TITLE: Preserving system and associated composition

The present invention relates to the cosmetic use of a combination of at least one derivative having a fatty chain of diglutamide lysine or compound of formula (i), as defined below, in particular of sodium dilauramidoglutamide lysine, and of at least one sequestering agent chosen from the salts of formula (ii) as defined below, as preserving system. It also relates to a composition, preferably a cosmetic composition for removing make-up from and/or cleansing keratin materials, comprising an aqueous phase comprising said combination of compounds i and ii, and optionally at least one specific polyol.

Cosmetic compositions are sensitive to microbial contamination during manufacture or use by the consumer. Preserving agents are thus used in cosmetic compositions to kill the microbes which come into contact with these compositions. Preserving agents protect the products from microbial contamination which can occur during the manufacture (also known as primary contamination) or during the use of the cosmetic compositions (also known as secondary contamination).

Numerous types of conventional preservatives have been developed to provide cosmetic compositions with a sufficient antimicrobial activity. These preservatives make possible good protection of cosmetic compositions during primary and/or secondary contaminations.

Furthermore, a feeling of cutaneous comfort is desired by consumers after the cosmetic compositions have been applied. The term "comfortable skin feeling" is understood to mean soft, moisturizing, nontacky feelings after the application of a cosmetic composition. The balance between a sufficient antimicrobial activity and a comfortable cutaneous feeling after application of a cosmetic composition is thus often an objective to be achieved for formulators in the cosmetics field.

Furthermore, consumers expect an improvement in the cutaneous comfort after application, such as soft, moisturizing, nontacky feelings, in particular when the cosmetic compositions have to be applied repeatedly to the skin, as is the case for makeup-removing compositions

Removing makeup from the skin is very important for the care of keratin materials, in particular the skin or the lips, but also keratin fibers, such as the eyelashes. It must be as efficient as possible since fatty residues, such as excess sebum, the residues of cosmetic products used daily and makeup products, accumulate in particular in the skin folds and at the surface of the skin, and can block the skin pores and thus cause the appearance of spots.

Furthermore, the majority of makeup-removing compositions available are two-phase compositions, i.e. consisting of two distinct phases, in particular of an aqueous phase and of an oily phase, which require prior agitation before application. Such formulations make possible good removal of makeup but leave an often greasy finish on the skin.

There thus exists a need for cosmetic compositions which exhibit an improved cutaneous feeling during and/or after application. There also exists a need for cosmetic compositions which are stable and comfortable to apply to the skin, and nontacky. In particular, there exists a need for efficient makeup-removing compositions, comfortable on application, which exhibit a fluid texture and which do not require any agitation before application, while being stable.

One of the aims of the present invention is to provide a composition with a comfortable cutaneous feeling during and/or after application of said composition. Another aim of the present invention is to provide a composition having a good antimicrobial activity during primary and/or secondary contaminations, that is to say during manufacture and/or consumer use.

Another aim of the present invention is to provide a stable cosmetic composition, comprising the combination of derivative having a fatty chain of diglutamide lysine or compound of formula (i), and of at least one sequestering agent chosen from the salts of formula (ii). A subject matter of the present invention is thus the cosmetic use of such an i + ii combination as preserving system.

Sodium dilauramidoglutamide lysine and the derivatives having a fatty chain of diglutamide lysine or family of compounds of formula (i), described in detail below, is known for its surfactant properties. They belong to the category of germini surfactants.

For reasons of tolerance, the current tendency consists in reducing as much as possible the amount of preservative to be introduced into the formulations.

It is also desirable to design minimalist formulae, comprising as little as possible of surfactants and/or preservatives. It is in particular desirable to incorporate a biosurfactant, such as sodium dilauramidoglutamide lysine or its derivatives, in a reduced concentration in compositions, in particular cosmetic or dermatological compositions, while retaining a good antimicrobial preservation performance. Furthermore, antimicrobial compounds do not always exhibit a good compositional stability and/or a good antimicrobial activity over time, all the more so when the antimicrobial compound is combined with other antimicrobials which can have solubility incompatibilities, problems of odor, of compositional stability over time and/or of antimicrobial ineffectiveness. In addition, it is desirable for the composition to be able to be stable over time and for the antimicrobial activity to be effective even after several weeks. It is also advantageous to have compositions which do not have an unpleasant odor and/or for the latter not to appear during storage or over time.

These problems have been solved by the combination of following compounds i) and ii):

- i) at least one compound of following formula (i): in which Y' represent, independently of one another, a carboxylic acid group or an alkaline salt of a carboxylic acid group, such as a sodium salt of a carboxylic acid group; jl, kl, j2 and k2 represent an integer such that (jl, kl, j2, k2) = (0, 2, 0, 2); and

I represents an integer from 6 to 22, preferably from 8 to 16, preferably from 10 to 12, and

- ii) at least one sequestering agent chosen from the salts of following formula (ii), and also its solvates, such as the hydrates:

M ⁺ _n [ O-C(O)-CH2]2N-CH[C(O)O ]-(CH ₂ )2-C(O)O- (ii) in which formula (ii) M ⁺ , which are identical or different, are chosen from H ⁺ , alkali metal cations, alkaline earth metal cations and ammonium ions; and n is an integer such that the number of M ⁺ ensures the electrical neutrality of the molecule, preferably of between 2 and 4, more particularly equal to 2 or 4.

This is because it has been discovered that the combination of compounds of formula (i) and of formula (ii) as are defined above makes it possible to obtain an antimicrobial mixture exhibiting a marked improvement, indeed even a synergy, in antimicrobial activity. Moreover, it appears that the compositions comprising the compounds of formula (i) and of formula (ii) as are defined above remain stable even after several weeks, indeed even months, at ambient temperature, indeed even at temperatures greater than 25°C, in particular up to 45°C. Furthermore, it appears that the combination of the two compounds of formula (i) and of formula (ii) does not exhibit an odor even after several weeks.

