Cosmetic composition containing a chitosan-based elasticity mixture

Abstract

The present invention relates to a composition comprising a mixture that can form a flexible elastic thin film, comprising chitosan, one of its salts or derivatives, a modified polysaccharide, and a polyol, which provides a firming effect and elastically deforms to follow skin movement and mechanical deformation of the skin surface. The present invention also relates to a method for preparing a cosmetic composition according to the present invention, and also to a skin care method comprising the step of applying a cosmetic composition according to the present invention to the skin.

Description

[Technical Field]

[0001] The present invention relates to the field of cosmetics, and more specifically to a cosmetic composition comprising a mixture capable of forming an elastic thin film, which provides a firming effect and elastically deforms to follow the movement of the skin and the mechanical deformation of the skin surface. The present invention also relates to a method for preparing the cosmetic composition according to the present invention, and also to a skin care method comprising the step of applying the cosmetic composition according to the present invention to the skin. [Background technology]

[0002] Imparting a smoothing effect to cosmetic compositions is a well-established technique in cosmetic medicine. For this purpose, various active ingredients can be used that penetrate the skin and provide long-lasting, permanent effects. Various thin-film-forming polymers are also used for their smoothing effect and their immediate mechanical action on the skin surface. However, these smoothing substances have certain drawbacks. Firstly, when the product is applied to the skin, it is often unpleasant due to the lack of flexibility of the thin film formed. This lack of flexibility in the film makes it poorly stretchable and inelastic, resulting in poor durability of cosmetic compositions that rapidly crack and crumble.

[0003] The applicant has already described in International Publication WO2013 / 167835 a cosmetic treatment that provides a firming and smoothing effect, comprising a specific elastic composite comprising at least one gelling or thickening starch, at least one polyol, and at least one polymer selected from polyvinyl alcohol, vinylpyrrolidone polymers and vinylpyrrolidone copolymers, and latex. However, these compositions have the drawback of being too sticky; these compositions also lack adhesion to the skin (a peeling problem).

[0004] The inventors have now developed a cosmetic composition comprising a mixture of specific compounds capable of forming an elastic thin film with an immediate, visible, and permanent smoothing effect. The thin film thus formed is reversibly deformable, and as a result, after deformation, for example after stretching, it returns to the state it had before mechanical stress was applied, for example, the state it had before mechanical stress caused by skin deformation was applied. The thin film formed by the cosmetic composition comprising the mixture has greater resistance to fracture, and thus it is possible to maintain the mechanical properties of the thin film formed on the skin surface without impairing them. When incorporated into a cosmetic composition, this mixture capable of forming an elastic thin film has an improved combination of firming and elastic effects that can follow the movement of the skin without cracking. The effect obtained is comparable to a coating effect; this is because the cosmetic composition of the present invention provides elasticity to skin that is naturally stressed by various deformations, for example, changes in facial expressions or contact with hands or clothing. Thus, the inventors have succeeded in developing a cosmetic composition that can combine properties that are difficult to combine, namely, elasticity and firmness, thereby resolving the firmness / elasticity paradox. The novel cosmetic composition can effectively work to smooth the surface of the skin, and in particular can achieve partial or complete elimination of wrinkles, including moderate and deep wrinkles.

[0005] The cosmetic composition of the present invention possesses remarkable tensor and elasticity effects on the skin, namely properties associated with the simultaneous presence of chitosan, salts or derivatives, modified polysaccharides, and polyols. The cosmetic composition thus obtained enables a visible and permanent smoothing of the skin surface with very high comfort of use. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The first object of the present invention is, α-Chitosan, its salts and derivatives, and at least one polysaccharide selected from mixtures thereof, At least one modified polysaccharide different from β-polysaccharide a- and its mixtures thereof, c-at least one polyol This is a cosmetic composition containing a mixture that can form an elastic thin film. [Means for solving the problem]

[0007] In the following description, the term "cosmetic composition" refers to both the cosmetic composition according to the present invention and the cosmetic composition used in the method of the present invention. In the description, elastic mixtures or mixtures capable of forming elastic thin films are considered to be without distinction.

[0008] A polymer is said to be film-forming within the scope of the present invention if a continuous and homogeneous thin film is observed to form after the volatile substances present in the medium have evaporated. Subsequently, intermolecular bonds related to mechanical properties are formed between polymer chains and by other components such as plasticizers to create a thin film that does not penetrate the skin and provides resistance to water and sebum, as well as non-migration.

[0009] The elastic mixture of the cosmetic composition of the present invention contains an α-polysaccharide, also known as a shrinkable film-forming polymer, which provides an immediate smoothing / firming (lifting) effect. This shrinking action occurs when the material dries, and hydrogen bonds are formed between polymer chains to cause shrinkage.

[0010] The polysaccharide α of the present invention is conveniently unmodified or modified chitosan. The chitosan that can be used in the context of the present invention can be completely or partially deacetylated chitin. The molecular weight of the chitosan used is 20,000 g.mol. -1 From approximately 5,000,000 g.mol -1 It can vary up to 100,000 g.mol, preferably 100,000 g.mol. -1 From 700,000 g.mol -1It can vary up to a certain point. The degree of deacetylation of chitosan can preferably vary from 50% to 99%.

[0011] In preferred embodiments, polysaccharide a- is unmodified chitosan, or modified chitosan selected from alkylated chitosan, hydroxyalkylated chitosan, carboxylated chitosan, acylated chitosan, quaternized chitosan, and mixtures thereof.

