WO2012055855A1

WO2012055855A1 - Concentrated preparations of lae and their use

Info

Publication number: WO2012055855A1
Application number: PCT/EP2011/068629
Authority: WO
Inventors: Xavier Rocabayera Bonvila; María Teresa BELTRÁN PINA; María MINGUET BONVEHÍ
Original assignee: Laboratorios Miret, S.A.
Priority date: 2010-10-29
Filing date: 2011-10-25
Publication date: 2012-05-03

Abstract

The invention relates to concentrated preparations of 1-60% by weight of the Ethyl Lauroyl Arginate HCI (LAE) comprising (i), 1 o 99 % by weight of at least one solvent or surfactant selected from the group consisting of phenoxyethanol, benzyl alcohol, caprylyl glycol, hexylene glycol, pentylene glycol, decylene glycol, glyceryl monoester with a fatty acid selected from caprylic acid, capric acid, undecylenic acid and lauric acid, polyglycerine monoesters (polyglyceryl-3 caprylate), phenethyl alcohol, phenyl propanol and ethylhexyl glycerine, provided that when phenoxyethanol is present as the at least one solvent or surfactant its concentration shall be 2 to 99% by weight; (ii) optionally 0-20 % by weight of one or more organic acids with antibacterial activity; (iii) optionally 0-10 % by weight of one or more natural extracts with antibacterial activity; (iv) optionally 0-10 % by weight of one or more chelating agents; (v) optionally 0-10 % by weight of one or more antioxidants; and (vi) optionally 0-50% by weight of one ore more solvents or surfactants without antibacterial activity. These concentrations may be added to cosmetic compositions for personal care as preserving agents..

Description

H 65 212

CONCENTRATED PREPARATIONS OF LAE AND THEI R USE Technical Field

The present invention relates to novel combinations with Ethyl LauroyI Arginate HCI (hereafter designated as LAE) and their use in cosmetic preparations for personal care.

Background art

Personal care formulations are mainly emulsions or liquids which are intended to be left on the skin or hair to improve their condition. Most of them are based on non- ionic emulsifiers and incorporate emulsified vegetable oils, paraffin and silicones as treating agents for the skin or hair. Among these formulations, the following ones are representative: - Wet wipes (for babies, make-up removing wipes, self-tanning.. .),

- Make-up removers (milks, liquids),

- Facial creams,

- Body milks,

- Sun protection products (lotions, creams, sprays),

- Deodorants (roll-on),

- Hand or foot creams/treatments,

- Hair care products (shampoos, hair conditioners).

In particular, for the skin care market sector, the choice of the preserving system is of particular importance, since it needs to be very mild, because it is not rinsed off the skin. LAE does not show interactions with most of the ingredients present in this type of formulations, for that reason the personal care market is a good opportunity to introduce this product.

The personal care market in Europe is highly concerned about the risks of chemicals for human beings as well as for the environment. For this reason, in the last years, several preservatives are being banned or its use is being strongly limited. This is the case of formaldehyde and formaldehyde donors, such as DMDM hydantoin, which are being limited due to the inclusion of formaldehyde into the list of possible carcinogenic chemicals. Isothiazolinones are the best performing preservatives among the non-formaldehyde donors, but several cases of skin sensitization have taken place, and personal care formulators are starting to substitute them in order to be more aligned with the market trends.

The last preservatives to get a negative feedback from the market have been the widely used parabens. Parabens are the most popular preservatives in personal care formulations, because of their low sensitizing potential, as well as a good efficacy. Nevertheless, some studies have related them with a higher risk of breast cancer (Parabens: Myth and reality, Dene Godfrey, Cosmetics and Toiletries Vol 125 n°3 pages 80-83), and many manufacturers are marketing their products as "paraben- free".

