can be determined by HPSEC-MALLS.

[0020] The modified polysaccharide b- preferably represents from 0.1 to 15%, more preferably from 0.1 to 10%, and even more preferably from 0.5 to 8%, by weight relative to the total weight of the cosmetic composition. The modified polysaccharide b- may also preferably represent from 1 to 15%, more preferably from 2 to 10%, and even more preferably from 4 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, and making them more elastic and more flexible.

[0022] The polyol c- of the invention may be an alcohol having from 1 to 30 carbon atoms and 2 to 12 hydroxyl functions, and in particular an alcohol having from 2 to 10 carbon atoms and 2 to 4 hydroxyl functions. The polyol c- may also be a sugar such as glucose, sorbitol, mannitol. Advantageously, the polyol c- has a weight-average molecular weight which varies from 300 to 800 g. mol' 1 .

[0023] The polyol c- is advantageously selected from diols, starch hydrolysates, 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 mixtures thereof.

[0024] When the c- polyol is a starch hydrolyzate, and also meets the definition of a modified polysaccharide, in this case the b- modified polysaccharide is different from a starch hydrolyzate. This means that the starch hydrolyzate cannot be considered a b- modified polysaccharide.

[0025] According to one embodiment, the polyol c- is a diol selected from C2-Ci2 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] According to another embodiment, the polyol c- is a starch hydrolyzate selected from sorbitol, maltitol, xylitol, and mixtures thereof.

[0027] According to another embodiment, the polyol c- is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2) n -OH in which n varies from 1 to 10, and preferably from

[0028] According to a particularly advantageous embodiment, the polyol c- is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2) n-OH in which n = 1 (glycerol), n = 3 (POLYGLYCERIN-3 (PGL-S MB) or n = 6 (POLYGLYCERIN-6 (POLYGLYCERIN 500 MB)). POLYGLYCERIN-3 (PGL-S MB) and POLYGLYCERIN-6 (POLYGLYCERIN 500 MB) are marketed for example by the company SAKAMOTO YAKUHIN KOGYO. More specifically, it is glycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 1 or POLYGLYCERIN-3 (PGL-S MB) of formula H-(O-CH2-CH(OH)-CH2) n -OH in which n = 3.

[0029] The polyol c- preferably represents from 1 to 20%, preferably from 3 to 15%, and more preferably from 5 to 10%, by weight relative to the total weight of the cosmetic composition.

[0030] In one embodiment, the cosmetic composition of the invention comprises: a- from 0.1 to 15%, preferably from 0.5 to 10%, and more preferably from 1 to 5%, by weight of natural starch a-, b- from 1 to 15%, preferably from 2 to 10%, and more preferably from 4 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-, relative to the total weight of the cosmetic composition.

[0031] In one embodiment, the cosmetic composition of the invention comprises: a- from 0.1 to 15%, preferably from 0.5 to 10%, and more preferably from 1 to 5%, by weight of natural starch a-, b- from 0.1 to 15%, preferably from 0.1 to 10%, and more preferably from 0.5 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-, relative to the total weight of the cosmetic composition.

[0032] The quantities of each of the components a-, b- and c- are preferably chosen so that the cosmetic composition provides a pleasant sensation to the touch, 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 formulas, for example if it is a foundation or a serum, a compromise will be sought between adhesion 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 plasticity and elasticity.

[0033] The mass ratio of polyol c- / (natural starch a- + modified polysaccharide b-) is preferably between 20 / 80 and 80 / 20, and preferably 40 / 60 to 60 / 40.

[0034] According to a particularly advantageous embodiment, the cosmetic composition of the invention comprises a mixture capable of forming an elastic film comprising: a- at least one natural starch selected from tapioca starch (INCI name: TAPIOCA STARCH), its derivatives, and their mixtures, b- at least one modified polysaccharide selected from hydroxypropyl starch (INCI name: HYDROXYPROPYL STARCH), and c- at least one polyol selected from polyglycerol of formula H-(O-CH2- CH(OH)-CH2) n -OH in which n = 1 and / or 3 and / or 6, and preferably polyglycerol of formula H-(O-CH2-CH(OH)-CH2) n -OH in which n = 1 or 3, advantageously in the preferred weight % indicated above.

