Cosmetic composition comprising an elastic mixture based on chitosan, pullulan and polyglycerol

Abstract

A cosmetic composition comprising an elastic mixture based on chitosan, pullulan, and polyglycerol. The invention relates to an elastic mixture comprising chitosan or one of its salts, pullulan or one of its salts, and polyglycerol, 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 cosmetic composition comprising an elastic mixture according to the invention, a method for preparing a cosmetic composition according to the invention, and 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 mixture based on chitosan, pullulan and polyglycerol. Technical field

[0001] The present invention relates to the cosmetic field, and more particularly to an elastic mixture and a cosmetic composition comprising an elastic mixture according to the invention, which provide a tightening effect and deform elastically to follow the movements and mechanical deformations of the skin surface. The present invention also relates to a method for preparing an elastic mixture and 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] Communicating anti-wrinkle effects with immediate and lasting skin smoothing is a key asset and a powerful driver of innovation and consumer satisfaction. Currently, the immediate anti-wrinkle smoothing effect is primarily achieved through the incorporation of contractile film-forming polymers, known for their tightening effect. However, the effectiveness of these polymers is very limited, either due to their durability (the polymer film cracks) and lack of comfort, or due to an ineffective smoothing effect (the comfort / tightening effect paradox is not achieved). Furthermore, to date, the smoothing effect provided by tightening polymers is insufficient compared to consumer expectations and is not long-lasting at a sensorially acceptable dose.

[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 specific compound blend capable of forming an elastic film with an immediate, visible, and lasting smoothing effect. The solution proposed by the inventors consists of combining a tensile polymer (highly contractile but rigid) with a polymer possessing good elastic properties obtained through optimized plasticization (selection of glycols). 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 skin deformation. The film that forms The said mixture has greater resistance to breakage, which allows the mechanical properties of the film formed on the skin's surface to remain intact. Once incorporated into a cosmetic composition, the elastic mixture of the invention has an enhanced combined tightening and elastic effect, capable of following the skin's movements without cracking. The effect obtained is comparable to a sheathing effect, the elastic mixture of the invention providing elasticity to the skin naturally subjected to deformations, such as changes in facial expression or contact with hands or clothing.The inventors have thus succeeded in overcoming the paradox of skin tightening (wrinkle smoothing by contraction of the polymer film on the skin's surface) versus elasticity (for comfort and long-lasting effect), and in developing a cosmetic blend capable of combining performance characteristics that are difficult to reconcile: a tightening effect combined with an elastic effect, thereby resolving the skin tightening / elasticity paradox. Cosmetic compositions comprising the elastic blend of the invention are capable of effectively smoothing the skin's surface, notably achieving partial or total erasure of wrinkles, including medium and deep wrinkles.

[0005] The elastic blend of the invention exhibits remarkable skin-tightening and elastic properties, which are linked to the combination of polymers selected for their contraction properties with elastic polymers (elastic properties optimized by the combination with a selection of glycol-type plasticizers). Cosmetic compositions comprising the elastic blend of the invention provide a visible and lasting smoothing of the skin surface with very high user comfort. General description of the invention

[0006] The present invention relates first to an elastic or skin-tightening mixture comprising: a- at least one polysaccharide selected from chitosan, its salts, and mixtures thereof, b- at least one polysaccharide, different from polysaccharide a-, selected from pullulan, its salts, and mixtures thereof, and c- at least one polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 2 to 10, and d- water.

[0007] In the following description, we speak interchangeably of "elastic mixture" or "mixture capable of forming an elastic film" or "mixture with skin-tightening effect".

[0008] 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, the formation of a film is observed. Intermolecular bonds, responsible for mechanical properties, then form 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.

[0009] The elastic mixture of the invention comprises an α-polysaccharide, 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] The α- polysaccharide of the invention is advantageously an unmodified chitosan. The chitosan that may be used in the context of the invention may be fully or partially deacetylated chitins. The molecular mass of the chitosan used may vary from 20,000 to approximately 5,000,000 g·mol⁻¹, preferably from 100,000 to 700,000 g·mol⁻¹. The degree of deacetylation of the chitosan may preferably vary from 50 to 99%.

