WO2012080994A2

WO2012080994A2 - N-acylated amino acid ester as soothing agent

Info

Publication number: WO2012080994A2
Application number: PCT/IB2011/055773
Authority: WO
Inventors: Francine Baldo
Original assignee: L'oreal
Priority date: 2010-12-17
Filing date: 2011-12-19
Publication date: 2012-06-21
Also published as: WO2012080994A3; FR2968952A1

Abstract

A subject-matter of the present invention is the cosmetic use of an N-acylated amino acid ester as soothing agent. The present invention also relates to an N-acylated amino acid ester as dermatological agent for the prevention and/or treatment of skin disorders comprising an inflammatory component, such as dry patches, oedema and/or pimples, inflammatory erythema, pruritus, psoriasis, cutaneous atopy, atopic dermatitis, urticaria, contact dermatitis,eczema, seborrhoeic dermatitis, acne and inflammatory hyperpigmentation.

Description

N-Acylated amino acid ester as soothing agent

A subject-matter of the present invention is the cosmetic use of an N-acylated amino acid ester of formula (A) defined below as soothing agent.

The present invention also relates to an N-acylated amino acid ester of formula (A) defined below for the use thereof in a cosmetic composition. Such a cosmetic composition can be intended in particular to prevent and/or treat at least one of the uncomfortable cutaneous reactions defined below.

The present invention also relates to an N-acylated amino acid ester of formula (A) defined below as dermatological agent for the prevention and/or treatment of skin disorders comprising an inflammatory component and to the use of such a compound in a dermatological composition intended to prevent and/or treat the skin disorders comprising an inflammatory component which are defined below.

Finally, the present invention relates to a nontherapeutic cosmetic method for soothing the skin and/or scalp, comprising at least one stage of application, to the skin and/or scalp, of a composition comprising at least one N-acylated amino acid ester of formula (A) defined below.

Cutaneous irritation or uncomfortable cutaneous reactions can be brought about by an exogenous stress, of chemical origin, for example xenobiotics, antigens, allergens, cosmetic products, compounds capable of provoking irritation of the skin, or peeling products; of environmental origin (temperature, climate, UV radiation, atmospheric pollution, in particular heavy metals, ozone, cigarette smoke, and the like) or of mechanical origin (rubbing actions, shearing actions, cleaning, and the like) , and by any stress of endogenous origin, such as disorders involving an inflammatory and/or hormonal mechanism affecting the skin, mucous membranes, scalp and/or hair.

Under specific circumstances, the use in cosmetic or dermatological compositions of topical compounds in high concentrations, clearly intended for other effects, can also result in the appearance of cutaneous irritation or uncomfortable cutaneous reactions.

Thus, use is made of cosmetic compositions comprising, for example, keratoylitic and/or desquamating active principles for combating ageing and in particular exfoliating active principles and/or active principles which promote cell replacement, such as a-hydroxy acids (in particular lactic acid, glycolic acid or citric acid) , β-hydroxy acids (in particular salicylic acid) or retinoids (in particular retinoic acids, all-trans- or 13-cis-retinol, adapalene, and the like) .

If these active principles are used in excessively large amounts, they may provoke cutaneous irritation or an uncomfortable cutaneous reaction on the skin. The use of these compounds, in particular for users having irritable or delicate skin and/or an irritable or delicate scalp, thus has to be limited.

In addition, even some compounds which are regarded as inert in a cosmetic or dermatological composition, such as, for example, preservatives, surfactants, fragrances, solvents or propellants, may exhibit an irritant nature when they are applied to keratinous substances and in particular the skin, including the scalp, in particular in subjects having irritable and/or allergic skin, this irritant nature depending on the compound used and on the sensitivity of the skin and of the resident skin flora of the user.

Compounds capable of provoking irritation of the skin or an uncomfortable cutaneous reaction are consequently generally used in low doses.

However, the use of small amounts of these compounds may then prove to be not very advantageous with respect to the use of other less reactive, but less or not irritating, compounds which can therefore be used in larger amounts, or with respect to the purpose of the compound, such as, for example, the stability of the composition when emulsifiers are concerned, or the satisfactory preservation of the composition, when preservatives are concerned.

The intensity or the seriousness of the cutaneous irritation discussed above may vary according to different criteria, such as skin and/or scalp which has been weakened and/or already damaged, reactive skin or skin affected by rosacea, indeed even irritable skin, and from the viewpoint of the degree of exogenous or endogenous stress.

Typically, with regard to exogenous stress of chemical origin, the more or less high concentration of (a) susceptible compound (s) may provoke irritation of the skin and/or scalp or will have an impact on the intensity of the cutaneous irritation.

Thus, according to a first aspect, the present invention relates to cutaneous reactions which are expressed in the form of types of discomfort experienced on the skin and/or scalp by the user.

The discomfort can typically be red blotches, itching, feelings of heat and/or burning, tingling sensations, or tightness.

Cosmetic treatments make it possible to overcome these types of discomfort. These types of discomfort can be experienced after stress of mechanical or environmental origin, in particular after shaving the skin (beard, legs) , during a sudden fall in temperature, after a peeling operation, microabrasion or microdermabrasion, or also cleaning the skin and/or scalp.

According to a second aspect, the present invention relates to other visible skin signs which may also appear, or skin disorders, advantageously requiring this type of dermatological treatment.

Mention may in particularly be made, among these visible skin signs or skin disorders, of dry patches, oedema and/or pimples, inflammatory erythema, pruritus, psoriasis, cutaneous atopy, atopic dermatitis, urticaria, contact dermatitis, eczema, seborrhoeic dermatitis, acne and inflammatory hyperpigmentation or also irritable cutaneous reactions.

The physiological endogenous stress causing the skin disorders can, for example, be related to the abnormal production of proinflammatory mediators

(neuromediators, cytokines, chemokines) .

