WO2009071776A2

WO2009071776A2 - Antimicrobial composition that can be used in cosmetics and in dermatology

Info

Publication number: WO2009071776A2
Application number: PCT/FR2008/001346
Authority: WO
Inventors: Nadine Leconte
Original assignee: Laboratoire Nuxe
Priority date: 2007-09-28
Filing date: 2008-09-26
Publication date: 2009-06-11
Also published as: WO2009071776A3; FR2921558B1; FR2921558A1; EP2200432A2

Abstract

The invention concerns a novel antimicrobial composition. The composition comprises a combination of a lipoamino acid preferably comprising an alkylated chain containing from 8 to 18 carbon atoms, a hydroxylated fatty acid containing from 8 to 12 carbon atoms, such as 10-hydroxydecanoic acid, and an alkyl ether of glycerol such as ethylhexyl glycerol and dodecyl glycerol. Use as a preservative in cosmetic and dermatological compositions.

Description

ANTIMICROBIAL COMPOSITION FOR USE IN COSMETICS AND DERMATOLOGY

The present invention relates to compositions that can be used in cosmetics and in dermatology, and more particularly to a composition with a bactericidal effect that can be used as a preservative in these cosmetic and dermatological compositions.

The skin comprises superficial layers, namely the epidermis, and deeper layers, the dermis and the hypodermis, and each has specific properties allowing the whole to react and adapt to the conditions of its environment. The epidermis, which is composed of three types of cells, namely keratinocytes (90% of epidermal cells), melanocytes (2 to 3% of epidermal cells) and Langerhans cells, constitutes the outer layer and plays a role. fundamental to ensure the protection and maintenance of good trophicity. The dermis serves as a support for the epidermis and consists mainly of fibroblasts and an extracellular matrix essentially based on collagen and elastin. Collagen fibers contribute to the texture and tone of the skin, and elastin is responsible for its elasticity. Other cells, such as macrophages and leucocytes, are also present in the dermis layer. The hypodermis, which is the deepest layer of the skin, contains lipid-producing fat cells so that the subcutaneous tissue makes a fat layer that protects muscles, bones, and internal organs from shock.

To be accepted by users, cosmetic and dermatological compositions for the treatment and prevention of skin conditions by topical application must be pleasant to use and must have good physical properties, including consistency and lubricity, while ensuring satisfactory efficiency health and avoiding the disadvantages such as tugging, irritation or itching, that may cause certain active ingredients. They must also have good conservation properties by avoiding or limiting the risks of degradation and microbial contamination.

The problems associated with microbial contamination and the resulting instability have led to a great deal of research in the field of cosmetic, pharmaceutical and food compositions, in order to develop substances or compositions that may prevent or limit this contamination. Microbial contamination can occur during manufacturing or packaging (primary contamination), or, most often, during the storage and / or use of the products (secondary contamination), especially when this is done a relatively hot and humid environment, favorable to microbial growth, which is generally the case of cosmetics when the containers containing them have been opened and the users have opened them.

This microbial proliferation is manifested in the organoleptic characteristics of cosmetic products and in the health of users. It is accompanied by instability of the product manifested by a change in color, an appearance of unpleasant odor, a transformation of the texture, and these effects not only can impair the effectiveness of the product but can also make it uncomfortable for the user, and even sometimes be harmful, for example because of the risk of infection resulting from microbial growth. It is therefore desirable to protect cosmetic products by incorporating preservatives that prevent or limit bacterial growth to enhance consumer safety. Various preservatives have been used for its nombreu ^¬ years in the field of cosmetic and dermatological compositions, such as benzoic acid or p-hydroxy alkyl benzoates, and in particular the methyl p-hydroxy-benzoate (methylparaben ) and propyl p-hydroxybenzoate (Propylparaben), or alcohols, for example ethyl alcohol, benzyl alcohol and phenoxyethanol, or chlorphenesin or imidazolidinyl urea, alone or in combination. combination. The use of some of these preservatives has, however, sometimes been discouraged because they could have adverse effects on the health of users when their concentration is too high, for example by sometimes causing allergy or cutaneous intolerance reactions. . Hinokitiol has also been proposed as an antimicrobial preservative but has the disadvantage of being relatively unstable to light.

Other additives for cosmetic and food compositions have been proposed. Thus, there are known various substances and compositions having effects useful in cosmetic compositions to facilitate application to the skin, and for example the product Lipacid® is a lipoamino acid group palmitoyl used in cosmetics for its soothing properties. Patent FR 2,676,741 describes lipoamino acids of vegetable origin which can be incorporated into various cosmetic compositions. Patent application WO 9809611 discloses lauroyl chain lipoamino acids, and in particular lauroyl glutamate, having soothing properties for the skin. FR 2,765,105 proposes to combine lipoamino acids with zinc gluconate to prepare compositions with antibacterial and anti-inflammatory properties useful in the treatment of acne.

