HK1209675B - Use of zinc coceth sulfate as an antibacterial agent against propionibacterium acnes - Google Patents

Description

Use of zinc cocoeth sulfate as an antibacterial agent against propionibacterium acnes

Technical Field

The field of the present invention relates to the novel antibacterial properties of zinc cocoeth sulfate against the bacterium propionibacterium acnes; and to the use thereof in the cosmetic field and in the dermatological field for the treatment of acne and skin disorders associated with Propionibacterium acnes.

Background

Sebum is the secretory lipid film of the sebaceous glands of the skin, which is used to protect the skin and is mixed with sweat to prevent the skin from drying.

Sebum makes the skin water-repellent and participates in the development of the epidermal structure. Which avoids acidification thereof by microorganisms (in the presence of lactic acid and fatty acids) and guarantees a certain degree of impermeability. It makes the skin soft and participates in the development of the epidermis.

Sebum typically reaches the skin surface through the pores of the hair follicle.

During acne, excess sebum in the follicular infundibulum presents an environment that favors colonization by propionibacterium acnes. The appearance of acne lesions depends on an excessively intense pro-inflammatory reaction through innate immune receptors due to an excessively high density of propionibacterium acnes.

These bacteria in fact have the property of metabolizing the triglycerides of sebum by releasing the fatty acids that cause inflammation of the tissue.

Unexpectedly and surprisingly, the applicant has demonstrated that zinc cocoeth sulfate can be used as an antibacterial agent against propionibacterium acnes.

Disclosure of Invention

Zinc cocoanut alcohol polyether sulfate (ZChimmer)&Zetesol from Schwarz) Is an anionic surfactant which is much more resistant than the conventional sodium salt of lauryl ether sulfate due to the second dodecyl chain fixed to the metal. The presence of zinc molecules gives it a very interesting activity against pathogenic bacteria of oily skin and makes it possible to limit the preservatives sufficiently (concentrations of 2% to 7%).

The zinc cocoeth sulfate is a new generation surfactant that combines sulfate alkyl esters with zinc (lipophilic double chains of coconut cores/zinc).

Alkyl ether sulfates are the most widely used surfactants in cosmetic and bath products. In combination with binary or ternary mixtures, they are clear foaming agents (not affected by hard water) and have excellent cleaning ability.

Alkyl ether sulfates provide good tolerability to further improve skin and eyes, depending on the cation used to neutralize them.

This study on zinc cocoeth sulfate can demonstrate that it not only exploits good surfactant properties with excellent local tolerance, but also provides other interesting properties.

As with the alkyl ether sulfates, zinc coco polyether sulfate demonstrates its good cleaning performance: satisfactory foaming ability, soft and creamy foam, pleasant to use.

However, its compatibility with the skin is surprisingly shown, since it is much less potentially skin-aggressive than alkyl ether sulfates and is most likely related to its lipophilic double chain.

Furthermore, it appears that the hardness of water is not important for its cleaning ability.

The zinc cocoeth sulfate has an acidic pH of 4.5, approaching a skin pH of about 5.5.

Therefore, it does not make the skin rough, and acidity is one of the main characteristics of adult skin and skin of young children.

The zinc cocoeth sulfate showed no irritancy and sensitization potential.

Zinc cocoeth sulfate also demonstrates its good tolerance to mucous membranes.

This was confirmed by using the chick embryo chorioallantoic membrane test, the principle of which is based on observing the stimulatory effect that occurs within five minutes after the product is placed on the chorioallantoic membrane containing embryonated chicken eggs on the tenth day of incubation. The test was performed as a 1% solution of coco-alcohol polyether.

Bacteriological studies were carried out at final pH values of 5 to 6, 10% and 20% concentration of aqueous solution of zinc cocoeth sulfate.

Bacteriological studies were carried out on the bacterium, propionibacterium acnes, which causes acne-prone skin: a study conducted in the microbiology laboratory confirmed this bactericidal efficacy. This study has been confirmed on the finished product.

Accordingly, the present invention relates to a skin hygiene composition comprising zinc cocoeth sulfate as an antibacterial agent against propionibacterium acnes in combination with sodium lauroyl isethionate. According to another characteristic of the invention, the composition is effective as an antibacterial agent against propionibacterium acnes. More specifically, the composition is intended for the treatment of acne.

