Cosmetic tensing agent comprising helical glucan biopolymers

Abstract

The present invention relates to particular cosmetic agents having a tensing and / or adhesive effect, these agents comprising biopolymers that consist essentially of α-1,4-linked linear glucans. The invention also relates to the use of these agents for cosmetic applications, in particular for a smoothing effect, for improving complexion radiance, for extending the wear of makeup, or for limiting the penetration of sunscreens into the surface layers of the skin.

Description

cosmetic tightening agent comprising helical glucan biopolymers technical field

[0001] The invention relates to specific cosmetic agents exhibiting a tightening and / or adhesive effect. These agents comprise biopolymers composed primarily of polysaccharides, particularly linear glucans linked at α-1,4, and exhibiting a helical conformation. The invention also relates to the use of these agents for cutaneous cosmetic applications, notably for a smoothing effect, to improve skin radiance, to prolong makeup wear, or to limit the skin penetration of sunscreens. State of the art

[0002] Faced with a wide range of cosmetic products and taking into account current environmental concerns, consumers are increasingly skeptical of a system that encourages overconsumption, excessive packaging, and so on. As a result, some consumers feel the need to reconsider their skincare routines. However, the search for products with proven efficacy and multiple cosmetic benefits remains a prerequisite. This quest for simplicity in current skincare routines is reflected in the strong enthusiasm surrounding trends such as "skin streaming," which streamlines product use into a few key steps, and the hybridization of skincare and makeup.

[0003] Thus, one of the many challenges facing the cosmetics industry lies in combining product versatility, where results demonstrate the effectiveness of the formula, with a pleasant sensory experience. For skincare and makeup, the duration of effectiveness plays a crucial role in product claims. In skincare, the rapid perception of benefits is closely linked to users' interpretation of the products' functional performance. For makeup, the "long-lasting" effect is certainly one of the most frequently used claims. It refers to the extended wear of pigments, allowing for a polished appearance throughout the day.

[0004] Furthermore, sunscreens protect the skin against UV radiation. However, their effectiveness is reduced if they do not remain on the skin's surface. It is also known that they can penetrate the superficial layers of the skin. Therefore, the search for active cosmetic ingredients that limit the penetration of sunscreens into the superficial layers of the skin is also a need for consumers seeking skin protection against UV radiation.

[0005] In this context, tightening cosmetic agents represent particularly interesting candidates to meet contemporary consumer expectations.

[0006] There is therefore a need for new agents, with a noticeable tightening effect, an optimal adhesion effect, as well as an effect increasing the lifespan of sunscreens on the skin. Summary of the invention

[0007] To address this need, the invention proposes a novel tightening agent, comprising film-forming biopolymers, which provides an immediate tightening effect from the first application, smoothing and lifting the skin to make it softer and more radiant, while also combining adhesion and protective properties. Indeed, beyond this smoothing effect, the tightening agent prolongs makeup wear, thus ensuring high-performance coverage while limiting the penetration of sunscreens into the superficial layers of the skin.

[0008] Thanks to its remarkable physical properties, the tightening agent according to the invention offers multifunctional effectiveness and provides noticeable cosmetic benefits in the short term, thus meeting the needs of consumers to minimize the number of skincare products in their beauty routine.

[0009] The present invention thus relates to a cosmetic tightening agent comprising biopolymers in a helical conformation, in which said biopolymers comprise predominantly linear glucans linked in α-1,4; advantageously with molar masses between 360 Da and 630 kDa.

[0010] Preferably, the cosmetic tightening agent according to the present invention consists essentially of biopolymers which are predominantly in a helical conformation.

[0011] Advantageously, these specific biopolymers are foldamers that exhibit a strong tendency to adopt a compact and ordered conformation. In a helical conformation, these biopolymers contract, conferring tightening properties to the cosmetic agent.

[0012] Obtaining a helical biopolymer relies in particular on: the selection of a raw material rich in linear or branched polysaccharides and whose branches are hydrolyzable; obtaining helical structures of specific sizes, giving the cosmetic agent the tensing properties.

[0013] Indeed, the formation of a helical foldamer is determined by the size and linearity of the polysaccharide chains. These two parameters define the ability of the polysaccharides to interact with each other and fold into helices. It is by adopting this conformation that the biopolymer contracts and imparts its tightening properties to the cosmetic agent containing it.

[0014] Thus, according to a preferred object, the tensor agent according to the invention is essentially made up of biopolymers in a helical conformation, in which said biopolymers comprise mainly linear glucans linked in α-1,4, with molar masses between 360 Da and 630 kDa.

[0015] According to another preferred object, the tensor agent according to the invention is essentially made up of biopolymers predominantly in a helical conformation and in which said biopolymers mainly comprise linear glucans linked at α-1,4, of molar masses between 360 Da and 630 kDa.

[0016] In other words, the cosmetic tightening agent according to the present invention may include, in addition to biopolymers, minerals, proteins, and organic acids.

[0017] On the other hand, although the agent may contain biopolymers in the form of dimers, trimers, tetramers, pentamers, etc., the majority of biopolymers present in the tensor agent are in a helical conformation. Thus, at least 50% of the biopolymers present in the agent are in a helical conformation.

[0018] Furthermore, the biopolymers present in the agent are predominantly composed of linear glucans linked at α-1,4. More preferably, linear glucans linked at α-1,4 represent at least 70% by weight of the total weight of the agent, even more preferably, linear glucans linked at α-1,4 represent at least 90% by weight of the total weight of the agent.

[0019] According to a preferred object, the molar mass of the linear α-1,4-linked glucans present in the agent according to the present invention is between 360 Da and 630 kDa.

[0020] Thus, biopolymers preferably comprise at least 70%, by weight of the total weight of the agent, of linear α-1,4-linked glucans with molar masses between 360 Da and 630 kDa. More preferably, said biopolymers comprise at least 90%, by weight of the total weight of the agent, of linear α-1,4-linked glucans with molar masses between 360 Da and 630 kDa.

[0021] According to another particularly preferred object, linear glucans linked in a-1,4 suitable for forming biopolymers exhibiting helical conformation have a molar mass between 1080Da and 630 kDa.

[0022] According to another preferred object, the glucans suitable for forming biopolymers have an average molar mass between 8 kDa and 100 kDa, and even more preferably an average molar mass between 10 kDa and 50 kDa. This specific selection allows the agent to exhibit the desired film-forming properties and tensor effect.

[0023] According to another preferred aspect of the invention, the biopolymers are functionalized. Functionalizing the biopolymers by adding carbonyl and / or carboxyl groups further enhances the intrinsic adhesion properties of the agent according to the invention, improving its effectiveness and long-lasting durability. Indeed, the addition of these groups gives the tensor agent enhanced adhesion properties, resulting in greater durability over time.

[0024] Thus, depending on the object, glucans are preferentially functionalized by at least one carboxyl and / or carbonyl group.

[0025] According to another object, at least one linear glucan linked at α-1,4 is functionalized by at least one carboxyl and / or carbonyl group, even more preferentially a single carboxyl or carbonyl group.

[0026] Preferably, the agent according to the invention comprises at least 5% glucose (plus or minus 3%), i.e., at least 5 glucoses per 100 (plus or minus 3 glucoses), functionalized with a carboxyl and / or carbonyl group, which significantly improves the agent's adhesion capabilities. Most preferably, the agent according to the invention comprises between 5% and 20% glucose, i.e., 5 to 20 glucoses per 100, functionalized with a carboxyl and / or carbonyl group, which significantly improves the agent's adhesion capabilities; even more preferably, between 5% and 15% glucose, i.e., 5 to 15 glucoses per 100.

[0027] Obtaining helical biopolymers also depends on the composition and the structure of polysaccharides, in particular glucans contained in the plant raw material, especially its richness in polysaccharides, in particular linear or branched glucans and whose branches are hydrolyzable.