[0012] According to one embodiment, the cosmetic composition of the present invention contains 0.1 to 15%, preferably 0.5 to 10%, and more preferably 1 to 5%, of polysaccharide α- by weight relative to the total weight of the cosmetic composition.

[0013] Unmodified chitosan is conveniently selected from fungal chitosan (CHITOSAN FUNGAL) or crustacean chitosan, such as chitosan obtained from crabs, lobsters, squid, or shrimp. In a particularly preferred embodiment, polysaccharide a- is fungal chitosan (CHITOSAN FUNGAL).

[0014] The elastic mixture of the cosmetic composition of the present invention also contains a β-modified polysaccharide, also known as an elastic thin-film forming polymer, which imparts an elastic effect (comfort) to the composition. The β-modified polysaccharide of the present invention has the advantage of providing an elastic, dry thin film that is transparent when mixed with other components and remains transparent even after mechanical deformation (stretching). In particular, the thin film formed on the skin retains its transparency under the influence of numerous mechanical stresses, and as a result, the thin film does not disturb the color of the cosmetic composition deposited on the skin in which the mixture is introduced over time.

[0015] Modified polysaccharide b−, which is different from polysaccharide a−, is advantageously modified starch. The modified starch of the present invention is obtained from native starch that has been modified chemically and / or physically and / or enzymatically to improve its elastic properties. Native starch can be derived from a wide variety of sources, for example, corn, wheat, rice, buckwheat, barley, oat, millet, rye, sorghum, cassava, potato, sweet potato, tapioca, banana, plantain, malanga, taro, chestnut, legumes, starch of pea, etc., preferably native starch of corn, wheat, rice, cassava, potato, tapioca, pea, etc.

[0016] The modified starch used in the context of the present invention has the advantage that when mixed with other components of the present invention, it results in an elastic dry film that is transparent and remains transparent even after elongation when prepared in the form of a thin film (typically having a thickness of less than 1 millimeter). In fact, it is particularly advantageous in the context of the present invention that the film formed on the skin by the application of the cosmetic composition of the present invention retains its transparency under the influence of numerous mechanical stresses and does not disturb the color of the deposit on the skin over time.

[0017] Modified polysaccharide b− advantageously has a weight average molecular weight of more than 10 6 g.mol -1 and preferably has a weight average molecular weight of 10 6 ~10 9 g.mol -1 The weight average molecular weight can be determined by HPSEC-MALLS (high performance size exclusion chromatography linked online with multi-angle laser light scattering detection).

[0018] Preferred modified starches include alkylated starch, hydroxyalkylated starch, acetylated starch, starch hydrolyzate, oxidized starch, phosphorylated starch, hydroxyalkylated, phosphoric acid monoesterified, or acetylated phosphoric acid crosslinked starch, and mixtures thereof. More particularly preferred starches are alkylated starch, hydroxyalkylated starch, acetylated starch, oxidized starch, phosphorylated starch, hydroxyalkylated, phosphoric acid monoesterified, or acetylated phosphoric acid crosslinked starch, and mixtures thereof, and even more preferably hydroxyalkylated starch.

[0019] Modified polysaccharide b- is preferably selected from various hydroxyalkylated starches. In a preferred embodiment, modified polysaccharide b- is hydroxypropylated starch which may have the INCI name of HYDROXYPROPYL STARCH, for example, products such as Beaute By Roquette® ST720 marketed by ROQUETTE.

[0020] In a particularly preferred embodiment, modified polysaccharide b- has a weight average molecular weight of more than 10 6 g.mol -1 and preferably 10 6 ~10 9 g.mol -1 and is hydroxyalkylated starch, even more preferably hydroxypropylated starch. The weight average molecular weight can be determined by HPSEC-MALLS.

[0021] Modified polysaccharide b- is preferably 1 to 15% by weight ratio, preferably 2 to 10% by weight ratio, and more preferably 4 to 8% by weight ratio based on the total weight of the cosmetic composition.

[0022] The elastic mixture of the cosmetic composition of the present invention also contains polyol c- which helps in dispersion and plasticizes the polymer present in the cosmetic composition. Thus, polyol c- acts as a plasticizer by providing mobility between polymer chains and making the polymer chains more elastic and flexible.

[0023] The polyol C- of the present invention may be an alcohol having 1 to 30 carbon atoms and 2 to 12 hydroxyl functional groups, particularly an alcohol having 2 to 10 carbon atoms and 2 to 4 hydroxyl functional groups. The polyol C- may also be a sugar, such as glucose, sorbitol, or mannitol. Conveniently, the polyol C- is provided in 300 g.mol. -1 From 800g.mol -1 It has a weight-average molecular weight that varies up to [a certain point].

[0024] The c- in polyols is conveniently a diol, with the formula H-(O-CH2-CH(OH)-CH2). n Selected from polyglycerols of -OH (wherein n varies from 2 to 10, preferably from 2 to 4) and mixtures thereof.

[0025] According to one embodiment, the polyol c- is an aliphatic or aromatic linear or branched C2-C 12 The diol is selected from diols, preferably from 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, more preferably from propane-1,3-diol, butane-1,2-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol and mixtures thereof, and even more preferably from propane-1,3-diol.

[0026] According to another embodiment, the polyol c- is of the formula H-(O-CH2-CH(OH)-CH2) n It is a polyglycerol with -OH (where n varies from 2 to 10 in the formula).