With this scenario, several mild preservatives which show a lower efficacy than traditional ones, are starting to gain market share. All of them have in common some characteristics:

- higher MIC values than traditional preservatives (such as formaldehyde donors and isothiazolinones),

- mild to human beings and/or to the environment,

- higher price than traditional preservatives, since higher doses are needed,

- in most cases they are surfactants, being membrane disruption their mechanism of action against micro-organisms,

- they are more effective in blends containing two or more of them,

- in most cases, they provide additional benefits besides preservation, such as extra-moisturising, emolliency or emulsifying, and they are sold as "multifunctional" ingredients.

On the other hand, the personal care manufacturers are starting to consider the origin of the ingredients which constitute a formulation, and organisations such as E co cert (www.ecocert.com), the Soil Association (www.soilassociation.org), NaTrue (www.natrue.org) and BdiH (www.bdih.de) are issuing certificates to formulations and raw materials taking into account the origin (natural or synthetic) of surfactants, additives, extracts and also preservatives.

LAE fits into this category of preservatives, which is being required from the personal care market: based on natural products (LAE has obtained the Ecocert certificate);

mild to skin (low irritation potential);

fair efficacy against micro-organisms, better than other "green" preservatives; - its cationic nature confers LAE with added benefits, such as good emulsifying properties or being a good smoothing agent for skin or hair.

Unfortunately, LAE when used as only preservative shows the following drawbacks once incorporated into personal care formulations: a) limited compatibility with anionic thickeners and emulsifiers, such as carbomer and xanthan gum, this incompatibility being the cause of some alterations in the appearance of the formulation, and of a reduction of the efficacy as a preservative of LAE;

b) even in the absence of incompatible ingredients, the antimicrobial activity of LAE might not be enough for some formulations, to meet the pharmacopeia requirements (Class A) in terms of preservation of cosmetic formulations European Pharmacopeia 6.0, paragraph 5.1.3). Disclosure of the invention

Synergystic combinations of LAE with other preservatives, natural extracts, solvents or chelating agents with improved efficiency in anionic matrices, and better preservation ability against moulds and gram negative bacteria.

Formulations comprising:

(a) LAE (from 1 -60%) and

(b) one or more solvents or surfactants with antibacterial activity (1 -99%). And optionally:

(c) one or more organic acids with antibacterial activity (0-20%),

(d) one or more natural extracts with antibacterial activity (0-10%),

(e) one or more chelating agents (0-10%),

(f) one or more solvents or surfactants without antibacterial activity (0-50%) and

(g) one or more antioxidants (0-10%).

Suitable solvents or surfactants of the group (b) for the combination with LAE are phenoxyethanol, benzyl alcohol, caprylyl glycol, hexylene glycol, pentylene glycol, decylene glycol, glyceryl monoester with a fatty acid selected from caprylic acid, capric acid, undecylenic acid and lauric acid, polyglycerine monoesters (polyglyceryl- 3 caprylate), phenethyl alcohol, phenyl propanol and ethylhexyl glycerine. One or more of these products may be selected for the combination with LAE. It is a preferred embodiment of the present invention that the concentrated preparations contain at least two of the above solvents and surfactants.

Suitable organic acids of the group (c) which are optionally present are formic acid, acetic acid, propionic acid , lactic acid, undecylenic acid, lauric acid, sorbic acid, benzoic acid, cinnamic acid, salicylic acid, p-anisic acid, levulinic acid, dehydroacetic acid. At least one of these products is optionally present.

Suitable natural extracts with antibacterial activity of the group (d) which are optionally present are green tea extract, rosemary extract, cinnamon leaf oil, clove extract, curry leaf oil, orange oil, lemon grass oil, sesame oil, basil extract, clove bud oil, turmeric oil, ginger oil, thyme oil, anise oil, cinnamon bark oil, thymol, eugenol, anethole, propolis, grape fruit seed extracts and zingerone.