[0028] It follows that the glucans forming the agent according to the invention are preferably obtained from a plant chosen from the group consisting of oats (Avena sativa), chestnut (Castanea sativa), cassava (Manihot esculenta), green banana (Musa sapientum), rice (Oryza sativa), millet (Panicum miliaceum), potato (Solanum tuberosum), wheat (Triticum vulgare), maize (Zea mays) and mixtures thereof.

[0029] Finally, and advantageously, the tightening agent according to the present invention limits the cutaneous penetration of sunscreens into the superficial layers of the skin.

[0030] According to another particularly preferred object of the invention, the agent according to the invention is obtained by a preparation process comprising the following steps: Solubilization of plants containing glucans in water, Separation of soluble and insoluble phases, Enzymatic and / or chemical hydrolysis of the insoluble phase, possibly functionalization of specific glucans, purification

[0031] Thus, the invention also relates to a method of preparing the agent according to the invention, in particular biopolymers, more particularly glucans in helical conformation included in the cosmetic agent according to the present invention.

[0032] The invention also relates to a method for preparing α-1,4 glucans included in the cosmetic agent according to the present invention.

[0033] Furthermore, the invention relates to a cosmetic composition comprising at least 0.05% of a tensing agent according to any of the preceding objects, by weight of the total weight of the composition. Most preferably, the composition comprises between 0.05% and 10% of the tensing agent according to the invention. The cosmetic composition according to the invention may comprise, in addition to the tensing agent, at least one excipient, in particular a cosmetically acceptable excipient.

[0034] According to another aspect, the invention also relates to cosmetic uses of the tensing agent according to the invention or of a composition comprising it.

[0035] According to a preferred object, the invention relates to the cosmetic use of a tightening agent according to any one of the preceding objects, as a cosmetic tightening agent and adhesive.

[0036] The invention relates more advantageously to the use of this tightening agent according to the invention to improve skin radiance and / or smooth the skin and / or decrease the visibility of skin pores.

[0037] Furthermore, the invention also relates to the cosmetic use of said agent according to the invention to improve the hold of makeup, for example foundation, eyeshadow, etc.

[0038] Furthermore, the invention also relates to the use of said agent according to the invention to limit the penetration of sunscreens into the superficial layers of the skin. Thus, the present invention also relates to the tightening agent according to any of the objects previously described for its use in limiting the penetration of sunscreens into the skin, advantageously into the superficial layers of the skin.

[0039] Also, the inventor has developed a new tensing agent of natural origin, meeting current consumer expectations.

[0040] Other features and advantages will become apparent from the detailed description of the invention, the examples and figures that follow. Brief description of the Figures

[0041] Figure 1 represents the spectral bands, obtained from a Raman type spectrometer, which are characteristic of helical structures.

[0042] Figure 2 represents an illustration of the hold of the eyeshadow when the agent according to the invention is formulated in an emulsion (primer) compared with a placebo.

[0043] Figure 3 represents the visualization scale of the tensor effect on the model for evaluating the retraction strength of tensor polymers. This retraction is visually assessed on a 3-level scale ("-" no tensor effect; "+ / -" slight tensor effect; "+" tensor effect). Panel A describes a tensor effect "+", panel B describes a slight tensor effect "+ / -", and panel C describes no tensor effect "-". Detailed description of the invention

[0044] Definition

[0045] For the purposes of this invention, "cosmetic agent" or "agent" refers to an ingredient suitable for cosmetic use on the skin. The agent according to this invention is composed, in particular, of saccharides, such as glucans, which form biopolymers, themselves forming the agent.

[0046] By "majority" or "in majority", we mean the common term, namely at least 50%, in particular strictly greater than 50% or more than half.

[0047] By "consisting essentially of" in the sense of the invention, it is understood that other elements may be present in the agent, namely elements such as minerals, proteins, organic acids, which do not affect the essential characteristics of the agent according to the invention, namely a tensing and adhesive effect.

[0048] For the purposes of this invention, "biopolymer" refers to molecules (such as polymers) derived from plant-based raw materials, as opposed to synthetic molecules obtained through chemical synthesis. Biopolymers, as defined in this invention, can exist in various non-helical conformations (dimers, trimers, tetramers, pentamers, etc.) or in a helical conformation, in which case they are called foldamers.

[0049] The term "film-forming effect" refers to an effect that creates a film on the skin's surface that is imperceptible to the naked eye, homogeneous, flexible, and spreads easily. In cosmetics, consumers expect a film-forming agent to produce a film or continuous layer on the skin and hair that is flexible and supple.

[0050] The term "tightening effect" refers to a tightening effect on the skin. This effect is rapid, almost immediate. Through this tightening effect, the agent smooths the skin, reduces the appearance of pores, and diminishes the size of wrinkles and fine lines. This tightening capacity can be evaluated using one of the protocols described in Example 3.

[0051] For the purposes of this invention, "tensor agent" means an agent exhibiting a tensor effect.

[0052] A "naturally derived cosmetic agent" is defined as a cosmetic agent made from a raw material found in nature (plant, microorganism) that has undergone specific and defined chemical and / or biological processes to chemically modify it. These modifications are intentional and result in molecular structures that are no longer identical to molecules found in nature.

[0053] By "adhesive effect," we mean an effect of adhesion on the skin. This adhesion allows the agent to prolong the wear of the makeup pigments, thus ensuring a flawless appearance throughout the day by improving makeup hold without requiring reapplication. This adhesive capacity can be evaluated according to the protocol described in Example 2.

[0054] By "average molar mass" of a mixture of molecules within the meaning of the invention is meant the average of the molar masses of the different molecules present in the mixture, as a function of the number of molecules.

[0055] By "specific glucans" or "glucans of the size of interest", we mean, in the sense of the invention, glucans linked in α-1,4, advantageously with molar masses between 360 Da and 630 kDa.

[0056] tensor agent according to the invention

[0057] The present invention therefore relates to a cosmetic tightening agent comprising biopolymers in a helical conformation, in which said biopolymers comprise predominantly linear glucans linked in α-1,4, advantageously with molar masses between 360 Da and 630 kDa.

[0058] Preferably, the cosmetic tensing agent consists essentially of biopolymers in a helical conformation, in which said biopolymers comprise mainly linear glucans linked in α-1,4, advantageously with molar masses between 360 Da and 630 kDa.

[0059] Preferably, the cosmetic tightening agent is made up essentially of biopolymers, themselves mainly comprising linear glucans linked in α-1,4, and in which the majority of the biopolymers of the agent are in a helical conformation.

[0060] The helical structure of a biopolymer can be determined and quantified by Raman microspectrometer. A band around 1340 cm⁻¹ 1 This reflects the presence of helical structures in the tested sample. The larger the area under the curve, the more this helical conformation is represented in the tested sample. These results are shown in Figure 1. Thus, the agent according to the invention comprises a majority of biopolymers in helical form. In particular, the agent comprises at least 50% biopolymers in helical form.

[0061] The specific molecular structure containing α-1,4 linkages can be determined by chromatography after the action of an enzyme specific to the α-1,4 linkage between two glucose molecules. Another enzyme specific to the α-1,6 linkage between two glucose molecules was also used in a mixture with the first. The enzymatic reactions were carried out on a 100 g / L solution of the agent according to the invention. It was thus determined that the agent comprises a majority of linear glucans linked by α-1,4. In particular, the agent comprises at least 50% linear glucans linked by α-1,4; notably in the less than 70% of α-1,4 linear glucans; particularly at least 80% of α-1,4 linked linear glucans, more particularly at least 90% of α-1,4 linked linear glucans among the polysaccharides of the agent.

[0062] The molar masses of saccharide biopolymers can be determined by HPLC, followed by refractive index (RI) detection. Samples of the agent according to the invention are solubilized at 100 g / L and then diluted to the specified percentage in the mobile phase before injection into the HPLC / RI system. The molar mass of the saccharides is then evaluated by comparing the retention times of the peaks detected in the samples of the agent according to the invention with the retention times of previously injected standards.