Some glycerine derivatives are known for their activity against microorganisms responsible for unpleasant odors and can therefore be used in compo- Deodorant cosmetics, such as those described in US Pat. No. 5,516,510, which describes glycerol mono-alkyl ethers such as glycerol 2-ethyl hexyl ether and glycerin dodecyl ether having activity against gram-negative bacteria. positive. Another composition exhibiting antimicrobial activity and comprising a glycerol alkyl ether and a lipoamino acid is described in EP 747,047.

Some fatty acids are used in cosmetic compositions, for example for their antimicrobial properties such as 10-hydroxy-decanoic acid which can be used alone or in combination with another active ingredient such as sebacic acid, as described in the patent. FR 2,851,161, which teaches that such an association is effective for masking unpleasant odors and for treating microorganisms responsible for acne.

The development of new products or new compositions to ensure the conservation of cosmetic products under good conditions is still felt today as a necessity in order to find alternatives to existing products such as parabens and phenoxyethanol.

The work carried out by the Applicant has shown that the combination of certain derivatives of glycerin, lipoamino acids and a hydroxylated fatty acid provides an important antimicrobial effect making it possible to use it effectively in cosmetic and dermatological compositions to replace preservatives. such as parabens and phenoxyethanol. The present invention therefore relates to a new antimicrobial composition having a broad spectrum of activity useful in cosmetics and dermatology.

The subject of the invention is also a composition that can be used as a preservative in cosmetic and dermatological compositions. The invention also relates to a composition Cosme ^¬ tick and / or dermatological comprising such bactericidal composition providing effective action against bacterial growth and provides excellent conser- vation without causing adverse effects on the user, such than a reaction of intolerance or allergy.

Finally, the subject of the invention is the use of such a composition for the preparation of a dermatological composition with improved preservation without requiring the use of standard preservatives.

The antimicrobial composition for use in cosmetics and dermatology according to the present invention comprises in combination a lipoamino acid, a hydroxylated fatty acid having from 8 to 12 carbon atoms and a glycerin alkyl ether.

In the composition according to the present invention, the lipoamino acid preferably comprises an alkyl chain of 8 to 18 carbon atoms, and more particularly a capryloyl group, a lauroyl group and a palmitoyl group. The hydroxylated fatty acid may for example be 10-hydroxydecanoic acid.

The glycerin alkyl ether is preferably selected from ethyl hexyl glycerin and dodecyl glycerine.

It may be useful to add to the composition an alkyl chain diol of 8 to 12 carbon atoms such as 1,10-decane-diol.

The tests carried out have shown that the effectiveness of the composition of the invention is further improved by the addition of sebacic acid and / or butylene glycol. An advantage of the present invention is that it can be composed from commercially available products and, for example, a lipoamino acid such as Lipacid® (capryloyl glycine) can be chosen in proportions generally ranging from 0.5 to 2. % by weight relative to the total weight of the composition, a glycerin ether such as Sensiva® at 0.2 to 3% by weight, and a hydroxylated fatty acid such as Acnacidiol® at 1 to 5% by weight. These products that can be used in the composition of the invention are suitable for use in cosmetics because of their good safety.

The combination of antibacterial and preservative compounds according to the present invention is an effective alternative to the use of conventional preservatives. Not only does it have an antibacterial effect making it possible to use it as a preservative in cosmetic compositions, but it also has a potentiated effect on micro-organisms such as Candida albicans and Aspergillus niger compared to its components used in isolation, without having any effect. undesirable secondary.

The studies carried out on the combination according to the present invention have shown that it controls the production of skin sebum with good short-term efficiency and has sebum regulating properties in the longer term. It also has an effective deodorant activity, a moisturizing activity and a good emollient power. It also restores the natural acidity of the skin, promotes the balance of the skin's ecosystem, improves skin conditions such as seborrheic dermatitis responsible for skin irritation and flaking, and is active for treatment acne skin.

The combination of active principles according to the present invention is particularly remarkable by the speed of its effectiveness causing eradication of the main strains in a period of less than 48 hours. Its activity is particularly effective on the Escherichia coli, Pseudomonas aeruginas, Staphylococcus aureus and Candida albicans strains in less than 48 hours and on Aspergilus niger in a longer time. The antibacterial combination according to the invention also has the advantage of requiring only limited quantities of each of its components, that is to say amounts which are smaller than those recommended by the manufacturers of these components, which allows an improvement in the cutaneous tolerance of the composition.

