USE OF DIANHYDROHEXITOL TO ELIMINATE THE COSMETIC EFFECTS OF ACNE, DANDRUFF AND BAD ODORS

Abstract

The present application pertains to the field of cosmetics, more specifically the field of antimicrobial and/or bacteriostatic and/or bactericidal cosmetic agents, preferentially acting on bacterial and/or fungal strains on the human epidermis. Proposed is a use of dianhydrohexitol, preferentially isosorbide, to reduce the number of bacterial or fungal strains on the skin, in particular in the cutaneous microbiome, causing acne, dandruff buildup and bad odors.

Claims

1. A use of at least one dianhydrohexitol as bacteriostatic and/or bactericidal or/and antifungal agent.

2. The use of at least one dianhydrohexitol according to claim 1, wherein it has: bacteriostatic and/or bactericidal action on a bacterial strain selected among the Propionobacterium spp family, preferentially on the Propionobacterium acnes bacterial strain and/or on a strain of the Corynebacterium spp family, preferentially on the Corynebacterium xerosis bacterial strain, and/or on a strain of the Staphylococcus spp family, preferentially on the Staphylococcus epidermidis bacterial strain, and/or action on a strain of the Malassezia spp family, preferentially on the Malassezia furfur strain.

3. The use of at least one dianhydrohexitol according to claim 1, wherein the dianhydrohexitol is selected among isosorbide, isomannide, isoidide, preferentially isosorbide.

4. The use of at least one dianhydrohexitol according to claim 1, wherein the dianhydrohexitol concentration applied to the skin is at least 1 mg/cm.sup.2, preferentially at least 25 mg/cm.sup.2, and most preferentially at least 50 mg/cm.sup.2.

5. A non-therapeutic cosmetic use of at least one dianhydrohexitol according to claim 1, to promote the elimination of the cosmetic effects of acne.

6. The non-therapeutic cosmetic use according to claim 5, wherein the cosmetic effects of acne are selected among inflammation, or itching.

7. A dianhydrohexitol, for therapeutic use thereof in the treatment of acne.

8. The non-therapeutic cosmetic use according to claim 1, of at least one dianhydrohexitol to promote the elimination of the cosmetic effects of excessive flaking.

9. The non-therapeutic cosmetic use according to claim 8, wherein the cosmetic effects of excessive flaking are selected among inflammation, or itching.

10. A dianhydrohexitol, for therapeutic use thereof in the treatment of dandruff.

11. The non-therapeutic cosmetic use of at least one dianhydrohexitol according to claim 1, to reduce or prevent the formation of bad body odors, preferentially the bad odors resulting from the breakdown of sweat.

12. A dianhydrohexitol, for therapeutic use thereof in the treatment of bad body odors.

13. A non-therapeutic cosmetic method for caring for the skin or the scalp, comprising the following steps: cleaning the skin or the scalp, applying to the skin or scalp a cosmetic or dermatological preparation comprising at least one dianhydrohexitol, preferentially isosorbide, before, during or after the appearance of the cosmetic effects of acne or bad odors or dandruff, for a duration of at least 20 minutes, preferentially at least 2 hours, and most preferentially at least 6 hours, removing said preparation.

14. The non-therapeutic cosmetic method according to claim 13, for skin that is susceptible to bad odors, in particular linked to the breakdown of sweat by the cutaneous microbiome, wherein said preparation is applied to the skin under the arms or to the groin.

Description

DESCRIPTION OF EMBODIMENTS

[0016] It is to the applicant's credit to have discovered, unexpectedly, that non-derived dianhydrohexitols, preferentially isosorbide, have antimicrobial, and/or bactericidal and/or bacteriostatic, and/or antifungal effects on microbial strains that cause acne, dandruff buildup and bad body odors.