[0063] Thus, the molar mass of the biopolymers forming the agent according to the invention is between 360 Da and 630 kDa.

[0064] The tensor agent according to the invention is formed of particular biopolymers having a particular conformation and specifically selected sizes. Indeed, these biopolymers are essentially made up of glucans, in particular linear glucans linked at α-1,4, preferentially selected by their molar mass between 360 Da and 630 kDa, that is to say they are preferentially obtained by transformation of native glucans, in particular by hydrolysis.

[0065] Preferably, the invention therefore relates to a cosmetic tightening agent consisting essentially of biopolymers which mainly comprise linear glucans linked in α-1,4, of molar masses between 360 Da and 630 kDa, said biopolymers being mainly in a helical conformation.

[0066] Preferably, biopolymers mainly comprise linear glucans linked at α-1,4, with molar masses between 1080 Da and 630 kDa, said biopolymers being predominantly exhibiting a helical conformation.

[0067] Most preferably, the properties of the tensor agent according to the invention are further improved when the proportion of specifically selected glucans is at least 70%, by weight of the total weight of the agent, even more preferably at least 90% by weight of the total weight of the agent.

[0068] Thus, biopolymers comprise at least 70% linear glucans linked by α-1,4, with molar masses between 360 Da and 630 kDa. More preferably, biopolymers comprise at least 90% linear glucans linked by α-1,4, with molar masses between 360 Da and 630 kDa.

[0069] The size of these glucans is also specifically selected. Indeed, the inventor has determined that the film-forming properties and the tensor effect are maximum when the average molar mass of the glucans is preferentially between 8 kDa and 100 kDa, more preferably between 10 kDa and 50 kDa.

[0070] The distribution of the molar masses of the saccharides present in the agent according to the invention has also been determined. Thus, most preferably, the agent according to the invention comprises between 65% and 80% polysaccharides, between 20% and 30% oligosaccharides and at most 5% monosaccharides.

[0071] The elemental sugar composition of the agent was also determined by ion chromatography. The elemental sugars of the agent are advantageously at least 90% glucose and at most 10% fructose, very advantageously at least 95% glucose and at most 5% fructose.

[0072] According to another preferred object, the properties of the tensor agent according to the invention are further improved when the agent, in particular biopolymers, are functionalized, i.e. when specific glucans are functionalized, most preferably when the glucans are functionalized by at least one carboxyl and / or carbonyl group.

[0073] Thus, the cosmetic tightening agent comprises biopolymers consisting mainly of linear glucans linked in α-1,4, of which at least one glucan is functionalized by at least one carboxyl and / or carbonyl group, in which a majority of biopolymers are in a helical conformation.

[0074] This functionalization of specific glucans provides improved adhesion properties. To achieve this, carboxyl and / or carbonyl groups are added to these glucans.

[0075] To further improve adhesion properties and thus enable greater long-term durability, an optimal functionalization rate was determined. Therefore, depending on the specific product being considered, at least 5% of the glucose molecules are functionalized, and more preferably between 5% and 20%.

[0076] The functionalization rate of the agent according to the invention is expressed as the number of carboxyl and / or carbonyl groups per 100 units of elementary sugars. This functionalization rate is determined as follows. The quantity of carboxyl groups is determined by titrating a solution of the agent according to the invention with a 0.1M sodium hydroxide solution using an acid-base titration. The quantity of carbonyl groups is obtained after the reaction of the The solution of the agent according to the invention with hydroxylamine. The excess of hydroxylamine is determined by titration of the reaction with hydrochloric acid.

[0077] The dry matter content of the agent can be determined by weighing the residues obtained from drying the agent according to the invention at 105°C in an oven until a constant weight is reached. Thus, preferably, the agent according to the invention in solid form has a dry matter content of 900 mg / g to 1000 mg / g.

[0078] The tensing agent according to the invention thus very preferably comprises, at least 90% sugars, at most 5% minerals, at most 3% proteins, and at most 5% organic acids, by weight of the total weight of the agent.

[0079] The sugar content is preferably determined according to the DUBOIS method (Dubois M. et al., Analytical chemistry, 28, 3, 350-356, 1956).

[0080] The mineral ash content is preferably determined by weighing the residues from incineration at 550°C in an electric muffle furnace.

[0081] Protein content is preferentially determined by the KJELDHAL method (reference: Official method of analysis of the AOC 1975, 12th ed. W Horwitz, ED, New-York, p. 15-60).

[0082] The organic acid content is preferably determined by ion liquid chromatography by preparing a calibration curve of organic acids from commercial standards.

[0083] According to another preferred object, glucans are obtained from a raw material rich in saccharides of interest, notably chosen from the group consisting of oats (Avena sativa), chestnut (Castanea sativa), cassava (Manihot esculenta), green banana (Musa sapientum), rice (Oryza sativa), millet (Panicum miliaceum), potato (Solanum tuberosum), wheat (Triticum vulgare), maize (Zea mays) and mixtures thereof.

[0084] The tensor agent according to the invention can be in liquid or solid form.

[0085] When in liquid form, the agent according to the invention essentially consists of biopolymers, possibly accompanied by a stabilizer and / or preservative. Its dry matter content can be determined by weighing the residues obtained from drying the extract according to the invention at 105°C in an oven until a constant weight is reached.

[0086] Advantageously, the tensor agent according to the invention is in solid form, particularly in powder form.

[0087] When in solid form, the agent according to the invention can consist of the tensor agent as previously described or of the tensor agent with the addition of a support chosen from maltodextrin, gum arabic or soy lecithin.

[0088] According to another object, the agent according to the invention may optionally include an excipient, in particular selected from a preservative, an antioxidant, a stabilizer, an atomization support, and / or a combination thereof.

[0089] Method for preparing the agent according to the invention

[0090] Although the tensor agent according to the invention can be obtained by any means, according to a preferred embodiment, the preparation process includes at least one preparation step from a suitable raw material rich in saccharides, such as at least one hydrolysis, preferably at least one enzymatic and / or chemical hydrolysis.

[0091] Preferably, the agent is obtained by a preparation process comprising the following steps: The plant is solubilized in water to solubilize the glucans. Separation of the soluble and insoluble phases, recovery of the insoluble phase including glucans Enzymatic and / or chemical hydrolysis of the insoluble phase, Possibly functionalizing specific glucans, Purification

[0092] According to a particularly suitable embodiment, the agent according to the invention is therefore obtained by implementing the following steps: Solubilization of the plant in water for the purpose of solubilizing glucans at a rate of at least 50 g / L, Separation of the soluble and insoluble phases, recovery of the insoluble phase including glucans, Enzymatic and / or chemical hydrolysis of the insoluble phase, Possibly functionalizing glucans, Purification, Optionally, filtration and sterilization.

[0093] The solubilization of glucans is carried out in water, advantageously the Glucans are obtained from any raw material rich in linear or branched saccharides whose branches are hydrolyzable. Very preferably, such suitable raw materials can be oats (Avena sativa), chestnut (Castanea sativa), cassava (Manihot esculenta), green banana (Musa sapientum), rice (Oryza sativa), millet (Panicum miliaceum), potato (Solanum tuberosum), wheat (Triticum vulgare), maize (Zea mays).

[0094] The separation of the soluble and insoluble phases is carried out by any means known to those skilled in the art, for example, by centrifugation, filtration, or decantation. The separation of the soluble and insoluble phases is performed to recover the insoluble phase containing the glucans.

[0095] At least one hydrolysis is then performed to cleave the glucans to the desired size, advantageously an enzymatic and / or chemical hydrolysis. When the hydrolysis is enzymatic, the process includes a heat treatment step. This heat treatment step is advantageously carried out to inactivate the enzyme(s) present. This inactivation is then performed according to the recommendations of the supplier of the enzyme(s) used.

