Cosmetic composition including indirubin and a blend of antioxidants

Abstract

A cosmetic composition having at least one oil phase and comprising: a) indirubin; b) at least one ascorbic acid ester; etc.; or at least one salt of citric acid and piperidinol compound. Use of a mixture comprising at least one ascorbic acid ester and at least one salt of citric acid and piperidinol compound to stabilize the color of a cosmetic composition comprising indirubin as a coloring agent.

Description

Title of the invention: Cosmetic composition comprising indirubin and a mixture of antioxidants Technical field

[0001] The present invention relates to the field of colored cosmetic compositions comprising indirubin, for example dedicated to skin care and / or makeup, and to the use of a particular mixture of antioxidants to stabilize the color of the composition over time. Technological background

[0002] Cosmetic compositions, particularly for skin care and / or makeup, remain in very strong demand from consumers, for example to moisturize, treat, improve the appearance of the skin and / or reduce the signs of skin aging. The performance of the products is sought after, but also the sensory qualities, appearance and stability over time of the products.

[0003] At the same time, it is preferable to formulate cosmetic compositions with ingredients of natural origin or more environmentally friendly ingredients, including pigments or dyes of natural origin.

[0004] The use of natural colorants is known, but some colorants are difficult to stabilize in cosmetic compositions and can quickly lose their color, particularly under the effect of oxygen, heat and / or UV / visible radiation. Some colorants therefore require stabilization by protective ingredients such as, for example, antioxidants, possibly combined. For example, document FR 3107455 describes a cosmetic composition using astaxanthin as a coloring agent, the color of which is preserved and stabilized over time using a particular mixture of antioxidants. Other coloring materials of natural origin are also sought for their color, their intensity, their originality or for other properties that they allow to be combined in the formulations, such as, for example, biological or physicochemical activities.

[0005] To date, indirubin does not fall into the category of colorants listed in Annex IV of Cosmetic Regulation (EC) No. 1223 / 2009. However, given the high coloring power of this substance, the inventors consider that a color can be conferred on cosmetic compositions containing indirubin or cosmetic extracts which comprise it. Indirubin is a red lipophilic coloring substance of natural origin which can in particular come from dye plants, just like its blue isomer, indigotin (or indigo). Indirubin and indigotin are bis-indoles belonging to the family of indigoids (substances co lorantes of the indigo group). These molecules can be obtained from any indigo-bearing plant, called indigoferous, such as Isatis tinctoria, Indigofera tinctoria, Indigo suffruticosa, Philenoptera cyanescens or Polygonum tinctorium (also called Persicaria tinctoria'). In particular, indigo plants produce indoxyl derivatives. Indoxyl is a very unstable intermediate which, once released, oxidizes and dimerizes to give indigotine or indirubine (Fagbohoun L., Chemical study of natural dyes and traditional resinous materials in Benin in the artisanal domain, 2015).

[0006] However, the inventors have observed that cosmetic compositions colored by indirubin, in particular when they are in emulsion form, discolor rapidly over time, in particular under the effect of UV / visible radiation and heat. Indeed, the initial coloring degrades significantly and therefore does not comply with the defined stability criteria. In addition, this degradation may be accompanied by the appearance of unpleasant odors.

[0007] Consequently, there is still a need for cosmetic compositions comprising ingredients of natural origin, in particular coloring substances or pigments of natural origin, exhibiting good safety with respect to keratin materials, while having the coloring properties required for products that are at the same time aesthetic, effective, stable over time, and pleasant. In particular, there is a need to have colored cosmetic compositions, in particular in the form of emulsions, while limiting the variations in coloring over time and the appearance of unpleasant odors which may be linked to these degradations. In particular, there is a need to formulate cosmetic compositions comprising indirubin satisfying accelerated aging tests.

[0008] The applicant has unexpectedly and surprisingly observed that all of these problems can be solved by the composition according to the present invention. Summary of the invention

[0009] According to one aspect, the present invention relates to a cosmetic composition having at least one fatty phase and comprising: a) indirubin; (b) at least one ascorbic acid ester; and (c) at least one salt of citric acid and piperidinol compound.

[0010] Indeed, after much research, the inventors have demonstrated that it is possible to provide a cosmetic composition colored by indirubin whose color is preserved over time. In other words, the inventors have developed a particular combination of ingredients making it possible to protect the formula from discoloration linked to UV / visible radiation and / or heat. The composition cosmetic according to the present invention has an aesthetic, natural color with beautiful intensity, while preserving the integrity of the keratin materials. In addition, the color does not deteriorate over time and has good resistance to external conditions and good homogeneity.

[0011] According to another aspect, the present invention relates to the use of a mixture of at least one ascorbic acid ester and at least one citric acid salt and piperidinol compound for stabilizing the color of a cosmetic composition comprising indirubin as coloring agent. The combination according to the invention thus makes it possible to obtain colored compositions having very good stability over time as demonstrated in the examples. Detailed description

[0012] The general terms used hereinafter are defined below.

[0013] The expression “at least one” is equivalent to the expression “one or more”.

[0014] The expression “comprising” encompasses the expression “consisting of”.

[0015] The expression “from ... to ...” must be understood inclusively.

[0016] For the purposes of the present invention, the term “cosmetic composition” means a composition suitable for external topical application. It comprises a cosmetically acceptable carrier, i.e. a carrier compatible with keratin materials, in particular the skin (body, face, eye contour, eyelids, lips). The cosmetic composition may be a care and / or makeup product, preferably a skin care product. For example, the cosmetic composition may be used to moisturize, protect, treat the skin and / or reduce the signs of skin aging.

[0017] The name “INCI” designates the name of a cosmetic ingredient according to the international nomenclature (International Nomenclature of Cosmetic Ingredients).

[0018] For the purposes of the present invention, the term “free” means a mass quantity of substance less than or equal to 0.1% relative to the total mass of the composition, preferably less than or equal to 0.05%. Indirubin

[0019] The composition according to the invention contains indirubin, preferably of natural origin.

