ANTIMICROBIAL MIXTURE CONTAINING 4-(3-ETHOXY-4-HYDROXYPHENYL)BUTAN-2-ONE AND AN AMMONIUM COMPOUND, AND COSMETIC COMPOSITION CONTAINING SAME

Abstract

The invention relates to an antimicrobial mixture containing 4-(3-ethoxy-4-hydroxy-phenyl)butan-2-one and an ammonium compound chosen from a fatty-chain C.sub.20 to C.sub.24 tri-methylammonium salt and a (C.sub.8-C.sub.28)alkyldimethylbenzylammonium salt, and also to a cosmetic composition containing such a mixture. Use into caring for, making up and cleansing keratin materials.

Claims

1. An antimicrobial mixture comprising 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one and an ammonium compound chosen from: i) an alkyltrimethylammonium salt of formula RN.sup.+(CH.sub.3).sub.3 X.sup. (I) in which R denotes an alkyl group containing from 20 to 24 carbon atoms, X.sup. denotes a halide ion or a methosulfate ion; ii)

2. The antimicrobial mixture according to claim 1, wherein the ammonium compound is the alkyltrimethylammonium salt of formula (I).

3. The antimicrobial mixture according to claim 2, wherein for the trimethyl ammonium salt of formula (I), R is a behenyl group.

4. The antimicrobial mixture according to claim 2, wherein the alkyltrimethylammonium salt (I) is behenyltrimethylammonium chloride.

5. The antimicrobial mixture according to claim 2, which comprises 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one and the alkyltrimethylammonium salt of formula (I) in amounts such that the 4-(3-ethoxy-4-hydroxyphenyl) butan-2-one/salt (I) weight ratio ranges from 0.08 to 80.

6. The antimicrobial mixture according to claim 2, which has a 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one/alkyltrimethylammonium salt (I) weight ratio ranging from 10 to 60.

7. The antimicrobial mixture according to claim 2, which has a 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one/alkyltrimethylammonium salt (I) weight ratio ranging from 0.08 to 5.

8. The antimicrobial mixture according to claim 2, which has a 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one/alkyltrimethylammonium salt (I) weight ratio ranging from 3 to 80.

9. The antimicrobial mixture according to claim 1, wherein the ammonium compound is the alkyldimethylbenzylammonium salt of formula (II).

10. The antimicrobial mixture according to claim 9, wherein, for the alkyldimethylbenzylammonium salt of formula (II), R is an alkyl group comprising from 10 to 16 carbon atoms.

11. The antimicrobial mixture according to claim 9, wherein the alkyldimethylbenzylammonium salt (II) is an alkyldimethylbenzylammonium chloride.

12. The antimicrobial mixture according to claim 9, wherein the alkyldimethylbenzylammonium salt (II) is a mixture of lauryldimethylbenzylammonium chloride and myristyldimethylbenzylammonium chloride.

13. The antimicrobial mixture according to claim 12, wherein the alkyldimethylbenzylammonium salt (II) is chosen from the following mixtures: a) a mixture comprising from 60 mol % to 80 mol % of lauryldimethylbenzylammonium chloride and 20 mol % to 40 mol % of myristyldimethylbenzylammonium chloride b) a mixture comprising from 65 mol % to 75 mol % of lauryldimethylbenzylammonium chloride and 25 mol % to 35 mol % of myristyldimethylbenzylammonium chloride c) a mixture comprising from 68 mol % to 72 mol % of lauryldimethylbenzylammonium chloride and 28 mol % to 32 mol % of myristyldimethylbenzylammonium chloride d) a mixture comprising 70 mol % of lauryldimethylbenzylammonium chloride and 30 mol % of myristyldimethylbenzylammonium chloride.

14. The antimicrobial mixture according to claim 9, which comprises 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one and the alkyldimethylbenzylammonium salt of formula (II) in amounts such that the 4-(3-ethoxy4-hydroxyphenyl)butan-2-one/salt (II) weight ratio ranges from 5 to 120.