[0096] Radical functionalization is advantageously implemented to functionalize specific glucans by adding at least one carboxyl and / or carbonyl group to the glucose molecules forming the linear chain of these glucans. This functionalization can be achieved, in particular, by adding sodium hypochlorite, ozone, sodium periodate, hydrogen peroxide, peracetic acid, sodium bromide, or potassium permanganate, or mixtures thereof.

[0097] The agent obtained at this stage may be further concentrated. Preferably, the agent is purified by successive ultrafiltration steps through membranes of different porosity, retaining the glucans of interest at each step and / or by a chromatographic method.

[0098] The steps of the processes described above, taken individually, are usual in the field of extractions from natural raw materials, and a person skilled in the art is able to adjust the reaction parameters based on their general knowledge.

[0099] Composition according to the invention

[0100] The cosmetic agent according to the invention is preferably incorporated into a composition, this composition comprising a cosmetically acceptable medium. This is compositions in different galenic forms, adapted for topical administration on the skin, particularly human skin.

[0101] These compositions can take the form of oil-in-water emulsions, water-in-oil emulsions, multiple emulsions (water / oil / water or oil / water / oil), which may include microemulsions or nanoemulsions, or solutions, suspensions, hydrodispersions, aqueous gels, or powders. They can vary in consistency and have the appearance of a cream, lotion, milk, serum, ointment, gel, paste, or foam, or be in solid form.

[0102] These may be compositions comprising at least 0.05% of an agent according to the invention, preferably between 0.05 and 10%, by weight of the total weight of the composition.

[0103] These compositions include, in addition to the active ingredient, a physiologically acceptable and preferably cosmetically acceptable medium, meaning one that does not cause unacceptable discomfort to the user, such as redness, tightness, or tingling. This medium may, in particular, be an acceptable excipient.

[0104] The compositions according to the invention may contain as an adjuvant at least one compound selected from: - oils, which can be chosen in particular from among silicone oils, linear or cyclic, volatile or non-volatile; - waxes, such as ozokerite, polyethylene wax, beeswax or carnauba wax, - silicone elastomers, - surfactants, preferably emulsifying, whether non-ionic, anionic, cationic or amphoteric, - co-surfactants, such as linear fatty alcohols, - thickeners and / or gelling agents, - humectants, such as polyols like glycerin, - organic filters, - inorganic filters, - colorants, preservatives, fillers, pigments, minerals, - the sequestrators, - perfumes, - and their mixtures, without this list being exhaustive.

[0105] Examples of such adjuvants are cited in particular in the CTFA Dictionary (International Cosmetic Ingredient Dictionary and Handbook published by the Personal Care Product Council).

[0106] Of course, a person skilled in the art will take care to choose any additional compounds, active or inactive, and their quantity, in such a way that the advantageous properties of the mixture are not, or substantially not, altered by the envisaged addition.

[0107] These compositions are specifically intended to be used for the effects provided by the cosmetic agent according to the invention, in particular a tightening effect and an adhesive effect.

[0108] The invention also aims, according to another aspect, at a cosmetic skin care process to improve the condition of the skin, in particular for a smoothing effect and / or to improve the radiance of the complexion and / or to decrease the visibility of skin pores and / or to improve the hold of makeup and / or to limit the penetration of sunscreens into the skin.

[0109] Preferably the process consists of applying at least once a day to the skin of the face a composition according to the invention comprising in particular at least 0.05% by weight of dry matter of the tightening agent according to the invention.

[0110] cosmetic uses

[0111] Thus, the cosmetic agent according to the invention, or a composition comprising it, can be used for its various properties. In particular, the invention relates to its cosmetic use as a tightening and / or adhesive agent.

[0112] It can therefore be used in particular as an agent: to improve the radiance of the complexion and / or smooth the skin, and / or to decrease the visibility of skin pores, and / or for a perceptible cosmetic film effect, in order to feel the tightening efficacy, improve the overall appearance of the face and improve the hold of makeup pigments, and / or to limit the penetration of sun filters into the skin.

[0113] The invention therefore also relates to: the cosmetic use of an agent according to the invention: i. as a cosmetic tightening and / or adhesive agent, and / or ii. as a cosmetic agent to improve the radiance of the complexion and / or smooth the skin, and / or iii. as a cosmetic agent to reduce wrinkles and fine lines, and / or iv. as a cosmetic agent to reduce the visibility of skin pores, and / or v. as a cosmetic agent to improve the hold of makeup, due to its adhesive properties, allowing a long-lasting action, and / or vi. as an agent to limit the penetration of sunscreens into the skin.

[0114] The invention is now illustrated by non-limiting examples of compositions according to the invention and by results. Examples

[0115] Example - Agent according to the invention

[0116] The tensor agent in example 1a is obtained from the chestnut of the species Castanea sativa. The tensor agent in example 1a is obtained by the following process: Solubilization of 200 g / L of Castanea sativa containing glucans in water, Separation of soluble and insoluble phases, Enzymatic hydrolysis of the insoluble phase, Thermal treatment, Purification of specific glucans, Filtration

[0117] The tensor agent according to example a is in liquid form, it essentially comprises biopolymers, themselves comprising linear glucans linked in α-1,4, with molar masses between 360 Da and 360 kDa, the agent notably possesses the following characteristics: - Dry matter content = 90 g / L, (method by weighing the residues from drying the agent according to the invention at 105°C) - Sugar content = 98%, by weight relative to dry matter (DUBOIS method.

[0118] Example lb - Agent according to the invention

[0119] The tensor agent in example lb is, once again, obtained from the chestnut of the species Castanea sativa. The tensor agent in example lb is obtained by the following process: Solubilization of 200 g / L of Castanea sativa in water, Separation of soluble and insoluble phases, Enzymatic hydrolysis of the insoluble phase, Thermal treatment, Functionalization of specific glucans by adding carbonyl and / or carboxyl groups, Purification, Atomization

[0120] The tensor agent, according to example lb, is in powder form. It has the following characteristics: - Dry matter content = 950 mg / g (method by weighing the residues from drying the agent according to the invention at 105°C), of which: - Sugar content = 93%, by weight relative to dry matter, (DUBOIS method), - Sugars are made up of 98% glucose and 3% fructose. - Protein content = 1%, by weight relative to dry matter, (KJELDHAL method) - Mineral ash content = 3% by weight relative to dry matter (method determined by weighing the residues from incineration at 550°C), - Organic acid content = 3% by weight relative to dry matter (determined by liquid ion chromatography), - 97% of sugars have a molar mass between 360 and 360 kDa and 72% of sugars have a molar mass between 1260 Da and 360 kDa, - 96% of glucans are linear glucans linked at α-1,4, - 8% of glucoses are functionalized.

[0121] Example - Agent according to the invention

[0122] The tensor agent in example 1 is obtained from oat bran of the species Avena sativa. The tensor agent in example 2 is obtained by the following process: Solubilization of Avena sativa bran containing glucans in water, Separation of soluble and insoluble phases, Enzymatic hydrolysis of the insoluble phase, Thermal treatment, Purification of specific glucans, Filtration

[0123] The tensor agent according to example le is in liquid form. It essentially comprises biopolymers, themselves comprising linear glucans linked in α-1,4, with molar masses between 1kDa and 630 kDa.

[0124] Cosmetic studies of the agent according to the invention

[0125] Example 2 - Study of the adhesion properties of the agent according to the invention

[0126] The objective of this study is to evaluate the adhesion capacity of the agent according to the invention.

[0127] The study was conducted using a protocol adapted from the Elcometer 1542 Cross Hatch Adhesion Tester kit. The adhesion of the agent according to the invention was evaluated in comparison to Polyvinylpyrrolidone (PVP), a polymer known for its adhesive properties in cosmetics.