Suitable chelating agents of the group (e) which are optionally present are EDTA, citric acid, phytic acid, gluconic acid, gluconolactone, tetrasodium iminodisuccinate, tetrasodium dicarboxymethyl glutamate (GLDA) and trisodium ethylenediamine disuccinate, including their salts. In general, any suitable solvent which is commonly used in the preparation of formulations to be applied on the skin may be used in the context of the present invention. Such suitable conventional solvents are water, low chain alcohols such as ethanol, isopropanol and butanol, glycols such as propylene glycol, ethylene glycol, triethylene glycol, diethylene glycol, dipropylene glycol, and 1 ,3-propanediol, glycerine, polyols such as sorbitol, xylitol, maltitol and erythritol, polysorbates, alkyl polyglucosides, sucrose monoesters, vegetable oils, mineral oils, silicon oils. Combinations of these solvents may be used. The most suitable solvents are glycerine and ethanol. Such solvents may be present for purely technical reasons, any particular support to the antimicrobial activity of the formulations is not assumed.

Finally, an antioxidant may be added to the formulations of the present invention. Such anti-oxidants may be selected from tocopheryl acetate, tocopherols, flavonoids, flavonoids derivatives, ascorbic acid, ascorbyl palmitate, polyphenols, butylhydroxytoluene, butylhydroxyanisole, tert-butylhydroquinone and di-tert- butylhydroquinone (DTBHQ).

The described organic acids, natural extracts, chelating agents, antioxidants and surfactants without antibacterial activity or solvents are to be considered as illustrative and not restrictive, and the scope of the invention is, therefore, embodied in other forms without departing from its spirit or essential characteristics.

The formulations according to the present invention are concentrated preparations of LAE. LAE is generally present in preparations of 1 to 60 % by weight, more preferred 5 to 40 % by weight, even more preferably 8 to 30% and most preferably 10 to 20 % by weight, based on the total weight of the formulation. The preparations are usually in liquid form, but they may be solid as well, depending on their composition.

The formulations according to the present invention also comprise one or more solvents or surfactants with antibacterial activity. These solvents or surfactants are generally present in preparations of 1 to 99 % by weight, more preferred 20 to 90 % by weight, even more preferable 35 to 85% by weight, based on the total weight of the formulation. When phenoxyethanol is present in the concentrated preparation of the present invention then its amount shall be in the range of 2 to 99 % by weight, more preferred 20 to 90 % by weight, even more preferable 35 to 85% by weight, based on the total weight of the formulation.

The concentrated preparations are prepared in any usual manner which is known in the state of the art. The preparations are generally stable and may be stored for a considerable time.

The concentrated preparations are added to the personal care formulations which are intended to be preserved. There is no particular limitation to the kind of personal care formulation which may be combined with the concentrated preparation of the present invention. The concentrated preparation may be adapted to the personal care formulation which shall be preserved in the sense that the concentrated preparation of the present invention shall be suitable for the intended combination. It is the preferred use according to the present invention, that the concentrated preparations are added to a personal care formulation as a preserving agent. For the manner of addition any conventional method known in the art may be used.

The addition of the concentrated preparation of the present invention to the personal care formulation shall lead to a dilution of the components of the concentrated preparation. The amount of the concentrated preparation of the present invention which is added to the personal care formulation shall usually be in the range of 0.5 to 5 % by weight which accordingly represents a dilution by a factor 20 to 200. The initial concentrations of the ingredients in the concentrated preparation of the present invention and the factor of dilution shall determine the final concentrations of all ingredients in the final personal care formulation. Generally a final concentration of 0.01 to 0.4 % by weight of LAE, preferably 0.025 to 0.15 % by weight of LAE related to the total weight of the finally obtained personal care formulation is sufficient to obtain the wanted degree of preservation, due to the synergistic effect.

The above preferred use according to the present invention shall lead to cosmetic compositions which have not been described before. The present invention shall cover these new cosmetic compositions also when they have been prepared in a manner which is different from the method according to the use of the present invention.

The invention will be illustrated hereafter with a number of examples.