[0011] The unmodified chitosan of the invention is advantageously selected from chitosan of natural origin, in particular of fungal or crustacean origin, for example from crabs, lobsters, squid, or shrimp. In a particularly preferred embodiment, the α- polysaccharide is fungal chitosan. Fungal chitosan can be marketed, for example, under the name CHITOSAN FUNGAL.

[0012] The elastic mixture of the invention also comprises a β-polysaccharide selected from pullulan, its salts, and mixtures thereof, also called an elastic film-forming polymer, which provides an elastic (comfortable) effect to the mixture. The β-polysaccharide of the invention has the advantage of providing, when mixed with the other ingredients of the elastic mixture, 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 elastic mixture of the invention has been incorporated.

[0013] Pullulan is a water-soluble exopolysaccharide produced by the fungus Aureobasidium pullulans. It is a polysaccharide composed of maltotriose units, also known as α-1,4-;α,6-glucan. The three glucose units that make up the maltotriose are linked by α-1,4- glycosidic bonds, while the maltotriose units are linked to each other by α-1,6- glycosidic bonds.

[0014] The elastic mixture of the invention also comprises a c-polyglycerol, which aids in the dispersion and plasticizes the polymers present in the elastic mixture. Thus, the c-polyglycerol acts as a plasticizer by providing mobility between the chains polymer, making them more elastic and flexible, and providing an improved smoothing effect combined with better durability.

[0015] Polyglycerol c- is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 2 to 10, and preferably from 2 to 6.

[0016] According to a particularly advantageous embodiment, the c- polyglycerol is a polyglycerol of the formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 3 and / or 6 (POLYGLYCERIN-3 (PGL-S) and / or POLYGLYCERIN-6 (POLYGLYCERIN 500)), marketed, for example, by SAKAMOTO YAKUHIN KOGYO. More specifically, it is the polyglycerol of the formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 3 (POLYGLYCERIN-3), marketed by SAKAMOTO YAKUHIN KOGYO under the reference PGL-S. Compared to other polyols, PO-LYGLYCERIN-3 and / or POLYGLYCERIN-6 allow for a better level of plasticization of the α- and β- polysaccharides on the skin surface.

[0017] According to one embodiment, the elastic mixture of the invention comprises from 0.1 to 15%, preferably from 0.2 to 10%, and more preferably from 0.5 to 7%, by weight of polysaccharide a- relative to the total weight of said elastic mixture.

[0018] According to one embodiment, the elastic mixture of the invention comprises from 0.1 to 10%, preferably from 0.5 to 8%, and more preferably from 1 to 5%, by weight of β- polysaccharide relative to the total weight of said elastic mixture.

[0019] According to one embodiment, the elastic mixture of the invention comprises from 0.1 to 20%, preferably from 0.5 to 15%, and more preferably from 1 to 10%, by weight of c- polyglycerol relative to the total weight of said elastic mixture.

[0020] According to one embodiment, the elastic mixture of the invention comprises from 60 to 99%, preferably from 65 to 98%, and more preferably from 70 to 95%, by weight of water d- relative to the total weight of said elastic mixture.

[0021] According to a particularly advantageous embodiment, the elastic mixture of the invention comprises: a- at least one polysaccharide selected from chitosan (CHITOSAN), b- at least one polysaccharide selected from pullulan (PULLULAN), c- at least one polyglycerol selected from polyglycerol of the formula H-(O-CH2 -CH(OH)-CH2)n-OH in which n = 3 and / or 6 (POLYGLYCERIN-3 and / or POLY-GLYCERIN-6), and d- of water, advantageously in the % by weight indicated previously.

[0022] The weight ratio [polysaccharide a- / polysaccharide b-] within the elastic mixture advantageously varies from 1 / 4 to 4 / 1, and more advantageously from 1 / 3 to 2 / 1.

[0023] The weight ratio [(polysaccharide a- + polysaccharide b-) / polyglycerol c-] within the elastic mixture advantageously varies from 1 / 3 to 3 / 1, and more advantageously from 1 / 2 to 2 / 1.