[0128] The protocol is as follows. On day 0 (J0), the agent according to the invention in Example 1a, Example 1b, or Polyvinylpyrrolidone is dissolved at 70 g / L in water containing 1% sorbitan monolaurate. Each solution is spread onto a contrast card, using a film puller, to form a wet film 150 µm thick. The films are then dried for 24 hours at room temperature. After drying, the films are scored horizontally and vertically to create a grid pattern using the cutting tool from the kit.

[0129] A polymer exhibits strong adhesion if the cut edges are perfectly smooth, with no film peeling. Conversely, the appearance of increasingly large peeling areas indicates reduced adhesive properties. The extent of peeling areas was quantified by acquiring images using the Visioscan® VC 20 and then analyzed by software processing. The higher the value, the less adhesive the film.

[0130] The results are presented in Table 1 below.

[0131] [Table 1]

[0132] The lower the peel surface value, the more adhesive the agent. Thus, the agent according to the invention in example lb (functionalized) has a smaller peel surface, expressed by a 20% reduction in the number of white pixels, compared to the agent according to the invention in example la (non-functionalized), approaching that of a synthetic polymer, PVP. Functionalization by the addition of fillers thus confers to the agent according to the invention of example lb a stronger power of adherence.

[0133] Example 3 - Study of the sensory tensor effect of the agent according to the invention

[0134] Example 3. a Study of the agent according to the invention formulated in gel form on a panel of experts.

[0135] The tensing effect of an agent according to the invention can be defined by characterizing the retraction force on an in vitro model or by sensory study on a panel of experts.

[0136] The objective of this study is to quantify the sensory tightening effect, determined by a trained panel, after a single application of the agent according to the invention formulated as a gel, compared to a placebo. The tightening effect was assessed using a scoring scale from 0 to 10 (0: no perceived tightening effect, 10: significant tightening effect) by evaluators previously trained to quantify a tightening effect.

[0137] The scoring was performed 3 minutes, 5 minutes, and 10 minutes after the application of 80 pL of the agent according to the invention (example lb) formulated at different doses (0.16%, 0.32%, and 0.50%) or of the placebo to the crow's feet area. The trained panel consisted of 21 healthy volunteers.

[0138] The results are presented in Table 2 below.

[0139] [Table 2]

[0140] After application of the agent according to the invention, formulated as a gel at different doses to the crow's feet area: 95% of volunteers experienced a greater effect than that perceived with the placebo formula, even at a dose of 0.16%. This figure reached 100% of volunteers when the agent according to the invention was tested at a dose of 0.50%. Furthermore, the agent according to the invention exhibits a dose-dependent tightening effect.

[0141] Example 3. b Study of the agent according to the invention formulated as an emulsion on a panel of experts.

[0142] The objective of this study is to evaluate the sensory effects of the agent according to invention lb, formulated as an emulsion at different doses (0.32% and 0.50%), by a trained panel after a single application compared to a placebo. The evaluations were carried out in two stages. (8 minutes after application of 400 pL to the face; 5 minutes after application of 50 pL to the hand), on two predefined measurement areas. The effects of the agent were assessed using a scoring scale from 0 to 10 (0: no perceived effect, 10: significant effect) by 13 evaluators previously trained to quantify a sensory effect. The three products were ranked according to the intensity of the sensations perceived by each expert. The product eliciting the weakest sensations was ranked 1st, the one eliciting the strongest sensations was ranked 3rd, and the intermediate product was ranked 2nd. Each evaluator performed six series. The average of the rankings obtained across the six series was calculated for each product. This yielded a measure of sensory perception expressed as a percentage. The results are presented in Table 3 below.

[0143] [Table 3]

[0144] At a concentration of 0.32% in emulsion, the tightening effect of the agent according to the invention is perceived by a panel of trained experts on both the hand and the face. These effects become significant compared to the placebo formula when the agent according to the invention is incorporated at a dose of 0.50%. Thus, the tightening agent according to the invention exhibits a tightening effect.

[0145] Example 3.c Study on the retraction force in the presence of the agent according to the invention

[0146] The shrinkage strength of a biopolymer can be characterized by an in vitro test. This model is known to those skilled in the art and is described in patent application W02020025900. The test is performed on a homogeneous solution of a biopolymer diluted in water at a concentration of 10 wt%. The biopolymer solution is deposited onto an elastic backing strip. After drying at 22 ± 3°C and 40 ± 10% relative humidity, the strip exhibits a shrinkage width due to the tension exerted by the deposited biopolymer. This shrinkage is visually assessed on a 3-level scale ("-" no tensile effect, "+ / -" slight tensile effect; "+" tensile effect) shown in Figures 3A to 3C. Figure 3A shows a strip exhibiting a tensile effect, and Figure 3C shows a strip Figure 3A shows a band exhibiting a slight tensile effect, while Figure 3C shows a band with no tensile effect. A product is considered to have a tensile effect with this test if the shrinkage is marked "+", i.e., only the bands shown in Figure 3A.

[0147] The tightening effect of several biopolymers was tested on this model. The biopolymers tested are: - Biopolymers according to the invention in example - Specific chestnut glucans - Biopolymers according to the invention of example lb - Functionalized specific glucans from chestnut - Biopolymers according to the invention of example - Specific glucans from Avena sativa The results are presented in Table 4 below.

[0148] [Table 4] according to the invention present a tightening effect.

[0150] Example 4 - Effectiveness of the agent according to the invention for its smoothing effect

[0151] Example 4. a Sensory study of the smoothing effect of the agent

[0152] The objective of this study is to evaluate the sensory effects of the agent according to the invention, formulated as an emulsion at different doses (0.32% and 0.50%), by a trained panel after a single application compared to a placebo. The evaluations were performed after 8 minutes. After applying 400 pL to a predefined measurement area on the face, the effects of the agent were assessed using a scoring scale from 0 to 10 (0: no perceived effect, 10: significant effect) by 13 evaluators previously trained to quantify sensory effects. The three products were ranked according to the intensity of the sensations perceived by each expert. The product eliciting the weakest sensations was ranked 1, the one eliciting the strongest sensations was ranked 3, and the intermediate product was ranked 2. Each evaluator performed six rounds. The average of the rankings obtained across the six rounds was calculated for each product. This yielded a measure of sensory perception expressed as a percentage.

[0153] The results are presented in Table 5 below.

[0154] [Table 5]

[0155] At a concentration of 0.32% in emulsion, the smoothing effect of the agent according to the invention is perceived by a panel of experts on the face. The effect becomes significant compared to the placebo formula when the agent according to the invention is incorporated at a dose of 0.50%. Thus, the tightening agent according to the invention exhibits a smoothing effect.

[0156] Example 4. b Study of the effectiveness of the agent for a smoothing effect on the face.

[0157] The objective of this study is to evaluate in vivo, the efficacy at the facial level, of the agent according to the invention lb formulated at 0.32% in an aqueous gel and at 0.64% in a gel-cream, in comparison to their respective placebo formulas.

[0158] The study was conducted on two groups of healthy, Caucasian, female volunteers with slight to moderate crow's feet wrinkles and a dull complexion.

[0159] The volunteers were divided as follows:

[0160] Study of the agent according to the invention formulated at 0.32% in aqueous gel: placebo group: 18 subjects; group of the agent according to the invention at 0.32%: 19 subjects

[0161] Study of the agent according to the invention formulated at 0.64% in gel-cream: placebo group: 18 subjects group of the agent according to the invention at 0.64%: 18 subjects.

[0162] Both studies were conducted 15 minutes, 5 hours or 8 hours after a single application to the face using the study of skin microrelief by fringe projection.

[0163] The results of the agent at 0.32% in aqueous gel form, or 0.64% in gel-cream form, on the cutaneous microrelief are presented respectively in Tables 6 and 7 below.

[0164] [Table 6]

[0165] The results demonstrate that, as early as 15 minutes after a single application by Caucasian volunteers and compared to the placebo group, the agent according to the invention, formulated at 0.32% gel, significantly smooths the microrelief of the face. This smoothing effect continues for up to 8 hours after application, at which point a 6% reduction in the density of the patterns is observed in the subjects.