[0020] Preferably, the indirubin is derived from indigo-bearing plants, for example from the Brassicaceae or Polygonaceae family. In the context of the present invention, the indirubin is preferably derived from plant extracts, in particular from extracts of Isatis tinctoria and / or from extracts of Polygonum tinctorium. These extracts may further provide other properties to the composition according to the invention. For example, Isatis tinctoria was traditionally used in Europe to treat wounds, ulcers, snake bites or various inflammatory conditions. In traditional Chinese medicine, its roots are mainly used for their anti-inflammatory properties while the leaves are used for their antiseptic properties or to relieve skin irritations. Isatis tinctoria is also used in cosmetics for the emollient properties of the oil from its seeds, for the moisturizing activity of its leaf extracts or for the astringent and skin-protecting properties of its root extracts. Various properties are also attributed to Polygonum tinctorium (or Persicaria tinctoria) by traditional Asian medicines, such as antidotal properties against poison, insect bites or certain injuries, but also anti-inflammatory, antipyretic and depurative properties.

[0021] Indirubin may be contained in a plant extract in association with a fatty substance or a mixture of fatty substances.

[0022] Extracts usable according to the invention containing indirubin are also commercially available, such as for example Blush Oléoactif® from the company Hallstar (INCI name: Brassica Campestris (Rapeseed) Seed Oil (and) Polygonum Tinctorium Leaf Extract).

[0023] Preferably, the composition according to the invention comprises an extract of Isatis tinctoria and / or an extract of Polygonum tinctorium at a mass content of 0.0005% to 10%, preferably 0.1% to 5%, more preferably 0.1% to 2%, relative to the total mass of the composition.

[0024] Preferably, indirubin is used as a coloring agent of the composition according to the invention.

[0025] By coloring agent is meant here a colored substance soluble or dispersed in the medium which contains it (for example in water and / or in a fatty substance) providing a coloring visible to the naked eye. Indirubin being used as a coloring agent means that its presence and its content in the composition has an impact visible to the naked eye on the color of the composition. For example, indirubin may be present at a mass content of at least 0.00008%, preferably at least 0.00015%, relative to the total mass of the composition.

[0026] Preferably, indirubin is present in the composition according to the invention at a mass content of 0.00008% to 0.5%, preferably 0.00015% to 0.05%, preferably 0.00015% to 0.005%, relative to the total mass of the composition. Indeed, since indirubin has a very strong coloring power, such low proportions are sufficient to provide color to the composition, the intensity of which can be adjusted within these value ranges. Ascorbic acid ester

[0027] The composition according to the invention also contains at least one as- acid ester corbic acid. These compounds are generally known for their antioxidant properties.

[0028] In the context of the present invention, the inventors have demonstrated that the ascorbic acid ester in combination with a salt of citric acid and pi-peridinol compound makes it possible to obtain a protective action on the composition according to the invention, and more particularly a protective action on indirubin and its color.

[0029] Advantageously, the ascorbic acid ester is a fatty acid ester of ascorbic acid, the fatty acid being linear or branched and comprising 12 to 20 carbon atoms. The fatty acid is preferably saturated. The fatty acid may be, for example, palmitic acid or stearic acid.

[0030] Preferably, the ascorbic acid ester is an ester of ascorbic acid and palmitic acid. For example, ascorbyl palmitate, ascorbyl tetraisopalmitate or a mixture thereof may be used. Preferably, the ascorbic acid ester is ascorbyl tetraisopalmitate.

[0031] As non-limiting examples of ascorbic acid esters which can be used according to the invention, mention may be made of the products marketed under the names Nikkol VC-IP or Nikkol VC IPV (INCI names: Ascorbyl tetraisopalmitate) from the company Nikko Chemicals; Botaniceutical Bvcip (ascorbyl tetraisopalmitate) from the company Bo-tanigenics Inc.; Ascorbyl Palmitate from the company DSM Nutritional Products; Cosphaderm AP RSPO / MB (Ascorbyl Palmitate) from the company Cosphatec GmbH; Dermofeel AP MB (Ascorbyl Palmitate) from the company Evonik Personal Care.

[0032] The mass content of ascorbic acid ester in the composition according to the present invention may be at least 0.3%, preferably at least 0.4% relative to the total mass of the composition.

[0033] On the other hand, the mass content of ascorbic acid esters in the composition according to the present invention may be at most 1%, preferably at most 0.7% relative to the total mass of the composition. Indeed, the inventors have also observed better stability when the proportion of ascorbic acid ester was not too high.

[0034] Preferably, the mass content of ascorbic acid esters in the composition according to the present invention is from 0.3% to 1%, preferably from 0.4% to 0.7%, relative to the total mass of the composition. This makes it possible to combine better stability and sensoriality of the composition. Salt of citric acid and piperidinol compound

[0035] The composition according to the invention also contains at least one salt of citric acid and piperidinol compound.

[0036] Indeed, the inventors have demonstrated that the particular combination of a citric acid salt and piperidinol compound with an ascorbic acid ester makes it possible to preserve the color of the indirubin over time and therefore the composition according to the invention.

[0037] The compound piperidinol has the formula (I) below: [Chem.l] OH X Formula (I) where Rb R2, R3 and R4, identical or different, represent H or an alkyl chain, linear or branched, comprising 1 to 4 carbon atoms, and X represent H, hydroxyl (OH) or methyl (CH3).

[0038] Preferably, X is a hydroxyl (OH). For example, Rb R2, R3 and R4 are H and X is a hydroxyl (OH). As a piperidinol compound, mention may be made, for example, of 1-hydroxypiperidin-4-ol.

[0039] Advantageously, Rb R2, R3 and R4 are methyls. Preferably, Rb R2, R3 and R1 are methyls and X is a hydroxyl (OH). As a piperidinol compound, mention may be made, for example, of 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-ol.

[0040] Preferably, the salt of citric acid and piperidinol compound is a salt of citric acid and tetramethylhydroxypiperidinol.

[0041] Preferably, the salt of citric acid and piperidinol compound is tris(tetramethylhydroxypiperidinol) citrate. This salt is also called 2-hydroxy-1,2,3-propane tricarboxylate of 1,4-dihydroxy-2,2,6,6-tetramethylpiperidinium and has CAS No. 220410-74-2.

[0042] As non-limiting examples of salts of citric acid and piperidinol compound which can be used according to the invention, mention may be made of the products marketed under the names Tinogard Q (INCI name: Tris(tetramethylhydroxypiperidinol)citrate & Aqua & Ethanol) from the company BASF.

[0043] The mass content of citric acid salt and piperidinol compound in the composition according to the present invention may be at least 0.005%, preferably at least 0.006% relative to the total mass of the composition.