Another subject matter of the invention is a composition, in particular a cosmetic composition, comprising the combination of compounds of formula (i) and of formula (ii) as are defined above, characterized in that the composition contains less than 0.5% of additional preserving system, preferably less than 0.2% of additional preserving system, in particular less than 0.2% of 2- phenoxyethanol.

Advantageously, the composition according to the invention is devoid of additional preserving system, in particular devoid of 2-phenoxyethanol.

Another subject matter of the invention is a method for the nontherapeutic cosmetic treatment of keratin materials, comprising the application, to the keratin materials, of a composition, in particular a cosmetic composition, as described above. The method can be a cosmetic method for caring for, making up, fragrancing or cleansing keratin materials.

Another subject matter of the invention is a method for preserving a composition, especially comprising a physiologically acceptable medium, in particular a cosmetic composition, characterized in that it consists in incorporating, in said composition, an antimicrobial mixture as described above.

The results of the examples described below show the antimicrobial activity of the combination of compounds of formula (i) and of formula (ii) is improved according to the measurements of minimum inhibitory concentrations (MICs) carried out with several mixtures, vs. i) alone or ii) alone at equivalent amount. The antimicrobial activity is regarded as being synergistic when the antimicrobial mixture makes it possible to obtain a percentage of growth of the strain of less than or equal to 25%, indeed even of less than or equal to 20%. The combination of the compounds of formula (i) and of formula (ii) as are defined above, and also the composition comprising the compounds of formula (i) and of formula (ii), makes it possible to obtain an antimicrobial mixture exhibiting an excellent antimicrobial activity, especially with regard to molds, in particular with regard to microbial strains of Aspergillus niger but also Candida albicans and/or Enterococcus faecalis. According to one embodiment, a subject matter of the invention is an antimicrobial mixture comprising, or constituted of (or consisting of), i) compound of formula (i) as defined above and ii) compound of formula (ii) as defined above, the combination of i) and ii) representing, at a maximum, 5% by weight, preferably less than 4% by weight, preferably less than 3% by weight, preferably less than 1% by weight, with respect to the total weight of the composition. The term “keratin materials” is understood to mean the skin, mucus membranes and/or superficial body growths. Preferably, the keratin materials are the skin, in particular the skin of the face, the mucus membranes, such as the lips, and/or the superficial body growths, such as the eyelashes. The term “preserving system” denotes one or more agent(s) included in the cosmetic compositions with the aim of inhibiting the growth of the microorganisms which are found therein. Preserving system is understood to mean, within the meaning of the present invention, any antimicrobial preservative, that is to say any substance capable of opposing the detrimental changes of microbiological origin in a cosmetic product, in particular those of bacterial or fungal origin; “fungal” meaning relating to microscopic fungi and to yeasts. The list of the preserving agents accepted in cosmetic products appears in Annex V of Regulation (EC) No.1223/2009. The term “composition devoid of additional preserving system” is thus understood to mean a composition devoid of preserving agent accepted in cosmetic products, that is to say appearing in Annex V of Regulation (EC) No.1223/2009. The term “feeling of cutaneous comfort” can denote at least one feeling chosen from the group consisting of a soft, moisturizing, nontacky feeling on the skin, when and/or after the cosmetic compositions of the present invention are applied topically. Within the meaning of the present invention and unless otherwise indicated: - an "alkyl radical" is a saturated, linear or branched, C ₁ -C ₂₀ , preferably C ₁ -C ₆ , more preferentially C ₁ - C4, hydrocarbon radical, such as methyl or ethyl; - an "alkylene radical" is a saturated divalent hydrocarbon radical as defined above which can contain from 1 to 4 conjugated or nonconjugated -C=C- double bonds; in particular, the alkylene group contains 1 or 2 unsaturation(s); The expression “optionally substituted” assigned to the alkyl radical implies that said alkyl radical can be substituted by one or more radicals chosen from the radicals i) hydroxyl, ii) C ₁ -C ₄ alkoxy, iii) acylamino, iv) amino optionally substituted by one or two identical or different C1-C4 alkyl radicals; - an "alkoxy radical " is an alkyl-oxy radical for which the alkyl radical is a linear or branched C ₁ -C ₁₆ , preferentially C1-C8, hydrocarbon radical; - the expression “at least one” is equivalent to “one or more”; and - throughout the patent application, the wording "comprising one" means "comprising at least one", unless otherwise specified.

Detailed description

Compound of formula (i)

The compound of formula (i) is defined as follows, and comprises its stereoisomers:

[Chem 1] in which:

Y' represent, independently of one another, a carboxylic acid group or an alkaline salt of a carboxylic acid group, such as a sodium salt of a carboxylic acid group; jl, kl, j2 and k2 represent an integer such that (jl, kl, j2, k2) = (0, 2, 0, 2); and

I represents an integer from 6 to 22, preferably from 8 to 16 and more preferably from 10 to 12.

This compound of formula (i), as indicated above, is commonly used as gemini surfactant. Such a gemini surfactant of formula (i) is described in particular in the application WO 2004/020394.

According to a specific embodiment of the invention, in the formula (i), I represents an integer ranging from 8 to 22, in particular from 8 to 12, jl = j2 = 0 and kl = k2 = 2.

Preferably, in the formula (i), Y' represents -COONa, jl = j2 = 0, kl = k2 = 2 and I = 10.

Mention may in particular be made, as compounds of formula (i ), of sodium dilauramidoglutamide lysine, sodium dimyristoylglutamide lysine and sodium distearoylglutamide lysine. According to a specific embodiment of the invention, the compound of formula (i) is sodium dilauramidoglutamide lysine. Sodium dilauramidoglutamide lysine is sold by Asahi Kasei Chemicals under the names Pellicer L-30, Pellicer LB-1O and Pellicer LB-30G.