[0166] Thus, the agent according to the invention smooths the skin surface quickly and this effect continues throughout the day.

[0167] [Table 7]

[0168] As early as 15 minutes after a single application by Caucasian volunteers, and compared to the placebo group, the agent according to the invention, formulated at 0.64% in a gel-cream, smooths the skin's microrelief. This smoothing effect is visible for up to 5 hours after application of the formula, during which a 6% reduction in the density of the patterns was measured. Thus, by rapidly smoothing fine lines, the agent according to the invention, formulated at 0.64% in an emulsion, helps to enhance the appearance of facial skin.

[0169] Example 4.c Study of the effectiveness of the agent for a smoothing effect on the body.

[0170] The objective of this study is to evaluate in vivo the efficacy on the body of the agent according to the invention lb formulated at 0.16% in an aqueous gel, compared to its placebo formula.

[0171] The study was conducted on 19 healthy, Caucasian, female volunteers with altered skin microrelief on their thighs.

[0172] The smoothing effect of the agent according to the invention lb on the body was evaluated 4 hours after a single application according to the following method: study of the cutaneous microrelief by projection of fringes.

[0173] The results of the agent on the cutaneous microrelief are presented in Table 8 below.

[0174] [Table 8]

[0175] 4 hours after a single application to the thighs by Caucasian volunteers and compared to placebo, the agent according to the invention formulated at 0.16% in gel significantly smooths the skin microrelief (decrease in the parameter Sa, characteristic of the roughness of the skin surface).

[0176] Thus, the agent according to the invention makes it possible to quickly smooth the skin microrelief on the thighs.

[0177] In conclusion, after a single application on the thigh area by Caucasian volunteers and compared to the placebo formula, the agent according to the invention formulated at 0.16% in gel, quickly smooths the skin microrelief.

[0178] Example 5 - Efficacy of the agent according to the invention for its effects on the radiance of the complexion

[0179] The protocol for this study is identical to that of example 4.b.

[0180] Both studies were conducted 15 minutes, 5 hours, or 8 hours after a single application to the face using the following method: a skin radiance assessment by expert visual evaluation.

[0181] The results of the agent in aqueous gel form on skin radiance are presented in Table 9 below.

[0182] [Table 9]

[0183] Compared to placebo, the agent according to the invention lb formulated at 0.32% in aqueous gel rapidly and significantly improves the characteristic parameters of the radiance of the complexion of Caucasian volunteers.

[0184] Indeed, as soon as 15 minutes after a single application, the agent according to the invention in an aqueous gel allows a 16% increase in skin radiance, the complexion is brighter and an 18% increase in pink color, the complexion is fresher, the application of the agent also significantly reduces olive color and eye fatigue compared to placebo.

[0185] These effects continue for up to 8 hours after application, with an 11% increase in skin radiance and a 17% increase in pinkness. A reduction in olive discoloration and eye fatigue is also observed.

[0186] Thus, the agent according to the invention in aqueous gel form quickly boosts the radiance of the complexion and this effect continues throughout the day.

[0187] The results of the gel-cream agent on skin radiance are presented in Table 10 below.

[0188] [Table 10]

[0189] Compared to the pacebo, the agent according to the invention formulated at 0.64% in gel-cream rapidly and significantly improves the characteristic parameters of the radiance of the complexion of Caucasian volunteers.

[0190] Indeed, as soon as 15 minutes after a single application, the agent according to the invention in a gel- The cream allows for a 23% increase in skin radiance, the complexion is brighter and 20% of pink color, the complexion is fresher, the application of the agent improves the healthy appearance by reducing the olive color and the state of fatigue of the eyes significantly compared to the placebo.

[0191] These effects continue for 5 hours after application, with an increase in skin radiance and pinkness. A reduction in olive color and eye fatigue is also observed.

[0192] By acting within 15 minutes on the main parameters of complexion radiance, the agent according to the invention, formulated at 0.64% in gel-cream form, provides a rapid and long-lasting radiance boost.

[0193] In conclusion, after a single application by Caucasian volunteers and compared to the placebo group, the agent according to the invention, formulated at 0.32% in an aqueous gel, improves skin texture and radiance rapidly and throughout the day. Formulated at 0.64% in a gel-cream, the agent according to the invention provides an instant radiance boost, an effect that lasts for 5 hours after application.

[0194] Example 6 - Efficacy of the agent according to the invention for its soothing effects

[0195] Example 6. a Sensory evaluation of the agent according to the invention formulated as an emulsion

[0196] The objective of this study was to evaluate the sensory effects of the agent according to the invention, formulated as an emulsion at different concentrations (0.32% and 0.50%), by a trained panel after a single application compared to a placebo. Evaluations were performed 5 minutes after application of 50 pL to the forearm, on a predefined measurement area. The effects of the agent were assessed using a scoring scale from 0 to 10 (0: no perceived effect, 10: significant effect) by 13 evaluators previously trained to quantify sensory effects. The three products were ranked according to the intensity of the sensations perceived by each expert. The product eliciting the weakest sensations was ranked 1st, the one eliciting the strongest sensations was ranked 3rd, and the intermediate product was ranked 2nd. Each evaluator performed 6 rounds.The average of the rankings obtained in the six series is determined for each product. This gives a measure of sensory perception expressed as a percentage.

[0197] The results are presented in Table 11 below.

[0198] [Table 11]

[0199] The agent according to the invention also makes it possible to bring a feeling of softness to the formula.

[0200] Example 6. b - Effect on the softness of the body's skin

[0201] The objective of this study is to evaluate in vivo the efficacy on the body of the agent according to the invention lb formulated at 0.16% in an aqueous gel, compared to its placebo formula.

[0202] The study was conducted on 19 healthy, Caucasian, female volunteers with altered skin microrelief on their thighs.

[0203] The effect of the agent according to the invention lb on the body was evaluated 4 hours after a single application according to the TOUCHY finger® method.

[0204] Skin softness was assessed by an augmented and connected human finger, the TOUCHY finger®, before and then 4 hours after a single application of the agent according to the invention formulated at 0.16% in gel and the placebo formula on the thighs.

[0205] This device, developed by the Tribology and Systems Dynamics Laboratory (LTDS) of École Centrale de Lyon and the CNRS, is equipped with vibration sensors and a pressure force sensor. It takes the form of a half-ring that slips onto the tip of the index finger. When a surface is touched, the vibrations and pressure force recorded by the device are converted into a softness parameter.

[0206] Thus, when you touch a surface, it generates a friction noise that varies in intensity depending on the nature of the surface. The rougher the surface, the louder the sound produced and the greater the amplitude of the vibrations; conversely, touching a smooth surface generates a soft sound and small vibrations.

[0207] A decrease in the amplitude of vibrations, denoted "A" and measured in decibels (dB), is therefore characteristic of an improvement in measured softness. Velvet was used as a reference in terms of softness.

[0208] The measurement shown corresponds to the deviation from this standard of softness.

[0209] The results of the agent in aqueous gel form on skin softness are presented in Table 12 below.

[0210] [Table 12]

[0211] Four hours after a single application to the thighs by Caucasian volunteers, the agent according to the invention, formulated at 0.16% gel, significantly improves skin softness. The sensation of softness recorded after application of the formula is close to the perception of velvety softness.

[0212] Thus, the agent according to the invention improves the softness of the skin.

[0213] In conclusion, after a single application to the thigh area by Caucasian volunteers and compared to the placebo formula, the agent according to the invention formulated at 0.16% in gel improves skin softness. Example 7 - Effectiveness of the agent according to the invention for its adhesive effects

[0214] Example 7a - Makeup application - Eyeshadow with primer

[0215] The objective of this study is to evaluate in vivo the influence of the agent according to the invention lb formulated at 0.16% in emulsion (primer), on the hold of an eyeshadow compared to a placebo formula.