[0035] In the mixture capable of forming an elastic film of the cosmetic composition of the invention, the natural starch a-, the modified polysaccharide b-, and the polyol c-, are preferably present in proportions such that the elasticity of the dry film (free of water), with a thickness of between 50 and 1,000 microns, obtained from said mixture is characterized by: - a loss of elasticity, measured after at least one pull, less than 20%, and - resilience of at least 50%.

[0036] The elasticity of the elastic mixture present in the cosmetic composition of the invention can be measured by a method well known to those skilled in the art, for example with a TA.XT Plus reference texturometer (Stable Micro Systems), by measuring the force exerted by a dry film obtained from the mixture and undergoing a tensile test at an imposed speed. The thickness of the film chosen to carry out this measurement is preferably between 50 and 1,000 microns, and more preferably between 200 and 400 microns.

[0037] Tensile testing involves applying two opposing forces to the sample. The ends of a film sample are clamped between two jaws of the tensile testing machine, one fixed and the other attached to a pneumatic piston. The sample is then subjected to uniaxial stretching at a set speed over a given distance. The forces are recorded by the force sensor located on the fixed part of the machine, and a diagram is drawn showing the force exerted by the sample as a function of the elongation of the sample, as well as a diagram showing the force exerted by the sample as a function of time.

[0038] The residual strain rate is preferably measured after at least one tensile step, at a set distance equal to one third of the sample length, for example at a distance ranging from one third to four times its length. Successive stretching cycles can also be carried out by gradually increasing the stretching distance.

[0039] The quantity of elastic mixture introduced into the cosmetic composition of the invention is advantageously chosen according to the desired cosmetic effect and the desired viscosity. Indeed, the viscosity of the product must be compatible with regular, pleasant and sufficient application to the skin. The quantity of mixture capable of forming an elastic film is chosen in particular to allow the formation of an elastic film at the time of application of the cosmetic composition to the skin.

[0040] The proportions between the different components will be optimized to achieve the right viscoelasticity and good adhesion to the skin. Depending on the formula, for example if it is a foundation or a serum, a compromise will be sought between adhesion to the skin and the viscoelasticity of the cosmetic composition. For example, if the formula contains powders, the quantity of polyol to be introduced will be greater in order to maintain the plasticity and elasticity of the cosmetic composition.

[0041] 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 natural starch a-, modified polysaccharide b-, and polyol c-, as defined above. The mixture of natural starch a-, modified polysaccharide b-, and polyol c-, as defined above, is also called a mixture of active ingredients.

[0042] The cosmetic composition of the invention may further comprise an aqueous phase, which may comprise 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.

[0043] According to a variant of the invention, the cosmetic composition may further comprise at least one cosmetic active ingredient. The cosmetic active ingredient may in particular be advantageously chosen from a moisturizing agent, an anti-wrinkle agent, an antioxidant agent, an anti-free radical agent, an agent for repairing the destructive effects of ultraviolet rays, or a slimming agent such as caffeine. Preferably, the cosmetic active ingredient is chosen from 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.

[0044] The cosmetic composition of the invention may further comprise a gelling agent. As gelling agent, mention may advantageously be made of 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), copolymers with bis-decyltetradeceth-20 ether base (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 may also advantageously be mentioned, preferably chosen from ammonium acryloyldimethyltaurate / VP copolymer (Aristoflex® AVC from Clariant International Ltd.), acrylate / C10-30 alkyl acrylate crosspolymer (Carbopol® Ultrez 21) or Polyacrylate Crosspolymer-6 (such as SEPIMAX ZEN™ sold by SEPPIC). Particularly advantageously, the gelling agent is chosen from 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), alcaligenes polysaccharides (such as Alcasealan sold by Iwase Cosfa),Sclerotium gum (INCI name: Sclerotium Gum) (such as Amigel® sold by Alban Muller International (Croda)), acrylate / C10-30 alkyl acrylate crosspolymer (Carbopol® Ultrez 21), Polyacrylate Crosspolymer-6 (such as SEPIMAX ZEN™ sold by SEPPIC), ammonium acryloyldimethyltaurate / VP copolymer (Aristoflex® AVC from Clariant International Ltd.), and mixtures thereof.,

[0045] The cosmetic composition of the invention may further comprise one or more cosmetic excipients such as opacifying agents, perfumes, reflective agents, coalescing agents, preservatives such as chlorphenesin (INCI name: CHLORPHENESIN), protective agents against UVA and UVB ultraviolet rays, in particular filters, organic pigments and nano-pigments, such as zinc, iron and titanium oxides.

[0046] 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.