Thus, sodium dilauramidoglutamide lysine can be represented by the following formula (il):

[Chem 2] with X representing a hydrogen atom or a sodium atom.

The compound(s) of formula (i) can be present in the composition in a content as active material within the range from 0.05% to 3% by weight, preferably from 0.05% to 1.5% by weight, more preferably still from 0.05% to 1% by weight, preferably from 0.1% to 0.6% by weight, with respect to the total weight of the composition.

Sequestering compound (or agent) (ii)

The composition according to the invention also comprises at least one sequestering agent chosen from the salts of formula ii) as are defined above.

According to a specific embodiment of the invention, the sequestering agent(s) are a) of formula (ii) as are defined above, in which M ⁺ , which are identical or different, are chosen from alkali metal cations, alkaline earth metal cations and ammonium ions.

When M ⁺ , which are identical or different, are chosen from alkali metal cations and ammonium ions, then n is equal to 4.

When M ⁺ , which are identical or different, are chosen from alkaline earth metal cations, then n is equal to 2.

The term "alkali metal cations" is understood in particular to mean the Na ⁺ and K ⁺ ions.

The term "alkaline earth metal cations" is understood in particular to mean the Mg ²⁺ and Ca ²⁺ ions.

Preferably, the M ⁺ cations are identical. Preferably, M ⁺ are chosen from alkali metal cations.

Preferably, M ⁺ is Na ⁺ .

Preferably, the sequestering agent has the following formula (ii ¹ ), and also its optical isomers, and its solvates, such as the hydrates:

[Chem 3]

Na ⁺ 4[ O-C(O)-CH2]2N-CH(COO )-(CH ₂ )2-C(O)O- (ii‘)

This compound of formula ( ii ') is tetrasodium glutamate diacetate (CAS No.: 51981-21-6). This compound is sold in particular by Akzo Nobel under the name Dissolvine GL-47-S.

Preferably, the content as active material of the compound(s) (ii) of formula (ii) is within the range from 0.025% to 2%, with respect to the total weight of the composition, preferably from 0.05% to 1%, preferably from 0.05% to 0.6%, with respect to the total weight of the composition.

Advantageously, the ratio by weight of the compound of formula (i) to the compound of formula (ii) in the composition is within the range from 0.1 to 10, preferably from 0.1 to 8, preferably from 0.1 to 6, preferably from 0.5 to 6, indeed even from 1 to 6.

Advantageously, the use, or composition, according to the invention comprises one or more additional ingredients chosen from water, fatty substances, in particular liquid fatty substances, such as oils, polyols having from 2 to 10 carbon atoms, gelling agents, film-forming or non-film-forming polymers, thickening or nonthickening polymers, colorants, such as pigments, natural or synthetic direct dyes, fragrances, fillers, UV screening agents, plant extracts, cosmetic and dermatological active principles, and salts.

Advantageously, the cosmetic use, or composition, according to the invention is provided in the form of an aqueous gel, of an aqueous or aqueous/alcoholic solution, in the form of a dispersion of the lotion type, of an emulsion of liquid or semiliquid consistency of the milk type or of a suspension or emulsion of soft, semisolid or solid consistency of the cream or gel type, or also of a multiple emulsion, a microemulsion, a vesicular dispersion of ionic and/or nonionic type, or wax/aqueous phase dispersions.

Aqueous phase

Advantageously, the composition according to the invention comprises a physiologically acceptable aqueous phase. The term "physiologically acceptable" is understood to mean a medium compatible with keratin materials.

The composition according to the invention preferably comprises an aqueous phase comprising water and optionally one or more organic solvent(s) soluble in water, at 25°C. This (these) solvent(s) can advantageously be chosen, for example, from C ₂ to C ₆ alkanols (aliphatic C ₂ to C ₆ monoalcohols), preferentially comprising from 2 to 4 carbon atoms, preferably chosen from ethanol, propanol, butanol, isopropanol, isobutanol and their mixtures; polyols having in particular from 2 to 20 carbon atoms, preferably from 2 to 6 carbon atoms, such as glycerol, diglycerol, propylene glycol, isoprene glycol, dipropylene glycol, butylene glycol, hexylene glycol, 1,3-propanediol, pentylene glycol, polyethylene glycols having from 2 to 200 ethylene oxide units and their mixtures.

Preferably, the composition according to the invention comprises at least one organic solvent chosen from polyols having from 2 to 20 carbon atoms, preferably from 2 to 6 carbon atoms, preferably from glycerol, diglycerol, propylene glycol, isoprene glycol, dipropylene glycol, butylene glycol, hexylene glycol, 1,3-propanediol, pentylene glycol and their mixtures, preferably from butylene glycol, hexylene glycol, 1,3-propanediol, pentylene glycol and their mixtures.

Preferably, the composition according to the invention additionally comprises a specific polyol iii) which can also act as copreservative, in combination with i) and ii). Butylene glycol is preferably chosen as specific polyol (iii) in combination with i) and ii) in the present composition, in particular for its copreserving effect, further improving the preserving effect of the combination of the compounds i) and ii) according to the present invention.

The composition generally comprises from 30% to 99% by weight, preferably from 50% to 99% by weight, of water, with respect to the total weight of the composition, preferably from 60% to 98% by weight, preferably from 80% to 97% by weight.

The amount of organic solvent(s) can range, for example, from 0.1% to 15% by weight, preferably from 0.5% to 10% by weight, better still from 0.8% to 5% by weight, with respect to the total weight of the composition.

Additional antimicrobial (or preservative)

According to an embodiment which is not favored for the present invention, the composition can comprise at least one additional antimicrobial. Thus, said additional antimicrobial is not the compound i) and neither is it the sequestering agent ii) as are defined above.

