WO2013092872A2

WO2013092872A2 - Cosmetic processes with glucosamine-based hydrogels

Info

Publication number: WO2013092872A2
Application number: PCT/EP2012/076397
Authority: WO
Inventors: Maria Dalko
Original assignee: L'oreal
Priority date: 2011-12-22
Filing date: 2012-12-20
Publication date: 2013-06-27
Also published as: WO2013092872A3

Abstract

The invention relates to a non-therapeutic cosmetic process for improving the barrier function of the skin and/or for moisturizing the skin, comprising the application to the skin of a composition comprising, in a physiologically acceptable medium, a hydrogel formed from compounds of formula (I). The use of the said hydrogel as a skin moisturizer or as an anti-ageing agent.

Description

Cosmetic processes with glucosamine-based hydrogels

The present invention relates to the treatment of the skin with glucosamine-based hydrogels.

Generally, hydrogels consist of water-insoluble polymers that are capable of constituting a gel with substantial absorbent power. Specifically, they may occasionally contain up to 99% of water in their final form. The products obtained have a high degree of flexibility when compared with living tissues, and, as they consist predominantly of water, they are naturally compatible with these tissues. However, these hydrogels have essentially superficial action.

Hydrogels based on small non-polymeric molecules are also described in the literature. By virtue of their particular structure, these molecules are capable of self-associating via non-covalent hydrogen bonds to form organized systems. These sparingly water-soluble systems have a high water-absorbing capacity to form "supramolecular" hydrogels.

Glucosamine derivatives are described in the literature as being particularly advantageous for forming hydrogen or systems in water, for treating wounds (B. Xu et al., Chem. Commun., 2007, 843-845) .

The skin is a tissue in which the cells are joined together and integrally attached to each other. Skin tissue forms an outer coating comprising sebaceous or sweat glands, and hair follicles. The skin and, in particular, the scalp are epithelia which undergo continual renewal. The renewal, or desquamation, is a coordinated and finely regulated process resulting in the imperceptible and invisible removal of the superficial cells. Human skin is constituted of two compartments, namely an upper compartment, the epidermis, and a deep compartment, the dermis.

The epidermis is conventionally divided into a basal layer of keratinocytes that constitutes the germinal layer of the epidermis, a spinous layer consisting of several layers of polyhedral cells positioned on the germinal cells, one to three "granular" layers consisting of flattened cells containing distinct cytoplasmic inclusions, keratohyalin granules, and finally an assembly of upper layers known as the cornified layer (or stratum corneum), consisting of keratinocytes at the terminal stage of their differentiation, known as corneocytes.

Corneocytes are anuclear cells mainly consisting of a fibrous material containing cytokeratins, surrounded by a cornified envelope. New corneocytes undergo permanent production to compensate for the continual loss of epidermal cells from the cornified layer by a mechanism known as desquamation.

However, there is an imbalance between the production of cells in the basal layer and the level of desquamation may especially lead to the formation of scales at the surface of the skin. Similarly, a deficit in the terminal desquamation of the cells of the stratum corneum, for various reasons, can result in the formation of large, thick cell clusters which are visible to the naked eye, known as "squamae", or, in other situations, in a thinning of the stratum corneum. Disorders in this terminal differentiation may result in fragility of or even failure of the barrier properties of the epidermis, chronic dehydration of the stratum corneum, loss of mechanical elasticity, tautness, and also a lack of radiance and transparency of the skin.

As examples of factors that promote this impairment in the quality of the skin surface, mention may be made of stress, the winter period, excess sebum or a lack of moisturization. These disorders also arise in the case of the dry skin of the elderly.

Thus, impairment of the skin barrier may arise in the presence of external attacking factors such as irritants (detergents, acids, bases, oxidizing agents, reducing agents, concentrated solvents, and harmful gases or fumes), mechanical stresses (frictions, impacts, abrasion, stripping of the surface, spraying with dusts or particles, shaving or hair removal), thermal or climatic disequilibria (cold, dryness, radiations), xenobiotics (harmful microorganisms, allergens) or internal attacking factors such as psychological stress.