[0017] The use according to the invention makes it possible to inhibit the growth of pathogenic bacterial and/or fungal strains involved in acne, dandruff buildup and bad body odor formation, on the human epidermis, until these strains disappear from the human epidermis. The present invention relates to the use of at least one dianhydrohexitol as bacteriostatic and/or bactericidal and/or antifungal agent. Preferentially, the at least one dianhydrohexitol has:

[0018] bacteriostatic and/or bactericidal action on a bacterial strain selected among the Propionobacterium spp family, preferentially on the Propionobacterium acnes bacterial strain and/or on a strain of the Corynebacterium spp family, preferentially on the Corynebacterium xerosis bacterial strain, and/or on a strain of the Staphylococcus spp family, preferentially on the Staphylococcus epidermidis bacterial strain, and/or

[0019] action on a strain of the Malassezia spp family, preferentially on the Malassezia furfur strain.

[0020] Use of Dianhydrohexitol in the Treatment of Acne

[0021] The present invention relates to the non-therapeutic cosmetic use of at least one dianhydrohexitol to promote the elimination of the cosmetic effects of acne. The cosmetic effects of acne being selected among inflammation or itching. The invention also relates to dianhydrohexitol for use in the therapeutic treatment of acne. Preferentially the dianhydrohexitol is isosorbide.

[0022] According to another aspect, the invention proposes a use of isosorbide to reduce or eliminate the strains of Propionobacterium acnes (also referred to as Cutibacterium acnes) from the human microbiome, and also to attenuate or get rid of the cosmetic symptoms of acne, in particular redness, irritation and itching.

[0023] Preferentially, the use according to the invention makes it possible to reduce or eliminate inflammation, visible as redness for example at the acne comedones, and/or to reduce or eliminate skin itching localized on the acne comedones.

[0024] According to one preferred embodiment, the dianhydrohexitol is selected among isosorbide, isomannide, isoidide, preferentially isosorbide.

[0025] Additionally, the dianhydrohexitol concentration applied to the skin is at least 1 mg/cm.sup.2, preferentially at least 25 mg/cm.sup.2, and most preferentially at least 50 mg/cm.sup.2.

[0026] According to one embodiment, dianhydrohexitol has antimicrobial action. More particularly, dianhydrohexitol has bacteriostatic and/or bactericidal and/or antifungal action, reducing or preventing the growth, or eliminating the presence of bacterial and/or fungal strains involved in acne, preferentially the presence of bacterial strains. Preferentially, the bacterial strain is selected among the commensal propionic bacteria, the genus of which is commonly referred to as Propionobacterium spp, preferentially the bacterial strain is Propionobacterium acnes.

[0027] According to another embodiment of the use according to the invention, dianhydrohexitol is an agent to control the unwanted effects that commensal propionic bacteria have on the skin, preferentially of the Propionobacterium spp genus, and more preferentially Propionobacterium acnes.

[0028] According to an alternative use according to the invention, the at least one dianhydrohexitol can be used in combination with at least one other cosmetic or dermatological active agent having the same activity or function.

[0029] Use of Dianhydrohexitol in the Treatment of Dandruff

[0030] The present invention relates to the non-therapeutic cosmetic use of at least one dianhydrohexitol to promote the elimination of the cosmetic effects of excessive flaking. The cosmetic effects of excessive flaking being selected among inflammation or itching. The invention also relates to dianhydrohexitol for therapeutic use thereof in the treatment of dandruff. Preferentially the dianhydrohexitol is isosorbide.

[0031] According to another aspect, the invention proposes a use of isosorbide to reduce or eliminate the strains of Malassezia furfur from the human microbiome, in order to get rid of dandruff from the scalp, or to attenuate the buildup thereof, or to make it less visible by reducing its size or amount

[0032] Preferentially, the use according to the invention makes it possible to get rid of dandruff from the scalp, or to attenuate the buildup thereof, or to make it less visible by reducing its size or amount.

[0033] According to one preferred embodiment, the dianhydrohexitol is selected among isosorbide, isomannide, isoidide, preferentially isosorbide.

[0034] Additionally, the dianhydrohexitol concentration applied to the skin is at least 1 mg/cm.sup.2, preferentially at least 25 mg/cm.sup.2, and most preferentially at least 50 mg/cm.sup.2.