The additional antimicrobial or additional preservative can be chosen from sodium dehydroacetate; benzenecarboxylic acids optionally substituted on the phenyl group by one or more groups chosen from hydroxyl, (Ci-Cio)alkyl and (Ci-Cio)alkylcarbonyl, and also their salts of bases, in particular of alkali and alkaline earth metals, preferably benzoic acid or sodium benzoate; hydroxybenzoic acid esters optionally substituted on the phenyl group by one or more groups chosen from (Ci-Cio)alkyl, such as parabens, in particular methylparaben, ethylparaben, propylparaben ou butylparaben; potassium sorbate; salicylic acid optionally substituted by a (Ci-C ₈ )alkylcarbonyl group, preferably salicylic acid; chlorhexidine digluconate, chlorphenesin, polyaminopropyl biguanide, benzyl alcohol, myrtrimonium bromide, LAE (Ethyl Lauroyl Arginate HCI), phenoxyethanol, octopirox, behentrimonium chloride, cetrimonium chloride, pyridines substituted in the 3 position by an RR'N- C(O)- amide group and their solvates, such as the hydrates, with R and R', which are identical or different, representing a hydrogen atom, a (Ci-C ₆ )alkyl group, such as methyl or ethyl, a (C ₂ -C ₆ )alkenyl group, such as allyl, or a (hetero)aryl(Ci-C ₄ )alkyl group, such as benzyl or picolyl, and their mixtures.

As indicated above, preferably, the composition according to the invention contains less than 0.5% of this type of additional preservative, in particular less than 0.5% of preservative(s) listed in the preceding section, preferably less than 0.2% of additional preserving system, in particular less than 0.2% of 2-phenoxyethanol.

Preferably, the composition according to the invention contains less than 0.5%, preferably less than 0.2%, by weight, with regard to the total weight of the composition, and preferably is devoid, of additional preservative having an aromatic ring, that is to say devoid of or free from preservative (other than i) or ii)) exhibiting at least one aromatic ring.

Other ingredients

The composition can also comprise ingredients commonly used in cosmetics, such as active principles, antioxidants, fragrances, neutralizing agents, surfactants or their mixtures. Of course, a person skilled in the art will take care to choose the optional additional additives and/or their amount such that the advantageous properties of the composition according to the invention are not, or not substantially, detrimentally affected by the envisaged addition. pH of the composition

The pH of the composition according to the invention is generally of between 3 and 10 approximately, preferably between 3 and 8 approximately, preferably between 4 and 7 approximately, preferably between 5 and 6.5 and preferably between 5.5 and 6.

It can be adjusted to the desired value by means of acidifying or alkaline agents generally used for the treatment of keratin materials, or alternatively using conventional buffer systems.

According to one embodiment, the cosmetic composition according to the invention can comprise a neutralizing agent, such as an acid and/or a base.

According to an alternative form, the composition according to the invention can comprise at least one base.

The base can be chosen from inorganic bases, such as, for example, alkali meta! hydroxides i.e. sodium hydroxide, potassium hydroxide, ammonium hydroxides, aqueous ammonia, organic bases, such as, for example, monoethanolamine, diethanolamine, triethanolamine, triisopropylamine, tri(2- hydroxy-l-propyl)amine, N,N-dimethylethanolamine, 2-amino-2-methyl-l-propanol, 2-amino-2- methyl-l,3-propanediol, triethylamine, dimethylaminopropylamine and amphoteric bases (that is to say, bases having both anionic and cationic functional groups), such as primary, secondary, tertiary or cyclic organic amines, amino acids. Mention may be made, as examples of amphoteric bases, of glycine, lysine, arginine, taurine, histidine, alanine, valine, cysteine, trihydroxymethylaminomethane (TRISTA), triethanolamine and any one of their mixtures.

According to a specific embodiment, the base of the composition is chosen from sodium hydroxide, potassium hydroxide, ammonium hydroxides, aqueous ammonia, monoethanolamine, diethanolamine, triethanolamine, tromethamine and any one of their mixtures. According to a specific embodiment, the base of the composition is chosen from sodium hydroxide, triethanolamine and their mixture.

According to a specific embodiment, the base of the composition according to the invention is present at a concentration by weight of less than 0.5%, preferably of less than 0.25%, by weight, with respect to the total weight of the composition.

According to an alternative form, the composition according to the invention can comprise at least one acid.

The acid can be chosen from inorganic acids, such as hydrochloric acid, sulfuric acid or nitric acid, organic acids, such as acetic acid, lactic acid, glycolic acid, mandelic acid, citric acid or ascorbic acid, and any one of their mixtures.

The acid can be chosen from organic acids, such as benzoic acid, anisic acid, salicylic acid and any one of their mixtures.

According to a specific embodiment, the acid of the composition according to the invention is present at a concentration by weight of less than 0.5%, preferably of less than 0.25%, by weight, with respect to the total weight of the composition. According to a specific embodiment of the invention, the composition is devoid of surfactant other than a compound (i) of formula (i), as defined above.

According to an alternative embodiment, the composition comprises at least one surfactant other than a compound (i) of formula (i), as defined above, in particular one or more nonionic, anionic, cationic, zwitterionic or amphoteric surfactants, in particular chosen from nonionic surfactants.

Said surfactant can be a hydrocarbon or silicone surfactant and can have, at 25°C, an HLB (hydrophilic-lipophilic balance) within the Griffin sense preferably of greater than or equal to 8.

The HLB value according to Griffin is defined in J. Soc. Cosm. Chem., 1954 (Volume 5), pages 249-256. Reference may be made to the document Kirk-Othmer's Encyclopedia of Chemical Technology, Volume 22, pages 333-432, 3rd edition, 1979, Wiley, for the definition of the emulsifying functions and properties of surface-active agents, in particular pages 347-377 of this reference.