EXAMPLES

Determination of biocidal activity

The concentrated preparations described in the following examples were investigated in the following Challenge test.

Microorganisms used in examples 1 to 9

Escherichia coli ATCC 8739

Pseudomonas aeruginosa ATCC 9027

Staphylococcus aureus ATCC 6538

Candida albicans ATCC 10231

Aspergillus niger ATCC 16404

Inoculum: 10⁵-10⁶ CFU/mL

(CFU = Colony Forming Units)

The desired preservation level is to accomplish the European Pharmacopeia requirements (Class A) in terms of preservation of cosmetic formulations (See Table below):

Preparation for topical application

Logarithmic reduction

2 days 7 days 14 days 28 days

Bacteria A 2 3 - Nl

B - - 3 Nl

Yeasts and A - - 2 Nl

Moulds B Nl

Nl: No increment

The class A criteria are the ones which are recommended to meet. In some cases, if class A criteria cannot be met, for instance due to some non-desired reactions, class B criteria shall be applied.

Example 1

Formulation F

Formulation F is a liquid with low viscosity and good stability. Formulations F' and Ld are prepared to compare their antimicrobial efficiency with that of Formulation F, in order to see the separate contributions of LAE alone and the rest of ingredients without LAE.

The formulations are used as a preservative for a wet wipes impregnating liquid formulation, shown in the below table.

Limit of detection: 100 CFU/mL = 2 log CFU/mL

Formulation F at 0.6 % meets class A criteria, containing 0.1 % of LAE, while LAE alone (Formulation Ld) is not able to meet class A criteria at higher dosage (0.2%). Formulation F' is not able to preserve the formulation against bacteria and moulds, showing that it is the combination of the two preservatives which has the maximum antimicrobial effect. To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14 days for moulds according to the European Pharmacopeia. However, in some cases the growth of moulds at day 14 is below the limit of detection in each formulation, under these circumstances the synergistic effect for moulds has been calculated at 7 days. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply.

Logarithmic reduction (F) > Logarithmic reduction (Ld) + Logarithmic reduction (F') Example 2

Formulation A

Formulation A is a liquid with low viscosity and good stability. Formulations A' and L are prepared to compare their antimicrobial efficiency with that of Formulation A, in order to see the separate contributions of LAE alone and the rest of ingredients without LAE.

The preservative blends are added to the cream below, which is a basic moisturising cream.

Results of the challenge test are shown in the following table:

Limit of detection: 100 CFU/g = 2 log CFU/g

Formulation A is the only preservative system that meets class A criteria at 0.5% dosage. This blend is even better than LAE used alone at 0.1 % (double dose of active than that of formulation A applied at 0.5%), which fails against bacteria. Formulation A' is not able to preserve the cream against bacteria and moulds, showing that it is the combination of the preservatives which has the maximum antimicrobial effect. The dose of LAE necessary to preserve correctly the formulation is three times less when used in combination with the other products comprised in formulation A.

To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14 days for moulds. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply. Logarithmic reduction day L 0.5% A' 0.5% A 0.5% (L+A^«)

Bacteria 7 -0.5 0.3 4.8 -0.2

Moulds 14 0.8 -0.2 2.8 0.6

Logarithmic reduction (A) > Logarithmic reduction (L) + Logarithmic reduction (Α')

Example 3

Formulation D

Formulation D is a liquid with low viscosity and good stability. Formulations D' and Lge are prepared to compare their antimicrobial efficiency with that of Formulation D, in order to see the separate contributions of LAE alone and the rest of ingredients without LAE. The different blends are added to the moisturizing cream described in Example 2. Results of the challenge test are shown in the table below:

Limit o etect on: g = og g

Formulation D at 0.25% and 0.5% meets class A criteria. Four times more LAE than that corresponding to 0.25% of formulation D, is still not able to preserve against bacteria. Formulation D' is not able to preserve the formulation against bacteria, but achieves class B for moulds and class A for yeasts, showing that it is the combination of the preservatives which has the maximum antimicrobial effect. In this case, when combined with other ingredients of formulation D, it is possible to preserve the moisturising cream with six times less LAE than when the active is used alone.