The moisturizers conventionally used, such as humectants, moisturizing polymers or fatty substances such as petroleum jelly, temporarily modify the surface properties of the skin. These active agents may bring about mechanical suppleness of the stratum corneum, an increase in its state of moisturization, and improvement of the microrelief of the skin by formation of a film at the surface of the skin.

Generally, these effects are not long-lasting, and last for only a few hours. Furthermore, after cleansing the skin, these active agents are removed and the mechanical suppleness effect on the skin and the improvement of the texture of the skin or of its optical properties disappear.

Moreover, the use of film-forming agents on the skin, in particular the use of moisturizing polysaccharides such as carrageenan, often lead to a "tensioning" effect on the skin, an increase in the elastic modulus of the skin, and this surface rigidification leads to skin discomfort. There is thus a need for active agents that improve the state of moisturization of the skin, in particular in the case of dry or elderly skin, especially by preventing tautness and discomfort sensations when they are applied to the skin. It has been found, unexpectedly, that these aims can be achieved by using particular hydrogels that promote a long-lasting improvement in the surface quality of the skin, in particular in the state of moisturization of the skin.

The inventors have discovered that certain hydrogels described hereinbelow are good agents for improving the barrier function of the skin. These hydrogels are thus good skin moisturizers, in particular for dry skin. Furthermore, when these hydrogels are applied to the skin, they do not cause any sensation of discomfort or any tautness of the skin. Thus, a subject of the present invention is a non-therapeutic cosmetic process for improving the barrier function of the skin and/or for moisturizing the skin, comprising the application to the skin of a composition comprising, in a physiologically acceptable medium, a hydrogel formed from compounds of formula (I) below. The said cosmetic process is suitable for treating dry skin.

A subject of the invention is also the cosmetic use of a hydrogel comprising compounds of formula (I) below as skin moisturizer.

Moreover, in the course of chronological and/or actinic ageing, the epidermis undergoes many modifications and degradations that are reflected, with age, by impairment in the microrelief, the appearance of wrinkles and fine lines, and impairment in the mechanical properties of the skin, with a decrease in the firmness and elasticity of the skin, and loss of radiance of the complexion. At the tissue level, ageing is manifested by disruption of the architecture of the epidermis, of the dermal-epidermal junction of the dermis and also of the blood irrigation and innervation systems, and a slowing down of various types of metabolism, such as those involved in the equilibrium of the barrier function. At the cellular level, ageing is reflected by impairment in the physiology or metabolism of the main cell types of the dermis (fibroblasts) and of the epidermis (keratinocytes).

The importance of having available products that are capable of reinforcing/stimulating the various layers of the skin may thus be understood.

Thus, the aim of the invention is to provide a composition for preventing and/or treating the signs of ageing of the skin and/or of photo-ageing, in particular for reducing ptosis, reducing the loss of firmness of the skin, reducing the visibility of skin wrinkles or fine lines, or improving the quality and/or transparency of the skin.

Unexpectedly, the inventors have observed that a particular hydrogel proves to be particularly advantageous for preventing or treating disorders associated with ageing of the skin, whether it be of chronobiological or photobiological origin.

A subject of the invention is also the use, especially the cosmetic use, of at least one hydrogel comprising at least one compound of formula (I), for preventing and/or treating the signs of ageing of the skin.

For the purposes of the invention, the expression "signs of ageing of the skin" means any change in the external appearance of the skin due to ageing, whether it be chronobiological and/or photo-induced ageing, for instance wrinkles and fine lines, wizened skin, flaccid skin, thinned skin, lack of elasticity and/or tonicity of the skin, lack of density and/or firmness of the skin, but also any modification of the skin that is not automatically reflected by a modified outer appearance, for instance any internal degradation of the skin following exposure to ultraviolet radiation.