[0027] In a particularly favorable embodiment, the polyol c- is of the formula H-(O-CH2-CH(OH)-CH2) n Polyglycerols of the form -OH (wherein n=3 and / or 6) (Polyglycerin-3 (PGL-S MB) and / or Polyglycerin-6 (POLYGLYCERIN 500 MB)), which are marketed, for example, by SAKAMOTO YAKUHIN KOGYO. More specifically, the polyol c- is of the form H-(O-CH2-CH(OH)-CH2) n Polyglycerol-3 of the form -OH (wherein n=3) is marketed by SAKAMOTO YAKUHIN KOGYO under reference PGL-S MB. Compared with other polyols, polyglycerin-3 allows for better levels of plasticization of polysaccharide α and modified polysaccharide β on the skin surface.

[0028] The polyol c- is preferably present in a weight ratio of 1 to 20% of the total weight of the cosmetic composition, preferably 3 to 15%, and more preferably 5 to 10%.

[0029] In one embodiment, the cosmetic composition of the present invention is In relation to the total weight of the cosmetic composition, a- 0.1-15% by weight, preferably 0.5-10%, more preferably 1-5% polysaccharide a-; b- 1-15% by weight, preferably 2-10%, more preferably 4-8% modified polysaccharide b-; and c- 1-20% by weight, preferably 3-15%, more preferably 5-10% polyol c- Includes.

[0030] The amounts of components a-, b-, and c- are preferably chosen so that the cosmetic composition provides a pleasant feel to the touch without being too sticky, while ensuring good adhesion to the skin. Therefore, the proportions of components a-, b-, and c- are adjusted to satisfy a desired compromise between tackiness and adhesion. Depending on the formulation, for example, if the formulation is a foundation or serum, the compromise will be sought between adhesion to the skin and the viscoelasticity of the composition. For example, if the formulation contains powder, the amount of polyol introduced will be greater in order to maintain a certain degree of plasticity and elasticity.

[0031] The mass ratio between polyol c- and the two polysaccharides a- and b- is preferably between 20 / 80 and 80 / 20, and preferably between 40 / 60 and 60 / 40.

[0032] In a particularly favorable embodiment, the cosmetic composition of the present invention is α-At least one polysaccharide selected from fungal chitosan (CHITOSAN FUNGAL), At least one modified polysaccharide selected from β-hydroxypropyl starch, and c-Formula H-(O-CH2-CH(OH)-CH2) n At least one polyol selected from polyglycerols of the form -OH (wherein n=3 and / or 6) (polyglycerin-3 and / or polyglycerin-6) The mixture contains, conveniently, the preferred weight ratio % shown above, and can form an elastic thin film.

[0033] In the mixture capable of forming an elastic thin film of the cosmetic composition of the present invention, polysaccharide a-, modified polysaccharide b-, and polyol c- are preferably such that the elasticity of the dry thin film (water-free) obtained from the mixture, having a thickness between 50 microns and 1000 microns, - The loss of elasticity, when measured after at least one tensile, must be less than 20%, and - At least 50% recovery They exist in proportions characterized by the following:

[0034] The elasticity of the elastic mixture present in the cosmetic composition of the present invention can be measured by a method widely known to those skilled in the art, for example, by measuring the force exerted by a dried thin film obtained from the mixture and subjected to a tensile test at an imposed rate using a texturerometer of reference TA.XT Plus (Stable Micro Systems). The thickness of the thin film selected for this measurement is preferably between 50 and 1000 microns, and more preferably between 200 and 400 microns.

[0035] A tensile test requires applying two opposing forces to a sample. The ends of the thin film sample are clamped between two jaws of a tensile testing machine: one is fixed and the other is 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 force sensors placed on the fixed part of the machine, and a graph is drawn showing the force exerted by the sample as a function of the sample's elongation, and similarly, a graph showing the force exerted by the sample as a function of time.

[0036] The residual deformation rate is preferably measured after at least one stretching 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 that length. Continuous stretching cycles can also be performed by gradually increasing the stretching distance.

[0037] The amount of elastic mixture introduced into the cosmetic composition of the present invention is conveniently selected depending on the desired cosmetic effect and desired viscosity. In fact, the viscosity of the product must be suitable for regular, comfortable, and sufficient application to the skin. The amount of mixture capable of forming an elastic thin film is selected in particular to enable the formation of an elastic thin film when the cosmetic composition is applied to the skin.

[0038] The proportions between different components will be optimized to achieve appropriate viscoelasticity and good adhesion to the skin. Depending on the formulation, for example, if the formulation is a foundation or serum, a compromise will be sought between skin adhesion and the viscoelasticity of the cosmetic composition. For example, if the formulation contains powder, the amount of polyol introduced will be greater in order to maintain the plasticity and elasticity of the cosmetic composition.

[0039] In a convenient embodiment, the cosmetic composition of the present invention contains a mixture comprising polysaccharide a-, modified polysaccharide b-, and polyol c-, as defined above, in a weight ratio of 0.5 to 50%, preferably 1 to 30%, more preferably 5 to 25%, relative to the total weight of the cosmetic composition, which can form an elastic thin film.

[0040] The cosmetic composition of the present invention may further contain an aqueous phase, and therefore may contain water. Preferably, the composition contains 40-99%, preferably 50-90%, and more preferably 60-70% water by weight relative to the total weight of the cosmetic composition.