Preferably, the surfactant according to the invention is chosen from: a) anionic surfactants, such as: salts of polyoxyethylenated fatty acids, in particular those derived from alkaline salts, and their mixtures; phosphoric esters and their salts, such as DEA oleth-10 phosphate (Crodafos N ION from Croda) or monopotassium monocetyl phosphate (Amphisol K from Givaudan); sulfosuccinates, such as disodium PEG-5 citrate lauryl sulfosuccinate and disodium ricinoleamido MEA sulfosuccinate; alkyl ether sulfates, such as sodium lauryl ether sulfate; isethionates; acylglutamates, such as disodium hydrogenated tallow glutamate (Amisoft HS-21 R from Ajinomoto) and sodium stearoyl glutamate (Amisoft HS-11 PF from Ajinomoto) and their mixtures; soybean derivatives, such as potassium soyate; citrates, such as glyceryl stearate citrate (Axol C 62 Pellets from Degussa); proline derivatives, such as sodium palmitoyl proline (Sepicalm VG from SEPPIC) or the mixture of sodium palmitoyl sarcosinate, magnesium palmitoyl glutamate, palmitic acid and palmitoyl proline (Sepifeel One from SEPPIC); lactylates, such as sodium stearoyl lactylate (Akoline SL from Karlshamns AB); sarcosinates, such as sodium palmitoyl sarcosinate (Nikkol sarcosinate PN) or the 75/25 mixture of stearoyl sarcosine and myristoyl sarcosine (Crodasin SM from Croda); sulfonates, such as sodium C14-17 sec-alkyl sulfonate (Hostapur SAS 60 from Clariant); glycinates, such as sodium cocoyl glycinate (Amilite GCS-12 from Ajinomoto); salts of C16-C30 fatty acids, in particular those deriving from amines, such as triethanolamine stearate and/or 2-amino-2-methylpropane-l,3-diol stearate; b) amphoteric or zwitterionic surfactants, for instance N-acylamino acids, such as N- alkylaminoacetates (for instance trimethylglycine), disodium cocoamphodiacetate, amine oxides, such as stearamine oxide, or also silicone surfactants, for instance dimethicone copolyol phosphates, such as that sold under the name Pecosil PS 100® by Phoenix Chemical; c) nonionic surfactants with an HLB of greater than or equal to 8 at 25°C, such as: - saccharide esters and ethers, such as the mixture of cetylstearyl glucoside and of cetyl and stearyl alcohols, for instance Montanov 68 from SEPPIC; - oxyethylenated and/or oxypropylenated ethers (which can comprise from 1 to 150 oxyethylene and/or oxypropylene groups) of glycerol; - oxyethylenated and/or oxypropylenated ethers (which can comprise from 1 to 150 oxyethylene and/or oxypropylene groups) of fatty alcohols (in particular C ₈ -C ₂₄ and preferably C12-C18 alcohol), such as the oxyethylenated ether of cetearyl alcohol having 30 oxyethylene groups (CTFA name: Ceteareth-30), the oxyethylenated ether of stearyl alcohol having 20 oxyethylene groups (CTFA name: Steareth-20) and the oxyethylenated ether of the mixture of C ₁₂ -C ₁₅ fatty alcohols comprising 7 oxyethylene groups (CTFA name: C12-15 Pareth-7) sold under the name Neodol 25-7® by Shell Chemicals; - esters of fatty acid (in particular of C8-C24 and preferably C16-C22 acid) and of polyethylene glycol (which can comprise from 1 to 150 ethylene glycol units), such as PEG-50 stearate and PEG-40 monostearate sold under the name Myrj 52P® by ICI Uniqema; - esters of fatty acid (in particular of C8-C24 and preferably C16-C22 acid) and oxyethylenated and/or oxypropylenated glycerol ethers (which can comprise from 1 to 150 oxyethylene and/or oxypropylene groups), for instance PEG-200 glyceryl monostearate sold under the name Simulsol 220 TM® by SEPPIC; polyethoxylated glyceryl stearate having 30 ethylene oxide groups, for instance the product Tagat S® sold by Goldschmidt, polyethoxylated glyceryl oleate having 30 ethylene oxide groups, for instance the product Tagat O® sold by Goldschmidt, polyethoxylated glyceryl cocoate having 30 ethylene oxide groups, for instance the product Varionic LI 13® sold by Sherex, polyethoxylated glyceryl isostearate having 30 ethylene oxide groups, for instance the product Tagat L® sold by Goldschmidt, and polyethoxylated glyceryl laurate having 30 ethylene oxide groups, for instance the product Tagat I® from Goldschmidt; - esters of fatty acid (in particular of C8-C24 and preferably C16-C22 acid) and oxyethylenated and/or oxypropylenated sorbitol ethers (which can comprise from 1 to 150 oxyethylene and/or oxypropylene groups), for instance polysorbate-20 sold under the name Tween 20® by Croda or polysorbate-60 sold under the name Tween 60® by Croda; - poloxamers, which are propylene oxide and ethylene oxide copolymers; - copolymers of propylene oxide (PO) and of ethylene oxide (EO), also called EO/PO polycondensates, which are copolymers consisting of polyethylene glycol and polypropylene glycol blocks. Preferably, the EO/PO polycondensate is chosen from polyethylene glycol/polypropylene glycol/polyethylene glyco! triblock polycondensates, for example those having the following chemical structure:

H-(O-CH ₂ -CH ₂ ) _a -(O-CH(CH ₃ )-CH ₂ )b-(O-CH ₂ -CH ₂ ) _a -OH, in which formula a ranges from 2 to 150 and b ranges from 1 to 100; preferably, a ranges from 10 to 130 and b ranges from 20 to 80.