These types of cutaneous irritation employ a cascade of reactions which, by the recruitment of infiltrating blood cells (neutrophils, macrophages, and the like) and the substances which they release (cytokines, lymphokines, chemokines, and the like) , give rise to the persistent irritating process which is characterized mainly by irritation of the skin or involution of the hair bulb and its matrix environment when located on the scalp.

Surprisingly, the Applicant Company has demonstrated the fact that the N-acylated amino acid esters of formula (A) , in particular isopropyl

N-lauroylsarcosinate, demonstrate properties which justify in particular the advantage thereof in incorporating them in soothing cosmetic compositions with the aim of preventing and/or treating uncomfortable cutaneous reactions, and in incorporating them in dermatological compositions with the aim of treating skin inflammation and/or irritation, on the other hand.

As indicated above, cosmetic care or dermatological treatment will be favoured according to the nature and the source of the cutaneous reaction.

The N-acylated amino acid esters of formula (A) have already been taken advantage of as emollients in the formulation of cosmetic compositions intended for the care of the skin.

They have also been described as solubilizing agents for some molecules which easily crystallize, such as certain imidopercarboxylic acid derivatives, such as described in Application FR 0 852 018.

However, to the knowledge of the inventors, no document mentions the antiirritant , soothing and/or anti^¬ inflammatory properties of the N-acylated amino acid esters of formula (A) .

Thus, the present invention is targeted at protecting, according to a first aspect, the cosmetic use of a compound of formula (A) :

R'i(CO)N(R'₂)CH(R'₃) (CH₂) _n (CO) OR' ₄ (A) in which:

n is an integer equal to 0, 1 or 2,

R' i represents a linear or branched C5 to C₂₁ alkyl or alkenyl radical,

R' ₂ represents a hydrogen atom or a Ci to C3 alkyl group, R' 3 represents a radical chosen from the group formed by a hydrogen atom, a methyl group, an ethyl group and a linear or branched C3 or C4 alkyl chain,

R' 4 represents a linear or branched Ci to C₁₀ alkyl radical, a linear or branched C₂ to C₁₀ alkenyl radical or a sterol residue, and

the part -N (R' ₂) CH (R' ₃) (CH₂) _n (CO) - is chosen from the following amino acids: valine, leucine, isoleucine, serine, threonine, proline, hydroxyproline, β-alanine, aminobutyric acid, aminocaproic acid, sarcosine or N-methyl-β-alanine,

as soothing agent.

Still according to this first aspect, the present invention is also targeted at protecting the cosmetic use of such a compound of formula (A) in accordance with the invention, the said compound being intended to prevent and/or treat uncomfortable cutaneous reactions of the skin and/or scalp. These cutaneous reactions can be chosen in particular from red blotches, itching, feelings of heat and/or burning, tingling and tightness .

Still according to this first aspect, the compound of formula (A) in accordance with the invention can be employed in a cosmetic composition. In addition, it can be employed in combination with at least one compound capable of provoking irritation of the skin and/or scalp .

The present invention is also targeted at protecting a nontherapeutic cosmetic method for soothing the skin and/or scalp, comprising at least one stage of application, to the skin and/or scalp, of a composition comprising at least one N-acylated amino acid ester of formula (A) in accordance with the invention.

According to the present invention, the term "uncomfortable cutaneous reaction" is understood to mean all discomfort of the skin and/or scalp provoked by the types of stress brought to mind above and taking in particular the form of red blotches, itching, feelings of heat and/or burning, tingling or tightness.

These uncomfortable cutaneous reactions are advantageously induced by at least one condition chosen from the action of a peeling product, of microabrasion or microdermabrasion, of cleaning the skin and/or scalp, of shaving the skin, of temperature or of climate .

The present invention is also targeted at protecting, according to a second aspect, a compound of formula (A) in accordance with the invention as dermatological agent for the prevention and/or treatment of skin disorders comprising an inflammatory component.

Thus, the compound of formula (A) in accordance with the invention is more particularly of use in combating skin disorders chosen from dry patches, oedema and/or pimples, inflammatory erythema, pruritus, psoriasis, cutaneous atopy, atopic dermatitis, urticaria, contact dermatitis, eczema, seborrhoeic dermatitis, acne and inflammatory hyperpigmentation.

Still according to this second aspect, the compound of formula (A) in accordance with the invention can be employed in a dermatological composition. In addition, it can be employed in combination with at least one compound capable of provoking irritation of the skin and/or scalp.

The present invention is furthermore targeted at a compound of formula (A) in accordance with the invention as antiirritant and/or antiinflammatory agent .

Finally, the present invention is targeted composition, in particular a dermatological composition, comprising a compound of formula (A) in accordance with the invention, intended to treat cutaneous irritation and/or inflammation, in particular of the skin and/or scalp.

According to the present invention, "cutaneous disorder" comprising an inflammatory component is understood to mean all manifestations on the skin and/or scalp provoked by inflammatory and/or allergic reactions, whatever the source thereof, which may be given material form by the appearance of dry patches, oedema and/or pimples, inflammatory erythema, pruritus, psoriasis, cutaneous atopy, atopic dermatitis, urticaria, contact dermatitis, eczema, seborrhoeic dermatitis, acne and/or inflammatory hyperpigmentation.

It is thus possible to use, including in compositions intended for irritable and/or allergic skin and/or mucous membranes and/or scalps, agents capable of provoking irritation of the skin, such as cosmetic active principles (e.g.: keratolytic and/or desquamating agents) , dermatological active principles (e.g.: retinoids), some surfactants (preservatives, fragrances, solvents, propellants) and their mixtures, provided that the said cosmetic or dermatological compositions comprise at least one N-acylated amino acid ester of formula (A) , preferably isopropyl N-lauroylsarcosinate.