[0044] On the other hand, the mass content of citric acid salt and piperidinol compound in the composition according to the present invention may be at most 0.05%, preferably at most 0.04% relative to the total mass of the composition.

[0045] Preferably, the mass content of citric acid salt and piperidinol compound in the composition according to the present invention is from 0.005% to 0.05%, preferably from 0.006% to 0.04%, relative to the total mass of the composition. This allows for a better stability and sensoriality of the composition.

[0046] Advantageously, the mass ratio of the amount of ascorbic acid ester to the amount of citric acid salt and piperidinol compound is from 45:1 to 60:1. Fat phase

[0047] The composition according to the invention comprises at least one fatty phase. For example, the composition according to the invention may be an anhydrous composition, an oily solution or an emulsion comprising a fatty phase.

[0048] The fatty phase allows the good solubilization of the indirubin pigment in the composition according to the invention. Indeed, indirubin being lipophilic, this component is distributed in the fatty phase.

[0049] The fatty phase comprises at least one fatty substance.

[0050] For the purposes of the invention, the term “fatty substance” means an organic compound that is immiscible in water at room temperature (25°C) and at atmospheric pressure (1,013.105 Pa; 760 mm Hg). More particularly, the solubility in water of this type of compound is less than 5%, preferably 1% and more preferably less than 0.1% by mass. This type of compound generally has in its structure a hydrocarbon chain comprising at least 6 carbon atoms or a chain of at least two siloxane groups.

[0051] The fatty substances can be hydrocarbon, silicone or fluorinated.

[0052] For the purposes of the present invention, the term “hydrocarbon” means a compound containing at least one hydrocarbon group (i.e. a group containing hydrogen and carbon atoms), and optionally oxygen, nitrogen, sulfur and / or phosphorus atoms. The hydrocarbon compound may, for example, contain alcohol, ester, ether, carboxylic acid, amine and / or amide groups. More particularly, in the context of the present invention, a hydrocarbon compound does not contain a silicon or fluorine atom.

[0053] For the purposes of the present invention, the term “silicone” means a compound comprising at least one silicon atom, and in particular at least one Si-O group. Examples that may be mentioned are organopolysiloxanes.

[0054] “Fluorinated” means a compound containing at least one fluorine atom.

[0055] Fatty substances can be liquid or non-liquid at room temperature (25°C) and at atmospheric pressure (1,013.105 Pa; 760 mm Hg). Liquid fatty substances include oils. Non-liquid fatty substances are generally used in cosmetic compositions as structuring agents, for example to provide consistency to the composition or increase the viscosity of the fatty phase.

[0056] By “oil” we mean a fatty substance that is liquid at room temperature (25°C) and at atmospheric pressure (1,013.105 Pa; 760 mm Hg). Oils or fatty substances Liquids can be volatile or non-volatile. They can be mineral oils (paraffin, alkanes and hydrocarbons of mineral origin), synthetic oils (synthetic alkanes and hydrocarbons, synthetic triglycerides, alcohols, synthetic fatty acids or esters, oxyethylenated or oxypropylenated fatty esters and ethers, silicone oils, etc.), oils of vegetable origin or a mixture of these oils.

[0057] By “non-liquid fatty substance” is meant a solid compound or a compound having a viscosity greater than 2 Pa.s at a temperature of 25°C and at a shear rate of 1 s1, measured with a Rheomat RM 180 (generally with spindle 1 or 2). Among the non-liquid fatty substances, we can for example cite butters, waxes and more generally non-liquid fatty alcohols (such as myristic alcohol, cetyl alcohol, stearyl alcohol, etc.), non-liquid fatty acid and / or fatty alcohol esters (such as octyldodecyl behenate, isocetyl behenate, cetyl lactate, stearyl octanoate, octyl octanoate, etc.), non-liquid fatty amines and ethers.

[0058] By “wax” is meant a compound that is solid or substantially solid at room temperature (25°C) and under atmospheric pressure (1,013.105 Pa; 760 mm Hg). It may be waxes of vegetable origin (sunflower, rice, candelilla waxes, hydrogenated castor oil, cork or sugar cane fiber waxes, etc.), animal waxes (beeswax, lanolin wax, lanolin derivatives, etc.), mineral waxes (paraffin, petrolatum, ozokerite, lignite, ceresin, microcrystalline wax, etc.), synthetic waxes (polyolefins such as polyethylene waxes, polyalphaolefins, hydrogenated polyisobutenes, etc.) or a mixture of these waxes. Preferably, the waxes that can be used in the present invention are non-silicone. Preferably, the waxes that can be used are chosen from waxes of plant origin.

[0059] For the purposes of the present invention, the term “butter” (or “pasty fatty substance”) means a fatty substance with a reversible solid / liquid state change and comprising a liquid fraction and a solid fraction at a temperature of 25°C and at atmospheric pressure (760 mm Hg). In other words, the starting melting temperature of the pasty compound may be lower than 25°C. The liquid fraction of the pasty compound (butter) measured at 25°C may, for example, represent 10 to 90% by mass of the compound. Preferably, the butter(s) have an end-of-melting temperature of lower than 60°C. For the purposes of the present invention, the end-of-melting temperature corresponds to the temperature at which 95% of the sample has melted. The measurement of the melting temperature and the determination of the end-of-melting temperature may be carried out according to the protocol described in document WO2020 / 127383.Among the butters of vegetable origin, we can for example cite shea butter, cocoa butter, almond butter, mango butter, etc.

[0060] Advantageously, the composition according to the invention has a total mass content of fatty substance of at least 10%, preferably at least 15%, relative to the total mass of the composition.

[0061] The composition according to the invention may have a total mass content of fatty substances of at most 99%, preferably at most 60%, preferably at most 40%, relative to the total mass of the composition.

[0062] Preferably, the composition according to the invention may have a total mass content of fatty substances of 10% to 60%, preferably of 15% to 40%, relative to the total mass of the composition.

[0063] As examples of fatty substances which can be used in the context of the present invention, mention may be made of hydrocarbons comprising 6 to 16 carbon atoms, hydrocarbon oils comprising more than 16 carbon atoms, vegetable oils (triglycerides, fatty acids), glycerides, fatty alcohols, fatty esters (or fatty acid and / or fatty alcohol esters, other than triglycerides), fatty acid ethers, silicone oils and mixtures thereof.