A subject of the invention is also the use, especially the cosmetic use, of at least one hydrogel comprising at least one compound of formula (I) for preventing, reducing and/or treating wrinkles or fine lines, or impairment of the microrelief. A subject of the invention is also the use, especially the cosmetic use, of at least one hydrogel comprising at least one compound of formula (I), for reinforcing the mechanical properties of the skin, in particular for combating wizened, flaccid, slackened and/or thinned skin, and/or for reinforcing and/or restoring the elasticity or firmness of the skin.

According to yet another of its aspects, the present invention is directed towards a cosmetic process for stimulating, restoring or regulating the metabolism of aged skin cells, comprising at least one step of administering, to an individual in need thereof, at least an effective amount of at least one hydrogel comprising at least one compound of formula (I).

According to yet another of its aspects, the present invention is directed towards a cosmetic process for preventing and/or treating signs of ageing of the skin, comprising at least one step of administering, to an individual in need thereof, at least an effective amount of at least one hydrogel comprising at least one compound of formula (I). According to another of its aspects, the invention is directed towards a cosmetic or dermatological composition comprising at least an effective amount of at least one hydrogel comprising at least one compound of formula (I) in combination with at least one additional active agent chosen especially from a sweetener, an amino acid, a peptide, inosine or a derivative thereof, guanosine or a derivative thereof, an extracellular calcium receptor agonist, a calcium channel agonist, an anti- wrinkle active agent, an anti-ageing active agent, a moisturizer, a depigmenting agent, an antioxidant, a calmative, an energetic agent, a slimming agent, a photoprotective agent, a desquamating agent, a sunscreen, in particular a UV- screening agent, and an anti-dandruff agent, and mixtures thereof.

Sebum normally constitutes a moisturizer for the epidermis and may be involved in the homeostasis of the epidermis, and especially in the proliferation and/or differentiation of epidermal cells.

It is the natural product of the sebaceous gland, which is an annex of the pilosebaceous unit. It is essentially a more or less complex mixture of lipids. Conventionally, the sebaceous gland produces squalene, triglycerides, aliphatic waxes, cholesterol waxes and, possibly, free cholesterol (Stewart, M.E., Semin. Dermatol. 11 , 100-105 (1992)). The action of bacterial lipases converts a variable proportion of the triglycerides formed into free fatty acids.

The sebocyte constitutes the competent cell of the sebaceous gland. The production of sebum is associated with a programme of terminal differentiation of this cell. During this differentiation, the metabolic activity of the sebocyte is essentially directed towards the biosynthesis of lipids (lipogenesis) and more precisely towards fatty acid neosynthesis.

Hyperseborrhoeic or greasy skin is especially characterized by an exaggerated secretion and excretion of sebum. Conventionally, a sebum level of greater than 200 g/cm² measured on the forehead is considered as being characteristic of such greasy skin.

Such skin is also often associated with a desquamation defect, a shiny complexion, a thick skin grain, dilated pores or an irregular relief, which manifestations are perceived as being skin imperfections or aesthetic defects. The appearance and/or visibility of the pores is also a characteristic of greasy skin. The shininess of the skin is also associated with the dilation of the pores, whence the interest in finding active agents for reducing the size of dilated the pores.

To combat hyperseborrhoeia, the prior art has already proposed various compounds, which, by topical application to the skin, are capable of reducing the lipogenesis of the sebocytes and consequently of limiting the production of sebum. The treatments currently available for hyperseborrhoeia are not entirely satisfactory, especially with regard to the side effects that are frequently associated therewith, such as irritant effects with certain topical agents such as retinoids and benzoyl peroxides.

There is thus still a need for novel active agents that are capable of exerting beneficial cosmetic or therapeutic action on greasy skin or greasy-prone skin and/or the associated cutaneous aesthetic defects or pathological disorders. There is also a need for novel active agents that are capable of exerting beneficial cosmetic or therapeutic action on greasy scalp conditions.