The term "irritable and/or allergic skin and/or mucous membranes and/or scalps" is understood to mean, according to the invention, skin and/or mucous membranes and/or scalps which react to external attacks, sometimes in an exaggerated fashion.

Such skin and/or mucous membranes and/or scalps are then more subject to the development of a cutaneous reaction which may involve immunological or inflammatory mechanisms, in contrast to a cutaneous reaction involving mechanisms of neurogenic origin characterizing sensitive skin.

The term "to prevent" or "prevention" is understood to mean, according to the invention, the fact of reducing the risk of the occurrence or of slowing down the occurrence of a given phenomenon, namely, according to the first aspect of the present invention, the effect of discomfort generated by cutaneous reactions, such as red blotches, itching, feelings of burning, tingling and tightness, or skin disorders comprising an inflammatory component, such as set out above.

A composition in accordance with the invention, namely intended for the implementation of the invention, can be a cosmetic or dermatological composition according to the application envisaged and thus comprises a physiologically acceptable medium.

The term "physiologically acceptable medium" is understood to mean a medium compatible with all keratinous substances, such as skin, scalp, nails, mucous membranes, eyes and hair, or any other cutaneous region of the body. A physiologically acceptable medium is preferably a cosmetically or dermatologically acceptable medium, that is to say a medium without unpleasant odour, colour or appearance, which is fully compatible with the administration route under consideration.

According to the invention, the term "soothing agent" is understood to mean an agent which helps in reducing the discomfort of the skin and/or scalp, for example by soothing the feelings of itching or by toning down the red blotches, it being possible, for example, for this discomfort to be due to the dehydration thereof or to the application of a mechanical stress (shaving) . N-ACYLATED AMINO ACID ESTERS

The N-acylated amino acid ester according to the present invention is advantageously chosen from the N-acylated amino acid esters of formula (A) as defined above .

In the formula (A) of the amino acid esters presented above, the R'i(CO)- group is an acyl group of an acid preferably chosen from the group formed by capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, linoleic acid, linolenic acid, oleic acid, isostearic acid, 2-ethylhexanoic acid, coconut oil fatty acids and palm kernel oil fatty acids .

In addition, these fatty acids may exhibit a hydroxyl group .

More preferably still, the acid will be an acid chosen from the group formed by capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid .

It will preferably be lauric acid.

The -N (R'₂) CH (R'₃) (CH₂) _n (CO) - part of the amino acid ester is chosen from the following amino acids: valine, leucine, isoleucine, serine, threonine, proline, hydroxyproline, β-alanine, aminobutyric acid, aminocaproic acid, sarcosine or N-methyl-p-alanine .

More preferably still, it will be sarcosine.

The part of the amino acid esters corresponding to the -OR' 4 group can be obtained from the alcohols chosen from the group formed by methanol, ethanol, propanol, isopropanol , butanol , tert-butanol, isobutanol ,

3-methyl-l-butanol, 2-methyl-l-butanol, fusel oil, pentanol , hexanol, cyclohexanol , octanol ,

2-ethylhexanol, decanol, lauryl alcohol, myristyl alcohol, cetyl alcohol, cetearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, jojoba alcohol, 2-hexadecyl alcohol, 2-octyldodecanol and isostearyl alcohol.

Preferably, the alcohols will be chosen from the group formed by methanol, ethanol, propanol, isopropanol, butanol, tert-butanol, isobutanol, 3-methyl-l-butanol and 2-methyl-l-butanol, preferably formed by methanol, ethanol, propanol, isopropanol and butanol.

Preferably, the alcohol will be isopropanol.

These amino acid esters can be obtained in particular from natural sources of amino acids. In this case, the amino acids originate from the hydrolysis of natural plant proteins (oats, wheat, soya, palm, coconut) and then necessarily result in mixtures of amino acids which will subsequently have to be esterified and then N-acylated. The preparation of such amino acids is more particularly described in Patent Application FR 2 796 550, which is incorporated here by way of reference .

According to a preferred embodiment, an N-acylated amino acid ester which is particularly suitable in the invention is of formula (A), in which:

- the R'i(CO)- group is an acyl group of an acid chosen from the group formed by capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid, preferably lauric acid,

- the -N (R'₂) CH (R'₃) (CH₂) _n (CO) - part is sarcosine, and

- the part of the amino acid esters corresponding to the -OR' 4 group is obtained from the alcohols chosen from the group formed by methanol, ethanol, propanol, isopropanol and butanol, preferably isopropanol.

The N-acylated amino acid ester more particularly preferred for the use thereof in the present invention is isopropyl N-lauroylsarcosinate of formula (B) :

ρ^υ·™·¹·^- NCHjG—OCHCBs

CN₃ CH3 (_B) such as the product sold under the trade name "Eldew SL-205" by Ajinomoto.

According to the present invention, the N-acylated amino acid ester can be used in an amount sufficient to produce the desired effect, that is to say in an amount sufficient to sooth the skin and/or scalp or to prevent and/or treat irritation of the skin and/or scalp or an uncomfortable cutaneous reaction induced by any type of stress mentioned above, for example by a compound capable of inducing cutaneous irritation.

Preferably, an N-acylated amino acid ester in accordance with the invention is employed in a content ranging from 0.1% to 25% by weight, preferably from 0.5% to 15% by weight, preferably from 1% to 10% by weight and very preferably from 1% to 5% by weight, with respect to the total weight of the cosmetic composition .

Preferably, an N-acylated amino acid ester in accordance with the invention is employed in a content ranging from 0.1% to 30% by weight, preferably from 1% to 15% by weight, with respect to the total weight of the dermatological composition. COMPOSITION

According to a first embodiment of the invention, an N-acylated amino acid ester in accordance with the invention can be incorporated in a cosmetic composition intended to prevent and/or treat at least one of the uncomfortable cutaneous reactions defined above.