[0216] The study was conducted on 21 healthy female volunteers with eyelid creases.

[0217] Before applying eyeshadow, an emulsion containing the agent according to the invention, formulated at 0.16%, and a placebo formula were applied to each eyelid. The eyeshadow's staying power was evaluated 6 hours after application using digital photographs taken with the Visia-CR®.

[0218] The results of the agent formulated at 0.16% in emulsion on the hold of eyeshadow compared to a placebo formula are presented in Table 13 below, as well as in Figure 2.

[0219] [Table 13]

[0220] Compared to the placebo, the agent according to the invention, formulated at 0.16% in an emulsion, significantly improves the staying power of eyeshadow in Caucasian volunteers. Six hours after application, 67% of subjects showed greater eyeshadow staying power on the side treated with the emulsion containing 0.16% of the agent according to the invention.

[0221] Compared to the placebo formula, the agent according to the invention formulated at 0.16% thus significantly improves the hold of eyeshadow in Caucasian volunteers.

[0222] Example 7b - Eyeshadow makeup application

[0223] The objective of this study is to evaluate in vivo the influence of the agent according to the invention formulated at 0.16% in powder, on the hold of an eyeshadow compared to a placebo formula.

[0224] The study was conducted on a Caucasian panel of 16 healthy volunteers. Eyeshadow wear was assessed using photographs taken with a VISIA-CR® system. This wear was evaluated 6 hours (t6h) after application of the purple eyeshadow to the volunteers' eyelids.

[0225] The results of the agent formulated at 0.16% in powder on the hold of eyeshadow compared to a placebo formula are presented in Table 14 below.

[0226] [Table 14]

[0227] Compared to the placebo formula, the agent according to the invention, formulated at 0.16% in a powder, significantly improves the staying power of eyeshadow in Caucasian volunteers (+36.1%, p<0.05). Six hours after application, 69% of subjects showed greater eyeshadow staying power on the side treated with the powder containing 0.16% of the agent according to the invention.

[0228] Compared to the placebo formula, the agent according to the invention, formulated at 0.16% in powder form, significantly improves the hold of eyeshadow in Caucasian volunteers.

[0229] Example 7c - Makeup hold - Foundation

[0230] The objective of this study is to evaluate in vivo the influence of the agent according to the invention lb formulated at 0.16% in a foundation formula, on the hold of a foundation compared to a placebo formula.

[0231] The study was conducted on a Caucasian panel consisting of 28 healthy volunteers and on an Asian panel consisting of 17 healthy volunteers.

[0232] The hold of the foundation was evaluated 6 hours after application to half of the face on digital photographs taken with Visia-CR® for the Caucasian panel and by clinical scoring of pore visualization by a dermatologist for the Asian panel.

[0233] The results on the Caucasian panel of the agent formulated at 0.16% in emulsion on the hold of the foundation compared to a placebo formula are presented in Table 15 below.

[0234] [Table 15]

[0235] 6 hours after application by Caucasian volunteers and compared to the placebo formula, the agent according to the invention formulated at 0.16% in a foundation formula significantly promotes the hold of makeup.

[0236] The results on the Asian panel of the agent formulated at 0.16% in emulsion on the hold of the foundation compared to a placebo formula are presented in Table 16 below.

[0237] [Table 16]

[0238] After application of foundation, the visibility of pores in Asian volunteers is reduced.

[0239] Compared to the placebo formula, this coverage effect is superior with the foundation containing the agent according to the invention at 0.16%, 6 hours after application, indicating better long-lasting wear. 71% of subjects also showed a reduction in the visibility of pores on the side treated with the active ingredient, compared to 59% on the side treated with the placebo.

[0240] Compared to the placebo formula, the agent according to the invention, formulated at 0.16%, significantly improves the staying power of foundation in Caucasian volunteers and Asians.

[0241] Example 8 - Study of the properties of the tensing agent on the skin penetration of sunscreens.

[0242] The objective of this study is to evaluate the ability of the agent according to the invention to limit the skin penetration of sunscreens, for example, octocrylene, butyl methoxydibenzoylmethane, ethylhexyl salicylate.

[0243] The penetration of sunscreens is evaluated in human skin expiants previously treated with the agent according to the invention formulated at 0.32% or 1% in the cosmetic composition comprising said sunscreens, presented in example ll.j in comparison to the placebo formula.

[0244] The treated explants are subjected to a continuous UV radiation source. Stripping is performed on the explants. They are then analyzed using ATR-FTIR spectroscopy at a wavenumber of 950 to 1125 cm⁻¹, characteristic of these solar filters. The higher the relative intensity of the FTIR marker band, the more solar filters are present on the surface of the explant.

[0245] Table 17 indicates the relative intensities of the FTIR marker band (between 950-1125cm-l), this intensity is proportional to the amount of sunscreens present on the skin surface.

[0246] [Table 17]

[0247] It is observed that for samples treated with cosmetic compositions containing the agent according to the invention at 0.32% or 1%, the sunscreens are significantly less present in the layers of the skin; this difference is significant from layer N2 onwards.

[0248] It is also observed that this effect appears to be amplified with the cosmetic composition containing 1% of the agent according to the invention.

[0249] The agent according to the invention therefore makes it possible to limit the penetration of sunscreens into the superficial layers of the skin.

[0250] Example 9 - Rapid lifting effect on wrinkles

[0251] The objective of this study is to evaluate, in vivo, the influence of the agent according to the invention, formulated at 0.32% in gel, compared to a placebo formula, on crow's feet wrinkles. The lifting properties at the wrinkle level are assessed using a fringe projection device dedicated to 3D measurement of skin relief (AEVA-HE). 2 , Eotech), linked to associated software, at the level of the crow's foot of the panel volunteers. The study was conducted on a Caucasian panel of 21 healthy volunteers. Profile roughness was calculated immediately after application at 0 hours (t0) and 15 minutes after application (t15min). The roughness results are presented in Table 18. The roughness values ​​at t0 and t15min represent the average value for the panel. The difference A / t0 (%) represents the difference between the t15min value and the value at t0, expressed as a percentage.

[0252] [Table 18]

[0253] Compared to the placebo formula, the agent according to the invention reduces roughness by 5.4% compared to the placebo. The agent according to the invention therefore significantly increases the lifting effect on wrinkles. The lifting effect on wrinkles is increased by 5.4% compared to the placebo formula.

[0254] Example 10 - Fast firming effect

[0255] The objective of this study is to evaluate, in vivo, the influence of the agent according to the invention, formulated at 0.16% in gel, compared to a placebo formula, on the biomechanical surface properties of the skin. The biomechanical surface properties of the skin are measured and calculated using a Cutometer® MPA 580 and associated software, at the level of the inner thighs of the volunteers.

[0256] The study was conducted on a Caucasian panel of 21 healthy volunteers. The biomechanical properties of the skin surface, namely firmness, elasticity, and tone, were determined directly after application of the gel at 0 hours (tOh) and after 4 hours (t4h).

[0257] The results for the biomechanical properties are presented in Table 19 for skin firmness, Table 20 for skin elasticity, and Table 21 for skin tone. The values ​​for each biomechanical property at 0 hours and 4 hours correspond to the average value of the panel. The difference A / t0 (%) corresponds to the difference between the t4h value and the t0h value; it is expressed as a percentage.

[0258] [Table 19]

[0259] Compared to the placebo formula, the agent of the invention significantly increases skin firmness. Skin firmness is increased by 5% compared to the placebo formula.

[0260] [Table 20]

[0261] Compared to the placebo formula, the agent of the invention significantly increases skin elasticity. Elasticity is increased by 8% compared to the placebo formula.

[0262] [Table 21]

[0263] Compared to the placebo formula, the agent of the invention significantly increases skin tone. Skin tone is increased by 34% compared to the placebo formula.