[0035] According to one embodiment, dianhydrohexitol has antimicrobial action. More particularly, dianhydrohexitol has bacteriostatic and/or bactericidal and/or antifungal action, reducing or preventing the growth, or eliminating the presence of bacterial and/or fungal strains involved in excessive skin flaking, preferentially in dandruff buildup in the scalp. Preferentially, the fungal strain is selected among the fungal strains of the Malassezia spp family, preferentially the fungal strain is Malassezia furfur.

[0036] According to another embodiment of the use according to the invention, dianhydrohexitol is an agent to control the unwanted effects that the fungal strains of the Malassezia spp family have on the skin and the scalp, preferentially on the Malassezia furfur bacterial strain. Among these unwanted effects, are dandruff buildup as mentioned above, but also pityriasis versicolor, seborrheic dermatitis, pityrosporum folliculitis.

[0037] According to an alternative use according to the invention, the at least one dianhydrohexitol can be used in combination with at least one other cosmetic or dermatological active agent having the same activity or function.

[0038] Use of Dianhydrohexitol in the Treatment of Bad Body Odors

[0039] The present invention relates to the non-therapeutic cosmetic use of at least one dianhydrohexitol in order to reduce or prevent bad body odors, preferentially the bad odors resulting from the breakdown of sweat. The invention also relates to dianhydrohexitol for the therapeutic use thereof in the treatment of bad body odors. Preferentially the dianhydrohexitol is isosorbide.

[0040] According to another aspect of the invention, a use of isosorbide is proposed to reduce or eliminate the Corynebacterium xerosis, and Staphylococcus epidermidis strains from the human microbiome, in order to attenuate or prevent the appearance of bad odors resulting from the breakdown of sweat by these microorganisms. Isosorbide is used alone, or in combination with other active agents already used for this purpose.

[0041] According to one preferred embodiment, the dianhydrohexitol is selected among isosorbide, isomannide, isoidide, preferentially isosorbide.

[0042] Additionally, the dianhydrohexitol concentration applied to the skin is at least 1 mg/cm.sup.2, preferentially at least 25 mg/cm.sup.2, and most preferentially at least 50 mg/cm.sup.2.

[0043] According to one embodiment, dianhydrohexitol has antimicrobial action. More particularly, dianhydrohexitol has bacteriostatic and/or bactericidal and/or antifungal action, reducing or preventing the growth, or eliminating the presence of bacterial and/or fungal strains involved in the formation of bad body odors. Preferentially, the bacterial strain is selected among the bacterial strains of the Corynebacterium spp family, preferentially the bacterial strain is Corynebacterium xerosis, and/or the bacterial strain is selected among the Staphylococcus spp family, preferentially the bacterial strain is Staphylococcus epidermidis, and/or the bacterial strain is selected among the Propiobacterium spp family, preferentially the bacterial strain is Propiobacterium acnes.

[0044] According to another embodiment of the use according to the invention, dianhydrohexitol is an agent for controlling the unwanted effects on the skin of bacterial strains of the Corynebacterium spp family, preferentially Corynebacterium xerosis, and/or of the Staphylococcus spp family, preferentially is Staphylococcus epidermidis, and/or of the Propiobacterium spp family, preferentially on Propiobacterium acnes. Among these unwanted effects, are bad odors as mentioned above, but also skin infections.

[0045] According to an alternative use according to the invention, the at least one dianhydrohexitol can be used in combination with at least one other cosmetic or dermatological active agent having the same activity or function.

[0046] Dianhydrohexitol

[0047] The aqueous solution in question can contain only one dianhydrohexitol, or can also 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 the mixtures of at least two of these products. Preferentially, the aqueous solution only contains one dianhydrohexitol which is isosorbide.