According to a second embodiment of the invention, an N-acylated amino acid ester in accordance with the invention can be incorporated in a dermatological composition intended to prevent and/or treat at least one of the skin disorders defined above.

As indicated above, a composition in accordance with the invention comprises a physiologically acceptable medium.

The physiologically acceptable medium can comprise water or organic solvents, such as Ci-Cs alcohol, in particular ethanol, isopropanol, tert-butanol or n-butanol; a polyol, such as glycerol; a glycol, such as butylene glycol, isoprene glycol, propylene glycol or polyethylene glycols, such as PEG-8; polyol ethers; acetone; or ethyl acetate.

A composition according to the invention is preferably intended for topical use.

A composition in accordance with the invention can thus constitute a composition for the treatment or care of the skin (including the scalp) , keratinous fibres (hair, eyelashes, eyebrows) , nails or lips, or a sun- protection or artificial-tanning composition, or a product for cleaning or removing makeup from the skin, hair, eyebrows or eyelashes, a deodorant product or also a scenting product. It is then generally colourless or weakly coloured, and it can optionally comprise cosmetic or dermatological active principles. It can then be used as care base for the skin or lips (lip balms, which protect the lips from the cold and/or the sun and/or the wind) or as day or night care cream for the skin of the face and/or body. In addition, it can be provided in a form of a treating or nontreating and colouring or noncolouring shampoo and of a conditioning compound.

A composition in accordance with the invention can also constitute a coloured cosmetic composition and in particular a composition for making up the skin, keratinous fibres (hair or eyelashes) and/or mucous membranes, in particular a foundation, a blusher, a face powder, an eye shadow, a mascara, an eyeliner, a concealer compound in the form of a stick, an nail varnish, a lipstick or a lip gloss, optionally exhibiting care or treatment properties.

A composition in accordance with the invention can be provided in the formulation forms conventionally used for topical application and in particular in the form of dispersions of the lotion or serum type, of emulsions with a liquid or semiliquid consistency of the milk type, obtained by dispersion of a fatty phase in an aqueous phase (O/W) or vice versa (W/O), or of suspensions or emulsions with a soft, semisolid or solid consistency of the cream or gel type, or of multiple (W/O/W or 0/W/O) emulsions, of microemulsions , of vesicular dispersions of ionic and/or nonionic type, or of wax/aqueous phase dispersions. These compositions are prepared according to the usual methods .

The composition can also be provided in the form of a transdermal system which makes possible active or passive release of the active principle (s) by passage through the skin, for example of patch or gel patch (hydrogel) type.

When a composition in accordance with the invention is in the form of an emulsion, the proportion of the oily phase of the emulsion can range, for example, from 5% to 80% by weight and preferably from 5% to 50% by weight, with respect to the total weight of the composition. The oils, the emulsifiers and the coemulsifiers used in the composition in the form of an emulsion are chosen from those conventionally used in the cosmetics or dermatological field.

The emulsifier and coemulsifier generally present in a composition in accordance with the invention in a proportion ranging from 0.3% to 30% by weight and preferably from 0.5% to 20% by weight, with respect to the total weight of the composition. In addition, the emulsion can comprise lipid vesicles.

Use may also advantageously be made, in a composition in accordance with the invention, of moisturizing agents, among which may in particular be mentioned:

- glycerol,

- (hydroxyethyl ) urea or Hydrovance® from National Starch,

- polyols,

- amino acids and their N-acylated derivatives,

- pyrrolidone carboxylic acid and its salts and N-acylated derivatives,

- sugars, their alkyl ethers and their alkyl esters,

- heterogeneous polysaccharides,

- trehalose,

- ectoin,

- glycosaminoglycans and their sulphates,

- phospholipids and polymers comprising phosphorylcholine groups,

- cholesterol,

- phytosterols , and

- hyaluronic acid.

Use will be made, as oils, for example, of hydrocarbon oils of vegetable origin, synthetic esters and ethers, silicone oils and their mixtures.

It will also be possible to add surface-active agents in order to homogenize the mixture of the aqueous and nonaqueous phases.

Furthermore, as set out above, a compound of formula (A) in accordance with the invention also exhibits the advantage of preventing and/or treating cutaneous irritation or an uncomfortable cutaneous reaction which might have been provoked by a compound capable of provoking irritation of the skin and/or scalp, and also of making it possible to increase the amount of this compound having irritant nature in cosmetic or dermatological compositions in comparison with the normal amount used, for the purpose of an increase in effectiveness of these compounds.

Thus, according to one embodiment of the invention, an N-acylated amino acid ester in accordance with the invention can be incorporated in a cosmetic or dermatological composition which comprises a compound capable of provoking irritation of the skin and/or scalp .

According to another embodiment, the said N-acylated amino acid ester in accordance with the invention can be incorporated in a separate cosmetic or dermatological composition, according to the aspect of the invention as discussed above, intended to prevent and/or treat cutaneous irritation or an uncomfortable cutaneous reaction, which will be applied after and/or before the cosmetic and/or dermatological composition comprising the compound capable of provoking irritation of the skin and/or scalp, depending on whether it is desired to set in motion an inflammatory phase, which may be of use in said applications (vasodilation, depilation, and the like) or, on the contrary, to prevent it. In the case of certain desquamating agents or peeling agents, for example, it may in fact be advantageous to apply, in a first step, the composition comprising the said peeling agent and then, in a second step, to apply a soothing composition comprising at least one N-acylated amino acid ester in accordance with the invention, the said at least one N-acylated amino acid ester in accordance with the invention being intended to reduce the discomfort reactions generated by the peeling and thus to sooth the skin and/or scalp.

Thus, according to an alternative form of the invention, an N-acylated amino acid ester in accordance with the invention is incorporated in a separate composition intended to be applied after the cosmetic or dermatological composition comprising at least one compound capable of provoking irritation of the skin and/or scalp.