The Applicant has now discovered, surprisingly and unexpectedly, that the use of at least one hydrogel formed from compounds of formula (I) below proves to be useful for preventing and/or treating, effectively and without the drawbacks mentioned above, greasy skin or greasy-prone skin and/or associated cutaneous aesthetic effects.

A subject of the present invention is thus a cosmetic process for treating and/or preventing greasy skin or greasy-prone skin and the associated cutaneous aesthetic defects, comprising the topical application to the skin of a composition comprising, in a cosmetically acceptable medium, at least one compound of formula (I):

A subject of the present invention is also the cosmetic use of at least one compound of formula (I)

in which: A denotes a radical chosen from amino acids, dipeptides and tripeptides;

R denotes a radical chosen from saturated linear C1 -C18 alkyls, unsaturated linear C2-C18 alkyls, saturated branched C3-C18 alkyls, unsaturated branched C3-C18 alkyls, (C1 -C3)alkylaryls and aryls;

the aryl radicals are especially chosen from phenyl, naphthyl and indoles as an agent for treating and/or preventing greasy skin or greasy-prone skin and/or the associated cutaneous aesthetic defects.

According to these uses, the compound of formula (I) is advantageously contained in a composition comprising a cosmetically acceptable medium.

For the purposes of the present invention, the term "preventing" means reducing the risk or probability of manifestation of a given phenomenon. A compound of the invention may advantageously be used for treating and/or preventing greasy skin or greasy-prone skin and/or the associated cutaneous signs.

The invention is directed towards all bodily skin, including the scalp, and, preferably, the skin of the face, neckline, neck, arms and forearms, or even more preferably the skin of the face (in particular of the forehead, nose, cheeks and chin), neckline and neck.

According to one embodiment, a cutaneous aesthetic defect may be chosen from skin imperfections caused by hyperseborrhoeia and/or a scalp disorder.

The aesthetic cutaneous signs of hyperseborrhoeia, or greasy skin, which are more particularly considered by the invention may be shiny and/or thick skin and/or skin whose follicular orifices or pores are dilated, or even, in certain cases, are filled with tiny cornified spicules or with comedones. Greasy skin is often associated with a desquamation defect and with a thick skin grain.

The aesthetic cutaneous signs, or imperfections, of greasy skin or greasy-prone skin may be chosen in particular from a thick skin grain, shiny or glossy skin, skin with dilated pores or follicular orifices, skin with pores or follicular orifices filled with cornified spicules or with comedones, rough skin or skin with an irregular relief, or skin with an impairment of the complexion.

Greasy skin or greasy-prone skin may also show impairments in the skin's complexion, such as a sallow, non-uniform or dull complexion.

The invention relates to a cosmetic process dedicated in particular to individuals with greasy skin or greasy-prone skin and/or the associated cutaneous aesthetic effects.

An individual concerned by a cosmetic treatment process of the invention is naturally an individual who has, or who is liable to have, at least one of the cosmetic care indications defined previously.

Preferably, a process according to the invention will comprise the topical application of a composition according to the invention to facial skin and/or the scalp.

The process according to the invention may prove to be most particularly suitable:

- for preventing and/or treating the aesthetic effects of greasy skin or greasy- prone skin,

- for preventing and/or treating skin with dilated pores or follicular orifices, or skin with pores or follicular orifices filled with cornified spicules or comedones,

- for preventing and/or treating rough skin or skin with an irregular relief,

- for preventing and/or treating an impairment of the skin's complexion, such as a sallow, non-uniform or dull complexion,

- for preventing and/or treating shiny or glossy skin,

- for preventing and/or treating an aesthetic defect of the scalp associated with excessive excretion and/or secretion of sebum, or

- for improving the comfort of the skin or the scalp.