Another aspect of the present invention relates to the non-therapeutic use of a composition comprising zinc cocoeth sulfate as an antibacterial agent against propionibacterium acnes.

Unlike certain similar types of skin cleansing compositions, which claim the necessity of the presence of a salt or an additional glycyrrhizic or glycyrrhetinic acid derivative, the subject compositions of the present application are specifically completely free of such salts or additional derivatives.

Preferably (the skin hygiene composition of the present invention) in a therapeutic and/or hygienic cosmetic product for acne-prone skin and/or oily skin having a tendency to acne.

The hygiene of acne-prone skin and/or oily skin with a tendency to acne requires the use of products adapted to the microbial flora of the tissue fragility and the accompanying pathology.

Preferably, within the framework of the development of an oily skin cleansing product for acne-prone skin and/or having a tendency to acne, several criteria need to be met:

good grease removal capacity of-decanedioic fat chemical composition

Good surfactant tolerance, in such a way as not to stimulate the sebaceous glands by a rebound effect

Regulation of sebaceous gland function

-limiting the growth of the relevant bacteria.

Another object of the present invention relates to a composition, more preferably a cleansing composition for acne-prone skin and/or having a tendency to acne, comprising zinc cocoeth sulfate as antibacterial agent against Propionibacterium acnes, in combination with it

-the anionic surfactant sodium lauroyl hydroxymethylethanesulfonate;

-and/or another antibacterial agent selected from extracts of myrtle, more particularly, extracts of myrtle as described in EP1112079, polyglycerol-3 monocaprylate, glyceryl decanoate, cetrimide;

and/or anti-seborrhoeic agents selected from the group consisting of laurin glycerides, extracts of Chinese fan palm, pumpkin seed oil, extracts of Urtica dioica and the like as described in WO2011/073370, and the like.

In a particular embodiment of the invention, the vehicle base of the composition according to the invention is combined with an anionic surfactant essentially as a binary mixture, in which the zinc cocoeth sulfate may be combined with sodium lauroyl isethionate; and the ratio of nonionic surfactant to active ingredient is expressed as 80/20. The presence of low concentrations of amphoteric substances stabilizes the final viscosity.

Sodium lauroyl hydroxymethylethanesulfonate (sodium lauroyl hydroxymethanesulfonate: (Innospec) is one of the anionic surfactant classes with better tolerance. It was used on the skin for many years, demonstrating its excellent biocompatibility with the skin (5% to 10% concentration) in the pediatric field as well as in the specific reactivity field.

In another preferred embodiment of the invention, zinc cocoeth sulfate, as an antibacterial agent against propionibacterium acnes, will be used in combination with another active ingredient:

antibacterial agents such as extracts of myrtle, preferably of myrtle as described in EP1112079, polyglycerol-3 monocaprylate, glyceryl decanoate, cetrimide;

or the extract of the plants such as the lauric acid ester of glycerin, the extract of the Chinese fan palm, the pumpkin seed oil and the extract of the nettle, has complementary effect on the acne pathology.

Preferably, the anionic surfactants zinc cocoeth sulfate and sodium lauroyl hydroxymethylethanesulfonate (e.g., sodium cocoyl isethionate) will be combined in the skin cleansing and disinfecting composition)。

Further, it is known that bipolar nonionic surfactants, due to their fatty chains combined with oxyethylene chains into ether-form molecular structures, provide extremely compliant products:

polysorbate 20 combining cyclized sorbitol with ethoxylated lauryl chain

Ethoxylated hydrogenated castor oil (40EO)

Ceteareth-60 myristyl glycol, the fatty chain of which provides skin surface protection.

Buffered with EDTA 2Na and citric acid at pH 5, this formula is well suited for oily skin pH. The acidic pH is involved in the antibacterial and anti-5-alpha-reductase activity of glycerol laurate in combination with the anti-inflammatory agent zinc cocoeth sulfate.

Preferably, the compositions of the present invention are topically applicable.

More preferably, the composition of the present invention is in the form of a liquid cleansing gel, a foaming agent or an aerosol.

It is a further object of the present invention to provide a cosmetic method for cleansing (and/or cleansing) acne-prone skin and/or oily skin having a tendency to acne, characterized in that a composition comprising zinc cocoeth sulfate is applied to said skin.