According to another alternative embodiment in accordance with the invention, an N-acylated amino acid ester in accordance with the invention is incorporated in a separate composition intended to be applied before the cosmetic or dermatological composition comprising at least one compound capable of provoking irritation of the skin and/or scalp.

Mention may in particular be made, among these compounds capable of provoking irritation of the skin and/or scalp, of cosmetic compounds or active principles, dermatological compounds or active principles, surfactants, in particular anionic surfactants, preservatives, detergents, fragrances, in particular scenting alcoholic solutions, solvents, propellants and their mixtures.

Mention may more particularly be made, as dermatological or cosmetic active principles, of certain desquamating agents which may also be peeling agents .

Mention may be made, among peeling agents specifically, of abrasive/exfoliating particles from natural or synthetic, organic or mineral sources. Mention may more particularly be made of pumice particles, silica particles, polyethylene beads, nylon beads and fruit kernel powders.

Among these desquamating agents, the following are capable of provoking irritation of the skin and/or scalp: saturated monocarboxylic acids (acetic acid) and unsaturated monocarboxylic acids, saturated and unsaturated dicarboxylic acids, saturated and unsaturated tricarboxylic acids; a-hydroxy acids and β-hydroxy acids of monocarboxylic acids; a-hydroxy acids and β-hydroxy acids of dicarboxylic acids; a-hydroxy acids and β-hydroxy acids of tricarboxylic acids, keto acids, a-keto acids, β-keto acids of polycarboxylic acids, of polyhydroxymonocarboxylic acids, of polyhydroxydicarboxylic acids and of polyhydroxytricarboxylic acids.

Mention may particularly be made, among a-hydroxy acids or their esters, of: glycolic acid, dioic acids, such as octadecenedioic acid or Arlatone Dioic DCA, sold by Uniqema, citric acid, lactic acid, tartaric acid, malic acid or mandelic acid, or their esters, such as the di (C₁₂/C₁3) alkyl tartrate or Cosmacol ETI, or the citrate triester of branched C₁₂-13 alcohols or Cosmacol ECI, sold by Sasol.

Mention may be made, among the β-hydroxy acids, of: salicylic acid and its derivatives (including 5- (n-octanoyl ) salicylic acid).

Mention may be made, among the a-keto acids, of ascorbic acid and its derivatives. Mention may be made, among the other desquamating agents, of: pyruvic acid, gluconic acid, glucuronic acid, ketogulonic acid, glycolic acid, oxalic acid, malonic acid, succinic acid, acetic acid, gentisic acid, cinnamic acid or azelaic acid; phenol; resorcinol; urea and its derivatives,

(hydroxyethyl ) urea or Hydrovance® from National Starch; oligofucoses ; jasmonic acid and its derivatives; ascorbic acid and its derivatives; trichloroacetic acid; Saphora japonica extract and resveratrol.

Among the desquamating agents, those capable of acting on the enzymes involved in the desquamation or the decomposition of corneodesmosomes may also be capable of provoking irritation of the skin and/or scalp or an uncomfortable cutaneous reaction.

Mention may in particular be made, among these, of chelating agents with inorganic salts, such as EDTA; N-acyl-Ν,Ν' ,Ν' -ethylenediaminetriacetic acid; aminosulphonic compounds and in particular N- (2- hydroxyethyl ) piperazine-N' -2-ethanesulphonic acid (HEPES) ; 2-oxothiazolidine-4-carboxylic acid

(procysteine) derivatives; derivatives of a-amino acids of glycine type (as described in EP 0 852 949, and the sodium methylglycinediacetate sold by BASF under the trade name Trilon M®) ; honey; or sugar derivatives, such as O-octanoyl-6-D-maltose, O-linoleyl- 6-D-glucose and N-acetylglucosamine .

Retinoids are also compounds capable of provoking irritation of the skin and/or scalp. Mention may be made, for example, among them, of retinol and its esters, retinal, retinoic acid and its derivatives, such as those described in the documents FR-A-2 570 377, EP-A-199 636, EP-A-325 540 and EP-A- 402 072, and adapalene. The salts and derivatives, such as the cis or trans forms, the racemic mixtures and the dextrorotatory or laevorotatory forms of the compounds mentioned above are also regarded as compounds capable of provoking irritation of the skin and/or scalp.

Other dermatological or cosmetic active principles capable of provoking irritation of the skin and/or scalp are also mentioned below:

- urea and its derivatives, such as (hydroxyethyl ) urea or Hydrovance® from National Starch,

- certain vitamins, such as vitamin D and its derivatives, such as vitamin D3, vitamin D2, calcitriol, calcipotriol , tacalcitol, 24,25-diOH- vitamin D3, 1-OH-vitamin D2 and 1 , 24-diOH-vitamin D2 ; or vitamin B9 and its derivatives,

- peroxides, such as benzoyl peroxide or aqueous hydrogen peroxide solution,

- agents for combating hair loss, such as minoxidil and its derivatives, such as aminexil,

- hair dyes and colorants, such as aminophenols and their derivatives, for example para- phenylenediamine (p-PDA) , N-phenyl-p-PDA, toluene- 2,5-diamine sulphate, meta-phenylenediamine (m-PDA) , toluene-3, 4-diamine and ortho-phenylenediamine (o-PDA) ,

- antiperspirant agents, such as aluminium salts, for example aluminium chlorohydrate,

- deodorant agents,

- depilatory and/or permanent-wave active principles, such as thioglycolates or aqueous ammonia solution,

- thioglycolate and its salts,

- phenoxyethanol,

1, 2-pentanediol,

- scenting alcoholic solutions (fragrances, eaux de toilette, aftershaves or deodorants) ,

- anthralins (dioxyanthranol ) ,

- anthranoids (for example those described in the document EP-A-319028) , - lithium salts,

- depigmenting agents (e.g.: hydroquinone, vitamin C at a high concentration, kojic acid),

- certain slimming active principles having a warming effect,

- nicotinates and their derivatives,

- capsaicin,

- antilouse active principles (pyrethrin) ,

- antiproliferatives, such as 5-fluorouracil or methotrexate,

- antiviral agents,

antiparasitics,

antifungals,

antipruritics,

- antiseborrhoeics ,

- certain sunscreens,

- H₂O₂ donors resulting in effects of loss of non- scalp hair,

- agents for the treatment of greasy skin, such as, for example, certain antibacterials , or benzoyl peroxide ,

- propigmenting agents, such as psoralens and methylangelicins , and

- their mixtures.