[0041] According to a variation of the present invention, the cosmetic composition may further contain at least one cosmetic active ingredient. The cosmetic active ingredient may be conveniently selected from moisturizers, anti-wrinkle agents, antioxidants, free radical scavengers, agents for repairing the destructive effects of ultraviolet radiation, or slimming agents such as caffeine. Preferably, the cosmetic active ingredient is selected from hyaluronic acids such as sodium hyaluronate. Accordingly, according to one aspect of the present invention, the present invention relates to a cosmetic composition comprising water and at least one cosmetic active ingredient in a weight ratio ranging from 0.01% to 5% relative to the total weight of the cosmetic composition.

[0042] The cosmetic composition of the present invention may further contain a gelling agent. The gelling agent may preferably be a natural or synthetic polysaccharide, and is preferably xanthan gum (e.g., Rhodicare® XC or T sold by Solvay Novecare, or Keltrol® CG LAXT sold by CP Keltro), agar (e.g., Ina Agar CS83 sold by Iwase Cosfa), gellan gum (e.g., Kelcogel® CG-LA sold by Azelis), or carrageenan (e.g., Cargill Examples of natural or synthetic polysaccharides may be selected from corn starch, carboxymethylcellulose ether (e.g., Satiagum® VPC430 sold by Beauty), cellulose and its derivatives, such as hydroxyethylcellulose (e.g., Klucel® GF and Natrosol® 250HHX sold by Ashland) and hydroxypropylcellulose, carboxymethylcellulose ether (e.g., Blanose® 7H3SF sold by Ashland), bis-decyltetradeceth-20 ether copolymer (e.g., Adeka Nol GT-700 sold by Adeka), sclerotium gum (INCI name: Sclerotium Gum) (e.g., Amigel® sold by Alban Muller International (Croda)), and mixtures thereof. Synthetic polymers, such as ammonium acryloyldimethyl taurate / VP copolymer (Aristoflex® AVC obtained from Clariant International Ltd.), may also be conveniently mentioned.Particularly advantageous, the gelling agent is selected from xanthan gum (e.g., Rhodicare® XC or T sold by Solvay Novecare, or Keltrol® CG LAXT sold by CP Keltro), gellan gum (e.g., Kelcogel® CG-LA sold by Azelis), hydroxyethylcellulose (e.g., Klucel® GF and Natrosol® 250HHX sold by Ashland), sclerotium gum (INCI name: Sclerotium Gum) (e.g., Amigel® sold by Alban Muller International (Croda)), ammonium acryloyldimethyl taurate / VP copolymer (Aristoflex® AVC obtained from Clariant International Ltd.), and mixtures thereof.

[0043] The cosmetic composition of the present invention may further contain at least one pH adjusting agent. This pH adjusting agent is preferably selected from alkali hydroxides, such as sodium hydroxide or ammonium hydroxide, triethanolamine, 2-amino-2-(hydroxymethyl)-1,3-propanediol, borate, phosphate, pyrophosphate, 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 selected from alkali hydroxides, and more preferably selected from alkali hydroxides, such as sodium hydroxide. The pH adjusting agent is preferably used in an amount that can impart a pH ranging from 4 to 7 to the cosmetic composition. According to one embodiment, the pH adjusting agent is present in an amount ranging from 0.01% to 1% by weight relative to the total weight of the cosmetic composition.

[0044] The cosmetic composition of the present invention may further contain one or more cosmetic excipients, such as opacifying agents, fragrances, reflectors, flocculants, preservatives (e.g., chlorphenesin (INCI name: CHLORPHENESIN)), UVA and UVB ultraviolet protective agents (especially filters), organic pigments and nanopigments (e.g., zinc oxide, iron oxide and titanium dioxide).

[0045] The cosmetic composition of the present invention may be in the form of a gel, lotion, serum, suspension, oil-in-water emulsion, water-in-oil emulsion, or mask, and is preferably in the form of a serum or oil-in-water emulsion.

[0046] Another object of the present invention relates to a method for preparing a cosmetic composition according to the present invention as described above.

[0047] The method for preparing the cosmetic composition of the present invention involves the following steps: (i) A step of preparing a mixture capable of forming an elastic thin film by dissolving at least one polysaccharide a-, at least one modified polysaccharide b-, and at least one polyol c- in water, and (ii) Dispersing the mixture obtained in step (i) in an aqueous phase containing, if necessary, active ingredients and / or excipients for cosmetic use. Includes.

[0048] Conveniently, step (i) is carried out with stirring at a temperature ranging from 50°C to 120°C, preferably from 70°C to 100°C, for a period of 5 minutes to 1 hour, 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 (i), the elastic mixture can be prepared by first dissolving polyol c- in water. Then, polysaccharide a- is dissolved or dispersed in the mixture based on water and polyol c-, with heating and stirring as needed. Once polysaccharide a- is dissolved or dispersed, modified polysaccharide b- is then added, with heating to thoroughly homogenize the various components. Conveniently, polysaccharide a- and modified polysaccharide b- are added continuously with stirring at a temperature ranging from 50°C to 120°C, preferably from 70°C to 100°C, for a period of 5 minutes to 1 hour, preferably for about 30 minutes. The mixture obtained at the end of step (i) is then cooled to room temperature (20°C).

[0050] In step (ii), the mixture prepared in step (i) is added to an aqueous phase containing a cosmetic active ingredient and / or other cosmetic excipients.

