EP1651171A2

EP1651171A2 - Cosmetic use of a biguanide derivative as an anti-ageing active substance for the skin

Info

Publication number: EP1651171A2
Application number: EP04786009A
Authority: EP
Inventors: Pierre Jean-Paul Potier; Nobumichi-André Sasaki; Maria Conception Achab; Gisèle FRANCK; Joanna Bakala; Françoise PICOT
Original assignee: PHARMAMENS
Current assignee: PHARMAMENS
Priority date: 2003-07-29
Filing date: 2004-07-29
Publication date: 2006-05-03
Also published as: FR2858227A1; WO2005011566A3; FR2858227B1; CA2534135A1; JP2007500172A; WO2005011566A2

Abstract

The invention relates to the cosmetic use of a biguanide derivative as an anti-ageing active substance for the skin.According to the invention, metformin is particularly appropriate for use.

Description

Title: Cosmetic use of a biguanide derivative as an anti-aging active ingredient for the skin.

The present invention relates to the cosmetic use of a biguanide derivative as an anti-aging and restructuring active ingredient for the skin.

In mammals in general, especially in humans, the skin consists of two main parts, namely an outer layer, the epidermis and an inner layer, the dermis.

The epidermis ensures the impermeability of the skin and its resistance. It is renewed approximately every four weeks by the elimination of superficial dead cells. The epidermis is mainly composed of three types of cells which are the keratinocytes, very majority, the melanocytes and the Langerhans cells. Each of these cell types contributes by its own functions to the essential role played in the body by the skin. The dermis provides the epidermis with solid support. It is also its nourishing element. It is mainly composed of fibroblasts dispersed in a complex medium, called extracellular matrix, mainly composed of collagen fibers, elastin, hyaluronic acid and proteoglycans.

Collagen represents the "cement" of the dermis. It gives the skin solidity, resistance and ensures hydration (therefore its flexibility). Elastin provides elasticity and tone. Hyaluronic acid gives volume and participates in hydration.

Over the days, the skin ages, which manifests itself firstly by the appearance of fine lines and then of wrinkles, especially on the face and / or by sagging of the skin. Aging first affects the epidermis whose thickness is reduced. The power of cell division in its basal layer decreases and the renewal time of the superficial corneal layer lengthens. The maturation of these cells is imperfect and keratinization no longer leads to the creation of a regular horny layer. and homogeneous. There is concomitantly a disorganization of the deep part of the skin, a slowing down of cell renewal as well as a reduction in the production of collagen and elastin.

Besides the chronobiological cause of aging, there are also so-called external causes such as: the sun, tobacco, lack of sleep, vitamin deficient diets. We also know that the alteration in hormone production (mainly estrogen deficiencies) associated with menopause accentuates skin aging. It contributes to the reduction of collagen and elastin in the dermis and to the reduction of the renewal of the cells of the epidermis. The skin is thus less supple, less thick, with a feeling of dryness and sagging

The structuring elements of the skin (collagen, elastin, keratin) are the first responsible for our appearance. Indeed, changes in the level of elastin and keratins as well as the density of the collagen network are responsible for the loss of elasticity, wrinkles and sagging of the skin. It is partly on them that cosmetic products act.

For many years, cosmetic products have been known to combat aging of the skin. However, none is satisfactory to date.

However, surprisingly, the inventors have discovered that a biguanide derivative, advantageously metformin, had an anti-aging and restructuring effect on the epidermis and the papillary dermis and therefore on the skin.

Pharmaceutical compositions based on biguanides are already known. They are used in oral form in the treatment of certain forms of diabetes, and mainly of type II diabetes insulin-dependent, as antihyperglycemic agents that promote the return to glycemic control.

Metformin is the most widely used biguanide derivative in this type of treatment. This medicine is administered orally in the form of tablets containing 500, 850 mg or 1 g of active ingredient.

The daily dosage is between 1 and 2 g.

The clinical evaluation of metformin in phase I showed the absence of toxicity of the molecule studied at hypoglycemic doses. Tolerance to the product appears to be good, its chronic toxicity almost zero. There is no change in the growth or behavior of the animals; blood count, uremia and liver function are not altered.