Mention may be made, as preservatives, of phenoxyethanol , chlorhexidine and benzalconium chloride .

Mention may be made, as surfactants, of anionic, cationic and amphoteric surfactants, more particularly anionic surfactants, such as alkyl sulphates and alkyl ether sulphates, for example lauryl sulphate and lauryl ether sulphate, and their salts, in particular sodium salts .

According to a preferred embodiment of the invention, the compouind capable of provoking irritation of the skin and/or scalp is chosen from retinoids, -hydroxy acids, β-hydroxy acids, saturated and unsaturated dicarboxylic acids, such as octadecenedioic acid or Arlatone Dioic DCA, sold by Uniqema, anionic, cationic or amphoteric surfactants, 5- (n-octanoyl ) salicylic acid, antiperspirant active principles, such as aluminium salts, N- (2-hydroxyethyl) piperazine-N' -2- ethanesulphonic acid (HEPES) and cinnamic acid and their mixtures, and also desquamating agents, such as ketogulonic acid or glycolic acid.

The compound capable of provoking irritation of the skin and/or scalp can be present in the composition in accordance with the present invention in an amount sufficient to provoke an irritation reaction of the skin and/or scalp. By way of example, it can be present in a content ranging from 0.0001% to 70% by weight, preferably from 0.01% to 50% by weight and better still from 0.1% to 30% by weight, with respect to the total weight of the composition.

The N-acylated amino acid ester used according to the invention can also be combined with at least from 0.00001% to 95% by weight and preferably from 0.1% to 20% by weight of an antiinflammatory agent, a soothing agent or their mixture.

Mention may be made, as examples of "antiinflammatory agents", of:

- an antagonist of inflammatory cytokines;

- a steroidal antiinflammatory (hydrocortisone, betamethasone, dexamethasone, and the like) ;

- a nonsteroidal antiinflammatory, such as aspirin or paracetamol;

and their mixtures.

The term "antagonist of inflammatory cytokines" according to the invention is understood to mean a compound capable of inhibiting the synthesis and/or the release of one or more inflammatory cytokines. The definition of an antagonist of inflammatory cytokines also includes compounds which inhibit or block the binding of these cytokines to their receptor (s) .

Mention may be made, for example, of the compounds which are antagonists of IL-1, of IL-8, of TNF-a and of TNF-β, the tripeptide Lys-Pro-Val (KPV) , and all the aMSH derivatives and related peptidomimetics characterized by an activity of aMSH type by binding to the receptor or by control of the release of IL1, IL8 or TNF-a, all the inhibitors of cytokine release (therapeutic category of the CSAIDs, for cytokine suppressive antiinflammatory drugs) , the family of substituted pyrimidine N-oxides (EP99401719.2 (priority FR9809509) and EP99402771.2 (priority FR9814211)) lipoxin A4 inducers, algal extracts capable of modulating the production of cytokines by keratinocytes , such as Phycosaccharide® sold by Codif, the aqueous/glycolic extract of the alga Laminaria saccharina, in particular Phlorogine®, sold by SECMA, extracts of Aloe vera or Gingko biloba; the natural antagonist of IL-1 (IL-1RA) and the extract of the bark and roots of Terminalia sericea or Sericoside 3058500, sold by Indena.

According to a specific embodiment of the invention, the antiinflammatory agent is chosen from algal extracts capable of modulating the production of cytokines by keratinocytes, such as Phycosaccharide®, sold by Codif, the aqueous/glycolic extract of the alga Laminaria saccharina, in particular Phlorogine®, sold by Secma, Aloe vera extracts, the extract of the bark and roots of Terminalia sericea or Sericoside 3058500, sold by Indena, or peptide derivatives, such as Skinasensyl® from Cognis LS .

The antiinflammatory agents are preferably present in the compositions in accordance with the invention at a concentration which can vary from 0.00001% to 10% by weight approximately, with respect to the total weight of the composition. More preferably, the concentration of antiinflammatory compound can vary between 0.0005% to 2% by weight, with respect to the total weight of the composition.

Mention may be made, as examples of "soothing agents" which can be used in the compositions in accordance with the invention, of:

• allantoin;

• β-glycyrrhetinic acid, the extracts comprising it, such as, for example, the extract of Glycyrrhiza glabra (liquorice) , and the complexes comprising it, such as the allantoin/glycyrrhetinic acid complex;

• lyophilized or nonlyophilized plankton, the extracts thereof and the complexes thereof;

• aescin and the plant extracts comprising it, such as horse chestnut extract;

• xanthine derivatives, such as diethylaminoethyltheophylline hydrochloride ;

• waters and extracts (for example aqueous, aqueous/ alcoholic or aqueous/glycolic extracts) of flowers and plants, such as cornflower water, camomile water, mint water, lime water, rose water, Rosaceae (e.g.: Rosa gallica) extracts, peony extracts, hawthorn extracts, yarrow extracts, mallow extracts, marigold extracts, sweet clover extracts, sage extracts, elderberry water, Ginkgo biloba extracts, arnica extracts, oregano extracts, green tea extracts, waterlily flower extracts, iris extracts, birch bark extracts or Aloe vera extracts;