[0024] According to one embodiment, the elastic mixture of the invention may further comprise one or more cosmetic excipients such as preservatives like chlorphenesin and glycols such as pentylene glycol, or pH-adjusting agents such as alkali hydroxides (sodium hydroxide or ammonium hydroxide, for example). When present, the pH-adjusting agent is advantageously used in an amount that gives the cosmetic composition a pH ranging from 4.0 to 6.0, and preferably from 5.0 to 6.0.

[0025] A second object of the invention relates to a cosmetic composition comprising an elastic mixture as defined according to the invention. Thus, the elastic mixture of the invention can be used as such, as an ingredient in a cosmetic composition.

[0026] The amount of elastic mixture introduced into the cosmetic composition of the invention is advantageously chosen according to the desired cosmetic effect and viscosity. Indeed, the viscosity of the product must be compatible with regular, pleasant, and sufficient application to the skin. The amount of elastic mixture to be incorporated into the cosmetic composition is chosen in particular to allow the formation of an elastic film upon application of the cosmetic composition to the skin.

[0027] In an advantageous embodiment, the cosmetic composition of the invention contains from 10 to 100%, preferably from 15 to 95%, and more preferably from 15 to 90%, by weight relative to the total weight of the cosmetic composition, of the elastic mixture of the invention consisting of polysaccharide a-, polysaccharide b-, poly-glycerol c-, and water d-, ​​as defined above.

[0028] In an advantageous embodiment, the cosmetic composition of the invention contains from 0.5 to 30%, preferably from 1 to 25%, and more preferably from 2 to 25%, by weight of α-polysaccharide, β-polysaccharide, and β-polyglycerol, as defined above, relative to the total weight of the cosmetic composition. The mixture of α-polysaccharide, β-polysaccharide, and β-polyglycerol, as defined above, is also referred to as the mixture of active ingredients.

[0029] According to one embodiment, the cosmetic composition of the invention comprises from 0.1 to 15%, preferably from 0.2 to 10%, and more preferably from 0.5 to 5%, by weight of a- polysaccharide relative to the total weight of said cosmetic composition.

[0030] According to one embodiment, the cosmetic composition of the invention comprises from 0.1 to 10%, preferably from 0.5 to 5%, and more preferably from 1 to 5%, by weight of β- polysaccharide relative to the total weight of the cosmetic composition.

[0031] According to one embodiment, the cosmetic composition of the invention comprises from 0.1 to 20%, preferably from 0.5 to 15%, and more preferably from 1 to 5%, by weight of polyglycerol c- relative to the total weight of the cosmetic composition.

[0032] According to one embodiment, the cosmetic composition of the invention comprises from 15 to 99%, preferably from 15 to 90%, and more preferably from 15 to 80%, by weight of water relative to the total weight of the cosmetic composition. In the case of an oil-in-water emulsion, the amount of water preferably varies from 40 to 60% by weight relative to the total weight of the cosmetic composition. In the case of a water-in-oil emulsion, the amount of water preferably varies from 15 to 60% by weight relative to the total weight of the cosmetic composition. In the case of an aqueous dispersion, the amount of water represents at least 60%, and preferably at least 70% by weight relative to the total weight of the cosmetic composition.

[0033] In one embodiment, the cosmetic composition of the invention comprises: a- from 0.1 to 15%, preferably from 0.2 to 10%, and more preferably from 0.5 to 5%, by weight of polysaccharide a- selected from chitosan, its salts, and mixtures thereof, b- from 0.1 to 10%, preferably from 0.5 to 5%, and more preferably from 1 to 5%, by weight of polysaccharide b- selected from pullulan, its salts, and mixtures thereof, and c- from 0.1 to 20%, preferably from 0.5 to 15%, and more preferably from 1 to 5%, by weight of polyglycerol c- of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 2 to 10, relative to the total weight of the cosmetic composition.

[0034] 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 makeup composition, such as a foundation, or a skincare composition, such as a cream or 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 polyglycerol c- to be introduced will be greater in order to maintain a certain plasticity and elasticity of the formula.