15. A composition comprising, in a physiologically acceptable medium, an antimicrobial mixture according to claim 1.

16. The composition according to claim 15, which comprises at least one additional ingredient chosen from water, oils, polyols containing from 2 to 10 carbon atoms, gelling agents, surfactants, film-forming polymers, dyestuffs, fragrances, fillers, UV-screening agents, plant extracts, cosmetic and dermatological active agents, and salts.

17. The composition according to claim 15, wherein the 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one is present in a content ranging from 0.01% to 5% by weight relative to the total weight of the composition.

18. A non-therapeutic cosmetic treatment process for caring for and/or making up and/or cleansing keratin materials, comprising the application to said keratin materials of a composition according to claim 15.

19. A process for conserving a composition comprising a physiologically acceptable medium which incorporating into said composition an antimicrobial mixture as defined in claim 1.

20. (canceled)

21. A non-therapeutic cosmetic treatment process for caring for and/or making up and/or cleansing keratin materials, comprising the application to said keratin materials of a composition according to claim 16.

Description

EXAMPLE 1: DETERMINATION OF THE SYNERGISTIC ANTIMICROBIAL ACTIVITY AS MIC

[0059] The demonstration of a synergistic antimicrobial activity effect with a mixture of 4-(3-ethoxy4-hydroxyphenyl)butan-2-one (referred to as substance A) and of ammonium compound (referred to as substance B) is performed by calculating the synergy index (or FIC index).

Formulation

[0060]
FIC Index=(MICa with B/MICa)+(MICb with A/MICb)

with: [0061] MICa with B: minimum concentration of product A in the combination A+B which makes it possible to obtain an inhibitory effect [0062] MICb with A: minimum concentration of product B in the combination A+B which makes it possible to obtain the inhibitory effect. [0063] MICa: minimum inhibitory concentration of product A alone. [0064] MICb: minimum inhibitory concentration of product B alone.

[0065] This formula was described for the first time in the article by F. C. Kull, P. C. Eisman, H. D. Sylwestrowka, and R. L. Mayer, Applied Microbiology 9:538-541, 1961.

[0066] For each compound tested alone, the MIC is considered as the first concentration which makes it possible to obtain a microbial growth percentage of less than or equal to 25%.

[0067] As regards the combinations tested, MICa with b and MICb 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:

[0068] When the FIC index value is less than or equal to 1, it is considered that the combination of test compounds has a synergistic effect.

[0069] The results obtained are summarized in the following tables.

[0070] The combination of compounds A and B was tested on the following strains or a part of these strains: Aspergillus niger, Candida albicans, Pseudomonas aeruginosa.

[0071] The microbial strain Aspergillus niger ATCC 6275, and a double-concentration Sabouraud broth liquid culture medium supplemented with polyoxyethylenated (20 OE) sorbitan monopalmitate (Tween 40 from Croda) and Phytagel BioReagent were used.

[0072] The microbial strain Candida albicans ATCC 10231 and a double-concentration Sabouraud broth liquid culture medium were used.

[0073] The microbial strain Pseudomonas aeruginosa ATCC 9027 and a double-concentration nutritive broth liquid culture medium were used.

[0074] A 96-well microplate and an incubation time of 32.5 C. are used.

[0075] The incubation time of the microplate is: [0076] from 24 hours to 48 hours aerobically for Aspergillus niger; [0077] from 18 to 24 hours aerobically for Candida albicans and Pseudomonas aeruginosa.

Tests

[0078] For each compound:

[0079] A=4-(3-ethoxy-4-hydroxyphenyl)-2-butanone compound

[0080] B=behenyltrimethylammonium chloride (as a mixture at 79% by weight with 18% of isopropyl alcohol and 3% of water sold under the name Genamin KDMF by the company Clariant*) [0081] It is considered that the isopropyl alcohol present has no influence on the MIC results obtained.