• asiatic acid and the plant extracts comprising it, such as Centella asiatica;

• bisabolol;

• fruit extracts, such as pineapple extract, papaya extract or guava extract;

• algae, in particular of the Laminaria type (for example, red or brown algae) , such as the extract of brown alga Padina pavonica, for example HPS 3 Padina Pavonica, sold by Alban Muller;

pyrrolidonecarboxylates and in particular zinc pyrrolidonecarboxylate (Zn-PCA) or copper pyrrolidonecarboxylate (Cu-PCA) ;

oils of vegetable origin, such as canola seed oil and shea butter oil;

essential oils, for example of coriander, of balm, of lavender, of mint or of camomile, and their mixtures; acexamic acid and tranexamic acid (trans-4- ( aminomethyl) cyclohexanecarboxylic acid) ;

ursolic acid and the extracts comprising it, such as rosemary leaf extract;

polysaccharides comprising fucose, such as Fucogel 1000, sold by Solabia (aqueous solution comprising 1% by dry weight of polysaccharide comprising fucose, galactose and galacturonic acid) ; electrolytes and in particular an aqueous mixture comprising from 30% to 35% of magnesium chloride, from 20% to 28% of potassium chloride, from 3% to 10% of sodium chloride, from 0.2% to 1% of calcium chloride, from 0.1% to 0.6% of magnesium bromide and from 0.1% to 0.5% of insoluble materials, the said mixture being referred here to as "Dead Sea bath salts" as it corresponds to the main salts present in the Dead Sea;

galactolipids , for example resulting from oats, such as, for example, digalactosyl diglyceride or monogalactosyl diglyceride;

amino acids, their derivatives and their salts, such as the sodium salt of amino acids grafted to cocoyl chains, sold in the form of a mixture under the name Sepicalm S by Seppic, capryloylglycine, sold under the name Lipacide C8G by Seppic, and the mixture of capryloylglycine, of cinnamon and of sarcosine sold under the name Sepicontrol A5 by Seppic;

TNF-a antagonists, such as lisofylline, A802715, sulfasalazine, CDP-571 (anti-TNF-a) antibody or MDL-201112;

substance P antagonists, such as sendide, spantide II, the peptides described in Application EP-A-680749 and the filamentous bacterium extracts described in Application EP-A-761204;

• CGRP antagonists, such as CGRP 8-37, anti-CGRP antibodies or plant extracts having a CGRP-antagonist activity (e.g.: Iris pallida) .

• divalent strontium, zinc, manganese, magnesium or calcium salts, such as those described in the documents WO-A-96/19184, WO-A-96/19182 and WO-A-96/19228;

and their mixtures.

In particular, the soothing agent can advantageously be chosen from allantoin, β-glycyrrhetinic acid, the extracts comprising it, such as, for example, the extract of Glycyrrhiza glabra (liquorice) , and the complexes comprising it, such as the allantoin/glycyrrhetinic acid complex; lyophilized or nonlyophilized plankton, the extracts thereof and the complexes thereof; waters and extracts of flowers and plants: camomile water, lime water, rose water or birch extracts; bisabolol; essential oils, for example of coriander; algae, in particular of the Laminaria type (for example, red or brown algae) , such as the extract of brown alga Padina pavonica , for example HPS 3 Padina Pavonica, sold by Alban Muller; acexamic acid and tranexamic acid (trans-4- (aminomethyl) cyclohexane- carboxylic acid) ; ursolic acid and extracts comprising it, such as the rosemary leaf extract; polysaccharides comprising fucose, such as Fucogel 1000, sold by Solabia; electrolytes and in particular an aqueous mixture, such as "Dead Sea bath salts"; amino acids, such as Sepicalm S and VG from Seppic, and divalent magnesium salts, such as magnesium gluconate.

The expression "of between" or "ranging from" should be understood as meaning limits included.

The examples below are given by way of illustration, without any limiting nature.

Unless otherwise indicated, the values in the examples below are expressed as % by weight, with respect to the total weight of the composition.

In the examples below, the compounds are, as the case may be, cited by their chemical names or by their CTFA names (International Cosmetic Ingredient Dictionary and Handbook) . The compositions are produced in a way conventional to persons skilled in the art.

EXAMPLES

Example 1: Evaluation of the antiinflammatory effects of the N-acylated amino acid ester

Protocol

The test consists in evaluating the effects of Eldew SL-205 on the response of the surface epidermal cells to an irritant agent, such as PMA (phorbol myristate acetate) . This is because PMA stimulates the secretion of IL-8 and PGE2.

In this test, an irritant situation for the skin, the production of IL-8 and PGE2 being intensified.

NCTC human keratinocytes (NCTC-2544) are cultured in 96-well plates for 24 hours. These cells are subsequently treated (or not, in the case of the controls) with Eldew SL-205 and incubated for 24 hours at 37°C and 5% C0₂.

After incubation, the cells are again treated (or not, in the case of the controls) with medium comprising the irritation inductor (PMA 0.1 yg/ml) and then again left to incubate for 24 hours.

An inductor-free control was carried out and all the treatments were carried out in n=3. The supernatants are subsequently collected in order to assay the amounts of IL-8 and PGE2 secreted.

The assaying of these markers of inflammation was carried out using ELISA kits according to the procedures recommended by the supplier. The Eli-pair kit, sold by Diaclone under the reference 851.530.015, was employed for the assaying of IL-8 and the kit sold by R&D Systems under the reference KGE004 was employed for the assaying of PGE2.

The PMA strongly stimulated the secretion both of the IL-8 (108.3 yg/ml) and of PGE2 (384.5 ng/ml) .

The reference compounds dexamethasone (10^~7) and indomethacin (10^~6) respectively blocked these effects, which thus validates the tests.