To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14 days for moulds according to the European Pharmacopeia. However, in some cases the growth of moulds at day 14 is below the limit of detection in each formulation, under this circumstance the synergistic effect for moulds has been calculated at 7 days. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply. Logarithmic reduction day Lge 0.5% D' 0.5% D 0.5% (Lge+D')

Bacteria 7 -0.5 1 .3 4.8 0.8

Moulds 7 0.5 1 .3 2.9 1.8

Logarithmic reduction (D) > Logarithmic reduction (Lge) + Logarithmic reduction (D')

Example 4

Formulation C

Formulation C is a liquid with low viscosity and good stability. Formulations C and Lbe are prepared to compare their antimicrobial efficiency with that of Formulation C, in order to see the separate contributions of LAE alone and the rest of ingredients without LAE.

The different blends are added to the moisturizing cream described in Example 2.

Limit of detection: 100 CFU/g = 2 log CFU/g Formulation C at 0.5% is the only preservative that meets class A criteria. The same amount of LAE added alone fails with the bacteria. Formulation C is not able to preserve the formulation against bacteria and moulds, showing that it is the combination of the two preservatives which has the maximum antimicrobial effect. In this case, it is necessary to use 50% more of LAE than that present in formulation C to achieve a correct preservation level in this cream.

To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14 days for moulds. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply.

Logarithmic reduction (C) > Logarithmic reduction (Lbe) + Logarithmic reduction (C) Example 5

Formulation E

Formulation E is a liquid with low viscosity and good stability. Formulations E' and Lc are prepared to compare their antimicrobial efficiency with that of Formulation E, in order to see the separate contributions of LAE alone and the rest of ingredients without LAE.

Results of the challenge test are shown in the table below:

Formulation E at 0.5% meets class A criteria, containing 0.075% of LAE, while LAE alone is not able to meet class A criteria at higher dosage (0.1 %). Formulation E' is not able to preserve the formulation against bacteria, showing that it is the combination of the preservatives which has the maximum antimicrobial effect. In this case, a synergistic effect is seen since it is possible to preserve the formulation with half the amount of LAE when it is in formulation E compared to LAE alone.

To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14. days for moulds. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply.

Logarithmic reduction (E) > Logarithmic reduction (Lc) + Logarithmic reduction (Ε')

Example 6

Formulation B

Formulation B is a liquid with low viscosity and good stability. Formulations B' and L are prepared to compare their antimicrobial efficiency with that of Formulation B, in order to see the separate contributions of LAE alone and the rest of ingredients without LAE.

The different blends are added to the moisturizing cream described in Example 2. esults of the challenge test are shown in the table below:

Formulation B is the only preservative that meets class A criteria when added at 0.5%. Even at half of this dose, including only 0.025% of LAE, this blend is able to meet class B criteria of the European Pharmacopeia. This blend is better than LAE at higher amounts which fail against bacteria. Formulation B' is not able to preserve the formulation against bacteria, being class B for moulds and class A for yeasts, showing that it is the combination of the preservatives which has the maximum antimicrobial effect. To achieve the full preservation of the formulation, three times less LAE is necessary if used as part of formulation B.

Logarithmic reduction (B) > Logarithmic reduction (L) + Logarithmic reduction (Β')

Example 7

Formulation H

Formulation H is a liquid with low viscosity and good stability. Formulations H' and Lb are prepared to compare their antimicrobial efficiency with that of Formulation H, in order to see the separate contributions of LAE alone and the rest of ingredients without LAE.