[0048] In this regard, the applicant indicates that generally, the dianhydrohexitols are synthesized in the presence of water (or water is generated during their synthesis): the recovery of said dianhydrohexitol in this reaction medium immediately provides a composition in the form of an aqueous solution of dianhydrohexitol which can be used according to the invention. Dianhydrohexitol solutions can in particular be obtained according to the methods described in above-mentioned patent applications EP1287000 and WO03/043959. The choice can be made to keep all or part of the water used during the preparation of the dianhydrohexitol or to eliminate all the water so as to obtain a product in solid form that will be put back into an aqueous solution by simply adding water, which is another possibility for preparing an aqueous solution of dianhydrohexitol that can be used according to the invention.

[0049] 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 1,4-3,6-dianhydrohexitol ethers or esters.

[0050] According to one preferred embodiment, the dianhydrohexitol is selected among isosorbide, isomannide, isoidide, preferentially isosorbide.

[0051] Cosmetic or Dermatological Preparation

[0052] By “cosmetic or dermatological preparation”, the applicant means any composition intended for being placed in contact with human or animal skin.

[0053] The cosmetic or dermatological preparation according to the invention comprises as active agent for the non-therapeutic treatment of acne, at least one dianhydrohexitol, preferentially selected among isosorbide, isomannide, isoidide, preferentially isosorbide.

[0054] The cosmetic or dermatological preparation according to the invention comprises as active agent for the non-therapeutic treatment of dandruff, at least one dianhydrohexitol, preferentially selected among isosorbide, isomannide, isoidide, preferentially is isosorbide.

[0055] The cosmetic or dermatological preparation for topical use according to the invention comprises as active agent for the non-therapeutic treatment of bad odors, at least one dianhydrohexitol, preferentially selected among isosorbide, isomannide, isoidide, preferentially is isosorbide.

[0056] Additionally, the dianhydrohexitol concentration applied to the skin or scalp is at least 1 mg/cm2, preferentially at least 25 mg/cm2, and most preferentially at least 50 mg/cm2.

[0057] According to one preferred embodiment, the cosmetic or dermatological preparation according to the invention comprises 0.1% to 50% by weight of dianhydrohexitol, preferentially 0.5 to 25%, more preferentially 1% to 25%, even more preferentially 2% to 15%, and most preferentially 5% to 9%.

[0058] According to a highly preferred embodiment, the cosmetic or dermatological preparation according to the invention contains as the sole antimicrobial and/or bactericidal and/or bacteriostatic and/or antifungal agent, at least one dianhydrohexitol, preferentially selected among isosorbide, isomannide, isoidide, preferentially is isosorbide.

[0059] The cosmetic or dermatological preparation according to the invention makes it possible to reduce or eliminate redness and/or itching caused by acne, to get rid of dandruff from the scalp, or to attenuate its buildup, or to make it less visible by reducing its size or amount, to reduce or prevent bad body odors, preferentially the bad odors resulting from the breakdown of sweat.

[0060] The cosmetic preparation can be a skin product, a hair product, make-up or a hygiene product.

[0061] Among the skincare products, the cosmetic preparation according to the invention can be selected among day creams, sun creams, after-sun creams, self-tanners, masks. Among the hair care products, the cosmetic preparation according to the invention is preferentially selected among shampoos, conditioners (creams, masks, lotions), styling products (sprays, gels, waxes), coloring products. Among the make-up products, the cosmetic preparation according to the invention is preferentially chosen among foundations and eye shadows. Among the hygiene products, the cosmetic preparation according to the invention is preferentially chosen among washing gels, shower gels, cleansing or make-up removing wipes, hydroalcoholic solutions or gels, soaps, deodorants, antiperspirants, body sprays, more preferentially, among deodorants or antiperspirants, which can be in stick, gel, powder or spray form.

[0062] The cosmetic or dermatological preparation can in particular be selected among anti-acne creams or lotions.

[0063] The cosmetic or dermatological preparation can in particular be selected among anti-dandruff shampoos, anti-dandruff body and hair shower gels.

[0064] Non-Therapeutic Treatment Method

[0065] The invention proposes a non-therapeutic cosmetic method for caring for the skin or the scalp, comprising the following steps:

[0066] cleaning the skin or the scalp,

[0067] applying to the skin or scalp a cosmetic or dermatological preparation comprising at least one dianhydrohexitol, preferentially isosorbide, before, during or after the appearance of the cosmetic effects of acne or bad odors or dandruff, for a duration of at least 20 minutes, preferentially at least 2 hours, and most preferentially at least 6 hours,

[0068] removing said preparation.

