USE OF DIANHYDROHEXITOL FOR THE PRESERVATION OF COSMETIC PREPARATIONS

Description

Technical field

[0001] The present application is in the field of cosmetics, more precisely in the field of antimicrobial and / or bacteriostatic and / or bactericidal, and / or antifungal preservatives, preferably on bacterial and / or fungal strains present in cosmetic or dermatological preparations. Preferably, a use of isosorbide is proposed to reduce or eliminate the effects of the degradation of said preparation following contamination by microorganisms of the human skin microbiome or present in the atmosphere. Isosorbide is used alone or in addition to other preservatives already used for this purpose. Prior art

[0002] In Pilz et al. patent US9295626, a method for preserving cosmetic, dermatological and pharmaceutical preparations by using bactericidal compounds based on isosorbide monoester and / or diester is disclosed. This patent has a minimum inhibitory concentration for isosorbide equal to 10% on many strains (col. 27, Table 2), including the following strains that can be found in the skin microbiome: Aspergillus brasiliensis, Candida albicans, Staphylococcus aureus.

[0003] Stoer et al.'s US9993000 patent also discloses the use of isosorbide derivatives, here ethers, as a bactericidal agent to preserve cosmetic compositions, in particular by inhibiting the growth of a multitude of bacterial strains, including Propionobacterium acnes. Technical problem

[0004] Human skin is colonized by a resident bacterial flora, which constitutes the skin microbiome. Although this flora is mostly non-pathogenic, there may be abnormal situations where it becomes so. One abnormal situation is that of contamination of the skin microbiome by an external pathogenic microorganism, through contact with a contaminated environment. A second abnormal situation is that of the appearance of an imbalance in the interactions between the microorganisms constituting the skin microbiome, which results in the proliferation of one microorganism to the detriment of other microorganisms.Such proliferation may be widespread over a large area of the skin, or perhaps more localized, for example in areas of the skin richer in water and warmer, or for example on the face or scalp due to the presence of nutrient reserves for said microorganisms, such as triglycerides located in the glands at the base of the hair or body hair. Apart from the potentially harmful consequences for the health of the skin or the individual, these abnormal situations also cause cosmetic inconveniences, particularly visual, tactile, or olfactory, which can harm the individual's comfort or image, and thus disrupt or degrade their social life.

[0005] A cosmetic or dermatological preparation is generally packaged aseptically in a hermetic container with an orifice through which the product is expelled, usually by mechanical action, in order to be applied to the human body. This expulsion operation systematically leads to contact between the cosmetic or dermatological product and the atmosphere or the human body, and in particular with the human topical microbiome, mainly the skin microbiome. This contact can lead to contamination of the cosmetic or dermatological preparation by microorganisms of a very varied nature: bacteria, yeasts, fungi. These microorganisms can find nutritive organic substances and water in the cosmetic or dermatological preparation, and thus develop there in an uncontrolled manner.Such proliferation of microorganisms must be avoided because these microorganisms are potentially pathogenic, and can, to a lesser extent, through their development, modify the cosmetic or dermatological preparation in such a way that it becomes inactive or its use becomes unpleasant, in particular due to the appearance of unpleasant odors or a change in texture or sensory profile.

[0006] There is a growing consumer need for products of natural origin these days. The use according to the invention meets this need, by proposing to use at least dianhydrohexitol, because dianhydrohexitols are indeed molecules of natural origin, produced from cereal starch for example. Description of the embodiments

[0007] It is to the applicant's credit to have discovered, unexpectedly, that non-derivatized dianhydrohexitols, preferably isosorbide, have antimicrobial and / or bactericidal and / or bacteriostatic, and / or antifungal effects on microbial strains responsible for the contamination and physicochemical degradation of cosmetic or dermatological preparations.

[0008] The invention relates more particularly to the use of at least one dianhydrohexitol in a cosmetic or dermatological preparation for topical use to limit or prevent the proliferation of microorganisms of the human skin microbiome.

[0009] It is also proposed to use isosorbide as a preservative in cosmetic or dermatological preparations, alone or in addition to another known preservative. Use of dianhydrohexitol in the preservation of cosmetic preparations

[0010] The present invention relates to the use of at least one dianhydrohexitol in a cosmetic or dermatological preparation for topical use to limit or prevent the proliferation of microorganisms of the human skin microbiome or present in the atmosphere.