Mention may in particular be made, as polycondensates, of the polyethylene glycol/polypropylene glycol/polyethylene glycol triblock polycondensates sold under the "Synperonic" names by Uniqema, such as the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (13 EO/30 PO/13 EO) (MW: 2900) sold under the name Synperonic PE/L 64 NAA LQ (Poloxamer 184), the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (8 EO/30 PO/8 EO) (MW: 2500) sold under the name Synperonic PE/L 62 (INCI name: Poloxamer 182), the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (6 EO/67 PO/6 EO) (MW: 4400) sold under the name Synperonic PE/L 121 (INCI name: Poloxamer 401), the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (46 EO/16 PO/46 EO) (MW: 5000) sold under the name Synperonic® PE/F38 (INCI name: Poloxamer 108), the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (128 EO/54 PO/128 EO) (MW: 14 000) sold under the name Synperonic® PE/F108 (INCI name: Poloxamer 338), the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (11 EO/21 PO/11 EO) (MW: 2200) sold under the name Synperonic® PE/L44 (INCI name: Poloxamer 124), the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (5 EO/21 PO/5 EO) (MW: 1630) sold under the name Synperonic* PE/L42 (INCI name: Poloxamer 122), the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (98 EO/67 PO/98 EO) (MW: 12 000) sold under the name Synperonic® PE/F127 (INCI name: Poloxamer 407), the condensates of ethylene oxide, of propylene oxide and of ethylene oxide (97 EO/39 PO/97 EO) (MW: 10800) sold under the name Synperonic® PE/F88 (INCI name: Poloxamer 238) and their mixtures.

Preferably, the poloxamer is the condensate of ethylene oxide, of propylene oxide and of ethylene oxide (13 EO/30 PO/13 EO) (MW: 2900), in particular such as sold under the name Synperonic PE/L 64 NAA LQ by Croda (INCI name: Poloxamer 184); d) cationic surfactants, such as optionally polyoxyalkylenated primary, secondary or tertiary fatty amine salts, quaternary ammonium salts and their mixtures; and e) their mixtures.

Preferably, the composition according to the invention comprises a mixture of at least one amphoteric surfactant, such as those mentioned above (group b), and at least one nonionic surfactant, such as those mentioned above (group c). Preferably, the mixture comprises disodium cocoamphodiacetate and a poloxamer, preferably the condensate of ethylene oxide, of propylene oxide and of ethylene oxide (13 EO/30 PO/13 EO) (MW: 2900), in particular such as sold under the name Synperonic PE/L 64 NAA LQ by Croda (INCI name: Poloxamer 184).

Preferably, the content of surfactant (i.e. of active material) generally ranges from 0.05% to 10% by weight, with respect to the total weight of the composition, and preferably from 0.1% to 5% by weight and more particularly still from 0.4% to 2% by weight. This is because such a surfactant contributes in particular to the formation of micelles within the composition. These micelles can be demonstrated by physicochemical methods, such as the XRD optical method.

Preferably, the composition according to the invention is substantially devoid of oily phase (also referred to as fatty phase). The term "substantially devoid of oily phase" is understood to mean that the composition according to the invention exhibits a content of oily phase of less than or equal to 1% by weight, with respect to the total weight of the composition, preferably of less than or equal to 0.5% by weight, preferentially of less than or equal to 0.1% by weight. Advantageously, the composition according to the invention is completely devoid of oily phase. Preferably, the term "oil" is understood to mean a fatty substance which exists in the liquid form at ambient temperature (20- 25°C) and at atmospheric pressure (760 mmHg). The "fatty substance" comprises at least one "fatty" hydrocarbon chain, that is to say a linear hydrocarbon chain of at least 4 carbon atoms which is saturated or unsaturated and optionally substituted, and in particular a linear C ₅ -C ₃ o hydrocarbon chain.

Preferably, the composition according to the invention is substantially devoid of EDTA (ethylenediaminetetraacetic acid). The term "substantially devoid of EDTA" is understood to mean that the composition according to the invention exhibits a content of EDTA of less than or equal to 0.5% by weight, with respect to the total weight of the composition, preferably of less than or equal to 0.3% by weight, preferentially of less than or equal to 0.1% by weight. Advantageously, the composition according to the invention is completely devoid of EDTA.

According to a preferred embodiment of the invention, the composition is in the form of a micellar water comprising the compounds i) and ii), and water.

Preferably, the composition of the present invention is transparent.

The term "transparent composition" is understood to mean, within the meaning of the present invention, a composition exhibiting a turbidity value of less than 20 NTU, preferably of less than 15 NTU, preferably of less than 10 NTU. Preferably, the turbidity of the compositions is at least equal to 1 NTU.

The NTU (nephelometric turbidity unit) is the unit of measurement of the turbidity of a composition. The measurement of the turbidity is carried out, for example, with a 2100P model turbidimeter from Hach, the tubes used for the measurement being referenced AR397A cat 24347-06. The measurements are carried out at ambient temperature (from 20°C to 25°C).

Preferably, the composition is transparent and exhibits a turbidity value of between 1 and 20 NTU, preferably between 1 and 15 NTU, preferably of less than 10 NTU.

Preferably, the composition according to the invention is packaged in a transparent UV-resistant packaging.

The present invention also relates to a nontherapeutic cosmetic treatment method for caring for and/or making up and/or cleansing keratin materials, comprising the application, to said keratin materials, of a composition according to the invention as defined above.

The present invention advantageously relates to the use of the composition as defined above for removing makeup from and/or cleansing keratin materials, preferably skin and/or mucus membranes (such as the lips) and/or keratin fibers (such as eyelashes). A subject matter of the present invention is in particular a method for removing makeup from and/or cleansing keratin materials, preferably skin and/or mucus membranes (such as the lips) and/or keratin fibers (such as eyelashes), comprising the application, to the keratin materials, of a composition according to the invention.