[0069] The invention proposes a non-therapeutic cosmetic method for caring for skin that is susceptible to acne, which comprises the steps of:

[0070] cleaning the skin,

[0071] applying to the skin a cosmetic or dermatological preparation comprising at least one dianhydrohexitol, preferentially isosorbide, before, during or after the appearance of the cosmetic effects of acne, for a duration of at least 20 minutes, preferentially at least 2 hours, and most preferentially at least 6 hours,

[0072] removing said preparation.

[0073] The invention proposes a non-therapeutic cosmetic method for caring for the scalp, which comprises the steps of:

[0074] cleaning the scalp,

[0075] applying to the scalp a cosmetic or dermatological preparation comprising at least one dianhydrohexitol, preferentially isosorbide, before, during or after the appearance of dandruff, for a duration of at least 20 minutes, preferentially at least 2 hours, and most preferentially at least 6 hours,

[0076] removing said preparation.

[0077] The invention proposes a non-therapeutic cosmetic method for caring for skin that is susceptible to bad odors, in particular linked to the breakdown of sweat by the cutaneous microbiome, comprising the steps of:

[0078] cleaning the skin,

[0079] applying to the skin a cosmetic or dermatological preparation comprising at least one dianhydrohexitol, preferentially isosorbide, preferentially under the arms or to the groin, before, during or after the appearance of bad odors, for a duration of at least 20 minutes, preferentially at least 2 hours, and most preferentially at least 6 hours,

[0080] removing said composition.

EXAMPLE

Example 1: In Vitro Measurements of the Effect of Isosorbide on Microbial Strains that Cause Acne

[0081] The samples are prepared under sterile conditions and deposited in microplates (2-ml wells) with the concentrations hereunder. Two analysis controls were produced:

[0082] a positive control corresponding to 0.5% Phenonip®;

[0083] a negative control consisting of 0.85% physiological saline solution.

[0084] Samples and controls are contaminated by a Propionobacterium acnes bacterial strain with around 1.43×10.sup.5 to 4.15×10.sup.5 colony forming units per milliliter, denoted cfu/ml. After contamination, the samples are carefully mixed by suction-discharge cycles in order to ensure a uniform distribution of the microorganism. The whole is incubated at 22° C. during 28 days.

[0085] The microbial population is sampled and counted at 24 hours, 7, 14, 21 and 28 days for the Propionobacterium acnes bacterial strain. The contaminated samples are collected and then deposited in serial dilutions in microtiter plates, in the presence of culture medium, which is a saline solution with 0.85% sodium chloride, and a dehydrogenase activity indicator reagent, which is 2,3,5-triphenyltetrazolium chloride (denoted TTC). The results are presented in the following pages with the variation of the microbial population over the 28 days of study, for the tested microbial strain.

[0086] The measurements of microbial populations in the samples collected at each time, are carried out according to the following microtiter method, for one sample collection. In the 96 wells with a volume of 250 μL of a microtiter plate, 20 μL of the collected sample are diluted by a factor of 10 by dispersion in 180 μL of Letheen broth (Difco, ref. 268110) containing 1.5% of Tween 80 (Sigma, ref. P1754) and TTC (Sigma, ref. T8877). The microplate 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 a growth makes it possible to determine the log number of each microorganism at each time.

[0087] The measurements of microbial populations taken at each collection time are expressed as colony forming units/ml.