[0047] Another subject of the invention relates to a process for preparing a cosmetic composition according to the invention, as described previously.

[0048] 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 at least one natural starch a-, at least one modified polysaccharide b-, and at least one polyol c-, in water, and (ii) dispersion of the mixture obtained in step (i) in an aqueous phase optionally comprising cosmetic active ingredients and / or excipients.

[0049] The natural starch a-, polysaccharide b- and polyol c- components used in the process for preparing the cosmetic composition of the invention are as defined above.

[0050] Advantageously, step (i) is carried out, 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).

[0051] In step (i), the elastic mixture can be prepared by first dissolving the polyol c- in water. The natural starch a- is then dissolved or dispersed in the mixture of water and polyol c-, with the optional addition of heat and stirring. Once the natural starch a- is dissolved or dispersed, the modified polysaccharide b- is then added, with the addition of heat to ensure homogenize the different constituents with each other. Advantageously, the natural starch a- and the modified polysaccharide b- 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).

[0052] In step (ii), the mixture prepared in step (i) is added to an aqueous phase comprising cosmetic active ingredients and / or other cosmetic excipients.

[0053] According to another embodiment, the cosmetic composition of the invention is prepared by successively adding each of the components natural starch a-, modified polysaccharide b-, and polyol c-, directly into the aqueous phase of the cosmetic composition, without prior mixing. Advantageously, the components natural starch 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).

[0054] In the particular case of an emulsion, the components natural starch a-, modified polysaccharide b-, and polyol c-, are added to the dispersing aqueous phase before dispersion of the fatty phase.

[0055] Finally, a final object of the invention relates to a skin care method comprising a step of applying a cosmetic composition as defined according to the invention, to at least one part of the body and / or the face, for a smoothing and firming (firming) effect.

[0056] In one embodiment, the step of applying to 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, a loss of elasticity, or sagging. skin, to obtain an effect chosen from a smoothing effect, a tightening effect, a skin plumping effect, or a combination of one of these effects.

[0057] The cosmetic composition directly applied to the skin forms, after application and gradual evaporation of the water in the composition, a film which has elastic-type mechanical properties with a texture which is particularly well suited to makeup. In addition, this type of texture has useful properties both in terms of aesthetics and comfort of use, particularly 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.

[0058] The skin care method may comprise the topical application to the areas of the skin concerned of an effective amount of a cosmetic composition according to the invention as defined above, to obtain a second skin sensation.

[0059] In addition to the preceding provisions, the invention also comprises other provisions which will emerge from the additional description which follows, which relates to the preparation of cosmetic compositions according to the invention and comparative cosmetic compositions.

[0060] Examples:

[0061] In the following examples, and unless otherwise indicated, all percentages are given in mass percentages, the ingredients are designated by their INCI name, and the temperature is indicated in degrees Celsius.

[0062] Methods for characterizing elastic films: - Elastic properties (fatigue resistance): Fatigue resistance was assessed using a TA.XT Plus texturometer (Stable Micro Systems). The prepared elastic films were cast into Teflon® molds and dried at 33°C under 50% relative humidity to achieve a thickness of 200 to 400 μm dry. 5 x 3 cm specimens were then cut and subjected to repeated stretching: 25 cycles of 50% stretching back and forth at 1 mm / second. Elastic properties (fatigue resistance) were ranked from most elastic (+++) to least elastic (+). - Evaluation of the contractile effect on nitrile support: The contractile effect of the elastic films was evaluated visually at room temperature (20°C). A nitrile glove cut into a 3 x 5 cm test piece was used as a support. The elastic mixtures were spread with a spatula on the nitrile support to obtain a dry film mass of 0.05 g, which corresponds to a dry film thickness (or remaining dry mass) of 33 • μm, and then left to dry for 24 hours at room temperature (20°C). During the drying of the elastic films, they shrink more or less and are classified into three categories: Category 1: the support is not retracted, the film does not show any contractile effect, Category 2: the support has slightly retracted compared to the start of the test, a contractile effect is visible, Category 3: the support has retracted and rolled up on itself, the contractile effect is significant. - In vivo smoothing effect characterization test at 15 minutes and after 4 hours: The test consists of evaluating and comparing the smoothing and tightening effect on the area of ​​the corner of the eye called "crow's feet" after 4 hours on a panel of three volunteers. The elastic mixture was applied to the crow's feet and then allowed to dry for 15 minutes. Visual observations were made immediately after drying and after 4 hours. Evaluation criteria: +++ means that the product has a very significant smoothing / tightening effect on crow's feet, ++ means that the product has a significant smoothing / tightening effect on crow's feet, + means the product has a slightly visible smoothing effect on crow's feet, and x means the product has no smoothing effect.