The different blends are added to the moisturizing cream described in Example 2. Results of the challenge test are shown in the table below:

Limit of detect on: g = og g

Formulation H at 0.5 % meets class A criteria, while LAE alone is not able to meet class A criteria at the same dosage (0.1 %). Formulation H' is not able to preserve the formulation against bacteria according to class A requirements, being class B instead, showing that it is the combination of the preservatives which has the maximum antimicrobial effect.

To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14 days for moulds according to the European Pharmacopeia. However, in some cases the growth of moulds at day 14 is below the limit of detection in each formulation, under this circumstance the synergistic effect for moulds has been calculated at 7 days. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply. Logarithmic reduction day Lb 0.5% H' 0.5% H 0.5% (Lb+H')

Bacteria 7 0.8 2.1 4.9 2.9

Moulds 7 1 .8 0.7 2.9 2.5

Logarithmic reduction (H) > Logarithmic reduction (Lb) + Logarithmic reduction (Lb+H'). Example 8

Formulation G

Formulation G is a liquid with medium viscosity and good stability. Formulations G' and Lb are prepared to compare their antimicrobial efficiency with that of Formulation G, in order to see the separate contributions of LAE alone and the rest of ingredients without LAE.

Results of the challenge test are shown in the table below:

Formulation G at 0.5 % meets class A criteria, while LAE alone is not able to meet class A criteria at the same dosage (0.1 %). Formulation G' is not able to preserve the formulation against bacteria, showing that it is the combination of the preservatives which has the maximum antimicrobial effect.

To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14 days for moulds according to the European Pharmacopeia. However, in some cases the growth of moulds at day 14 is below the limit of detection in each formulation, under this circumstance the synergistic effect for moulds has been calculated at 7 days. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply. Logarithmic reduction day Lb 0.5% G^* 0.5% G 0.5% (L+G')

Bacteria 7 0.8 0.1 4.2 0.9

Moulds 7 1 .8 0.8 2.9 2.6

Logarithmic reduction (G) > Logarithmic reduction (Lb) + Logarithmic reduction (G')

Example 9

Formulation I

Formulation I is a liquid with low viscosity and good stability. Formulations and Le are prepared to compare their antimicrobial efficiency with that of Formulation I , in order to see the separate contributions of LAE alone and the rest of ingredients without LAE.

Results of the challenge test are shown in the table below:

Formulation I at 0.5 % meets class A criteria, while LAE alone is not able to meet class A criteria at the same dosage (0.1 %). Formulation Γ is not able to preserve the formulation against bacteria, yeasts or moulds, since the chelating agent alone lacks of antimicrobial efficacy in this matrix. The combination of the two preservatives and chelating agents has the maximum antimicrobial effect. To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14 days for moulds. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply.

Logarithmic reduction (I) > Logarithmic reduction (Le) + Logarithmic reduction (Γ)

Example 10

This trial was performed with Formulation A (see Example 2) and Formulation B (see Example 6). I n this case the base is a cream-gel with a very high amount of anionic compound, which is well known to decrease LAE activity.

* SIMULGEL EPG (SEPPIC)

The test to check preservative performance was made inoculating three groups of microorganisms. Group I and Group II are bacteria, and Group III contains yeasts and moulds.

Results of the challenge test are shown in the table below:

Limit of detection: 100 CFU/g = 2 log CFU/g

From above table it is possible to conclude that in spite of the presence of anionic compounds, the presence of LAE in the blends is necessary in order to obtain a good preservation of the cream-gel. A' and B' fail to achieve the desired class A requirements of the European Pharmacopeia against both groups of Bacteria. The preservation ability of A' and B' against yeasts and moulds is good.

To demonstrate the synergistic effect of the combination the logarithmic reduction at 7 days has been taken for bacteria and at 14 days for moulds according to the European Pharmacopeia. However, in some cases the growth of moulds at day 14 is below the limit of detection in each formulation, under this circumstance the synergistic effect for moulds has been calculated at 7 days. In the case of yeasts, all treatments achieve complete elimination; therefore, the synergy calculation does not apply.