Preferably, the ratio by weight of compounds i)/ii) in the composition according to the invention is greater than 1, preferably greater than 2, preferably greater than 3, preferably greater than 4, preferably greater than 5. Advantageously, the ratio by weight of compounds i)/i i) in the composition according to the invention is within the range from 0.1 to 12, preferably from 1 to 10, preferably from 2 to 8, which makes it possible in particular to optimize the makeup-removing effectiveness while guaranteeing good preservation of the makeup-removing formula.

Another subject matter of the present invention is a method for the preservation of a composition comprising a physiologically acceptable medium, in particular a cosmetic or dermatological composition, characterized in that it consists in incorporating, in said composition, a combination of compounds i) and ii) as is defined above. A subject matter of the present invention is in particular the use of a combination of compounds i) and ii) as is defined above as antimicrobial agent, in particular with regard to microbial strains of Candida albicans, Aspergillus niger, Escherichia coll, Staphylococcus aereus and/or Enterococcus faecalis.

The invention is now illustrated by the following nonlimiting examples. The percentages are expressed by weight, with respect to the total weight of composition (% w/w), unless otherwise mentioned.

EXAMPLES

1 - Determination of the synergy of antimicrobial activity as MIC

A synergistic antimicrobial activity effect with a mixture of sodium dilauramidoglutamide lysine (referred to as substance A) and of tetrasodium glutamate diacetate (referred to as substance B) was demonstrated by the calculation of the synergy index (or FIC index) according to the following formula:

[Math. 1]

FIC Index = (MIC g.f A. with B / MIC of A) + (MIC of B with A/ MIC of B) with:

- MIC of A with B: minimum concentration of product A in the combination A + B which makes it possible to obtain an inhibitory effect;

- MIC of B with A: minimum concentration of product B in the combination A + B which makes it possible to obtain the inhibitory effect;

- MIC of A: minimum inhibitory concentration of the product A alone;

- MIC of B: minimum inhibitory concentration of the product B alone. This formula was described for the first time in the paper by F.C. Kull, P.C. Eisman, H.D. Sylwestrowka and R.L. Mayer, Applied Microbiology, 9:538-541, 1961.

For each compound tested alone, the MIC is regarded as the first concentration which makes it possible to obtain a percentage of microbial growth of less than or equal to 25%.

As regards the combinations tested, MIC of A with B and MIC of B with A are the respective concentrations of A and of B in the combinations which make it possible to obtain a microbial growth percentage of less than or equal to 25%.

Interpretation of the FIC Index:

When the value of the FIC Index is less than or equal to 1, it is considered that the combination of the test compounds exhibits a synergistic effect.

Microbial strains used: Candida albicans ATCC 10231 and Aspergillus niger ATCC 6275.

The strains originate from the American Type Collection (ATCC) and are kept in the laboratory according to the requirements of the standard NF EN 12353.

Liquid culture medium used: Sabouraud broth supplemented with polyoxyethylenated (20 EO) sorbitan monopalmitate(Tween 40 from Croda) and with Phytagel© BioReagent, at double concentration (i.e., a mixture of 5 g of Phytagel + 0.6 g of Tween 40 + 60 g of Sabouraud broth).

A 96-well microplate at an incubation temperature of 30°C +/- 1°C under aerobic conditions (C. albicans and A. niger} was used.

Incubation time of the microplate: 18 to 48 h under aerobic conditions.

Trials

For each compound:

A = (i) sodium dilauramidoglutamide lysine (29%) + water (71%)

A' = (i) sodium dilauramidoglutamide lysine (27.3%) + water (66.7%) + butylene glycol (6%)

B = (ii) tetrasodium glutamate diacetate (47.5%) + water (52.5%) (brand name: Dissolvine® GL-47-S; Manufacturer: Akzo Nobel (Nouryon)

A 10% (weight/volume) stock solution was prepared by mixing 1 g of compound in 9 ml of aqueous l%o agar solution. Successive dilutions were made with the l%o agar solution.

Trials of the compounds A and B alone

50 pl of each of the daughter solutions obtained containing the compound A or B are added to the wells of the microplate. 100 pl of Sabouraud liquid nutrient broth inoculated at double concentration with the strain (Aspergillus niger or Candida albicans} and 50 pl of aqueous l%o agar solution are also added thereto.

Trials of the compounds A and B as a mixture

50 pl of each of the daughter solutions obtained containing the compound A and 50 pl of each of the daughter solutions obtained containing the compound B are added to the wells of the microplate. 100 pl of Sabouraud liquid nutrient broth inoculated at double concentration with the strain (Aspergillus niger or Candida albicans} are also added thereto. Microbial growth control

A positive microbial growth control was also prepared. The positive microbial growth control corresponds to the mixture of 100 pl of an aqueous l%o agar solution with 100 pl of Sabouraud liquid nutrient broth inoculated at double concentration with the strain (Aspergillus niger or Candida albicans) in the absence of the compounds A and B.

Absorbance control for the compounds A and B alone

An absorbance control was performed in parallel on the compounds A and B alone. This control corresponds to 100 pi of sterile Sabouraud liquid nutrient broth at double concentration + 100 pl of the compound A or B at double concentration.

In the three cases (absorbance control, growth control and trial), the final volume present in each of the wells of the microplate is 200 pl.

In the two cases (trial and growth control), the inoculum represents the concentration of the strain (Aspergillus niger or Candida albicans) present in the final volume of the wells (200 pl) and is of between 2 and 6.10 ⁵ cfu/ml of Aspergillus niger or Candida albicans.

The minimum inhibitory concentration (MIC) of each compound A and B, alone and in combination, was determined in a known way by means of optical density measurements at a wavelength of 620 nm.

The test as described above (trial, absorbance control and growth control) was performed again in order to test the combination A + B on strains respectively of Aspergillus niger and Candida albicans.