TABLE-US-00001 TABLE 1 Bactericidal effect of isosorbide on the Propionobacterium acnes strain Number of colony forming strains after: Dose Inoculum 24 h 7 days 14 days 21 days 28 days Positive 3.98 × 10.sup.5 4.00 × 10.sup.3 7.00 × 10.sup.4 4.00 × 10.sup.4 1.00 × 10.sup.4 1.00 × 10.sup.4 control Negative 3.98 × 10.sup.5 0 0 0 0 0 control 1% 3.98 × 10.sup.5 0 0 0 0 0 5% 3.98 × 10.sup.5 0 0 0 0 0 9% 3.98 × 10.sup.5 0 0 0 0 0

[0088] After 24 hours, no colony forming strain is observed: isosorbide made it possible to kill the entire inoculum. Isosorbide is a bactericide of the Propionobacterium acnes strain.

Example 2: In Vitro Measurements of the Effect of Isosorbide on Microbial Strains that Cause Dandruff

[0089] The samples are prepared under sterile conditions and deposited in microplates (2-ml wells) with the concentrations hereunder. Two analysis controls were produced:

[0090] a positive control corresponding to 0.5% Phenonip®;

[0091] a negative control consisting of 0.85% physiological saline solution.

[0092] Samples and controls are contaminated by a Malassezia furfur fungal strain with around 1.50×10.sup.4 to 3.80×10.sup.4 colony forming units per milliliter, denoted cfu/ml. After contamination, the samples are carefully mixed by suction-discharge cycles in order to ensure a uniform distribution of the microorganism. The whole is incubated at 22° C. during 28 days.

[0093] The microbial population is sampled and counted at 24 hours, 7, 14, 21 and 28 days for the bacterial strain. The contaminated samples are collected and then deposited in serial dilutions in microtiter plates, in the presence of culture medium, which is a saline solution with 0.85% sodium chloride, and a dehydrogenase activity indicator reagent, which is 2,3,5-triphenyltetrazolium chloride (denoted TTC). The results are presented in the following pages with the variation of the microbial population over the 28 days of study, for the tested microbial strain.

[0094] The measurements of microbial populations in the samples collected at each time, are carried out according to the following microtiter method, for one sample collection. In the 96 wells with a volume of 250 μL of a microtiter plate, 20 μL of the collected sample are diluted by a factor of 10 by dispersion in 180 μL of Letheen broth (Difco, ref. 268110) containing 1.5% of Tween 80 (Sigma, ref. P1754) and TTC (Sigma, ref. T8877). The microplate 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 a growth makes it possible to determine the log number of each microorganism at each time.

[0095] The measurements of microbial populations taken at each collection time are expressed as colony forming units/ml.

TABLE-US-00002 TABLE 2 Antifungal effect of isosorbide on the Malassezia furfur strain Dose of Number of colony forming strains after: isosorbide Innoculum 24 h 7 days 14 days 21 days 28 days Positive 1.5 × 10.sup.4 4.00 × 10.sup.3 1.00 × 10.sup.3 7.00 × 10.sup.2 1.00 × 10.sup.3 1.00 × 10.sup.3 control Negative 1.5 × 10.sup.4 0 0 0 0 0 control 1% 1.5 × 10.sup.4 0 0 0 0 0 5% 1.5 × 10.sup.4 0 0 0 0 0 9% 1.5 × 10.sup.4 0 0 0 0 0

[0096] After 24 hours, no colony forming strain is observed: isosorbide made it possible to kill the entire inoculum. Isosorbide is a bactericide of the Malassezia furfur strain.

Example 3: In Vitro Measurements of the Effect of Isosorbide on Microbial Strains that Cause Bad Body Odors

[0097] The samples are prepared under sterile conditions and deposited in microplates (2-ml wells) with the concentrations hereunder. Two analysis controls were produced:

[0098] a positive control corresponding to 0.5% Phenonip®;

[0099] a negative control consisting of 0.85% physiological saline solution.

[0100] Samples and controls are contaminated by three bacterial strains, Staphylococcus epidermidis, Corynebacterium xerosis and Propionobacterium acnes, with around 1.43×10.sup.5 to 4.15×10.sup.5 colony forming units per milliliter, denoted cfu/ml. After contamination, the samples are carefully mixed by suction-discharge cycles in order to ensure a uniform distribution of the microorganism. The whole is incubated at 22° C. during 28 days.