[0035] According to a particularly advantageous embodiment, the cosmetic composition of the invention comprises an elastic mixture according to the invention based on: a- at least one polysaccharide selected from chitosan (CHITOSAN), b- at least one polysaccharide selected from pullulan (PULLULAN), c- at least one polyglycerol selected from polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 3 and / or 6 (POLYGLYCERIN-3 and / or POLY- GLYCERIN-6), d- water, advantageously in the % by weight indicated previously.

[0036] According to one embodiment, the cosmetic composition of the invention 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. In one aspect, the cosmetic composition of the invention may contain 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.

[0037] According to one embodiment, the cosmetic composition of the invention may further comprise at least one gelling agent for the aqueous phase of the composition, preferably selected from hydrophilic gelling agents suitable for gelling the aqueous phase. In the case where the cosmetic composition of the invention also comprises an oily phase, for example an oily phase, the cosmetic composition of the invention may also comprise at least one gelling agent for the oily phase of the composition, preferably selected from lipophilic gelling agents suitable for gelling the oily phase.

[0038] According to one embodiment, the cosmetic composition of the invention may further comprise at least one pH adjusting agent. This pH adjusting agent is advantageously chosen from alkali hydroxides such as sodium hydroxide or ammonium hydroxide, triethanolamine, 2-amino-2-(hydroxymethyl)-1,3-propanediol, borates, phosphates, pyrophosphates, ascorbic acid and its salts such as trisodium citrate dihydrate, sorbic acid and its salts, phosphoric acid and its salts, citric acid and its salts, lactic acid and its salts, boric acid and its salts, acetic acid and its salts, preferably alkali hydroxides, and more preferably an alkali hydroxide such as sodium hydroxide. When present, the pH adjusting agent is advantageously used in an amount that gives the cosmetic composition a pH ranging from 4.0 to 7.0, and preferably from 4.0 to 6.5.

[0039] According to one embodiment, 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 and glycols of the pentylene glycol type, UVA and UVB ultraviolet protection agents, in particular filters, organic and / or inorganic pigments, such as zinc, iron and titanium oxides.

[0040] The cosmetic composition of the invention may be in the form of a gelled or non-gelled aqueous composition of a gelled or non-gelled emulsion, of the oil-in-water or water-in-oil type, of a cream, of a serum, of a mask, or of a foundation.

[0041] In the case of an oil-in-water emulsion, for example a skincare cream, the elastic mixture of the invention forms the continuous phase of said emulsion.

[0042] In the case of a water-in-oil emulsion, for example a foundation, the elastic mixture of the invention forms the dispersed phase of said emulsion.

[0043] Another object of the invention relates to a method for preparing an elastic mixture according to the invention, as described above, said method comprising a step of dissolving at least one polysaccharide a-, at least one polysaccharide b-, and at least one polyglycerol c-, in water d-.

[0044] Advantageously, the dissolution step is carried out, under stirring, at a temperature ranging from 50 to 90°C, and preferably from 70 to 90°C, for a duration ranging from 5 minutes to 1 hour, and preferably for about 30 minutes. The mixture obtained at the end of the dissolution step is then cooled to room temperature (20°C).

[0045] During the dissolution step, the elastic mixture can be prepared by first dissolving the c- polyglycerol in water. The α- polysaccharide is then dissolved or dispersed in the water-α- polyglycerol mixture, possibly with the addition of heat and stirring. Once the α- polysaccharide has dissolved or dispersed, the β- polysaccharide is then added, with heat added to thoroughly homogenize the different components. Advantageously, the α- and β- polysaccharides are added successively, with stirring, at a temperature ranging from 50 to 90°C, and preferably from 70 to 90°C, for a period ranging from 5 minutes to 1 hour, and preferably for about 30 minutes. The mixture obtained after the dissolution step is then cooled to room temperature (20°C).

[0046] The invention also relates to a method for preparing a cosmetic composition according to the invention, as described above, said method comprising the following steps: (i) preparation of an elastic mixture according to the invention by dissolving in water: - at least one α- polysaccharide selected from chitosan, its salts, and mixtures thereof, - at least one β- polysaccharide selected from pullulan, its salts, and mixtures thereof, and - at least one c- polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 2 to 10, and (ii) dispersion of the elastic mixture obtained in step (i) in an aqueous phase possibly including cosmetic active ingredients and / or excipients.