[0011] Preferably, the microorganisms are chosen from bacteria and fungi, and are preferably responsible for the inactivation of cosmetic active ingredients, and / or the appearance of unpleasant odors, and / or a change in the texture of a cosmetic or dermatological preparation.

[0012] According to a preferred embodiment, the dianhydrohexitol is chosen from isosorbide, isomannide, isoidide, preferentially isosorbide.

[0013] Additionally, the use in a cosmetic or dermatological preparation is made at a dianhydrohexitol content of 0.1% to 50% by weight, preferably 0.5% to 25% by weight, more preferably 1% to 25% by weight, even more preferably 2% to 15% by weight, and most preferably 5% to 9% by weight, relative to the total weight of the composition.

[0014] According to one embodiment of the use according to the invention, dianhydrohexitol is an antimicrobial and / or bactericidal and / or bacteriostatic and / or antifungal agent, and makes it possible to reduce or prevent the development of bacterial and / or fungal strains from the human topical microbiome, in said cosmetic or dermatological preparation.

[0015] Preferably, the bacterial strain is chosen from the family Propionobacterium spp, preferentially the bacterial strain is Propionobacterium acnes; and / or the bacterial strain is chosen from the family Corynebacterium spp, preferentially the bacterial strain Corynebacterium xerosis ; and / or the bacterial strain is chosen from the family Staphylococcus spp , preferentially the bacterial strain is Staphylococcus epidermis ; and the fungal strain is chosen from the family Malassezia spp, preferentially the fungal strain is Malassezia furfur.

[0016] According to a variant of the use according to the invention, dianhydrohexitol is used in combination with other biocides commonly used in cosmetic or dermatological preparations, such as acids, alkaline salts of benzoic acid or sorbic acid or propionic acid; or other biocides such as phenoxyethanol or chlorphenesin. Dianhydrohexitol

[0017] The aqueous solution in question may contain a single dianhydrohexitol, as it may contain several. These dianhydrohexitols (1,4 - 3,6-dianhydrohexitols) are isosorbide (1,4-3,6-dianhydrosorbitol), isomannide (1,4-3,6-dianhydromannitol), isoidide (1,4-3,6-dianhydroiditol) and mixtures of at least two of these products. Preferably, the aqueous solution contains only one dianhydrohexitol which is isosorbide.

[0018] In this regard, the Applicant indicates that generally, dianhydrohexitols are synthesized in the presence of water (or water is generated during their synthesis): by recovering said dianhydrohexitol in this reaction medium, a composition is immediately available in the form of an aqueous solution of dianhydrohexitol that can be used according to the invention. The dianhydrohexitol solutions can in particular be obtained according to the processes described in the aforementioned patent applications EP 1 287 000 and WO 03 / 043959. It is possible to choose to keep all or part of the water used during the preparation of the dianhydrohexitol or to eliminate all of the water to obtain a product in solid form that will be put back into aqueous solution by simply adding water, which constitutes another possibility for preparing an aqueous solution of dianhydrohexitol that can be used according to the invention.

[0019] The applicant specifies that the term “1,4-3,6-dianhydrohexitol” does not include derivatives of 1,4-3,6-dianhydrohexitol, in particular such as ethers or esters of 1,4-3,6-dianhydrohexitol. Cosmetic or dermatological preparation

[0020] By “cosmetic or dermatological preparation”, the applicant means any composition intended to be placed in contact with human or animal skin.

[0021] The cosmetic or dermatological preparation according to the invention comprises as active preservative agent, in particular antibacterial and / or antifungal, at least one dianhydrohexitol, preferentially chosen from isosorbide, isomannide, isoidide, preferentially isosorbide.

[0022] According to a preferred embodiment, the cosmetic or dermatological preparation according to the invention comprises from 0.1% to 50% by weight of dianhydrohexitol, preferably from 0.5 to 25%, more preferably from 1% to 25%, even more preferably from 2% to 15%, and most preferably from 5% to 9%.