Results

The Eldew was tested, in the presence of PMA, at concentrations of 0.00002%, 0.0002% and 0.002%.

Table 1: Assaying of IL-8 and PGE2 secreted by the NCTC cells stimulated by PMA

Significant difference with respect to the control * p<0.05, ** p<0.01, *** p<0.001.

The Eldew significantly inhibits, and in a concentration dependent way, the secretion of IL-8 and PGE2, without any cytotoxic effect being observed.

Various compositions in accordance with the invention, comprising in particular Eldew SL 205, were prepared in a conventional way. They are expanded upon below.

Example 2 : Compositions

2.1 Shaving foam

* Sold under the trade name Eldew SL 205 by Ajinomoto ** Sold under the trade name Symwhite® Bio P 377 Symrise . Retinol-comprising treating cream

old under the trade name Eldew SL 205 by Ajinomoto. Treating lotion

% by weight

Isopropyl lauroyl sarcosinate* 3.00

Myrtrimonium bromide 0.03

Disodium EDTA 0.08

PEG-8 5.00

Glycerol 3.00

Castor oil 0.50

Phenylethylbenzenediol 0.50 Xanthan gum 0.20

Preservative 0.80

Fragrance 0.08

Water q . s . for 100

* Sold under the trade name Eldew SL 205 by Ajinomoto.

2.4 Aftersun soothing cream gel

* sold under the trade name Eldew SL 205 by Ajinomoto.

All these compositions make it possible to obtain soothing action.

Claims

1. Cosmetic use of a compound of formula i (CO)N(R'₂)CH(R'₃) (CH₂)n(CO)OR'₄ (A) in which:

n is an integer equal to 0, 1 or 2,

R' i represents a linear or branched C5 to C₂₁ alkyl or alkenyl radical,

R' ₂ represents a hydrogen atom or a Ci to C3 alkyl group,

R' 3 represents a radical chosen from the group formed by a hydrogen atom, a methyl group, an ethyl group and a linear or branched C3 or C4 alkyl chain,

as soothing agent.

2. Cosmetic use according to Claim 1, characterized in that the said compound of formula (A) is isopropyl N-lauroylsarcosinate of following formula (B) :

O O

CH₃(CH₂)₁₀C— NCH₂C OCHCH₃

CH₃ CH₃

(B)

3. Cosmetic use according to either one of the preceding claims, the said compound being intended to prevent and/or treat uncomfortable cutaneous reactions of the skin and/or scalp chosen from red blotches, itching, feelings of heat and/or burning, tingling and tightness .

4. Cosmetic use according to Claim 3, the said uncomfortable cutaneous reactions being induced by at least one condition chosen from the action of a peeling product, of microabrasion or microdermabrasion, of cleaning the skin and/or scalp, of shaving the skin, of temperature or of climate.

5. Cosmetic use according to one of the preceding claims, the said compound being present in a cosmetic composition intended in particular to prevent and/or treat at least one of the uncomfortable cutaneous reactions defined in Claim 3 or Claim 4.

6. Cosmetic use according to Claim 5, characterized in that the said compound is employed in a content ranging from 0.1% to 25% by weight, preferably from 0.5% to 15% by weight, preferably from 1% to 10% by weight and very preferably from 1% to 5% by weight, with respect to the total weight of the cosmetic composition .

7. Cosmetic use according to either of Claims 5 and 6, characterized in that the said cosmetic composition additionally comprises at least one compound capable of provoking irritation of the skin and/or scalp.

8. Cosmetic use according to either of Claims 5 and 6, characterized in that the said cosmetic composition is intended to be applied after and/or before a cosmetic and/or dermatological composition comprising a compound capable of provoking irritation of the skin and/or scalp.

9. Cosmetic use according to either of Claims 7 and 8, characterized in that the said compound capable of provoking irritation of the skin and/or scalp is chosen from cosmetic active principles, dermatological active principles, surfactants, fragrances and scenting alcoholic solutions, solvents, propellants, preservatives, detergents and their mixtures.

10. Nontherapeutic cosmetic method for soothing the skin and/or scalp, comprising at least one stage of application, to the skin and/or scalp, of a composition comprising at least one compound as defined in Claim 1 or Claim 2.

11. Compound of formula (A) as defined in either of Claims 1 and 2, as dermatological agent for the prevention and/or treatment of skin disorders comprising an inflammatory component.

12. Compound of formula (A) as defined in either of Claims 1 and 2, as antiirritant and/or antiinflammatory agent .

13. Compound according to Claim 11 as active principle in a dermatological composition intended to prevent and/or treat skin disorders comprising an inflammatory component .

14. Compound according to any one of Claims 11 to 13, characterized in that it is employed in a dermatological composition, in particular in a content ranging from 0.1% to 30% by weight and preferably from 1% to 15% by weight, with respect to the total weight of the dermatological composition.

15. Compound according to any one of Claims 11 to 14, characterized in that the said skin disorders are chosen from dry patches, oedema and/or pimples, inflammatory erythema, pruritus, psoriasis, cutaneous atopy, atopic dermatitis, urticaria, contact dermatitis, eczema, seborrhoeic dermatitis, acne and inflammatory hyperpigmentation.

16. Compound according to either of Claims 14 and 15, characterized in that the said dermatological composition additionally comprises at least one compound capable of provoking irritation of the skin and/or scalp.

17. Compound according to either of Claims 14 and 15, characterized in that the said dermatological composition is intended to be applied after and/or before a cosmetic and/or dermatological composition comprising at least one compound capable of provoking irritation of the skin and/or scalp.

18. Compound according to either of Claims 16 and 17, characterized in that the said compound capable of provoking irritation of the skin and/or scalp is as defined in Claim 9.

19. Composition comprising a compound of formula (A) as defined in either of Claims 1 and 2, which composition is intended to treat cutaneous irritation and/or inflammation.