[0047] Advantageously, step (i) is carried out, under stirring, at a temperature ranging from 50 to 90°C, and preferably from 70 to 90°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).

[0048] In step (i), the elastic mixture can be prepared by first dissolving the c- polyglycerol in water. The a- polysaccharide is then dissolved or dispersed in the water-c- polyglycerol mixture, possibly with the addition of heat and stirring. Once the a- polysaccharide has dissolved or dispersed, the b- polysaccharide is then added, with heat added to thoroughly homogenize the different components. Advantageously, the a- and b- polysaccharides are added successively, with stirring, at a temperature ranging from 50 to 90°C, and preferably from 70 to 90°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).

[0049] In step (ii), the mixture prepared in step (i) can be added to an aqueous phase comprising cosmetic actives and / or other cosmetic excipients.

[0050] According to another embodiment, the cosmetic composition of the invention is prepared by successively adding each of the components polysaccharide a-, polysaccharide b-, and polyglycerol c-, as defined according to the invention, directly into the aqueous phase of the cosmetic composition, without prior mixing. Advantageously, the components polysaccharide a-, polysaccharide b-, and polyglycerol c- are added successively, with stirring, at a temperature ranging from 50 to 90°C, and preferably from 70 to 90°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 the particular case of an emulsion, the oily phase can be added to the aqueous phase comprising the elastic mixture.

[0052] Another object of the invention relates to the use of an elastic mixture as defined according to the invention in a cosmetic composition as defined according to the invention intended to be applied to the skin, to form an elastic film providing a smoothing and / or sheathing effect on the skin.

[0053] 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 smoothing and firming effect.

[0054] In one embodiment, the step of applying to at least one part of the body and / or the face is performed 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 chosen from a smoothing effect, a tightening effect, a skin-bouncing effect, or a combination of one of these effects.

[0055] 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.

[0056] 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.

[0057] 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 and evaluation of elastic mixtures in relation to representative elastic mixtures of the state of the art, as well as to the preparation of cosmetic compositions according to the invention.

[0058] Examples:

[0059] In the examples, and unless otherwise indicated, all percentages are percentages by weight, ingredients are designated by their INCI name, and the temperature is indicated in degrees Celsius.

[0060] Example 1: Selection of plasticizer (polyglycerol c-1) for the preparation of an elastic mixture with a smoothing effect according to the invention

[0061] This example aims to select a plasticizer (polyglycerol c-) enabling the preparation of a film obtained from an elastic mixture comprising a first polymer selected for its shrinkage properties and a second polymer selected for its elastic properties. The plasticizers tested are PROPYLENE GLYCOL (Control 1), VEGETABLE GLYCEROL (Control 2), POLYGLYCERIN-3 (Invention 1), and a mixture of POLYGLYCERIN-3 + POLYGLYCERIN-6 (Invention 2).

[0062] [Tables 1] Control Phase 1 Control Phase 2 Invention 1 Invention 2 A WATER QSP 100% A Preservative 0.3% by weight CHLORPHENESIN A pH Adjuster < 0.1% by weight SODIUM HYDROWE QSP pH 55 A: GLYCOLS 9% by weight PROPYLENE GLYCOL 9% by weight VEGETABLE GLYCEROL i 6.75% by weight , i POLYGLYCERIN-3 9% by weight ■ POLYGLYCERIN-3 , ■ 2.2% by weight POLYGLYCERIN-3 B Polysaccharide α-(contractile polymer) 3% by weight CHITOSAN C Polysaccharide β-(elastic polymer) 8% by weight PULLULAI

[0063] The elastic mixtures were prepared according to the following process:

[0064] The ingredients of phase A were mixed in a deflocculator at 85°C.

[0065] Phase B was added to the previously prepared phase A.

[0066] The mixture was blended at 400 revolutions per minute for 30 minutes at 85°C.

[0067] The resulting mixture was cooled to room temperature (20°C).

[0068] Phase C was added to the mixture at room temperature (20°C), and the resulting dispersion was mixed for 15 minutes.

[0069] In vivo smoothing effect characterization test at 4 hours:

[0070] 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.