[0023] According to a very preferred embodiment, the cosmetic or dermatological preparation contains as the only antimicrobial and / or bactericidal and / or bacteriostatic and / or antifungal agent, at least one dianhydrohexitol, preferentially chosen from isosorbide, isomannide, isoidide, preferentially isosorbide.

[0024] The cosmetic or dermatological preparation according to the invention makes it possible to reduce or eliminate the inactivation of cosmetic active ingredients due to microbial degradation, and / or to reduce or eliminate the appearance of unpleasant odors, or the change in texture of said cosmetic or dermatological preparation.

[0025] The cosmetic preparation can be a skin product, a hair product, makeup, or a hygiene product.

[0026] Among skin care products, the cosmetic preparation according to the invention may be chosen from day creams, sun creams, after-sun creams, self-tanners, masks. Among hair care products, the cosmetic preparation according to the invention is preferably chosen from shampoos, conditioners (creams, masks, lotions), styling products (sprays, gels, waxes), coloring products. Among makeup products, the cosmetic preparation according to the invention is preferably chosen from foundations, eyeshadows. Among hygiene products, the cosmetic preparation according to the invention is preferably chosen from washing gels, shower gels, cleansing or makeup removing wipes, hydroalcoholic solutions or gels, soaps, deodorants, antiperspirants, body sprays. Example In vitro measurements of the effect of isosorbide on microbial strains

[0027] The samples are prepared under sterile conditions and placed in microplates (2ml wells) according to the concentrations below. Two analytical controls were carried out: a positive control corresponding to Phenonip ®< 0.5%; a negative control consisting of 0.85% physiological serum.

[0028] Samples and controls are contaminated by three bacterial strains, namely Staphylococcus epidermidis, Corynebacterium xerosis, And Propionobacterium acnes, at a rate of approximately 1.43.105 to 4.15.105 colony forming units per milliliter, noted as cfu / ml; and a fungal strain, namely Malassezia furfur, at a rate of approximately 1.50.104 to 3.80.104 cfu / ml. After contamination, the samples are carefully mixed by suction-discharge cycles to ensure homogeneous distribution of the microorganism. The whole is incubated at 22°C for 28 days.

[0029] Sampling and counting of the microbial population are carried out at 24 hours, 7, 14, 21 and 28 days for each microbial strain. The contaminated samples are taken and then deposited in serial dilutions in microtiter plates, in the presence of culture medium, which is a saline solution at 0.85% sodium chloride, and a reagent revealing dehydrogenase activity, which is 2,3,5-triphenyltetrazolium chloride (noted TTC). The results are presented in the following pages with the evolution of the microbial population over the 28 days of study, for the microbial strain tested.

[0030] Microbial population measurements in the samples taken at each time point are performed using the following microtitration method for one sample. In the 96 wells of a 250 µL volume of a microtitration plate, 20 µL of the sample are diluted by a factor of 10 by dispersion in 180 µL of Letheen broth (Difco, ref 268110) containing 1.5% Tween 80 (Sigma, ref P1754) and TTC (Sigma, ref T8877). The microtiter plate is incubated for 48 hours at 32.5°C, and the growth of the microorganisms is monitored by the color change, from colorless to red / pink. The highest reciprocal dilution indicating growth allows the determination of the log number of each microorganism at each time point.

[0031] The microbial population measurements taken at each sampling time are expressed in colony-forming units / ml. [Table 1] Bactericidal effect of isosorbide on the strain Propionobacterium acnes Number of colony-forming strains after: Dose Innoculum 24 h 7 days 14 days 21 days 28 days Positive witness 3,98.10 5< 4,00.10 3< 7,00.10 4< 4,00.10 4< 1,00.10 4< 1,00.10 4< Negative witness 3,98.10 5< 0 0 0 0 0 1 % 3,98.10 5< 0 0 0 0 0 5% 3,98.10 5< 0 0 0 0 0 9% 3,98.10 5< 0 0 0 0 0