In addition to the above antibacterial combination, the composition according to the invention may contain various substances and excipients chosen according to their known properties, the final application considered and the envisaged dosage form. Thus, hydrating agents, emulsifiers, surfactants, thickeners, hydrophilic and lipophilic gelling agents, viscosifying agents, antioxidants, vegetable oils, lipids, texturizing agents, a specific solvent such as a glycol as well as water and various additives to improve the physical properties of the compositions. It is also advantageous to incorporate filters or sunscreens chosen according to the desired degree of protection, as well as perfumes. If necessary, a complementary preservative such as dehydroacetic acid may also be added.

The gelling agents or thickeners may for example be chosen from acrylate copolymers, for example acrylate palmeth acrylate copolymer, or natural gums, for example a xanthan gum.

The moisturizing or humectant may be selected from a polyol, sorbitol, maltitol, pentaerythritol, glycerin, propylene glycol, polyethylene glycol, polyacrylates and glyceryl polymethacrylates, glycerol or glycerol derivatives. In general, any moisturizing agent suitable for cosmetic or dermatological compositions may be used in the present invention.

Various emulsifying agents may be used depending on the intended use and may be chosen for example from crosslinked copolymers of the acidic type. acrylic acid / alkyl acrylate (e.g. Carbopol 1342® and Pemulen TRi®), polysorbates (e.g. Tween 20 or Tween ^® 60), sorbitan esters. It is also possible to use emulsifying agents such as stearic or palmitic acid derivatives, and for example PEG 100® stearate, stearic or palmitic acid mono- or diglycerides, glycerol stearate, polyethylene stearate, and the like. glycol, a steareth or a ceteart, an emulsifiable silicone. or natural emulsifiers such as glucosides (cetearyl and arachidyl) or hydrogenated lecithins.

Ultraviolet protection agents may also be incorporated in the compositions, and for example sunscreens such as benzophenone or a benzophenone derivative, a dibenzoylmethane derivative such as 4-isopropyl dibenzoylmethane, or cinnamate and more particularly ethylhexyl methoxycinnamate. It is also possible to use anti-ultraviolet screen pigments, which may for example be chosen from titanium dioxide, zinc oxide or aluminum oxide. Thus, the antimicrobial composition of the invention can be incorporated into cosmetic compositions such as moisturizing creams, nourishing creams, wrinkle creams, facial cleansing gels, toning lotions, make-up remover lotions, sunscreen creams, body milks, shampoos, hair products, anti-acne products, shower gels or creams, etc.

The features and advantages of the present invention will appear in more detail in the description which follows, relating to preferred embodiments. In these examples, parts and percentages are by weight unless otherwise indicated. Example 1

By conventional techniques, an anti-wrinkle cream having the following composition is prepared.

Water qs 100.0 Scent 0.8

Glycerin 5.0

Tromethamine 0.6

Invention Association 3.3 carbomer 0.3 emulsifier 5.0 esters, vegetable oils 17.0 various actives 17.0 powder 1.5

The combination of the invention consists of Lipacid® (0.5% of the total weight of the composition), ethyl hexyl glycerine (0.3% by weight) and Acnacidiol® (2.5% in weight) .

Example 2

A moisturizing gel having the composition indicated below is prepared.

Water qs

Perfume 0.8

Carbomer 0.3

Tromethamine 0.4 Glycols 5.0

Glycerin 4.0

Invention Association 3,3

Moisturizing active 10.0

The combination of the invention is identical to that used in Example 1.

Example 3

The effectiveness of the combination according to the invention was verified by the tests described below. Overall principle of the test:

This test consists of the artificial contamination of a preparation by means of an inoculum of microorganisms appropriate and prescribed by the European Pharmacopoeia. This inoculated preparation is kept away from light at 20-25 ° C for the duration of the test.

Samples are taken from the inoculated preparation at a given time interval (TO, T48H, T7J, T14J and T28J) in order to enumerate and search the microorganisms present.

The preservation properties are consistent if there is a significant decrease in the number of microorganisms in the seeded preparation during the period of the test. The different stages of the test are as follows:

Preparation of strains

The four strains used are those recommended by the European Pharmacopoeia namely:

- Pseudomonas aeruginosa (CIP82.118 ATCC 9027) - Staphylococcus aureus (CIP 4.83 ATCC 6538)

- Candida albicans (IP 48.72 (ATCC 10231)

- Aspergillus niger (IP 1431.83 ATCC 16404) and an additional strain (Enterobacterium):

Escherichia coli (CIP53.126 ATCC 8739) Each of the bacteria is subcultured on agar B and incubated 18 hours at 30-35 ^° C. (Staphylococcus, E Coli and Pseudomonas)

Candida albicans is subcultured on CT C agar and incubated for 48 hours at 20-25 ^° C. The Aspergillus niger is transplanted onto CT C agar and incubated for 7 days at 20-25 ^° C. until satisfactory sporulation is obtained.