[0071] 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.

[0072] Evaluation criteria:

[0073] +++ means that the product has a very significant smoothing / tightening effect on crow's feet,

[0074] ++ means that the product has a significant smoothing / tightening effect on crow's feet,

[0075] + means that the product has a slightly visible smoothing effect on crow's feet, and

[0076] X means that the product has no smoothing effect.

[0077] The results obtained for the four elastic mixtures tested are presented in Table 2 below:

[0078] [Tables2] Immediate tightening / stressing effect Control 1 Control 2 + + + i X Invention 1 4-4-4- Invention 2 Tightening / stressing effect after 4h X X. ++ Example 2: Skincare cream according to the invention

[0079] A skincare cream in the form of an oil-in-water emulsion corresponding to the composition of Table 3 below was prepared from an elastic mixture according to the invention.

[0080] [Tables3] i Phase INCI Name i Name i trade %by weight A iSTEAREFH-2 0.5 A i COCO-CAPRYLATE / ÇAPRATE & TOCOPHEROL iCETI0LC5C .............2.0 A AOYBEAN GLYCERIDES (AND) BÜTYROSPERMUM iPÂRKII (SHEA) BUTTER UNSAPONIFIABLES i (AND) ASCORBYL PALMITATE i LIPEX L'SENS 2.0 A Aimethicone Ldimethicone 100 CS 0.2 A i ETHYL-2-HEXYL STEARATE iDUBSO 2.9 A CETYL ALCOHOL 1.4 A iPROPYLENE GLYCOL (AND) i DICAPRYLATE / DICAPRATE i MIGLYOL 840 2.5 A STEARYL ALCOHOL 1.4 A i CANDELILLA WAX 1.5 A iSTEARETH-21 : BRU S721-PA 1.0 A iMANGO KERNEL BUTTER 0.5 Al i PURIFIED WATER QSP 100 Ai mORPHENESIN 0.3 Ai i SODIUM HYDROXIDE <0.1 A2 i POLYGLYORIN-3 jPGL-S 2.4 A3 ÎCHITOSAN iCHITOSAN FUNGAL ............M A4 iPULLULAN 1.2 A i CELLULOSE ÎCELLULOBEADS 1.0 |p_____ [CAPRYLYL GLYCOL_______________________ _____0.3

[0081] The composition was prepared according to the following process:

[0082] Phase A was solubilized in a Rayneri mixer at 80°C.

[0083] Phases B1 and B2 were heated in a water bath at 80°C in a mixer Rayneri. Phase B3 was dispersed into the previously prepared phase, then mixed at 300 rpm for 30 minutes. Phase B4 was then added.

[0084] Phase A was dispersed into phase B, then stirred for 10 minutes.

[0085] Phase C was added to the previously prepared mixture and then dispersed for 2 minutes in an Ultra-Turrax™ blender.

[0086] The resulting mixture was heated to 45°C, then phase D was added.

[0087] Once the composition had returned to room temperature, water was added to compensate for water loss. Example 3: Skincare cream according to the invention

[0088] A skincare cream in the form of an oil-in-water emulsion corresponding to the composition of Table 4 below was prepared from an elastic mixture according to the invention.

[0089] [Tables4] Phase Name INCI Commercial name % by weight A STEARETH-2 0.5 A COCO-CAPRYLATE / CAPRATE & TOCOPHEROL CETIOL C 5C 2.0 A SOYBEAN GLYCERIDES (AND) BUTYROSPERMUM PARKII (SHEA) BUTTER UNSAPONIFIABLES (AND) ASCORBYL PALMFTATE UPEX L'SENS 2.0 A DIMÊTHICONE DIMETHICONÊ 100 CS 0.2 À ETHYL-2-HEXYL STEARATE DUB SO 2.9 A CETYL ALCOHOL 1.4 A PROPYLENE GLYCOL (AND) DICAPRYLATE / DICAPRATÊ MIGLYOL 840 2.5 A STEARYL ALCOHOL 1.4 A CANDELILLA WAX 1.5 A STEARETH-21 BRIJS72LPA 1.0 A MANGO KERNEL BUTTER 0.5 B1 PURIFIED WATER QSP 100 B1 CHLORPHENESIN 0.3 B1 SODIUM HYDROXIDE < 0.1 B2 POLYGLYCERIN-3 PGL-S MB 3.5 B2 POLYGLYCERIN-6 POLYGLYCERIN 500 0.5 B2 POLYGLYCERIN-10 POLYGLYCERIN 750 0.5 B3 CHITOSAN CHITOSAN FUNGAL 1.5 B4 PULLULAN 1.0 Ç CELLULOSE CELLULOBEADS 1.0 D CAPRYLYL GLYCOL 0.3