[0051] According to another embodiment, the cosmetic composition of the present invention is prepared by directly and sequentially adding each of the components polysaccharide a-, modified polysaccharide b-, and polyol c- directly to the aqueous phase of the cosmetic composition without prior mixing. Conveniently, the components polysaccharide a-, modified polysaccharide b-, and polyol c- are added sequentially with stirring at a temperature ranging from 50°C to 120°C, preferably from 70°C to 100°C, for a period of 5 minutes to 1 hour, preferably for about 30 minutes. The mixture obtained at the end of step (i) is then cooled to room temperature (20°C).

[0052] In certain cases of emulsions, the components polysaccharide a-, modified polysaccharide b-, and polyol c- are added to the aqueous dispersion phase before the dispersion of the fatty phase.

[0053] Finally, the last object of the present invention relates to a skincare method comprising the step of applying a cosmetic composition, as defined according to the present invention, to at least a portion of the body and / or face.

[0054] In one embodiment, the step of applying to at least a portion of the body and / or face is performed on at least one skin area showing signs of aging or fatigue, such as loss of firmness, loss of elasticity, or sagging skin, particularly on the face and / or around the neck, in order to obtain an effect selected from a smoothing effect, a firming effect, a skin plumping effect, or one combination of these effects.

[0055] Cosmetic compositions applied directly to the skin form a thin film with elastic mechanical properties and a texture particularly well-suited for cosmetic use after application and the gradual evaporation of water in the composition. In addition, this type of texture has useful properties in terms of both aesthetics and comfort of use, especially near highly mobile areas (e.g., eyes and lips). The elastic properties of the cosmetic compositions of the present invention are particularly useful for application to areas of the body that are subject to significant movement, such as the skin of the face.

[0056] A skincare method may include topically applying an effective amount of the cosmetic composition according to the present invention, as defined above, to a relevant area of ​​skin in order to obtain a second skin sensation.

[0057] In addition to the provisions set forth herein, the present invention also includes other provisions which will become apparent from the following additional description relating to the preparation of cosmetic compositions and comparative cosmetic compositions according to the present invention. [Modes for carrying out the invention]

[0058] Examples

[0059] In the following examples, and unless otherwise indicated, all percentages are given as mass percentages, components are specified by their INCI names, and temperatures are given in degrees Celsius.

[0060] Methods for characterizing elastic thin films: - Elastic properties (fatigue resistance): Fatigue resistance was evaluated using a TA.XT Plus texturerometer (Stable Micro Systems). The prepared elastic thin film was poured into a Teflon® mold and then dried at 33°C at 50% relative humidity to achieve a thickness (dry) of 200–400 μm. Subsequently, 5 × 3 cm test specimens were cut and subjected to repeated stretching, i.e., 25 cycles of 50% stretching and unstretching in the longitudinal direction at 1 mm / sec. The elastic properties (fatigue resistance) were ranked from maximum elasticity (+++) to minimum elasticity (+). - Evaluation of shrinkage effect on nitrile supports: The shrinkage of the elastic thin film was visually evaluated at room temperature (20°C). Nitrile gloves cut into 3 × 5 cm test pieces were used as supports. The elastic mixture was spread on the nitrile support with a spatula to obtain a dry film mass of 0.05 g, corresponding to a dry film thickness (or residual dry mass) of 33 μm, and then dried at room temperature (20°C) for 24 hours. During the drying period, the elastic thin film shrank to varying degrees and was classified into three categories: Category 1: The support does not shrink, and the thin film shows no shrinkage effect whatsoever; Category 2: The support has shrunk slightly compared to the start of the test, and the shrinkage effect is visible; Category 3: The support material has contracted and curled up on top of itself, exhibiting significant shrinkage. - A method for characterizing the smoothing effect in vivo at 1 hour and 4 hours: The objective of the study was to evaluate and compare the smoothing effect on the area around the outer corner of the eye, known as the "crow's foot," in a panel of 10 volunteers after 1 hour and 4 hours. All measurements were performed at a temperature of 22°C and a relative humidity of 50%. 1. Obtaining traces The first trace was obtained before applying the cosmetic composition under evaluation. To create the trace, a thin-film forming resin was spread over the study area using a spatula. After drying, the replica of the skin area was peeled off. The manufactured product contains 2 mg.cm -2The sample was applied to crow footprints in the specified amount, left to dry for 15 minutes, and then measured at 1 hour and 4 hours later. Second traces were obtained one hour after application of the cosmetic composition, and then four hours later. The same protocol was replicated for each cosmetic composition under investigation. 2. Image Analysis To create shadows behind each muscle on the skin surface, each replica was placed on a support and illuminated using a grazing illumination device with a 35° incident angle. These shadows were then analyzed against high-resolution images of the replicas to obtain numerical values ​​for the gray level of each analyzed pixel. Equipment used: The following parameters are calculated by the QUANTIRIDES® software: number of wrinkles, mm 2 Total surface area of ​​wrinkles in units of millimeters, total length of wrinkles in millimeters, average length of wrinkles in millimeters, and average depth of wrinkles in micrometers. The smoothing effect was evaluated by comparing these parameters before and after the application of the cosmetic composition (1 hour and 4 hours after application). The greater the reduction in wrinkle areas, their length, and / or their surface or depth, the more pronounced the observed smoothing effect. Evaluation criteria: +++ means that the product has a very significant smoothing effect on crow footprints after 1 or 4 hours of application; ++ means that the product has a significant smoothing effect on crow footprints after 1 or 4 hours of application; A "+" indicates that the product has little to no smoothing effect on crow footprints after 1 or 4 hours of application.