[0064] The C6 to C16 hydrocarbons may be of mineral, vegetable or synthetic origin. They may be linear or branched, and are preferably alkanes. Among the synthetic C6 to C16 hydrocarbons, mention may be made, for example, of synthetic linear alkanes or isoparaffins such as isohexadecane, isodecane. Preferably, the C6 to C16 hydrocarbons are of vegetable origin. By way of example, mention may be made of n-decane (C10), n-undecane (C11), n-dodecane (C12), n-tridecane (C13), n-tetradecane (C14), n-pentadecane (C15), n-hexadecane (C16), or a mixture of alkanes (for example undecane and tridecane).

[0065] Hydrocarbon oils (or hydrocarbons comprising more than 16 carbon atoms) may be of mineral, vegetable or synthetic origin. They may be linear or branched compounds. Examples include paraffin oils, vaseline oil, polydecenes, hydrogenated polyisobutene. Hydrocarbon oils are preferably of vegetable origin, such as squalane.

[0066] The vegetable or vegetable-derived oils may be chosen from triglycerides, such as caprylic / capric acid triglycerides. Non-limiting examples of vegetable oils include sweet almond oil, macadamia oil, hazelnut oil, peanut oil, sesame oil, walnut oil, argan oil, jojoba oil, calendula oil, apricot oil, sunflower oil, olive oil, corn oil, soybean oil, hemp oil, rapeseed oil, cottonseed oil, coconut oil, pumpkin seed oil, grapeseed oil, arara oil, castor oil, avocado oil, mirabelle plum oil, shea butter oil and mixtures thereof.

[0067] Glycerides are esters of glycerol and one (monoglycerides) or more (diglycerides and triglycerides) fatty acids. They can be of natural origin (such as for example, triglycerides of capric / caprylic acids) or synthetic (for example, triglycerides of heptanoic or octanoic acids). Preferably, the glycerides are of natural origin.

[0068] The fatty alcohols suitable for implementing the invention may be more particularly chosen from saturated or unsaturated, linear or branched alcohols, comprising at least 6 carbon atoms, preferably from 8 to 30 carbon atoms. Non-limiting examples include cetyl alcohol, cetearyl alcohol, stearyl alcohol and their mixture (cetylstearyl alcohol), octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol or linoleyl alcohol. In the context of the present invention, the fatty alcohols which can be used as fatty substances are preferably of natural origin.

[0069] The so-called “fatty” esters have at least one hydrocarbon group, linear or branched, saturated or unsaturated, comprising at least 6 carbon atoms, preferably from 8 to 30 carbon atoms, optionally substituted, in particular by one or more hydroxyl groups. They can be chosen from fatty acid and / or fatty alcohol esters, optionally hydroxylated. These esters, different from the triglycerides mentioned above, may be chosen in particular from esters of saturated or unsaturated, linear or branched C1 to C26 aliphatic mono- or polyacids and esters of saturated or unsaturated, linear or branched C1 to C26 aliphatic mono- or polyalcohols, the total number of carbons in the esters being greater than or equal to 6. Non-limiting examples of fatty acid esters and / or fatty alcohols include octyldodecyl behenate, isocetyl behenate, linoleyl lactate, isocetyl laurate, hexyl laurate, isocetyl stearate,isodecyl oleate, isononyl isononanoate, octyl isononanoate, methyl acetyl ricinoleate, isostearyl palmitate, ethyl palmitate, isopropyl palmitate, 2-ethylhexyl palmitate, alkyl myristates such as isopropyl, butyl, cetyl myristate, butyl stearate, isobutyl stearate, isopropyl stearate or isostearate, isostearyl isostearate, octyl stearate, octyl hydroxystearate, isostearyl lactate, diisopropyl adipate, dioctyl malate, 2- laurate hexyldecyl, ethyl2-hexyl caprate / caprylate (or octyl caprate / caprylate), isostearyl neopentanoate, isodecyl, heptanoates (such as isostearyl heptanoate), octanoates (such as cetyl octanoate, cetearyl octanoate, tridecyl octanoate). ,

[0070] The fatty acid ethers have at least one hydrocarbon group, linear or branched, saturated or unsaturated, comprising at least 6 carbon atoms, optionally substituted, in particular by one or more hydroxyl groups. They may be more particularly chosen from ethers comprising from 8 to 30 carbon atoms, preferably from 8 to 24 carbon atoms. They are preferably of plant origin, such as dicaprylyl ether.

[0071] Silicone oils contain at least one silicon atom. Non-limiting examples of silicone oils include cyclomethicone, polydimethylsiloxanes or PDMS, dimethicone copolyol, silicone crosslinked polymers, dimethylpolysiloxane, diethylpolysiloxane, Cl-30 mixed polysiloxanes, phenylated polyorganosiloxanes, dimethiconol, and combinations thereof.

[0072] In the context of the present invention, hydrocarbon fatty bodies are preferably used, in particular of natural origin.

[0073] Preferably, the composition according to the invention is free of silicone fatty substances and fluorinated fatty substances.

[0074] Advantageously, the fatty phase of the composition according to the invention comprises at least 50% of saturated or substantially saturated oils, relative to the total mass of fatty phase. As non-limiting examples of saturated or substantially saturated oils, mention may be made of capric / caprylic acid triglycerides, squalane or coconut oil.

[0075] The fatty phase may further comprise additional ingredients soluble or miscible in oil such as, for example, solvents, formulating agents and / or liposoluble active ingredients. Additional compounds

[0076] The composition according to the invention may further comprise one or more formulation agents, in particular conventional cosmetic active ingredients or excipients.

[0077] These formulating agents can be chosen appropriately depending on the use of the composition of the invention.

[0078] Non-limiting examples of formulating agents include hydrophilic or lipophilic actives, water, organic solvents (e.g. lower alcohols and polyols), ionic or non-ionic, hydrophilic or lipophilic rheological (thickening or gelling) agents, softeners, humectants, opacifiers, stabilizers, emollients, anti-foaming agents, film-forming agents, emulsifiers, surfactants (anionic, cationic, non-ionic or amphoteric), fillers (e.g. mattifying powders, soft focus active touch powders, etc.), UV filters (or photoprotective agents, organic and / or inorganic, active in UVA and / or UVB), colorants, chelating agents (chelating), alkalinizing or acidifying agents, pH adjusters, preservatives, perfumes or any other ingredient usually used in the cosmetic and / or dermatological field.The quantities of these different compounds are those conventionally used in the fields considered. These compounds, depending on their nature, can be introduced into the fatty phase or into the aqueous phase.