[0090] The composition was prepared according to the following process:

[0091] Phase A was solubilized in a Rayneri mixer at 80°C.

[0092] Phases B1 and B2 were heated in a water bath at 80°C in a mixer Rayneri. Phase B3 was dispersed into the previously prepared phase, then mixed at 300 rpm for 30 minutes. Phase B4 was then added.

[0093] Phase A was dispersed into phase B, then stirred for 10 minutes.

[0094] Phase C was added to the previously prepared mixture and then dispersed for 2 minutes in an Ultra-Turrax™ blender.

[0095] The resulting mixture was heated to 45°C, then phase D was added.

[0096] Once the composition had returned to room temperature, water was added to compensate for water loss. Example 4: Foundation according to the invention

[0097] A foundation in the form of an oil-in-water emulsion corresponding to the composition of Table 5 below was prepared from an elastic mixture according to the invention.

[0098] [Tables5] Phase Nom INCI Dénomination commerciale % en poids Al COCO-CAPRYLATE / CAPRATE & TOCOPHEROL CETIOL C 5C 10,0 Al C9-12 ALKANE VEGFLIGt IT SiLK 5,0 Al UNDECANE, TRiMETHYLSILOXYSILYLCARBAMOYL PULLULAN, TRIDECANE, TOCOPHEROL, HELIANTHUS ANNUUS fSUNFLOWER) SEED OU TSPL-30-UT 10,0 A2 CAPRYLiC / CAPRIC TRIGLYCERIDE, STEARALKONÏUM HECTORITE, POLYGLYCERYL-3 DIISOSTEARATE, POLYGLYCERYL-3 POLYRÎCINOLEATE BENTONE LUXE 8,0 A3 IRON OXIDE, SODIUM MYRISTQYL GLUTAMATE, ALUMINUM HYDROXIDE SUN PURO 3,3 A3 TITANIUM DIOXIDE, SODIUM MYRISTQYL GLUTAMATE, ALUMINUM HYDROXIDE, VATWHÎTE A 9,9 A3 TITANIUM DIOXIDE, STEARIC ACID, ALUMINA SOLAVEIL 4,0 A3 POLYHYDROXYSTEARIC ACID, CAPRYLIC / CAPRIC APPLECARE PDS- 0,1 TRIGLYCERIDE, ISOSTEARIC ACID, LECITHÏN, POLYGLYCERYL-3 POLYRICINOLEATE 300 A3 COCO-CAPRYLATE / CAPRATE & TOCOPHEROL CETIOL C 5C 5,0 B1 EAU PURIFIEE QSP 100 B1 HYDROXYACETOPHENONE SYMSAVE 0,3 B1 SODIUM HYDROXIDE < 0,1 B1 POLYGLYCERIN-3 PGL-S 2,5 B1 POLYGLYŒRIN-6 POLYGLYCERIN 500 0,5 B2 CHITOSAN CHITOSAN FUNGAL 1,5 B3 PULLULAN 1.0 B4 PENTYLENE GLYCOL 1.0,

[0099] The composition was prepared according to the following process: The ingredients of phase A3 were mixed in a three-roll mill to disperse the pigments and form a pigment paste. Phases A1 and A2 were stirred in a Rayneri mixer at 200 rpm. Phase A3 was added to the previously prepared phase in an Ultra- mixer. Turrax™, to obtain phase A. Phase B1 was agitated at 500 revolutions per minute at 80°C. Phase B2 was added to phase Bl, dispersed for 30 minutes (until total dispersion), then cooled to room temperature (20°C). Phase B3 has been added to phase B. Phase B4 has been added to phase B. The emulsion was prepared by dispersing phase A into phase B at 1200 rpm for 3 minutes.