The following results were obtained with the mixture A + B or A' + B according to the invention on Candida albicans, respectively Aspergillus niger.

MIC of each compound A, A' and B alone with regard to Candida albicans and Aspergillus niger

[Table 1]

A + B combination: MIC with regard to Candida albicans

[Table 2]

A' + B combination: MIC with regard to Candida albicans

[Table 3]

A + B combination: MIC with regard to Aspergillus niger

[Table 4]

A' + B combination: MIC with regard to Aspergillus niger

[Table 5]

The results obtained show an improvement in the antimicrobial properties and in particular a synergy in the inhibitory activity for the following mixtures: 1.25% or 2.5% of A or A' and 0.5%, or also 1%, of B, i.e. for i/ii (sodium dilauramidoglutamide lysine/tetrasodium glutamate diacetate) ratios within the range from 0.7 to 3.1.

It appears from the results of the above tables that the combination of A and B, and more particularly of i) and ii) according to the invention, makes possible a marked antimicrobial improvement. It is the same with A', in the presence of butylene glycol, in combination with B.

In conclusion, the combination of A or A' and B, in particular of i and ii according to the invention, makes possible a marked antimicrobial improvement.

2- Evaluation of the stability and of the preserving effect of cosmetic compositions

The stability is evaluated as follows:

The formulas are placed in transparent UV-resistant packs, at a temperature of 4°C, AT, 37°C or 45°C, for a maximum duration of 2 months.

Cycle of 10 days, with descent to -20°C, plateau, then rise +20°C and plateau, for fixed durations of 6 h; a cycle thus lasts 24 h.

The stability also includes a visual observation which comprises the transparency of the formula, and the absence of visible particles, of color and of unpleasant odor.

The preserving effect is evaluated as follows:

TEST PROTOCOL FOR THE ANTIMICROBIAL EFFECTIVENESS The effectiveness of each formula is evaluated by means of a test which makes it possible to determine the level of antimicrobial protection of a composition. It consists in artificially contaminating the test product with various microorganisms (bacteria, yeasts and molds) and in monitoring the number of viable microbes over time.

A product which is satisfactorily protected must make possible decontamination of the microorganisms introduced, which decontamination is more or less rapid as a function of the microbial strains, of the type of product and of packaging article. The product is distributed in as many pill boxes as there are microorganisms to be tested. A graded suspension of microorganisms is introduced into each of these pill boxes. The effectiveness of the protection of the formulas is tested over a microbial spectrum which is limited but chosen from the species liable to contaminate the product, both during manufacture and during its use. It comprises, in this case, bacteria: Escherichia coli, Staphylococcus aereus and Enterococcus faecalis.

The sampling carried out in order to count the remaining microorganisms in the product takes place after 28 days of contact between the product and the microbe.

The antimicrobial effectiveness is regarded as in accordance or OK for a result (at 28 days): <1000 or <E3 or <10 ³ .

The dilutions carried out in order to perform the countings are inoculated on Petri dishes.

The kinetics (growth or decrease) for a given microbe at a given time is subsequently expressed in logarithmic reduction.

The results are as follows, tested on a composition of micellar water type.

Composition of micellar water type

A micellar water according to the invention using the combination i + ii as preserving system (according to different i/ii ratios by weight) is compared with the same micellar water using a conventional preservative, 2-phenoxyethanol. The three micellar waters each contain the same total content as active material of preservative (0.7% by weight with regard to the total weight of the composition).

[Table 6]

Procedure:

The PEG-6 CAPRYLIC/CAPRIC GLYCERIDES and the demineralized water are mixed in the final beaker. The preservatives, either the mixture of SODIUM DILAURAMIDOGLUTAMIDE LYSINE and of TETRASODIUM GLUTAMATE DIACETATE for examples 1 and 2 or PHENOXYETHANOL for example 3, are added.

The pH is adjusted to 5.5 with a 10% citric acid solution.

Microbiological results at 28 days after inoculum of strains respectively: Escherichia coli, Staphylococcus aereus and Enterococcus faecalis in the 3 formulas above.

It appears from the results of the above table that the combination of the compounds i) and ii) according to the invention makes possible an antimicrobial protection at least equivalent to that of the typical preservative phenoxyethanol, at the same total content as active material in each formula.

Results of stability and of preserving effect of the test compositions of micellar water type

[Table 7]

NOK = not in accordance with expectations / OK = in accordance with expectations

The results show that the formulas Ex. 1 and Ex. 2 according to the invention are stable while contributing a satisfactory antimicrobial effectiveness, this being the case for one and the same total content as active material of preservative (equal to 0.7% by weight with regard to the total weight of the composition).

3- Evaluation of the makeup-removing effectiveness of cosmetic compositions

Makeup-removing trials were carried out in vitro according to the following protocol:

Protocol for evaluation of the makeup-removing effectiveness:

A known amount of foundation (15 pl) is deposited on a Bioskin® support (artificial skin) and spread with the finger over a surface area delimited by a stencil in the shape of a circle with a diameter of 3 cm.

The foundation, thus spread, is subsequently dried in an oven at 37°C for 1 h and then brought back to ambient temperature (25°C). 1.5 g of test formula are deposited on a makeup-removing (cotton) pad (Demak'Up type) and then the cotton pad is applied using the hand to the surface to be freed from makeup. Six passes are carried out with the same cotton pad, and the same pressure in the same direction, and then the makeup-removing result is observed

Observation grid and evaluation scale:

[Table 8]

Table 9] It appears from the results of the above table that the combination of the compounds i) and ii) according to the invention makes possible a better makeup-removing effectiveness than that obtained with phenoxyethanol or

TETRASODIUM GLUTAMATE DIACETATE, this being the case for one and the same total content as active material (0.7%) in the composition.