[0079] The composition according to the invention may comprise at least one active ingredient. Among the assets, we can cite for example: - anti-pollution agents and / or anti-free radical agents and / or antioxidant agents (co-enzyme Q10 or ubiquinone); - lightening agents, depigmenting agents, pro-pigmenting agents and / or self-tanning agents; - anti-aging agents; - firming or anti-wrinkle agents, such as plant proteins and their hydrolysates (for example soy protein extract); - moisturizing agents (such as polyols such as glycerin); - anti-inflammatory agents (such as glycyrrhetinic acid and its salts); - soothing agents (allantoin, bisabolol, cornflower water), - antimicrobial or antibacterial agents (such as salicylic acid); - tensioning agents; - firming agents; - vitamins (such as retinol or vitamin A, ascorbic acid or vitamin C, tocopherol or vitamin E, niacinamide or vitamin PP or B3, panthenol or vitamin B5, biotin or vitamin B8 and their derivatives such as, for example, the esters of these vitamins); - essential oils.

[0080] Thanks to his knowledge of cosmetics, a person skilled in the art is able to choose the formulation agents to be added to the compositions of the invention and their quantities according to the desired properties without substantially altering the effects linked to the composition according to the invention and in particular to the protection of the indirubin compound in the composition.

[0081] Advantageously, the composition according to the invention further comprises at least one chelating agent.

[0082] Chelating agents (or chelating agents) are substances capable of binding positive ions to form a stable complex. They are generally used in cosmetics to bind metal ions possibly present in cosmetic compositions and which are likely to affect the stability and / or appearance of the compositions. In the context of the present invention, the inventors have observed that the presence of a chelating agent could improve the stability of the color of the composition according to the invention.

[0083] Among the chelating agents that can be used, mention may be made, for example, of ethylenediaminetetraacetic acid (EDTA) or one of its salts (for example the compounds with the INCI names Disodium EDTA, Tetrasodium EDTA, etc.), phytic acid or one of its salts (with the INCI name Phytic acid), citric acid, etidronic acid, oxalic acid. (Oxalic acid) and their derivatives.

[0084] Preferably, the chelating agent is chosen from ethylenediaminetetraacetic acid (EDTA), phytic acid and their derivatives.

[0085] Furthermore, the composition according to the invention may have different rheological profiles and be in any galenic form normally used in the field of cosmetology and dermatology. The composition may, for example, be in the form of an oily solution, a lotion, a serum, a mousse, a suspension, a dispersion, an emulsion (O / W emulsion or W / O emulsion, for example a cream, a gel-cream, a gel, a milk, a butter, a balm, etc.). It may also be in solid form (for example in the form of a stick), a paste, a powder.

[0086] A person skilled in the art will be able to choose the appropriate galenic form, as well as its method of preparation, on the basis of his general knowledge, taking into account on the one hand the nature of the constituents used, in particular their solubility in the support, and on the other hand the application envisaged for the composition.

[0087] According to one embodiment of the invention, the composition according to the invention may be an anhydrous composition.

[0088] For the purposes of the present invention, the term “anhydrous composition” means a composition having a water content of less than 3% by weight, preferably less than 1% by weight, even more particularly less than 0.5% by weight, relative to the total weight of the composition. In particular, water is not added during the preparation of the composition and the water content corresponds to the residual water provided by the mixed ingredients. The water may also be in the form of bound water, such as the water of crystallization of the salts or traces of water adsorbed by the raw materials used in the context of the invention. An anhydrous composition may be in liquid, gelled, pasty or solid form.

[0089] According to another embodiment of the invention, the composition according to the invention is an emulsion.

[0090] By “emulsion” is meant a composition consisting of an aqueous phase and a fatty phase, in which one of the phases is dispersed in the other, in particular in the form of droplets, so as to observe a macroscopically homogeneous mixture with the naked eye. It may, for example, be an “oil-in-water” emulsion (or “direct” emulsion, noted O / W) comprising a discontinuous fatty phase dispersed in a continuous aqueous phase, or a “water-in-oil” emulsion (noted W / O) comprising a continuous fatty phase in which a discontinuous aqueous phase is dispersed.

[0091] According to another preferred embodiment of the invention, the composition according to the invention is an oil-in-water emulsion, that is to say an emulsion comprising at least less a fatty phase dispersed in a continuous aqueous phase. Compositions in the form of an oil-in-water emulsion are particularly appreciated in the cosmetic field for the sensoriality they provide, such as for example a lighter, less greasy, less sticky, fresher sensation on application. Use

[0092] The invention also relates to the use of indirubin as a coloring agent in a cosmetic composition according to the present invention.

[0093] The present invention also relates to the use of a mixture comprising at least one ascorbic acid ester and at least one citric acid salt and piperidinol compound for stabilizing the color of a cosmetic composition comprising indirubin as a coloring agent.

[0094] The indirubin compound, the ascorbic acid ester and / or the citric acid salt of the piperidinol compound are as previously defined and may have one or more of the characteristics described above.

[0095] In addition, the cosmetic composition may have one or more of the characteristics described above.

[0096] The present invention also relates to the use of a cosmetic composition according to the invention for skin care and / or skin makeup.

[0097] The present invention also relates to a non-therapeutic cosmetic process for skin care comprising the application to the skin of a cosmetic composition according to the invention. Examples

[0098] The invention is illustrated in more detail by the non-limiting examples presented below. The compounds or raw materials used are named by their INCI name. Unless otherwise indicated, the percentages indicated are percentages by mass. The mention “qsp” means that the quantity must be sufficient for the composition to reach 100% of its final mass.