[0101] The microbial population is sampled and counted at 24 hours, 7, 14, 21 and 28 days for each bacterial strain. The contaminated samples are collected and then deposited in serial dilutions in microtiter plates, in the presence of culture medium, which is a saline solution with 0.85% sodium chloride, and a dehydrogenase activity indicator reagent, which is 2,3,5-triphenyltetrazolium chloride (denoted TTC). The results are presented in the following pages with the variation of the microbial population over the 28 days of study, for the tested microbial strain.

[0102] The measurements of microbial populations in the samples collected at each time, are carried out according to the following microtiter method, for one sample collection. In the 96 wells with a volume of 250 μL of a microtiter plate, 20 μL of the collected sample are diluted by a factor of 10 by dispersion in 180 μL of Letheen broth (Difco, ref. 268110) containing 1.5% of Tween 80 (Sigma, ref. P1754) and TTC (Sigma, ref. T8877). The microplate 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 a growth makes it possible to determine the log number of each microorganism at each time.

[0103] The measurements of microbial populations taken at each collection time are expressed as colony forming units/ml.

TABLE-US-00003 TABLE 3 Bactericidal effect of isosorbide on the Corynobacterium xerosis strain Number of colony forming strains after: Dose Inoculum 24 h 7 days 14 days 21 days 28 days Positive 3.2 × 10.sup.5 7.00 × 10.sup.4 1.00 × 10.sup.4 7.00 × 10.sup.3 4.00 × 10.sup.3 7.00 × 10.sup.3 control Negative 3.2 × 10.sup.5 0 0 0 0 0 control 1% 3.2 × 10.sup.5   4 × 10.sup.2 0 0 0 0 5% 3.2 × 10.sup.5   1 × 10.sup.2 0 0 0 0 9% 3.2 × 10.sup.5  3.7 × 10.sup.2 0 0 0 0

[0104] After 24 hours, the number of colony forming strains is reduced by at least 3 log 10 for the three doses tested. After 7 days, there is not any more colony forming strain: isosorbide is a moderate bactericide of the Corynobacterium xerosis strain.

TABLE-US-00004 TABLE 4 Bactericidal effect of isosorbide on the Staphylococcus epidermidis strain Number of colony forming strains after: Dose Inoculum 24 h 7 days 14 days 21 days 28 days Positive 1.43 × 10.sup.5 7.00 × 10.sup.4 4.00 × 10.sup.4 7.00 × 10.sup.4 1.00 × 10.sup.5 1.00 × 10.sup.5 control Negative 1.43 × 10.sup.5 0 0 0 0 0 control 1% 1.43 × 10.sup.5   4 × 10.sup.3 0 0 0 0 5% 1.43 × 10.sup.5   1 × 10.sup.3 0 0 0 0 9% 1.43 × 10.sup.5   7 × 10.sup.2 0 0 0 0

[0105] After 24 hours, the number of colony forming strains is reduced by at least 2 log 10 for the three doses tested. After 7 days, there is not any colony forming strain: isosorbide is a weak bactericide of the Staphylococcus epidermidis strain.

TABLE-US-00005 TABLE 5 Bactericidal effect of isosorbide on the Propionobacterium acnes strain Number of colony forming strains after: Dose Inoculum 24 h 7 days 14 days 21 days 28 days Positive 3.98 × 10.sup.5 4.00 × 10.sup.3 7.00 × 10.sup.4 4.00 × 10.sup.4 1.00 × 10.sup.4 1.00 × 10.sup.4 control Negative 3.98 × 10.sup.5 0 0 0 0 0 control 1% 3.98 × 10.sup.5 0 0 0 0 0 5% 3.98 × 10.sup.5 0 0 0 0 0 9% 3.98 × 10.sup.5 0 0 0 0 0

[0106] After 24 hours, no colony forming strain is observed: isosorbide made it possible to kill the entire inoculum. Isosorbide is a bactericide of the Propionobacterium acnes strain.

[0107] The invention is not limited to the examples described above, given only by way of example, but it encompasses all the alternatives that a person skilled in the art could contemplate in the context of the sought protection.