Claims

Demands

1. Elastic mixture characterized in that it comprises: a- at least one polysaccharide selected from chitosan, its salts, and mixtures thereof, b- at least one polysaccharide selected from pullulan, its salts, and mixtures thereof, and c- at least one polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n varies from 2 to 10, and d- water.

2. Elastic mixture according to claim 1, characterized in that the c- polyglycerol is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n -OH in which n varies from 2 to 6.

3. Elastic mixture according to claim 1 or claim 2, characterized in that the c- polyglycerol is a polyglycerol of formula H-(O-CH2-CH(OH)-CH2)n-OH in which n = 3 and / or 6 (POLYGLYCERIN-3 and / or POLYGLYCERIN-6).

4. Elastic mixture according to any one of claims 1 to 3, characterized in that it comprises from 0.1 to 15%, preferably from 0.2 to 10%, and more preferably from 0.5 to 7%, by weight of α- polysaccharide relative to the total weight of said mixture.

5. Elastic mixture according to any one of claims 1 to 4, characterized in that it comprises from 0.1 to 10%, preferably from 0.5 to 8%, and more preferably from 1 to 5%, by weight of β- polysaccharide relative to the total weight of said mixture.

6. Elastic mixture according to any one of claims 1 to 5, characterized in that it comprises from 0.1 to 20%, preferably from 0.5 to 15%, and more preferably from 1 to 10%, by weight of c- polyglycerol relative to the total weight of said mixture.

7. Elastic mixture according to any one of claims 1 to 6, characterized in that it comprises from 60 to 99%, preferably from 65 to 98%, and more preferably from 70 to 95%, by weight of water relative to the total weight of said mixture.

8. Cosmetic composition characterized in that it comprises an elastic mixture as defined according to any one of claims 1 to 7.

9. Composition according to claim 8, characterized in that the elastic mixture represents from 10 to 100%, preferably from 15 to 95%, and more preferably from 15 to 90%, by weight relative to the total weight of the cosmetic composition.

10. Composition according to claim 8 or claim 9, characterized in that the mixture of polysaccharide a-, polysaccharide b- and polyglycerol c- (mixture of active materials) represents from 0.5 to 30%, preferably from 1 to 25%, and more preferably from 2 to 25%, by weight relative to the total weight of the cosmetic composition.

11. Composition according to any one of claims 8 to 10, characterized in that it further comprises at least one cosmetic active ingredient, preferably selected from a moisturizing agent, an anti-wrinkle agent, an antioxidant agent, an anti-radical agent, an agent for repairing the destructive effects of ultraviolet rays, or a slimming agent, and more preferably a cosmetic active ingredient selected from hyaluronic acids.

12. Composition according to any one of claims 8 to 11, characterized in that it is in the form of a gelled or non-gelled aqueous composition, a gelled or non-gelled emulsion, a cream, a serum, a mask, or a foundation.

13. A method for preparing an elastic mixture according to any one of claims 1 to 7, characterized in that it comprises a step of dissolving at least one polysaccharide a-, at least one polysaccharide b-, and at least one polyglycerol c-, in water d-.

14. A method for preparing a cosmetic composition according to any one of claims 8 to 12, characterized in that it comprises the following steps: (i) preparation of an elastic mixture by dissolving at least one polysaccharide a-, at least one polysaccharide b-, and at least one polyglycerol c-, in water d-, ​​and (ii) dispersion of the elastic mixture obtained in step (i) in an aqueous phase optionally comprising cosmetic actives and / or excipients.

15. Use of an elastic mixture according to any one of claims 1 to 7 in a cosmetic composition intended to be applied to the skin, to form an elastic film providing a smoothing and / or sheathing effect on the skin.

16. A skin care method characterized in that it comprises a step of applying a cosmetic composition as defined according to any one of claims 8 to 12, to at least one part of the body and / or face.

17. The method according to claim 16, characterized in that the step application 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 chosen from a smoothing effect, a tightening effect, a skin bouncing effect, or a combination of one of these effects.