[0099] The compositions according to Examples 1 to 8 are prepared according to the procedure described below with the proportions in % indicated in Tables 1 and 2 below. In these examples, the indirubin and its color are provided by an extract of Polygonum Tinctorium leaves. The different compositions are also evaluated in terms of their organoleptic properties (appearance, color, odor) and their stability over time. [Tables 1] Compositions Hors invention P NOMS INCI (%) 1 2 3 4 5 A Aqua / water / eau 69,57 69,57 69,57 69,57 69,57 Disodium EDTA(a) 0,2 0,2 0,2 0,2 0,2 Citric acid®’ 0,03 0,03 0,03 0,03 0,03 Ethylhexylglycerin(c) 0,2 0,2 0,2 0,2 0,2 Propanediol(d) 3 3 3 3 3 Glycerin(e) 2 2 2 2 2 Butylène glycol® 4 4 4 4 4 B Polyacrylate crosspolymer-6 (g) 1 1 1 1 1 C Caprylic / Capric Triglycéride®’ 4 4 4 4 4 Squalane® 5 5 5 5 5 Sucrose Polystearate (and) Cetyl Palmitate® 3 3 3 3 3 Hydrogenated coconut oil(k) 5 5 5 5 5 D Brassica Campestris (Rapeseed) Seed OU (and) Polygonum Tinctorium Leaf Extract® 1 1 1 1 1 E Aqua / water / eau 1,5 1,5 1,5 1,5 1,9 Tocopherol(m) 0,5 - - - - Tocopherol (and) Helianthus Annuus (Sunflower) Seed Oil(n) - 0,5 - - - Helianthus Annuus (Sunflower) Seed OU (and) Rosmarinus Officinalis Extract®’ - - 0,5 - - Ascorbyl tetraisopalmitate®’ - - - 0,5 - Aqua / water / eau (and) alcohol (and) tris(tetramethylhydroxypiperidinol) citrate® - - - - 0,1 Total : 100 100 100 100 100 [Tableaux2] Compositions Hors invention Inv. P NOMS INCI (%) 6 7 8 9 10 A Aqua / water / eau 69,57 69,57 69,57 qsp qsp Disodium EDTA(a) 0,2 0,2 0,2 0,2 0,2 Citric acid®’ 0,03 0,03 0,03 0,03 0,03 Ethylhexylglycerin(c) 0,2 0,2 0,2 0,2 0,2 Propanediol(d) 3 3 3 3 3 Glycerin(e) 2 2 2 2 2 Butylène glycol® 4 4 4 4 4 B Polyacrylate crosspolymer-6 (g) 1 1 1 1 1 C Caprylic / Capric Triglycéride®’ 4 4 4 4 4 Squalane® 5 5 5 5 5 Sucrose Polystearate (and) Cetyl Palmitate® 3 3 3 3 3 Hydrogenated coconut oil(k) 5 5 5 5 5 D Brassica Campestris (Rapeseed) Seed OU (and) Polygonum Tinctorium Leaf Extract® 1 1 1 1 1 E Aqua / water / eau 1 1 1 0,5 0,5 Tocopherol(m) - 0,5 - 0,5 - Tocopherol (and) Helianthus Annuus (Sunflower) Seed Oil(n) - - 0,5 - - Helianthus Annuus (Sunflower) Seed OU (and) Rosmarinus Officinalis Extract®’ - - - - - Ascorbyl tetraisopalmitate®’ 1 0,5 0,5 - 0,5 Aqua / water / eau (and) alcohol (and) tris(tetramethylhydroxypiperidinol) citrate® - - - 0,1 0,1 Total : 100 100 100 100 100

[0100] In Tables 1 and 2 above: - the left column labeled “P” indicates the phases in which the compounds are present; - the references in parentheses (next to the INCI names of the compounds) indicate the trade names of the raw materials used comprising these compounds. The details of these raw materials are given below: (a) EDETA® BD (INCI name: Disodium EDTA), marketed by BASF. (b) Citric acid monohydrate powder (INCI name: citric acid), marketed by the company MERCK. (c) SENSIVA SC 50 (INCI name: ethylhexylglycerin) marketed by the company SCHÜLKE FRANCE SARL. (d) ZEMEA Propanediol, marketed by DuPont Tate & Lyle Bio Products. (e) Wilfarin EP997 (INCI name: glycerin), marketed by the company WILMAR. (f) BRONTIDE BG (INCI name: butylene glycol), marketed by the company AZELIS. (g) SEPIMAX ZEN (INCI name: polyacrylate crosspolymer-6), marketed by the company SEPPIC. (h) Dub MCT 5545 (INCI name: Caprylic / Capric Triglyceride), marketed by the company DUBOIS. (i) Squalane Neossance or Squalane Biossance from the company AMYRIS. (j) EMULGADE SUCRO PLUS (INCI name: Sucrose Polystearate & Cetyl Palmitate), marketed by BASF. (k) HYDROBASE 32-34 (INCI name: Hydrogenated coconut oil), marketed by the company PROD'HYG LABORATOIRES SA (1) Blush Oléoactif® (INCI name: Brassica Campestris (Rapeseed) Seed Oil & Polygonum Tinctorium Leaf Extract; with an indirubin content between 170 and 190 ppm), marketed by the company Hallstar. (m) COVIOX T70C (INCI name: Tocopherol), marketed by BASF. (n) DERMOFEEL® TOCOBALANCE (INCI name: Tocopherol & Helianthus Annuus Sunflower Seed Oil), marketed by the company EVONIK NUTRITION & CARE GMBH. (p) Phytrox Rosemary L4-CA DEOD (INCI name: Helianthus Annuus (Sunflower) Seed Oil & Rosmarinus Officinalis Extract), marketed by IMCD. (q) NIKKOL VC IP (INCI name: Ascorbyl tetraisopalmitate), from the company NIKKO CHEMICALS. (r) TINOGARD Q (INCI name: Aqua / water / eau & alcohol & tris(tetramethylhydroxypiperidinol) citrate (10%)), from BASF. Operating mode

[0101] A phase A is prepared by solubilizing in a beaker the disodium EDTA then the citric acid in water under agitation Rayneri equipped with a deflocculator until dissolution of these ingredients. Then the ethylhexylglycerin, the propanediol, the glycerin and the butylene glycol are added successively under agitation.

[0102] The gelling agent (phase B, polyacrylate crosspolymer-6) is then added to phase A and the mixture is left to stir at 1000 rpm (rotations per minute) until the gel forms (for approximately 5 minutes). The resulting mixture (phases A and B) is then heated to 75°C.

[0103] A phase C is previously prepared by mixing the oils and the mixture of emulsifiers (sucrose polystearate and cetyl palmitate). Phase C is then heated to 75°C.

[0104] The coloring matter (phase D) is then added to the hot phase C, without heating, and the mixture obtained is stirred for approximately 1 min under magnetic stirring.

[0105] The mixture of fatty phases C and D is then added to the hot aqueous mixture of phases A and B, with stirring using a flocculator at 1500 rpm. The emulsion obtained is left to cool to 35°C in a cold water bath with stirring.