[0061] Example 1: Preparation and Characterization of the Mixture

[0062] Two elastic mixtures, A and B, corresponding to the formulations in Table 1, and a mixture C, which is outside the scope of the present invention, were prepared:

[0063] [Table 1]

[0064] Three aqueous dispersions, each containing one of mixtures A, B, and C, were prepared according to the formulations shown in Table 2 below:

[0065] [Table 2]

[0066] Purified water, sodium hydroxide, and polyol c- were weighed into a beaker and mixed in a water bath at 80°C using a gelatinizing turbine at 150 rpm. Polysaccharide a- was weighed into a dish and then mixed into the beaker with fine splashes while stirring at 400 rpm. Once the mixture was homogeneous, polysaccharide b- was weighed into a dish and then mixed into the beaker while stirring at 600 rpm. Once the mixture was homogeneous, the prepared mixture was removed from the water bath and cooled to room temperature while stirring at 300-400 rpm. Subsequently, a resilient thin film was formed using the prepared mixture and evaluated.

[0067] The measured characteristics of elastic mixture A, elastic mixture B, and elastic mixture C are summarized in Table 3 below.

[0068] [Table 3]

[0069] Elastic mixtures A and B, containing three components a-, b-, and c-, enable the best compromise between tensor effects and elastic effects.

[0070] Example 2: Preparation and Characterization of the Mixture

[0071] We evaluated two elastic mixtures, D and E, corresponding to the formulations in Table 4:

[0072] [Table 4]

[0073] Two aqueous dispersions, each containing one of mixture D and one of mixture E, were prepared according to the formulations shown in Table 5 below:

[0074] [Table 5]

[0075] Purified water, sodium hydroxide, chlorphenesin, and polyol c- were weighed into a beaker and mixed in a 75°C water bath using a gelatinizing turbine. Polysaccharide a- was weighed into a dish and then mixed into the beaker with fine splashes while stirring at 600 rpm. Once the mixture was homogenized, polysaccharide b- was weighed into a dish and then mixed into the beaker while stirring at 600 rpm. Once the mixture was homogenized, the prepared mixture was removed from the water bath and cooled to room temperature. Subsequently, a resilient thin film was formed using the prepared mixture and evaluated.

[0076] The measured characteristics of elastic mixtures D and E are summarized in Table 6 below.

[0077] [Table 6]

[0078] Elastic mixture D, based on hydroxypropyl starch, offers a better compromise between tension and elasticity than elastic mixture E. Elastic mixture E, based on hydrolyzed starch, produces an elastic thin film, but does not have an immediate and permanent smoothing effect.

[0079] Example 3: Serum according to the present invention The serum compositions according to the present invention corresponding to the formulations in Table 7 were prepared according to the following protocol:

[0080] [Table 7]

[0081] The components of phase A1 were weighed into a beaker and then mixed in a water bath at 80°C with gentle stirring using a gelatinizing turbine. Phase A2 was weighed and added to phase A1. Phase B was weighed, emulsified with phase A, and then mixed at 600 rpm. Phase C1 was weighed and then gently stirred in a water bath at 80°C using a gelatinizing turbine. Phase C2 was weighed into a dish and then added to C1 as fine flakes. Phase C3 was weighed into a dish and then added to phases C1 and C2 as fine flakes. All of phase C was emulsified with phase A in a water bath at 80°C. The temperature was then cooled to room temperature. Phase D was weighed into a dish and then added to a beaker. Phases E and F were weighed into a dish and then added to a beaker.

[0082] The mixture prepared in this manner enabled the formation of elastic thin films having the following properties:

[0083] [Table 8]

[0084] Example 4: Eye cream according to the present invention The eye cream compositions according to the present invention corresponding to the formulations in Table 9 were prepared according to the following protocol:

[0085] [Table 9]

[0086] The components of Phase A were weighed into a beaker and then mixed in a water bath at 85°C with stirring using a gelatinizing turbine. Phase B1 was weighed into a beaker and then mixed in a water bath at 85°C with stirring using a gelatinizing turbine. Phase B2 was weighed into a dish and added to Phase B1 as fine flecks, and then mixed for 20 minutes with stirring at 300 rpm. Phase B3 was weighed into a dish and then added to Phase B1 and Phase B2 as fine flecks, and mixed for 30 minutes with stirring at 600 rpm. All of Phase B was de-bubbled by reducing the stirring speed to 200 rpm. Phase B was slowly poured into Phase A in a water bath at 85°C and emulsified in Phase A by gradually increasing the stirring speed to 800 rpm. The mixture was stirred at this speed for 10 minutes and then removed from the water bath. Phase C was weighed into a dish and then added to a beaker at a temperature of 50°C. Phase D was weighed and then added to a beaker at a temperature below 40°C.

[0087] The mixture prepared in this manner enabled the formation of elastic thin films having the following properties:

[0088] [Table 10]

[0089] Example 5: Serum and comparative serum according to the present invention The serum compositions according to the present invention corresponding to the formulations in Table 11 were prepared according to the following protocol:

[0090] [Table 11]

[0091] The components of Phase A were weighed into a beaker and then mixed in a water bath at 80°C with gentle stirring using a gelatinizing turbine. Phase B was weighed into a dish and emulsified in Phase A by increasing the stirring speed to 600 rpm. Phase C1 was weighed into a beaker and mixed in a water bath at 80°C with gentle stirring using a gelatinizing turbine. Phase C2 was weighed into a dish and added to Phase C1 as fine flecks. Phase C3 was weighed into a dish and added to Phases C1 and C2 as fine flecks. All of Phase C was emulsified in Phase A at 80°C and then returned to room temperature. Phase D was weighed into a dish and added to a beaker. Phases E and F were weighed into capsules and then added to a beaker.