[0082] A 10% (weight/volume) stock solution was prepared by mixing 1 g of compound in 9 ml of aqueous 1% agar solution. Successive dilutions were made with the 1% agar solution. [0083] Tests of compounds A and B alone

[0084] 50 L of each of the daughter solutions obtained containing compound A or B are added to the microplate wells. 100 L of Sabouraud liquid nutrient broth seeded with the strain Aspergillus niger and 50 L of aqueous 1% agar solution are also added thereto. [0085] Tests of compounds A and B as a mixture

[0086] 50 L of each of the daughter solutions obtained containing compound A and 50 L of each of the daughter solutions obtained containing compound B are added to the microplate wells. 100 L of Sabouraud liquid nutrient broth seeded at double concentration with the strain Aspergillus niger are also added thereto.

Microbial Growth Control

[0087] A positive microbial growth control was also prepared. The positive microbial growth control corresponds to a mixture of 100 L of aqueous 1% agar solution with 100 L of Sabouraud liquid nutrient broth seeded at double concentration with the strain Aspergillus niger in the absence of compounds A and B.

Absorbance Control of Compounds A and B Alone

[0088] An absorbance control was performed in parallel on compounds A and B alone. This control corresponds to 100 L of double concentration sterile Sabouraud liquid nutrient broth+100 L of double concentration compound A or B.

[0089] In the three cases (absorbance control, growth control and test), the final volume present in each of the microplate wells is 200 L.

[0090] In the two cases (test and control), the inoculum represents the concentration of the strain Aspergillus niger present in the final volume of the wells (200 L) and is between 2 and 610.sup.5 cfu/ml of Aspergillus niger.

[0091] The minimum inhibitory concentration (MIC) of each compound A and B alone and in combination was determined in a known manner by means of optical density measurements at a wavelength of 620 nm.

[0092] The test as described above (tests, absorbance control and growth control) was performed again to test the combination A+B on the strains Candida albicans and Pseudomonas aeruginosa.

[0093] The following results were obtained with

[0094] B1=behenyltrimethylammonium chloride (as a mixture at 79% by weight with 18% of isopropyl alcohol and 3% of water sold under the name Genamin KDMF by the company Clariant*) [0095] It is considered that the isopropyl alcohol present has no influence on the MIC results obtained.
Candida albicans

TABLE-US-00001 Concentrations tested (in weight %) 0 A 0.025 A 0.05 A 0.1 A 0.2 A 0 B1 73 73 49 9 0.002 B1 50 13 8 14 1 (FIC 0.63) (FIC 0.75) (FIC 1) 0.00395 B1 1 0 0 1 1 % MIC % MIC MIC of each compound of A of B1 as a mixture alone alone A % B1 % FIC Index Ratio A/B1 0.2 0.00395 0.025 0.002 0.63 12.5

[0096] The results obtained show synergistic inhibitory activity for the mixtures:

[0097] i) 0.025% of A and 0.002% of B1, i.e. ratio A/B1=12.5

[0098] ii) 0.05% of A and 0.002% of B1, i.e. ratio A/B1=25

[0099] iii) 0.1% of A and 0.002% of B1, i.e. ratio A/B1=50

Aspergillus niger

TABLE-US-00002 Concentrations tested (in weight %) 0 A 0.025 A 0.05 A 0.1 A 0.2 A 0.4 A 0 B1 150 113 112 75 5 0.049 B1 186 138 178 8 7 15 (FIC 0.31) (FIC 0.56) 0.1 B1 155 139 114 18 7 8 (FIC 0.37) (FIC 0.62) 0.2 B1 78 131 100 15 21 9 (FIC 0.49) (FIC 0.74) 0.4 B1 34 66 14 19 14 10 (FIC 0.60) (FIC 0.73) (FIC 0.98) 0.79 B1 8 20 26 35 20 50 MIC of each % MIC % MIC compound as a mixture of A alone of B1 alone A % B1 % FIC Index Ratio A/B1 0.4 0.79 0.1 0.049 0.31 2

[0100] The results obtained show synergistic inhibitory activity for the mixtures:

[0101] i) 0.05% of A and 0.4% of B1, i.e. ratio A/B1=0.125

[0102] ii) 0.1% of A and 0.4% of B1, i.e. ratio A/B1=0.25

[0103] iii) 0.1% of A and 0.2% of B1, i.e. ratio A/B1=0.5

[0104] iv) 0.1% of A and 0.1% of B1, i.e. ratio A/B1=1

[0105] v) 0.1% of A and 0.049% of B1, i.e. ratio A/B1=2

[0106] vi) 0.2% of A and 0.4% of B1, i.e. ratio A/B1=0.5

[0107] vii) 0.2% of A and 0.2% of B1, i.e. ratio A/B1=1

[0108] viii) 0.2% of A and 0.1% of B1, i.e. ratio A/B1=2

[0109] ix) 0.2% of A and 0.049% of B1, i.e. ratio A/B1=4

Pseudomonas aeruginosa

TABLE-US-00003 concentrations tested (in weight %) 0 A 0.0625 A 0.125 A 0.25 A 0.5 A 1 A 0 B1 114 59 65 41 15 0.001975 B1 68 85 64 49 45 49 0.00395 B1 93 65 75 52 51 21 0.0079 B1 36 35 31 25 18 8 (FIC 0.75) 0.0158 B1 30 5 0 1 0 40 (FIC 0.56) (FIC 0.63) (FIC 0.75) (FIC 1) 0.0316 B1 1 3 2 0 4 34 MIC of each % MIC % MIC compound as a mixture of A alone of B1 alone A % B1 % FIC Index Ratio A/B1 1 0.0316 0.0625 0.0158 0.56 3.95

[0110] The results obtained show synergistic inhibitory activity for the mixtures:

[0111] i) 0.0625% of A and 0.0158% of B1, i.e. ratio A/B1=3.95

[0112] ii) 0.125% of A and 0.0158% of B1, i.e. ratio A/B1=7.91

[0113] iii) 0.25% of A and 0.0158% of B1, i.e. ratio A/B1=15.82

[0114] iv) 0.5% of A and 0.0158% of B1, i.e. ratio A/B1=31.64

[0115] v) 0.5% of A and 0.0079% of B1, i.e. ratio A/B1=63.29

EXAMPLE 2: DETERMINATION OF THE SYNERGISTIC ANTIMICROBIAL ACTIVITY AS MIC

[0116] The demonstration of a synergistic antimicrobial activity effect with a mixture of 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one (referred to as substance A) and of (C.sub.12-C.sub.14)alkyldimethylbenzylammonium chloride (referred to as substance B2) is performed according to the protocol described in Example 1, using the strain Aspergillus niger.

[0117] B2=(C.sub.12-C.sub.14)alkyldimethylbenzylammonium chloride=mixture of 70 mol % of benzyldimethyldodecylammonium chloride and 30 mol % of benzyldimethyltetradecylammonium chloride (sold under the name Benzalkonium chloride product No. 12060 by the company Sigma-Aldrich)

[0118] The following results were obtained:

Aspergillus niger

TABLE-US-00004 Concentrations tested (in weight %) 0 A 0.025 A 0.05 A 0.1 A 0.2 A 0.4 A 0 B2 212 92 68 29 17 0.0025 B2 194 159 92 2 2 1 (FIC 0.5) (FIC 0.75) 0.005 B2 194 164 2 2 2 2 (FIC 0.63) (FIC 0.75) (FIC 1) 0.01 B2 2 2 2 2 2 2 MIC of each % MIC % MIC compound as a mixture of A alone of B2 alone A % B2 % FIC Index Ratio A/B2 0.4 0.01 0.05 0.005 0.63 10

[0119] The results obtained show synergistic inhibitory activity for the mixtures:

[0120] i) 0.05% of A and 0.005% of B2, i.e. ratio A/B2=10

[0121] ii) 0.1% of A and 0.005% of B2, i.e. ratio A/B2=20

[0122] iii) 0.1% of A and 0.0025% of B2, i.e. ratio A/B2=40

[0123] iv) 0.2% of A and 0.005% of B2, i.e. ratio A/B2=40

[0124] v) 0.2% of A and 0.0025% of B2, i.e. ratio A/B2=80