[0106] A phase E is prepared by mixing the antioxidant(s) (tocopherol, rosemary extract, ascorbyl tetraisopalmitate and / or tris(tetramethylhydroxypiperidinol) citrate) in water.

[0107] Phase E is then added to the previous emulsion (phases A, B, C and D) with Rayneri stirring equipped with a deflocculator. Stirring is maintained until homogenization. A smooth, homogeneous, pale pink, oil-in-water gelled emulsion (thick, gel-cream type composition) is thus obtained. Assessment methods

[0108] The stability of the compositions containing indirubin was studied after storage under different conditions, in particular under accelerated aging conditions in thermostatically controlled ovens at 50°C for 1 month and at 40°C for 3 months. The stability was also studied after storage under UV radiation for 10 hours (Sun-Test), using an Atlas Suntest CPS device from Ametek (samples exposed for a period of 10 hours to a UVA and visible UV spectrum, with wavelengths from 290nm to 800nm).

[0109] For each of the compositions 1 to 10, six glass bottles are subjected to stability testing: at room temperature (RT) in the dark, at room temperature (RT) in front of a window, under UV radiation for 10 h (Sun-Test) and in thermo- controlled in the dark at 4°C, 40°C and 50°C. An Atlas Suntest CPS device, from Ametek, is used for conditioning under UV radiation (samples exposed for a period of 10 hours to a UVA and visible UV spectrum, with wavelengths from 290 nm to 800 nm, surface energy density of 19800 kJ / m2).

[0110] After a certain time (t) of storage under these various conditions, the quality and color of the samples is evaluated by sensory analysis of the samples (appearance, color and odor) and by spectrophotometry.

[0111] The organoleptic evaluation consists of evaluating the overall characteristics of the samples with the naked eye (color, possible sedimentation, possible presence of precipitates, phase shift or volute) and their odor in comparison with the control composition stored in the dark at 4°C.

[0112] Spectrophotometric analysis consists of measuring color based on the L*, a*, and b* values ​​of the CIELAB color system. According to this color system, the L* value, which corresponds to lightness or brightness, varies from 0 (black or total absorption) to 100 (white or total reflection). The two parameters “a*” and “b*” express the deviation of the color from that of a gray surface of the same lightness. The “a*” values ​​vary between -60 and +60 along a horizontal green-red axis, and the “b*” values ​​vary between -60 and +60 along a vertical blue-yellow axis. Here, the L*, a*, and b* values ​​are measured directly on the samples using a KONICA MINOLTA CR-5 spectrophotometer and SpectraMagix NX software (KONICA MINOLTA). For color measurement, the sample is placed in a petri dish, approximately 1.5 cm thick. The measurement is carried out by transmittance (excluding specular reflection), with a measuring aperture of 8 mm.

[0113] Some variations in L*, a*, b* values ​​are barely or not at all perceptible to the naked eye. To better assess the color difference between the original color and the color after storage at the given accelerated condition, the AE value (or total color difference) can be calculated. The smaller this value, the less visually perceptible the color difference is. The AE color difference is calculated using the mathematical formula below: [Math.l] AE - A £ ) ” + ( A «*)" + ( A b )2 where the initial color (at TA, t=0) is taken as reference: AL*=L* - L*o, Aa*=a* - a*0, Ab*=b* - b*0. Results

[0114] The results are listed in Tables 3 and 4 below. [Tables 3] TA t = 0 (initial appearance) TA, darkness t = 1 month TA, daylight t = 1 month 1 Smooth, homogeneous composition, pale pink color L*o = 74.12 a*0 = 9.63 b*0 = -3.34 L* = 74.6 a* = 9.47 b* = -2.61 Total discoloration of the composition and oxidation odor. 2 Smooth, homogeneous composition, pale pink color L*o = 78.71 a*0 = 7.69 b*0 = -0.88 L* = 77.63 a* = 7.67 b* = -1.28 Total discoloration of the composition and oxidation odor. 3 Smooth, homogeneous composition, pale pink color L*o = 76.13 a*0 = 8.53 b*o = -l.47 L* = 74.15 a* = 9.07 b* = 1.61 Total discoloration of the composition and oxidation odor. 4 Smooth, homogeneous composition, pale pink color L*o = 74.97 a*0 = 10.36 b*0 = -3.89 L* = 74.4 a* = 9.65 b* = -3.71 Total discoloration of the composition. 5 Smooth, homogeneous composition, pale pink color L*o = 74.2 a*0 = 10.07 b*o = -3.17 L* = 74.02 a* = 9.76 b* = -2.38 Partial discoloration of the composition (paler pink).6 Smooth, homogeneous composition, pale pink in color L* = 77.53 a* = 7.82 b* = -2.85 Total discoloration of the composition. L*o = 78.74 a*0 = 8.59 b*0 = -2.92 7 Smooth, homogeneous composition, pale pink color L*o = 77.53 a*0 = 9.38 b*0 = -2.82 L*= 75.77 a*= 8.90 b*=-l.66 Total discoloration of the composition. 8 Smooth, homogeneous composition, pale pink color L*o = 75.63 a*0 = 8.96 b*0 = -3.13 L*= 73.62 a* = 8.21 b* = 0.36 The composition partially discolors and the color, inhomogeneous, turns significantly towards yellow (peach color). 9 Smooth, homogeneous composition, pale pink color L*o = 76.85 a*0 = 6.81 b*0 = -l.92 L* = 77.36 a* = 6.16 b* = -0.38 Slight discoloration. 10 Smooth, homogeneous composition, pale pink color L*o = 80.79 a*0 = 7.23 b*0 = -l.82 L* = 79.57 a* = 7.50 b* = -1.91 Stable original color. (table 3) [Tables 4] 50°C, 1 month 40°C, 3 months Sun Test, lOh 1 L* = 73.13 a* = 8.36 b* = -1.23 L* = 73.19 a*= 8.73 b*=-l,ll Total discoloration of the composition and oxidation odor. 2 L* = 74.78 a* = 3.34 b* = 5.27 The color turns yellow (peach tint). Oxidation odor L* = 75.87 a* = 4.79 b* = 3.69 The color turns yellow (peach tint). Oxidation odor. Total discoloration of the composition and oxidation odor. 3 L* = 70.57 a* = 7.61 b* = 5.56 The color turns yellow (peach tint). Oxidation odor L* = 72.51 a* = 8.18 b* = 4.03 Peach color. Oxidation odor Total discoloration of the composition and oxidation odor. 4 L* = 71.06 a* = 8.21 b* = 2.43 The color turns slightly yellow (peach tint). Oxidation odor L* = 74.16 a* = 9.22 b* = -1.29 Total discoloration of the composition. 5 L* = 73.34 a* = 8.81 b* = 0.28 The color turns slightly yellow (peach tint) L* = 73.55 a* = 9.25 b* = -1.27 Partial discoloration of the composition (paler pink).6 L* = 72.99 a* = 7.66 b* = 3.17 The color turns yellow (peach tint). Oxidation odor. L* = 74.63 a* = 6.81 b* = 1.82 The color turns slightly yellow (peach tint). Oxidation odor Total discoloration of the composition. 7 L* = 73.62 L* = 72.56 Total discoloration of the . a* = 8.21 b* = -0.36 Color turns slightly yellow (peach tint) a* = 7.47 b* = 4.29 Color turns yellow (peach tint) composition. 8 L* = 75.48 a* = 4.35 b* = 5.52 AE = 9.80 Color turns yellow (peach tint) L* = 75.36 a* = 4.47 b* = 4.77 AE = 9.09 Color turns yellow (peach tint) L* = 80.47 a* = 2.75 b* = 7.08 AE = 12.89 Composition partially fades and color turns yellow (peach color). 9 L* = 75.5 a* = 5.68 b* = 0.24 AE = 2.79 L* = 76.05 a* = 6.03 b* = -0.74 AE= 1.63 L* = 80.99 a* = 4.93 b* = 3.21 AE = 6.85 Slight discoloration. 10 L* = 78.32 a* = 6.69 b* = -0.09 AE = 3.06 L* = 78.71 a* = 7.53 b* = -0.67 AE = 2.40 L* = 83.77 a* = 5.76 b* = -0.32 AE = 3.64 The color variation is imperceptible to the naked eye (stable original color). (table 4)