Compounds of formula (I)

The aryl radicals are preferably chosen from phenyl, naphthyl and indoles, preferably naphthyl.

-COCH(A)NH- preferably denotes a radical derived from an amino acid, in particular from phenylalanine.

According to the invention, the compounds of formula (I) are preferably

compounds (1 ) and (2) below: 2-deoxy-2-{[N-(naphthalen-2-ylacetyl)-D-phenylalanyl]amino}-D-glucopyranose

2-deoxy-2-{[N-(naphthalen-2-ylacetyl)-L-phenylalanyl]amino}-D-glucopyranose

The compounds of formula (I) are especially described in the article by B. Xu et al., Chem. Commun., 2007, 843-845) . The compounds of formula (I) may be present in the cosmetic compositions in contents ranging from 0.001 % to 20% by weight, preferably from 0.01 % to 15% by weight and more preferably from 0.1 % to 5% by weight relative to the total weight of the cosmetic composition. The hydrogel is generally present in the composition in a content ranging from 1 % to 90% by weight relative to the total weight of the composition.

The compositions used according to the invention contain a physiologically acceptable medium, i.e. a medium that is compatible with cutaneous tissues such as the skin and the scalp. The physiologically acceptable medium may more particularly consist of water and optionally of a physiologically acceptable organic solvent chosen, for example, from lower alcohols comprising from 1 to 8 carbon atoms and in particular from 1 to 6 carbon atoms, for instance ethanol, isopropanol, propanol or butanol; polyethylene glycols containing from 6 to 80 ethylene oxide units, and polyols, for instance propylene glycol, isoprene glycol, butylene glycol, glycerol and sorbitol. The compositions according to the invention may be provided in any galenical form conventionally used for topical application and in particular in the form of aqueous or aqueous/alcoholic solutions, oil-in-water (O/W), water-in-oil (W/O) or multiple (triple: W/O/W or O/W/O) emulsions, aqueous gels or dispersions of a fatty phase in an aqueous phase using spherules, it being possible for these spherules to be polymeric nanoparticles, such as nanospheres and nanocapsules, or lipid vesicles of ionic and/or nonionic type (liposomes, niosomes or oleosomes). These compositions are prepared according to the usual methods.

In addition, the compositions used according to the invention can be more or less fluid and can have the appearance of a white or coloured cream, of an ointment, of a milk, of a lotion, of a serum, of a paste or of a foam. They may optionally be applied to the skin in the form of an aerosol. They can also be in solid form, for example in the form of a stick.

The composition used according to the invention comprises adjuvants commonly used in cosmetics, and chosen especially from water; oils; waxes, pigments, fillers, dyes, surfactants, emulsifiers; cosmetic active agents, UV-screening agents, polymers, thickeners, film-forming polymers, preserving agents, fragrances, bactericides, odour absorbers, antioxidants.

The amounts of these various adjuvants are those conventionally used in the field under consideration, for example from 0.01 % to 20 % of the total weight of the composition. The examples that follow illustrate the invention without, however, limiting its scope.

Example 1 :

0.1 g of compound 1 is heated at 50-85°C either in water (100 ml) or in an EtOH/water mixture for a few hours (from 1 to 24 hours).

The composition is allowed to cool to room temperature and is then left at room temperature for a few hours. A transparent gel is obtained. This gel is applied to the skin, and gives it a good moisturizing effect without any tautness.

Example 2:

A skin moisturizing care composition comprising the ingredients below is prepared: - Crosslinked acrylic acid (Carbopol 941 ) 0.3%

- Ulvane UR 0.5%

- Compound 1 or 2 0.5%

- Preserving agents qs - Water qs 100.0%

The gel is applied to the skin, and gives it a good moisturizing effect without any tautness.

Exemple 3

A composition B comprising 2,5% by weight of compound 1 in water has been prepared. 2,5 g of compound 1 had been heated at 65°C in water (100 ml) for one hours. The composition had been allowed to cool to room temperature and is then left at room temperature for 12h.