[0092] The mixture prepared in this manner enabled the formation of elastic thin films having the following properties:

[0093] [Table 12]

[0094] A serum formulation similar to the formulations in Table 11, but without the modified polysaccharide b-(HYDROXYPROPYL STARCH), was prepared using the same procedure as before. The resulting thin film was uncomfortable due to excessive adhesion and subsequently cracked due to insufficient elasticity.

[0095] The mixture prepared in this manner enabled the formation of a thin film having the following properties:

[0096] [Table 13]

[0097] Example 6: Eye cream and comparative cream according to the present invention The eye cream compositions according to the present invention corresponding to the formulations in Table 14 were prepared according to the following protocol:

[0098] [Table 14]

[0099] The components of Phase A were weighed into a beaker and then mixed in a water bath at 85°C with stirring using a gelatinizing turbine. Phase B1 was weighed into a beaker and then mixed in a water bath at 85°C with stirring using a gelatinizing turbine. Phase B2 was weighed into a dish and added to Phase B1 as fine splatter, and then mixed for 20 minutes with stirring at 300 rpm. Once Phase B was homogenized, Phase B3 was weighed and then added to Phases B1 and B2. All of Phase B was de-bubbled by reducing the stirring speed to 200 rpm. Phase B was slowly poured into Phase A in a water bath at 85°C and emulsified in Phase A by gradually increasing the stirring speed to 800 rpm. The mixture was stirred at this speed for 10 minutes and then removed from the water bath. Phase C was weighed into a dish and then added to a beaker at a temperature of 50°C. Phases D and E were weighed and then added to beakers at a temperature below 40°C.

[0100] The mixture prepared in this manner enabled the formation of elastic thin films having the following properties:

[0101] [Table 15]

[0102] A cream formulation similar to the one in Example 6, but without the modified polysaccharide b-(HYDROXYPROPYL STARCH), was prepared using the same procedure as described above. The resulting thin film was found to be uncomfortable due to excessive adhesion, and subsequently cracked due to insufficient elasticity.

[0103] The mixture prepared in this manner enabled the formation of a thin film having the following properties:

[0104] [Table 16]

[0105] Example 7: Cream according to the present invention Two cream compositions according to the present invention, corresponding to the formulations in Table 17, were prepared according to the following protocol:

[0106] [Table 17]

[0107] The components of Phase A were weighed into a beaker and then mixed in a water bath at 85°C with stirring using a gelatinizing turbine. Phase B1 was weighed into a beaker and then mixed in a water bath at 85°C with stirring using a gelatinizing turbine. Phase B2 was weighed into a dish and added to Phase B1 as fine flakes, and then mixed at 85°C for 30 minutes with stirring at 300 rpm. Phase B3 was weighed into a dish and then added to Phase B1 and Phase B2 as fine flakes, and mixed at 85°C for 30 minutes with stirring at 300 rpm. All of Phase B was de-bubbled by reducing the stirring speed to 200 rpm. Phase B was emulsified with Phase A in a water bath at 85°C, mixed for 10 minutes, and then removed from the water bath. Phase C was weighed into a dish, mixed using a spatula, then added to Phase B1 as a fine splatter, and finally mixed at 85°C for 30 minutes with stirring at 300 rpm. Phase D was weighed and then added to a beaker at a temperature below 40°C.

[0108] The mixture prepared in this manner enabled the formation of elastic thin films having the following properties:

[0109] [Table 18]

[0110] Example 8: Liquid foundation according to the present invention Liquid foundation compositions according to the present invention corresponding to the formulations in Table 19 were prepared according to the following protocol:

[0111] [Table 19]

[0112] The components of phase A1 were weighed into a beaker and mixed at room temperature with stirring using a gelatinizing turbine. Phase A2 was weighed into a dish and dispersed into phase A1, and mixed with stirring using a gelatinizing turbine at 150 rpm. Phase B1 was weighed into a beaker and mixed in a water bath at 80°C with stirring using a gelatinizing turbine. Phase B2 was weighed into a dish and added to phase B1 as fine flecks. Phase B3 was weighed into a dish and added to phases B1 and B2 as fine flecks. The mixture was then cooled to room temperature. Phases B4 and B5 were then added. All of phase B was emulsified in phase A, and then mixed with stirring using a gelatinizing turbine at 1000 rpm for 5 minutes, and then at 800 rpm for 30 minutes.

[0113] After application, the foundation provides a smoothing effect on the user's skin without any feeling of tightness throughout the day.

Claims

1. A cosmetic composition, α-Chitosan, its salts and derivatives, and at least one polysaccharide selected from mixtures thereof, At least one modified polysaccharide different from β-polysaccharide a- and mixtures thereof, and c-at least one polyol A cosmetic composition characterized by containing a mixture capable of forming an elastic thin film.

2. The composition according to claim 1, characterized in that the polysaccharide a- is unmodified chitosan, or modified chitosan selected from alkylated chitosan, hydroxyalkylated chitosan, carboxylated chitosan, acylated chitosan, quaternized chitosan, and mixtures thereof.