[0063] Example 1:

[0064] Two mixtures A and B corresponding to the formulas in Table 1 were compared:

[0065] [Table 1]

[0066] Two aqueous dispersions each comprising one of the mixtures A or B were prepared according to the formula in Table 2 below:

[0067] [Table 2]

[0068] The Al phase was weighed into a beaker, placed in a water bath at 85°C, and mixed using a deflocculating turbine at 150 rpm. The A2 phase was weighed into a dish, added to the Al phase, and mixed for 30 minutes at 600 rpm. The A3 phase was weighed into a dish, added to the Al phase, and mixed for 30 minutes at 600 rpm. Once homogenized, the prepared mixture was removed from the water bath and cooled to room temperature under stirring at 300-400 rpm. The thus prepared compositions were then used to form elastic films, which were evaluated.

[0069] The observed and measured characteristics for compositions 1 and 2 are summarized in the following Table 3:

[0070] [Table 3]

[0071] Composition 1 of the invention presents a better compromise between tensor effect and elastic effect than comparative composition 2. Composition 1 leads to an elastic film, presenting an immediate and lasting smoothing effect. On the contrary, comparative composition 2 leads to an elastic film presenting a reduced immediate smoothing effect.

[0072] Example 2:

[0073] Two elastic mixtures C and D respectively comprising hydroxypropyl starch (HYDROXYPROPYL STARCH) having a weight average molecular weight greater than 10 6 g. mol' 1and hydroxyethylcellulose (HEC), as b-modified polysaccharides, were prepared according to the procedure described below. Their compositions of elastic mixtures C and D are as follows:

[0074] [Table 4]

[0075] The elastic mixtures were prepared according to the following process: The ingredients of phase Al were placed in a water bath at a temperature of 85°C, and mixed in a deflocculator. Phases A2 and A3 were weighed and added to the previously prepared phase Al. The mixture was mixed at 600 rpm for 30 minutes at 85°C. The elastic mixtures obtained were cooled to room temperature (20°C).

[0076] The smoothing effect of these elastic mixtures was evaluated according to the characterization test described above. The results obtained for the two mixtures are presented in Table 5 below:

[0077] [Table 5]

[0078] Example 3:

[0079] Two elastic mixtures E and F comprising respectively hydroxypropyl starch (HYDROXYPROPYL STARCH) having a weight average molecular weight of 10 5 g. mol' 1 and 10 8 g. mol' 1 , as b-modified polysaccharides, were prepared according to the procedure described below. Their compositions of elastic mixtures E and F are as follows:

[0080] [Table 6]

[0081] The elastic mixtures were prepared according to the following process: The ingredients of phase Al were placed in a water bath at a temperature of 85°C, and mixed in a deflocculator. Phases A2 and A3 were weighed and added to the previously prepared phase Al. The mixture was mixed at 600 rpm for 30 minutes at 85°C. The elastic mixtures obtained were cooled to room temperature (20°C).

[0082] The smoothing effect of these elastic mixtures was evaluated according to the characterization test described above. The results obtained for the two mixtures are presented in Table 7 below:

[0083] [Table 7]

[0084] Example 4: Preparation and characterization of oil-in-water creams

[0085] An oil-in-water cream formula according to the invention (Formula 3) was prepared and compared with a comparative oil-in-water cream formula (Formula 4) free of b-modified polysaccharide, both formulas having the following compositions:

[0086] [Table 8]

[0087] The ingredients of phase Al were weighed into a beaker and then mixed using a deflocculating turbine in a water bath at 80°C. Phase A2 was weighed, added to phase Al in a fine rain, and mixed at 600 rpm for 30 minutes. Phase A3 was weighed, added to phase Al in a fine rain, and mixed at 600 rpm for 30 minutes. Phase B1 was weighed into a beaker and melted at 85°C. Phase B was emulsified into phase A at 1000 rpm for 5 minutes, then removed from the water bath. The speed was decreased to 800 rpm. Phases C, D, and E were then added during cooling. Phase F was added at 40°C.