On a reconstructed skin (Bioskin® noir), 400 microlitres of a mixture of oleic acid/water (20/80) have been applied and spread. The skin surface became oily. The film had a thickness of about 50 microns then it was stayed during 5 minutes at room temperature. 3 films had been prepared.

Film 1 = placebo (400 microlitres of a mixture of oleic acid/water (20/80)) had been applied then spread during 3 second with one finger.

Film 2 (invention) 200mg of composition B had been applied then spread during 3 second with one finger.

Film 3 : placebo + (400 microlitres of a mixture of oleic acid/water (20/80) + 200 microlitres of water had been applied then spread during 3 second with one finger.

After 5 mn, oily aspect of the films had been evaluated by two expects in a blind test.

Results

Film 1 : shiny, oily aspect

Film 2 : invention : mat aspect

Film 3 : shiny, oily aspect

Claims

1. Use, especially the cosmetic use, of at least one hydrogel comprising at least one compound of formula (I)

in which:

-COCH(A)NH- denotes a radical chosen from amino acids, dipeptides and tripeptides;

R denotes a radical chosen from saturated linear C1 -C18 alkyls, unsaturated linear C2-C18 alkyls, saturated branched C3-C18 alkyls, unsaturated branched C3-C18 alkyls, (C1 -C3)alkylaryls and aryls; for preventing and/or treating the signs of ageing and/or photo-ageing of the skin.

2. Use, especially the cosmetic use, of at least one hydrogel comprising at least one compound of formula (I) according to Claim 1 , for preventing, reducing and/or treating wrinkles or fine lines, or impairment of the microrelief.

3. Use, especially the cosmetic use, of at least one hydrogel comprising at least one compound of formula (I) according to Claim 1 , for reinforcing the mechanical properties of the skin, in particular for combating wizened, flaccid, slackened and/or thinned skin, and/or for reinforcing and/or restoring the elasticity or firmness of the skin.

4. Cosmetic use of a hydrogel comprising a compound of formula (I) according to Claim 1 , for reducing ptosis, reducing the loss of firmness of the skin, reducing the visibility of skin wrinkles or fine lines, or improving the quality and/or transparency of the skin.

5. Use, especially the cosmetic use, of at least one hydrogel comprising at least one compound of formula (I) according to Claim 1 , as a skin moisturizer.

6. Use, especially the cosmetic use, of at least one hydrogel comprising at least one compound of formula (I) according to Claim 1 , as an agent for treating and/or preventing greasy skin or greasy-prone skin and/or the associated cutaneous aesthetic effects.

7. Use according to one of the preceding claims, in which the aryl radicals are chosen from phenyl, naphthyl and indoles, preferably naphthyl.

8. Use according to one of the preceding claims, in which -COCH(A)NH- denotes a radical derived from an amino acid, in particular from phenylalanine.

9. Use according to one of the preceding claims, in which the compounds of formula (I) are chosen from the following compounds:

2-deoxy-2-{[N-(naphthalen-2-ylacetyl)-D-phenylalanyl]amino}-D-glucopyranose

2-deoxy-2-{[N-(naphthalen-2-ylacetyl)-L-phenylalanyl]amino}-D-glucopyranose

10. Use according to any one of the preceding claims, characterized in that the compound of formula (I) is present in the composition in a content ranging from 0.001 % to 20% by weight and preferably ranging from 0.01 % to 15% by weight relative to the total weight of the composition.

11. Use according to any one of the preceding claims, characterized in that the hydrogel is present in the composition in a content ranging from 1 % to 90% by weight relative to the total weight of the composition.

12. Use according to any one of the preceding claims, characterized in that the composition comprises a cosmetic adjuvant chosen from water, oils, waxes, pigments, fillers, dyes, surfactants, emulsifiers; cosmetic active agents, UV- screening agents, polymers, thickeners, film-forming polymers, preserving agents, fragrances, bactericides, odour absorbers and antioxidants.