3. The composition according to claim 1 or claim 2, characterized in that the polysaccharide a- is an unmodified chitosan selected from fungal chitosan (CHITOSAN FUNGAL), crustacean chitosan, and mixtures thereof, preferably fungal chitosan (CHITOSAN FUNGAL).

4. The composition according to one of claims 1 to 3, characterized in that the modified polysaccharide b- is a modified starch, preferably selected from alkylated starch, hydroxyalkylated starch, acetylated starch, starch hydrolysate, oxidized starch, phosphorylated starch, hydroxyalkylated, phosphate monoesterified, or acetylated phosphate cross-linked starch, and mixtures thereof, more preferably a modified starch selected from alkylated starch, hydroxyalkylated starch, acetylated starch, starch hydrolysate, oxidized starch, phosphorylated starch, hydroxyalkylated, phosphate monoesterified, or acetylated phosphate cross-linked starch, and mixtures thereof, and even more preferably a modified starch selected from hydroxyalkylated starch.

5. The composition according to claim 4, characterized in that the modified polysaccharide b- is hydroxypropyl starch.

6. The hydroxypropyl starch is 10 ６ g. mol －１ It has a weight-average molecular weight greater than 10 ６ ~10 ９ g. mol －１ The composition according to claim 5, characterized by having a weight-average molecular weight.

7. The aforementioned polyol c- is a diol, formula H-(O-CH ２ -CH(OH)-CH ２ ) ｎ The composition according to one of claims 1 to 6, characterized by being selected from polyglycerols of -OH (wherein n varies from 2 to 10, preferably from 2 to 4) and mixtures thereof.

8. The polyol c- is a diol selected from aliphatic or aromatic linear or branched C ２ -C １２ diols, preferably a diol selected from 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, more preferably a diol selected from propane-1,3-diol, butane-1,2-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol and mixtures thereof, even more preferably propane-1,3-diol, the composition according to one of claims 1 to 7, characterized in that.

9. The aforementioned polyol c- is of formula H-(O-CH ２ -CH(OH)-CH ２ ) ｎ -OH (wherein n varies from 2 to 10, preferably from 2 to 4) is a polyglycerol, preferably the polyol c- is H-(O-CH ２ -CH(OH)-CH ２ ) ｎ The composition according to one of claims 1 to 8, characterized in that it is a polyglycerol (polyglycerin-3 and / or polyglycerin-6) of the -OH group (wherein n = 3 and / or 6).

10. α - At least one polysaccharide selected from fungal chitosan (CHITOSAN FUNGAL), At least one modified polysaccharide selected from β-hydroxypropyl starch, and c-Formula H-(O-CH ２ -CH(OH)-CH ２ ) ｎ At least one polyol selected from polyglycerols of the form -OH (wherein n=3 and / or 6) (polyglycerin-3 and / or polyglycerin-6) The composition according to one of claims 1 to 9, characterized by comprising a mixture capable of forming a thin film.

11. The composition according to one of claims 1 to 10, characterized in that it contains polysaccharide a- in an amount of 0.1 to 15%, preferably 0.5 to 10%, more preferably 1 to 5%, by weight ratio with respect to the total weight of the cosmetic composition.

12. The composition according to one of claims 1 to 11, characterized in that it contains 1 to 15%, preferably 2 to 10%, more preferably 4 to 8%, of modified polysaccharide b- by weight relative to the total weight of the cosmetic composition.

13. The composition according to one of claims 1 to 12, characterized by containing 1 to 20%, preferably 3 to 15%, more preferably 5 to 10%, of polyol c- in weight ratio with respect to the total weight of the cosmetic composition.

14. The composition according to one of claims 1 to 13, characterized in that the weight ratio of polyol c- / (polysaccharide a- + modified polysaccharide b-) changes from 20 / 80 to 80 / 20, preferably from 40 / 60 to 60 / 40.

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

16. The composition according to any one of claims 1 to 15, characterized in that it contains water in an amount that varies by weight from 40% to 99% of the total weight of the cosmetic composition, preferably from 50% to 90%, and more preferably from 60% to 70%.

17. The composition according to one of claims 1 to 16, characterized in that it contains a pH adjusting agent, preferably an alkali hydroxide such as sodium hydroxide, more preferably in an amount that varies from 0.01% to 1% by weight relative to the total weight of the cosmetic composition.

18. The composition according to any one of claims 1 to 17, characterized in that it is in the form of a gel, lotion, serum, suspension, oil-in-water emulsion, or mask, preferably in the form of a serum or oil-in-water emulsion.

19. A method for preparing a cosmetic composition according to one of claims 1 to 18, comprising the following steps: (i) A step of preparing a mixture capable of forming a thin film by dissolving at least one polysaccharide a-, at least one modified polysaccharide b-, and at least one polyol c- in water, and (ii) Dispersing the mixture obtained in step (i) in an aqueous phase containing, if necessary, active ingredients and / or excipients for cosmetic use. Methods that include...

20. A skincare method characterized by comprising the step of applying a composition as defined in accordance with any of claims 1 to 18 to at least part of the body and / or face.

21. The method according to claim 20, characterized in that the step applied to at least part of the body and / or face is performed on at least one skin area showing signs of aging or fatigue, such as loss of firmness, loss of elasticity, or sagging skin, particularly on the face and / or neck, in order to obtain an effect selected from a smoothing effect, a firming effect, a skin plumping effect, or a combination of these effects.

Images