[0088] The characteristics measured for Formula 3 of the invention and comparative Formula 4 are summarized in the following Table 9:

[0089] [Table 9]

[0090] Formula 3 of the invention combining a natural starch based on tapioca a-, modified polysaccharide b-, and polyol c-, exhibits a smoothing effect significantly increased over time compared to the comparative Formula 4 free of b-modified polysaccharide, which crumbles over time and loses its smoothing effect.

[0091] Example 5: Preparation of an anti-wrinkle cream according to the invention

[0092] An anti-wrinkle cream according to the invention (Formula 5) having the following composition was prepared:

[0093] [Table 10]

[0094] The ingredients of phase Al were weighed into a beaker and then mixed using a deflocculating turbine in a water bath at 80°C. Phase A2 was weighed, added to phase Al, and then dispersed at 10,000 rpm for 5 minutes. Phase A3 was weighed, added to the previous phase, and then dispersed at 10,000 rpm for 30 minutes. The resulting phase was removed from the water bath. Phase A4 was weighed into a beaker and then dispersed in the previously prepared phase for 30 minutes. Phases A5, A6 and A7 were then added and then dispersed at 10,000 rpm for one minute. Phase B1 was dispersed separately, before adding phase B2. Phase B was then emulsified in the previously prepared phase A, at 700 rpm for 2 minutes, then dispersed at 10,000 rpm until a homogeneous mixture was obtained.

[0095] Formula 5 of the invention combining a natural starch based on tapioca a- , of modified polysaccharide b-, and polyol c-, exhibits a significant immediate and lasting smoothing / tightening effect.

Claims

Claims

1. Cosmetic composition characterized in that it comprises a mixture capable of forming an elastic film comprising: a- at least one natural starch selected from tapioca starch (TAPIOCA STARCH), its derivatives, and their mixtures, b- at least one modified polysaccharide, and c- at least one polyol.

2. Composition according to claim 1, 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.

3. Composition according to claim 2, characterized in that the modified polysaccharide b- is hydroxypropyl starch (HYDROXYPROPYL STARCH).

4. Composition according to claim 3, characterized in that the hydroxypropyl starch (HYDROXYPROPYL STARCH) has a weight average molecular weight greater than 10 6 g.moL 1 , preferably at least 10 7 g. mol 1 , and more preferably at least 10 8 g. mol' 1

5. Composition according to claim 4, characterized in that the hydroxypropyl starch (HYDROXYPROPYL STARCH) has a weight average molecular weight ranging from 10 6 at 10 9 g. mol 1 , preferably 10 7 at 10 9 g. mol 1 , and more preferably 10 8 at 10 9 g. mol' 1 .

6. Composition according to one of claims 1 to 5, characterized in that the polyol c- is selected from diols, starch hydrolysates, 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 mixtures thereof.

7. Composition according to one of claims 1 to 6, characterized in that the polyol c- is a diol selected from aliphatic or aromatic, linear or branched C2-C12 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.

8. Composition according to one of claims 1 to 6, characterized in that the polyol c- 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, the polyol c- preferably being a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 1 or 3.

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

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

11. Composition according to one of claims 1 to 10, characterized in that it comprises from 0.1 to 15%, preferably from 0.1 to 10%, and more preferably from 0.5 to 8%, by weight of modified polysaccharide b- relative to the total weight of the cosmetic composition.

12. Composition according to 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 polyol c- relative to the total weight of the cosmetic composition.

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

14. Composition according to one of claims 1 to 13, characterized in that the mixture of natural starch a-, modified polysaccharide b- and polyol c- (mixture of active materials) 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 one of claims 1 to 14, characterized in that it is in the form of a gel, a lotion, a serum, a suspension, an oil-in-water emulsion, or a mask, and preferably in the form of a serum or an oil-in-water emulsion.

16. Process for preparing a cosmetic composition according to one of claims 1 to 15, characterized in that it comprises the following steps: (i) preparation of a mixture capable of forming a film by dissolving in water: - at least one natural starch a- selected from tapioca starch (TAPIOCA STARCH), its derivatives, and their mixtures, - at least one b-modified polysaccharide, and - at least one c-polyol, and (ii) dispersion of the mixture obtained in step (i) in an aqueous phase optionally comprising cosmetic active ingredients and / or excipients.

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

18. Method according to claim 17, characterized in that the step of applying to 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 a loss of firmness, a loss of elasticity, or sagging skin, to obtain an effect chosen from a smoothing effect, a tightening effect, a skin plumping effect, or a combination of one of these effects.

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