The antihyperglycemic effect of metformin is due on the one hand to the increase in the activity of endogenous insulin and on the other hand to the action of metformin through mechanisms independent of insulin. Indeed, the action of metformin results in a decrease in the intestinal absorption of glucose, an increase in cellular absorption of blood glucose and a decrease in the production of glucose by the liver (suppression of neoglucogenesis) as well as the amount of insulin needed to normalize blood sugar. These effects result, in part, from the power of metformin to enhance the action of existing insulin by an increase in the activity of the insulin receptor enzyme tyrosine kinase, which triggers the signaling cascade " post-receptor ".

Metformin is also known in topical compositions to promote healing and as having an angiogenic action (FR 2

809 310).

In addition, certain derivatives of biguanides are also known to have an anti-inflammatory action (US 4,163,800).

However, none of these documents describes or suggests that biguanide derivatives, in particular metformin, have an anti-aging and restructuring cosmetic action on the epidermis and papillary dermis and that the use of a composition comprising them makes it possible to increase the production of type III collagen in the papillary dermis, to stimulate the proliferation of keratinocytes in the epidermis and / or to increase the thickness of the epidermis.

The present invention therefore relates to the cosmetic use of a biguanide derivative of general formula I below:

NH NH RI -NCNC-R3 R2 ^' IH (I) in which: the groups R1 and R2 represent, independently of one another, a hydrogen atom, a C ₁ -C ₇ alkyl group, a cycloalkyl group, a heterocycle, a C ₂ -C alkenyl group, an aryl group, an aralkyl group, an aryloxylalkyl group or a heteroaryl group or R1 and R2 taken together represent a C ₂ -C alkylene which may contain one or more heteroatoms and the group R3 represents a primary, secondary or tertiary amine or its cosmetically acceptable salt with the exception of the compound of formula

as an anti-aging and restructuring active ingredient for the epidermis and papillary dermis. By the term "C-ι-C alkyl group" is meant within the meaning of the present invention any Cι-C ₇ alkyl group, linear or branched, such as for example methyl, ethyl, propyl, isopropyl or butyl groups as well as their isomers. By the term "cycloalkyl group" is meant in the sense of the present invention any cycloalkyl group containing from 3 to 7 carbon atoms, such as for example the cyclohexanyl group.

By the term of “heterocycle”, one understands within the meaning of the present invention any cycle containing from 3 to 7 atoms, one or more of them being a heteroatom such as for example the atom of nitrogen, oxygen or of sulfur, the others being carbon atoms.

By the term "C ₂ -C alkenyl group" is meant in the sense of the present invention any C ₂ -C alkenyl group, linear or branched such as vinyl or allyl groups. By the term of “aryl group”, one understands within the meaning of the present invention any aromatic hydrocarbon group such as for example the phenyl group, which can contain one or more substituents, such as for example, a C ₁ -C ₇ alkyl group as defined above, a C ₂ -C ₇ alkenyl group as defined above, or a halogen. By the term "heteroaryl group" is meant within the meaning of the present invention any aromatic hydrocarbon group containing one or more heteroatoms, such as for example nitrogen or oxygen sulfur atoms, and which may carry one or more substituents, such as for example , a C-ι-C ₇ alkyl group as defined above, a C ₂ -C ₇ alkenyl group as defined above, or a halogen. Examples of heteroaryl groups are furyl, isoxazyl, pyridyl, pyrimidyl.

By the term "C ₂ -C ₇ alkylene group" is meant in the sense of the present invention any C ₂ -C ₇ alkylene group such as for example ethylene, trimethylene, tetramethylene or pentamethylene groups.

By the term "cosmetically acceptable salt" is meant within the meaning of the present invention any salt prepared from any non-toxic acid cosmetically acceptable, including organic and inorganic acids. Such acids include, acetic, benzenesulfonic, benzoic, citric, ethanesulfonic, fumaric, gluconic, glutamic, hydrobromic, hydrochloric-lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric, succinic, tartaric and paratoluenesulfonic. Advantageously, hydrochloric acid is used.