Claims

C LAI M S

1 . Concentrated preparations of 1 -60% by weight of the Ethyl Lauroyl Arginate HCI (LAE) comprising

(i) 1 to 99 % by weight of at least one solvent or surfactant selected from the group consisting of phenoxyethanol, benzyl alcohol, caprylyl glycol, hexylene glycol, pentylene glycol, decylene glycol, glyceryl monoester with a fatty acid selected from caprylic acid, capric acid, undecylenic acid and lauric acid, polyglycerine monoesters (polyglyceryl-3 caprylate), phenethyl alcohol, phenyl propanol and ethylhexyl glycerine, provided that when phenoxyethanol is present as the at least one solvent or surfactant its concentration shall be 2 to 99% by weight;

(ii) optionally 0-20 % by weight of one or more organic acids with antibacterial activity;

(iii) optionally 0- 0 % by weight of one or more natural extracts with

antibacterial activity;

(iv) optionally 0-10 % by weight of one or more chelating agents;

(v) optionally 0-10 % by weight of one or more antioxidants; and

(vi) optionally 0-50% by weight of one ore more solvents or surfactants without antibacterial activity.

2. A concentrated preparation according to claim 1 wherein the organic acids with antibacterial activity are selected from the group consisting of formic acid, acetic acid, propionic acid, lactic acid, undecylenic acid, lauric acid, sorbic acid, benzoic acid, cinnamic acid, salicylic acid, p-anisic acid, levulinic acid, dehydroacetic acid.

3. A concentrated preparation according to claim 1 wherein the natural extracts are selected from the group consisting of green tea extract, rosemary extract, cinnamon leaf oil, clove extract, curry leaf oil, orange oil, lemon grass oil, sesame oil, basil extract, clove bud oil, turmeric oil, ginger oil, thyme oil, anise oil, cinnamon bark oil, thymol, eugenol, anethole, propolis grape fruit seed extracts and zingerone.

4. A concentrated preparation according to claim 1 wherein the chelating agents selected from the group consisting of EDTA, citric acid, phytic acid, gluconic acid, gluconolactone, tetrasodium iminodisuccinate, tetrasodium dicarboxymethyl glutamate and trisodium ethylenediamine disuccinate, including their salts.

5. A concentrated preparation according to claim 1 wherein the antioxidants selected from the group consisting of tocopheryl acetate, tocopherols, flavonoids, flavonoids derivatives, ascorbic acid, ascorbyl palmitate, polyphenols,

butylhydroxytoluene, butylhydroxyanisole, tert-butylhydroquinone and di-tert- butylhydroquinone.

6. A concentrated preparation according to claim 1 wherein the solvents or surfactants without antibacterial activity are selected from water, low chain alcohols such as ethanol, isopropanol and butanol, glycols such as propylene glycol, ethylene glycol, thethylene glycol, diethylene glycol, dipropylene glycol, and 1 ,3-propanediol, glycerine, polyols such as sorbitol and xylitol, maltitol and erythritol, polysorbates, a Iky I polyglucoside, sucrose monoesters, vegetable oils, mineral oils, silicon oils

7. Concentrated preparations of 1 -60% by weight of the Ethyl Lauroyl Arginate HCI (LAE) consisting of

(ii) optionally 0-20 % by weight of one or more organic acids selected from the group consisting of formic acid, acetic acid, propionic acid, lactic acid, undecylenic acid, lauric acid, sorbic acid, benzoic acid, cinnamic acid, salicylic acid, p-anisic acid, levulinic acid, dehydroacetic acid; (iii) optionally 0-10 % by weight of one or more natural extracts selected from the group consisting of green tea extract, rosemary extract, cinnamon leaf oil, clove extract, curry leaf oil, orange oil, lemon grass oil, sesame oil, basil extract, clove bud oil, turmeric oil, ginger oil, thyme oil, anise oil, cinnamon bark oil, thymol, eugenol, anethole, propolis, grape fruit seed extracts and zingerone;