[0115] The results show that, when the compositions do not contain the combination of the compounds ascorbyl tetraisopalmitate and tris(tetramethylhydroxypiperidinol) citrate, the color of the compositions is altered after storage under accelerated conditions, and this alteration is more marked under the effect of the Sun-Test and light.

[0116] Indeed, whether in the Sun-Test or in daylight, compositions 1 to 4 and 7 completely lose their color. The discoloration is less pronounced in the case of compositions 5, 8 and 9 but a significant color difference is observed compared to the original color. The color therefore remains insufficiently stable and unsatisfactory. In addition, underlying degradation phenomena are accompanied by more or less pronounced odors.

[0117] On the other hand, for composition 10 according to the invention, no difference in color is observed to the naked eye after storage, whether under accelerated aging conditions (at 50°C for 1 month or at 40°C for 3 months), in the Sun-Test or in daylight. More particularly, under the effect of the Sun-Test, the difference in color (AE = 3.64) is imperceptible to the naked eye, unlike composition 9 where a notable difference is observed (AE = 6.85). The pale pink color of composition 10 was therefore stabilized for all storage conditions thanks to the mixture of antioxidants used.

[0118] Furthermore, the interpretation of the AE values ​​makes it possible to define an acceptability criterion or threshold below which the color cannot be substantially differentiated. A color difference AE < 4 is considered acceptable. The results show that composition 10 according to the invention is the only composition that satisfies this acceptability criterion after the Sun-Test. Finally, color differences AE < 5 are considered very good for natural coloring materials for which low AE values ​​are generally more difficult to obtain than for synthetic dyes.

[0119] In conclusion, thanks to the cocktail of protective agents used, the color of composition 10 according to the invention is much better preserved, whether after exposure to UV or under the effect of heat, unlike compositions 1 to 9 which do not include this specific mixture.

Claims

Claims

1. Cosmetic composition having at least one fatty phase and comprising: a) indirubin; b) at least one ascorbic acid ester; and c) at least one salt of citric acid and piperidinol compound.

2. Cosmetic composition according to claim 1, wherein the indirubin is derived from indigo-producing plants, preferably from extracts of Isatis tinctoria and / or extracts of Polygonum tinctorium.

3. Cosmetic composition according to claim 2, having a mass content of Isatis tinctoria and / or Polygonum tinctorium extract of 0.0005% to 10%, preferably of 0.1% to 5%, more preferably of 0.1% to 2%, relative to the total mass of the composition.

4. Cosmetic composition according to any one of the preceding claims, in which the indirubin is present at a mass content of 0.00008% to 0.5%, preferably 0.00015% to 0.05%, preferably 0.00015% to 0.005%, relative to the total mass of the composition.

5. A cosmetic composition according to any preceding claim, wherein the ascorbic acid ester is a fatty acid ester of ascorbic acid, the fatty acid comprising 12 to 20 carbon atoms, and preferably being saturated.

6. A cosmetic composition according to any preceding claim, wherein the ascorbic acid ester is a palmitic acid ester, preferably ascorbyl tetraisopalmitate.

7. Cosmetic composition according to any one of the preceding claims, wherein the content of ascorbic acid ester is from 0.3% to 1%, preferably from 0.4% to 0.7%, relative to the total mass of the composition.

8. A cosmetic composition according to any preceding claim, wherein the at least one salt of citric acid and piperidinol compound is tris(tetramethylhydroxypiperidinol) citrate.

9. Cosmetic composition according to any one of the preceding claims, wherein the content of citric acid salt and piperidinol compound is from 0.005% to 0.05%, preferably from 0.006% to 0.04%, relative to the total mass of the composition.

10. Cosmetic composition according to any one of the preceding claims-

11.

12.

13.

14. preceding, in which the fatty phase comprises a mass content of fatty substances of at least 10%, preferably at least 15%, relative to the total mass of the composition. Cosmetic composition according to any one of the preceding claims, further comprising at least one chelating agent. Cosmetic composition according to any one of the preceding claims, the composition being in the form of an emulsion, preferably an oil-in-water emulsion. Use of indirubin as a coloring agent in a cosmetic composition according to any one of the preceding claims. Use of a mixture comprising at least one ascorbic acid ester and at least one salt of citric acid and piperidinol compound for stabilizing the color of a cosmetic composition comprising indirubin as a coloring agent.