In one embodiment of the invention, the biguanide derivative according to the present invention is used to increase the production of type III collagen in the papillary dermis, to stimulate the proliferation of keratinocytes in the epidermis and / or to increase the thickness of the epidermis.

Advantageously, this biguanide derivative has a tightening and / or firming effect on the skin.

It is also used to prevent, reduce and / or suppress the appearance of wrinkles on the skin.

In a particular embodiment of the invention, the group R3 represents the secondary amine of the following formula:

In an advantageous embodiment of the invention, the group R3 represents NH ₂ .

In another embodiment of the invention, the groups R1 and R2 represent, independently of one another, a hydrogen atom or a C ₁ -C ₇ alkyl group.

Advantageously, the biguanide derivative is metformin, even more advantageously in the form of a hydrochloride. In particular, the derivative can be present in the form of a cosmetic composition for local use, advantageously of the oil, cream, foam, unit, lotion, ointment, liquid, gel, milk or "spray" type. The forms can be single-phase vehicles consisting of a neutral hydroxypropylcellulose gel or a charged gel formed of sodium carboxymethylcellulose. It is also possible to prepare creams, forms with a biphasic vehicle, comprising a hydrophilic phase dispersed in a lipophilic phase. Advantageously, this composition contains from 0.02 to 2% by weight of the biguanide derivative of general formula I or of its cosmetically acceptable salt and an appropriate excipient. These excipients can be chosen from compounds having good compatibility with this active principle. These are, for example, water-soluble polymers of the natural polymer type, such as polysaccharides (xanthan gum, locust bean gum, peptine, etc.) or polypeptides, cellulose derivatives of methylcellulose type, hydroxypropylcellulose, hydroxypropyl-methylcellulose or also synthetic polymers, polaxamers, carbomers, PVA or PVP. Finally there _. is within the reach of any person skilled in the art to add various cosolvent type excipients such as ethanol, glycerol, benzyl alcohol, humectants (glycerol), agents facilitating the diffusion (transcurol, urea) to this cosmetic composition ), or antibacterial preservatives (methyl p-hydroxybenzoate 0.15%). It can also contain surfactants, stabilizing agents, emulsifiers, thickeners, other active ingredients leading to a complementary or possibly synergistic effect, trace elements, essential oils, perfumes, dyes, collagen, chemical or mineral filters, moisturizers or thermal waters.

In a particular embodiment of the invention, the biguanide derivative or its cosmetically acceptable salt is combined with at least one other active principle. The present invention also relates to a cosmetic treatment method for aging the skin by applying a composition comprising a biguanide derivative of general formula I below:

(I) in which: the groups R1 and R2 represent, independently of one another, a hydrogen atom, a C ₁ -C ₇ alkyl group, a cycloalkyl group, a heterocycle, a C alkenyl group ₂ -C ₇ , an aryl group, an aralkyl group, an aryloxylalkyl group or a heteroaryl group or R1 and R2 taken together represent a C ₂ -C ₇ alkylene which may contain one or more heteroatoms and the group R3 represents a primary amine, secondary or tertiary or its cosmetically acceptable salt with the exception of the compound of formula

The examples below of compositions according to the invention and of activity study are given by way of illustration and without limitation.

EXAMPLES

Several pharmaceutical forms have been prepared without a preservative. The percentages are expressed by weight. Example of formulation 1:

Metformin: 1%.

Neutral hydroxypropylcellulose gel (Klucel d'Aqualon type 99 MF EP) at 2.9%: 100% supplement.

Example of formulation 2:

Metformin: 1%.

Gel loaded with sodium carboxymethylcellulose (Aqualon) at 4.5%: 100% complement. Example of formulation 3:

Metformin: 1% by weight relative to the lipophilic phase.

Hydrocerin emulsion (fatty excipient from Roc® containing petrolatum, paraffin oil, triglycerides, polyoxyethylene ethers and cerisine) at 33% (H / L): complement to 100%.

STUDY OF THE RESTRUCTURING AND ANTI-AGING ACTIVITY OF A

OINTMENT INCLUDING METFORMIN.