(iv) optionally 0-10 % by weight of one or more chelating agents selected from the group consisting of EDTA, citric acid, phytic acid, gluconic acid, gluconolactone, tetrasodium iminodisuccinate, tetrasodium dicarboxymethyl glutamate and trisodium ethylenediamine disuccinate, including their salts;

(v) optionally 0-10 % by weight of one or more antioxidants selected from the group consisting of tocopheryl acetate, tocopherols, flavonoids, flavonoids derivatives, ascorbic acid, ascorbyl palmitate, polyphenols, butylhydroxytoluene, butylhydroxyanisole, tert-butylhydroquinone and di-tert-butylhydroquinone; and

(vi) the remainder being water, low chain alcohols such as ethanol,

isopropanol and butanol, glycols such as propylene glycol, ethylene glycol, triethylene glycol, diethylene glycol, dipropylene glycol, and 1 ,3- propanediol, glycerine, polyols such as sorbitol and xylitol, matitol and erythritol, polysorbates, a Iky I polyglucoside, sucrose monoesters, vegetable oils, mineral oils, silicon oils.

8. A preparation according to claim 7 consisting of 17 % weight of LAE, 75 % weight of caprylyl glycol and 8 % by weight of glycerine.

9. A preparation according to claim 7 consisting of 10 % weight of LAE, 30 % by weight of caprylyl glycol, 40 % by weight of phenoxyethanol and 20 % by weight of glycerine.

10. A preparation according to claim 7 consisting of 10 % weight of LAE, 28 % by weight of caprylyl glycol, 37 % by weight of phenoxyethanol, 4 % by weight of sorbic acid, 1 1 % weight of glycerine and 10 % by weight of ethanol.

1 1 . A preparation according to claim 7 consisting of 20 % weight of LAE, 50 % by weight of glyceryl caprylate and 30 % by weight of ethanol.

12. A preparation according to claim 7 consisting of 15 % weight of LAE, 35 % by weight of benzyl alcohol, 40 % by weight of glyceryl caprylate and 10 % by weight of glycerine.

13. A preparation according to claim 7 consisting of 10 % weight of LAE, 66 % by weight of benzyl alcohol, 5 % by weight of cinnamic acid and 19 % by weight of glycerine.

14. A preparation according to claim 7 consisting of 20 % weight of LAE, 62 % by weight of benzyl alcohol, 3 % by weight of menthol, 5 % by weight of magnolia bark extract and 10 % by weight of salicylic acid.

15. , A preparation according to claim 7 consisting of 20 % weight of LAE, 22% by weight of benzyl alcohol, 5 % by weight of cinnamon leaf oil, 5 % by weight of cinnamic acid, 1 % by weight of tocopheryl acetate and 47 % by weight of glycerine.

16. A preparation according to claim 7 consisting of 10 % weight of LAE, 35% by weight of caprylyl glycol, 5 % by weight of gluconolactone, 15 % by weight of ethanol and 35 % by weight of deionised water.

17. Use of the concentrated preparations of any of the previous claims to be added as a preserving agent to a personal care formulation.

18. Cosmetic composition for personal care comprising a preservative system which comprises LAE and one or more solvents or surfactants selected from phenoxyethanol, benzyl alcohol, caprylyl glycol, hexylene glycol, pentylene glycol, decylene glycol, glyceryl monoester with a fatty acid selected from caprylic acid, capric acid, undecylenic acid and lauric acid, polyglycerine monoesters (polyglyceryl- 3 caprylate), phenethyl alcohol, phenyl propanol and ethylhexyl glycerine excluding phenoxyethanol alone, and optionally one or more organic acids with antibacterial activity and optionally one or more natural extracts with antibacterial activity and optionally one or more chelating agents and optionally one or more antioxidants; and optionally one ore more solvents or surfactants without antibacterial activity which preservative system is characterized for its enhanced preservative activity.