[0032] After 24 hours, no colony-forming strains were observed: isosorbide had killed the entire inoculum. Isosorbide is bactericidal for the strain Propionobacterium acnes. [Table 2] Antifungal effect of isosorbide on the strain Malassezia furfur Number of colony-forming strains after: Isosorbide dose Innoculum 24 h 7 days 14 days 21 days 28 days Positive witness 1,5.10 4< 4,00.10 3< 1,00.10 3< 7,00.10 2< 1,00.10 3< 1,00.10 3< Negative witness 1,5.10 4< 0 0 0 0 0 1 % 1,5.10 4< 0 0 0 0 0 5% 1,5.10 4< 0 0 0 0 0 9% 1,5.10 4< 0 0 0 0 0

[0033] After 24 hours, no colony-forming strains were observed: isosorbide had killed the entire inoculum. Isosorbide is bactericidal for the strain Malassezia furfur. [Table 3] Bactericidal effect of isosorbide on the strain Corynobacterium xerosis Number of colony-forming strains after: Dose Innoculum 24 h 7 days 14 days 21 days 28 days Positive witness 3,2.10 5< 7,00.10 4< 1,00.10 4< 7,00.10 3< 4,00.10 3< 7,00.10 3< Negative witness 3,2.10 5< 0 0 0 0 0 1 % 3,2.10 5< 4.10 2< 0 0 0 0 5% 3,2.10 5< 1.10 2< 0 0 0 0 9% 3,2.10 5< 3,7.10 2< 0 0 0 0

[0034] After 24 hours, the number of colony-forming strains is reduced by at least three log 10 for the three doses tested. After 7 days, there are no more colony-forming strains: isosorbide is a moderate bactericide of the strain Corynobacterium xerosis. [Table 4] Bactericidal effect of isosorbide on the strain Staphylococcus epidermis Number of colony-forming strains after: Dose Innoculum 24 h 7 days 14 days 21 days 28 days Positive witness 1,43.10 5< 7,00.10 4< 4,00.10 4< 7,00.10 4< 1,00.10 5< 1,00.10 5< Negative witness 1,43.10 5< 0 0 0 0 0 1 % 1,43.10 5< 4.10 3< 0 0 0 0 5% 1,43.10 5< 1.10 3< 0 0 0 0 9% 1,43.10 5< 7.10 2< 0 0 0 0

[0035] After 24 hours, the number of colony-forming strains is reduced by at least two log 10 for the three doses tested. After 7 days, there are no more colony-forming strains: isosorbide is a weak bactericide of the strain Staphylococcus epidermis.

[0036] The invention is not limited to the examples described above, only by way of example, but it encompasses all the variants that a person skilled in the art may envisage within the framework of the protection sought.

Claims

1. A use of at least one dianhydrohexitol to limit or prevent the proliferation of microorganisms of the human cutaneous microbiome in a cosmetic or dermatological preparation for topical use.

2. The use according to the preceding claim, characterised in that the microorganisms are selected from among bacteria and fungi, and are preferably at the origin of the inactivation of cosmetic active ingredients, and / or the apparition of bad odours, and / or a change in texture of a cosmetic or dermatological preparation.

3. The use according to one of the preceding claims, characterised in that the dianhydrohexitol is selected from among isosorbide, isomannide, isoidide, preferably isosorbide.

4. The use according to one of the preceding claims, in a cosmetic or dermatological preparation with a dianhydrohexitol content of 0.1% to 50% by weight, preferably 0.5% to 25% by weight, more preferably 1% to 25% by weight, even more preferably 2% to 15% by weight, and most preferably 5% to 9% by weight, relative to the total weight of the composition.

5. The use according to one of the preceding claims, characterised in that said at least one dianhydrohexitol is a bacteriostatic and / or bactericidal and / or antifungal agent, and that it allows reducing or preventing the development of bacterial and / or fungal strains derived from the human topical microbiome, in said cosmetic or dermatological preparation.

6. The use according to one of claims 2 to 5, characterised in that the bacterial strain is selected from among the Propionobacterium spp family, preferably the bacterial strain is Propionobacterium acnes; and / or the bacterial strain is selected from among the Corynebacterium spp family, preferably the Corynebacterium xerosis bacterial strain; and / or the bacterial strain is selected from among the Staphylococcus spp family, preferably the bacterial strain is Staphylococcus epidermis; and in that the fungal strain is selected from among the Malassezia spp family, preferably the fungal strain is Malassezia furfur.