The invention will be better understood with the following non-limiting examples, and specific embodiments constituting cosmetic and/or dermatological compositions according to the invention.

Detailed Description

Examples of compositions according to the invention

Example 1:

sodium lauroyl hydroxymethylethanesulfonate (sodium lauroyl hydroxymethanesulfonate: (Innospec)5 to 20%

Zinc cocoeth sulfate (Zetesol),Zchimmer&Schwarz)5 to 20%

Cocoiloyl amphoacetate 3 to 10%

Polysorbate 200.5-4%

Ceteareth-60 myristyl glycol 0.5 to 1.5%

Ethoxylated hydrogenated castor oil 0.5% to 2%

Glycerol laurate from 0.1 to 1%

0.1 to 0.5 percent of zinc gluconate

Citric acid/EDTA 2Na qsp pH 5

ZETESOLEvaluation of fungicidal Activity against Propionibacterium acnes

The log10 (parameter logR) of the reduction in the number of pathogens over time relative to the initial number of pathogens was evaluated.

The test strain was propionibacterium acnes ATCC 6919.

At a concentration of 20%ZetesolThe test was performed (i.e. 5% of the active ingredient zinc cocoeth sulfate).

Method of producing a composite material

-setting up the test product to be tested to about 10 in a titration test⁶CFU/ml Propionibacterium acnes suspension was contacted for 1, 5, 10, and 15 minutes.

Viable count (columbia) of the contents of 1ml of culture agar sample after each contact duration.

Incubate under anaerobic conditions at 36 ℃ for 72 hours.

-live count of the remaining bacteria by direct counting.

The reduction was calculated as log 10.

The plates were counted and the results compared to the value of CFU/ml.

The log10 calculation of the CFU/ml reduction value was performed according to the following formula:

log reduction Log10 (existing CFU value TO/remaining CFU value Tx)

The results shown in table 1 are the average of two independent experiments (except for 10 minutes in duration, which were carried out only once). See also fig. 1.

TABLE 1

Good bactericidal activity is properly observed from the first minute of contact, which is close to the time of use as a rinse product.

The activity was optimal at 15 minutes (maximum visual threshold reached).

Example 2:

another composition example according to the invention was carried out with the same evaluation of bactericidal activity according to the same protocol as mentioned above.

The compositions tested meet the following formulation:

zetesol Zn (20% concentration, i.e. 5% of the active ingredient coco polyether sulfate)

Iselux (concentration 10%, i.e. sodium lauroyl methyl isethionate 8% active ingredient)

Ceteareth-60 myristyl glycol, a thickening agent

-Cocoyl amphoacetic acid Na-ampholytic surfactant

-octylene glycol

-lactic acid

-sodium hydroxide

-a suitable amount of water

The results obtained are shown in table 2 below:

TABLE 2

A 1.9log reduction of the strain of propionibacterium acnes ATCC6919 was observed at 1 minute. It shows that the addition of sodium lauroyl hydroxymethylethanesulfonate can significantly improve the bactericidal activity of zinc cocoeth sulfate against propionibacterium acnes.

Evaluation of the fungicidal Activity of the product formulated according to example 1 against Propionibacterium acnes

The same protocol as above was used.

The product tested was:

dilution of the composition according to example 1 in sterile distilled water to 20% -dilution with a rinse product.

The strains tested were

Propionibacterium acnes ATCC 6919.

Propionibacterium acnes Sauvage (erythromycin resistance strain R)

Propionibacterium acnes Sauvage (erythromycin resistance Strain S)

The results shown in table 3 below are the average of two independent tests. Please refer to fig. 2.

TABLE 3

Even when diluted to 20%, the composition retained good activity.

Claims (3)

1. A hygienic composition for the skin comprising zinc cocoeth sulfate in combination with sodium lauroyl hydroxymethylethanesulfonate as an antibacterial agent against Propionibacterium acnes,

with the proviso that the composition is not:

2. a hygienic composition for skin according to claim 1 characterized in that it further comprises an antibacterial agent selected from the group consisting of myrtle extract, polyglycerol-3 monocaprylate, glyceryl caprate, cetrimide.

3. A sanitary composition for the skin according to claim 1 or 2, characterized in that it comprises an antiseborrheic agent selected from the group consisting of glycerol laurate, an extract of Chinese fan palm, pumpkin seed oil, an extract of Urtica dioica.