[0264] Finally, several composition examples are described in order to demonstrate the possible applications of the agent according to the invention integrated into a cosmetic composition.

[0265] Example 11 - Compositions according to the invention

[0266] Example 11. a Composition according to the invention

[0267] An example of a composition comprising the active ingredient according to the invention in the form of a lifting serum is shown in Table 22 below.

[0268] [Table 22]

[0269] The composition of example 11.a can in particular be obtained by the following process: Place A under agitation. Shake until homogeneous. Add B to A while stirring moderately. Shake for 20 minutes. - Add C to AB while stirring vigorously. Shake for 20 minutes. Add D then E under moderate stirring. Adjust the pH to 5.8 - 6.2 with F.

[0270] The composition then takes the form of a soft and shiny cream-gel, off-white in color.

[0271] Example 11. b Composition according to the invention

[0272] An example of a composition comprising the active ingredient according to the invention in the form of an eye contour treatment is shown in Table 23 below.

[0273] [Table 23]

[0274] The composition of example 11.b can in particular be obtained by the following process: Add B to A while stirring vigorously. Shake for 20 minutes. Add C then D under moderate stirring. Adjust the pH to 6.5 - 7.0 with E.

[0275] The composition then takes the form of a thick, glossy, off-white cream-gel.

[0276] Example 11. c Composition according to the invention

[0277] An example of a composition comprising the active ingredient according to the invention in the form of a firming treatment is shown in Table 24 below.

[0278] [Table 24]

[0279] The composition of example 11.c can in particular be obtained by the following process: Place A under moderate stirring and heat to 80°C. Place B under agitation and heat to 80°C. Emulsify B in A under shearing agitation for 10 minutes. - At room temperature, under moderate agitation, add C then D. Adjust the pH to 5.8 - 6.2 with E

[0280] The composition then appears as a soft and glossy emulsion, white in color.

[0281] Example 11.d Composition according to the invention

[0282] An example of a composition comprising the active ingredient according to the invention in the form of a firming body lotion is shown in Table 25 below.

[0283] [Table 25]

[0284] The composition of example 11.d can in particular be obtained by the following process: Place A under agitation. Shake until homogeneous. Emulsify B in A under shear agitation for 20 minutes. - Under moderate agitation, add C then D. Adjust the pH to 5.5 - 6.0 with E

[0285] The composition then appears as a soft and glossy emulsion, white in color.

[0286] Example 11. e Composition according to the invention

[0287] An example 11.e of a composition comprising the active ingredient according to the invention in the form of a smoothing primer is shown in Table 26 below.

[0288] [Table 26]

[0289] The composition of example 11.e can notably be obtained by the following process: Add A2 to Al under moderate stirring. Stir until homogeneous. Place B under vigorous stirring. Shake until homogeneous. - Emulsify B in A under shear stirring for 10 minutes. Add C then D and E under moderate stirring. Adjust the pH to 5 - 5.2 with F.

[0290] The composition then takes the form of a soft, satiny emulsion, white in color.

[0291] Example 11. f Composition according to the invention

[0292] An example of a composition comprising the active ingredient according to the invention in the form of a lifting foundation is shown in Table 27 below.

[0293] [Table 27]

[0294] The composition of example ll.f can in particular be obtained by the following process: Place Al under shear stirring. Stir until homogeneous. Add A2 to Al and homogenize under Turrax. Place Bl under stirring then add B2 and B3. - Add B very slowly to A under vigorous stirring. Homogenize under Turrax

[0295] The composition then appears as a thick, glossy emulsion of medium beige color.

[0296] Example 11. a Composition according to the invention

[0297] An example of a composition comprising the active ingredient according to the invention in the form of a long-lasting eyeshadow is shown in Table 28 below.

[0298] [Table 28]

[0299] The composition of example 11.g can in particular be obtained by the following process: Place Al under moderate agitation. Shake until homogeneous. Add A2 then A3 to A1 while stirring moderately. Stir until homogeneous. - Add B then C while stirring moderately.

[0300] The composition then takes the form of a thick, iridescent pink gel.

[0301] Example 11. h - Composition according to the invention

[0302] An example of a composition comprising the active ingredient according to the invention in the form of a tinted gel mascara is shown in Table 29 below.

[0303] [Table 29]

[0304] The composition of example 11.h can in particular be obtained by the following process: Add B to A while stirring vigorously. Stir until a homogeneous gel is obtained. Add the components of C while stirring vigorously, then homogenize. - Add D while stirring vigorously, then homogenize. Add E while stirring vigorously. Adjust the pH to 6.0 - 6.5 with F.

[0305] The composition then takes the form of a thick, glossy, intensely black gel.

[0306] Example 11. i Composition according to the invention

[0307] An example of a composition comprising the active ingredient according to the invention in the form of a two-phase fixing spray is shown in Table 30 below.

[0308] [Table 30]

[0309] The composition of example 11.i can in particular be obtained by the following process: Place Al under agitation. Shake until homogeneous. Add A2 then A3 to Al while stirring. Stir until homogeneous. Adjust the pH to 4.8 - 5.2 with A4. - Place B under stirring. Stir until homogeneous. Add B to A

[0310] The composition then appears as a transparent two-phase solution, comprising a colorless aqueous phase and a yellow oily phase.

[0311] Example 11. j Composition according to the invention

[0312] An example of a composition comprising the active ingredient according to the invention in the form of a sunscreen product is shown in Table 31 below:

[0313] [Table 31]

[0314] The composition of example ll.j can in particular be obtained by the following process: a. Add the premix A2 to Al under vigorous stirring. Stir for 20 minutes. b. Mix Bl for 30 minutes at 40°C. c. Add B2 to Bl and mix thoroughly. d. Pour B into A while stirring vigorously. Emulsify for 10 minutes. e. Add C, then D while stirring gently. Stir for 10 minutes.

Claims

Demands

1. Cosmetic tightening agent comprising biopolymers in a helical conformation, wherein said biopolymers predominantly comprise linear glucans linked at α-1,4.

2. A tensor agent according to the preceding claim, wherein at least one linear glucan linked at α-1,4 is functionalized by at least one carboxyl and / or carbonyl group.

3. A tensor agent according to any one of the preceding claims, characterized in that at least 5% of the glucoses forming the glucans are functionalized.

4. Tensor agent according to any one of the preceding claims, wherein the agent comprises predominantly biopolymers in a helical conformation.

5. Tensor agent according to any one of the preceding claims, wherein the biopolymers comprise predominantly linear α-1,4-linked glucans having a molar mass between 360 Da and 630 kDa.

6. Tensor agent according to the preceding claim, wherein at least 90% of the linear α-1,4-linked glucans have a molar mass between 360 Da and 630 kDa.

7. Tensor agent according to any one of the preceding claims, characterized in that the glucans are obtained from a plant selected from the group consisting of Avena sativa, Castanea sativa, Manihot esculenta, Musa sapientum, Oryza sativa, Panicum miliaceum, Solanum tuberosum, Triticum vulgare, Zea mays and mixtures thereof.

8. A tensor agent according to any one of the preceding claims, characterized in that the agent is obtained by a preparation process comprising the following steps: a. Solubilization of glucan-containing plants in water, b. Separation of soluble and insoluble phases, c. Enzymatic and / or chemical hydrolysis of the insoluble phase, d. Optionally, functionalization of specific glucans.

9. Cosmetic use of a tensing agent according to any one of the preceding claims, as a cosmetic tensing and adhesive agent.

10. Cosmetic use according to the preceding claim, to improve skin radiance and / or smooth the skin and / or reduce the visibility of skin pores.

11. Cosmetic use of an agent according to claim 9, to improve the hold of makeup.

12. Agent according to any one of claims 1 to 8, for its use in limiting the penetration of sunscreens into the skin.

13. Cosmetic composition comprising at least 0.05% of a tensing agent according to any one of claims 1 to 8, by weight of the total weight of the composition.

Images