13. Non-therapeutic cosmetic process for improving the barrier function of the skin and/or for moisturizing the skin, comprising the application to the skin of a composition comprising, in a physiologically acceptable medium, at least one hydrogel comprising at least one compound of formula (I):

in which:

14. Cosmetic process for stimulating, restoring or regulating the metabolism of aged skin cells, comprising at least one step of administering, to an individual in need thereof, at least an effective amount of at least one hydrogel comprising at least one compound of formula (I) according to Claim 13.

15. Cosmetic process for preventing and/or treating signs of ageing of the skin, comprising at least one step of administering, to an individual in need thereof, at least an effective amount of at least one hydrogel comprising at least one compound of formula (I) according to Claim 13.

16. Cosmetic process for treating and/or preventing greasy skin or greasy-prone skin and the associated cutaneous aesthetic defects, comprising the topical application to the skin of a composition comprising, in a cosmetically acceptable medium, at least one compound of formula (I) according to Claim 13.

17. Process according to the preceding claim, in which the cutaneous aesthetic effects are chosen from skin imperfections due to hyperseborrhoeia, and/or a scalp disorder.

18. Process according to either of Claims 16 and 17, in which the cutaneous aesthetic effects are chosen from a thick skin grain, shiny or glossy skin, skin with dilated pores or follicular orifices, skin with pores or follicular orifices filled with cornified spicules or with comedones, rough skin or skin with an irregular relief, or skin with an impairment of the complexion.

19. Process according to one of the preceding claims, in which the aryl radicals are chosen from phenyl, naphthyl and indoles, preferably naphthyl.

20. Process according to one of the preceding claims, in which -COCH(A)NH- denotes a radical derived from an amino acid, in particular from phenylalanine.

21. Process according to one of the preceding claims, in which the compounds of formula (I) are chosen from the following compounds:

2-deoxy-2-{[N-(naphthalen-2-ylacetyl)-D-phenylalanyl]amino}-D-glucopyranose

yl]amino}-D-glucopyranose

22. Process according to any one of the preceding claims, characterized in that the compound of formula (I) is present in the composition in a content ranging from 0.001 % to 20% by weight and preferably ranging from 0.01 % to 15% by weight relative to the total weight of the composition.

23. Process according to any one of the preceding claims, characterized in that the hydrogel is present in the composition in a content ranging from 1 % to 90% by weight relative to the total weight of the composition.

24. Process according to any one of the preceding claims, characterized in that the composition comprises a cosmetic adjuvant chosen from water, oils, waxes, pigments, fillers, dyes, surfactants, emulsifiers; cosmetic active agents, UV- screening agents, polymers, thickeners, film-forming polymers, preserving agents, fragrances, bactericides, odour absorbers and antioxidants.

25. Cosmetic care method, characterized in that it comprises the topical application of a cosmetic composition as defined in any one of Claims 1 to 6, especially to an individual subject to ageing or photo-ageing of the skin, for preventing and/or treating the signs of ageing and/or photo-ageing of the skin, in particular for reducing ptosis, reducing the loss of firmness of the skin, reducing the visibility of skin wrinkles or fine lines, or improving the quality and/or transparency of the skin.

26. Cosmetic or dermatological composition comprising at least an effective amount of at least one hydrogel comprising at least one compound of formula (I) in combination with at least one additional active agent chosen especially from a sweetener, an amino acid, a peptide, inosine or a derivative thereof, guanosine or a derivative thereof, an extracellular calcium receptor agonist, a calcium channel agonist, an anti-wrinkle active agent, an anti-ageing active agent, a moisturizer, a depigmenting agent, an antioxidant, a calmative, an energetic agent, a slimming agent, a photoprotective agent, a desquamating agent, a sunscreen, in particular a UV-screening agent, and an anti-dandruff agent, and mixtures thereof.