Suspensions of germs measuring between 10 ⁷ and 10 ⁸ CFU / ml are prepared in the appropriate diluents These strains are then checked and enumerated before carrying out the tests with the combination of the invention.

Realization of the tests (inoculation of the strains)

100 μl of each suspension of germs measuring 10 ⁷ and 10 ⁸ CFU / ml are added to the diluted product; the various pillboxes are homogenized and incubated in the dark at laboratory temperature (20-25 ^° C.) throughout the duration of the study (28 days).

Enumeration At each measurement time, an agar count is performed to quantify the microorganisms present in the product.

The result in numbers of seeds is then calculated in logarithm of base 10.

Base matrix used for the test

The matrix used for the test is an oil / water emulsion, very activated and therefore difficult to keep (the goal being to place in the most unfavorable conditions). This emulsion is composed as follows: Raw material% _

Water qs

Glycerin 5.0 carbomer 0.3

Other gelling agent 1,3 tromethamine 0.6

Fat phase (ester, vegetable oils, consistency factor) 17.0

Tribehenin PEG 20 esters 5.0

Active (anti-wrinkle, moisturizing) 17.0 Powder (boron nitride) 1.5

Perfume 0.8

The different tests tested are as follows: Trial 1

(Table 1) Matrix + ethylhexylglycerin 0.3% + capryloyl glycine 0.5% + mixture (butylene glycol, sebacic acid, decanediol, hydroxydecanic acid) 2.5%

Table 1

Trial 2

(Table 2) Matrix + capryloyl glycine 0.5%

Table 2

Trial 3

(Table 3) Matrix + Ethylhexylglycerin 0.3%

Table 3

Trial 4

(Table 4: Matrix + mixture (butylene glycol, sebacic acid, decanediol, hydroxy decanoic acid) 2.5%

Table 4

In the above tables, the inoculum corresponds to the amount of bacteria initially seeded before the onset of the action of the combination of the invention or comparison preservatives. It is found that only the combination according to the invention provides satisfactory results in accordance with the criteria of the pharmacopoeia on all strains, including Aspergillus niger.

In addition, it is found that the combination of the invention provides rapid results since the bacteria and yeasts comply with the criteria of pharmacopoeia from 48 hours (except Aspergillus niger, where the results are better at 14 days). This result is particularly interesting in the case of the primary contamination during manufacture of the cosmetic compositions, where it is important to be able to ensure an immediate preservative effect.

These results confirm that the composition of the invention is particularly useful as a preservative in cosmetic and dermatological compositions.

Claims

1. An antimicrobial composition for use in cosmetics and dermatology characterized in that it comprises in combination a lipoamino acid, a hydroxylated fatty acid having from 8 to 12 carbon atoms and a glycerin alkyl ether.

2. Composition according to claim 1, characterized in that the lipoamino acid has an alkyl chain of 8 to 18 carbon atoms.

3. Composition according to claim 2, characterized in that the lipoamino acid comprises a capryloyl group, a lauroyl group or a palmitoyl group.

4. Composition according to claim 1, characterized in that the hydroxylated fatty acid is 10-hydroxy-decanoic acid.

5. Composition according to claim 1, characterized in that the alkyl ether of glycerine is selected from 1 ethyl hexyl glycerin and dodecyl glycerine.

6. Composition according to any one of the preceding claims, characterized in that it comprises between 0.5 and 2% by weight, relative to the total weight of the composition, of lipoamino acid, from 0.2 to 3% by weight. of glycerine ether, and from 1 to 5% by weight of hydroxylated fatty acid.

7. Composition according to any one of the preceding claims, characterized in that it further comprises an alkyl chain diol of 8 to 12 carbon atoms.

8. Compositions according to claim 7, characterized in that the diol is 1, 10-decane-diol.

9. Composition according to any one of the preceding claims, characterized in that it further comprises sebacic acid and / or butylene glycol.

10. Cosmetic and / or dermatological composition characterized in that it contains a preservative constituted by a compositions according to any one of the preceding claims.

11. Use of a composition according to any one of claims 1 to 9 for the preparation of a dermatological composition with improved preservation.