The purpose of this study is to evaluate the restructuring and anti-aging activity of an ointment containing metformin at 1% (example of formulation 3) by examining the general morphology following panoptic coloring and by evaluation of the number of keratinocytes in mitosis and of the density of collagen III by immunostaining.

Operating mode

Explant preparation:

On a defatted breast plasty from a 59-year-old woman, 39 explants are prepared and put into survival in culture medium. They are divided into 3 lots (ointment, excipient only, control without treatment) of 12 explants and 1 lot of 3 explants. Application of products;

The products to be tested (ointment and excipient only) are applied topically to the explants at a rate of 4 mg per explant, for 10 days, the untreated batches receiving no treatment.

Histology:

At time T0, 3 explants are removed and are either fixed (ordinary Bouin) or frozen. At time D3, D5, D7 and D10, 3 explants from each batch are removed and treated as before.

The histological study is carried out: - on sections fixed in paraffin for observation of the general morphology after staining with Masson trichrome, - on frozen sections for the following immunostaining: I. Immunostaining of cells in mitosis with the anti-monoclonal antibody -Ki 67 (clone 7B11) with the nuclei counter-stained with propidium iodide. II. Immunolabelling of type III collagen with the polyclonal anti-collagen III antibody revealed in DAB (chromogenic revealing product of immunolabelling).

Results

1. General morphology: Changes in the skin structure were sought in the different compartments, epidermis, dermo-epidermal junction (JDE) and papillary dermis.

The observations made on all the explants show that the application of the ointment containing metformin induces a stimulation of the epidermal structure which results in an increase in its thickness and by a greater relief of the JDE. This represents an image of a younger epidermal structure. Indeed, a clear acanthosis (increase in the thickness of the epidermis) epidermal reaction with a thickness of up to 6 to 7 cell layers is observed from D5 of treatment for the batch having received the ointment containing metformin . It should be noted that the excipient alone has no effect on the skin structure of the explants treated.

2. Mitotic index of keratinocytes.

The mitotic keratinocytes, marked with anti-Ki 67, were counted over the entire length of the epidermis on the sections carried out.

The mitotic index, established with values obtained, is twice greater on D5 in the explants treated with the ointment containing metformin compared to the control explants and treated with the excipient. On the other hand, the values of the mitotic index on D5 had increased by 25% in the explants treated compared to those measured on D3. At D7 and D10, this index corresponds to the normal values for explants at this stage of survival.

These data clearly indicate that the application of the ointment containing metformin stimulates the proliferation of keratinocytes, especially after 5 days of treatment. This observation is perfectly correlated with the acanthosis visualized at the same time.

3. Density of type III collagen:

The labeling of type III collagen made it possible to examine its expression in the papillary dermis and along the JDE. The results obtained show that already on D3, in the batch of explants having received the ointment containing metformin, the labeling of collagen is slightly sharper along the JDE compared to that seen in the explants not treated and treated with the excipient.

At D5 until D10, the marking in the batch of explants having received the ointment is clearer in the papillary dermis and especially along the JDE. These results show that the application of the ointment containing metformin induces an increase in the expression of type III collagen in the papillary dermis and especially along the JDE. This overexpression reaches its maximum at D7 and is still very present at D10.

Conclusion

The application, on explants of human skin, of the ointment containing metformin at 1% for 10 days induces an increase in the thickness of the epidermis, a phenomenon more visible after 5 days of treatment but still very clearly detectable on D7 and J10.

This acanthosis is confirmed for an increase in the mitotic index of keratinocytes which gives D5 for the ointment double values of those noted with the control and the excipient and with an increase of about 25% compared to J3. This index returns, at D7 and D10, to normal values.

The ointment containing metformin also induces an increase in the expression of type III collagen in the papillary dermis and along the JDE which reaches its maximum on D7, and remains very visible on D10.

All of these observations reflect a stimulation of the epidermal structure as well as the restructuring of the epidermis and papillary dermis by metformin. These types of changes represent criteria for younger looking skin.

Claims

1. Cosmetic use of a biguanide derivative of general formula I below;

(I) in which: the groups R1 and R2 represent, independently of one another, a hydrogen atom, a Ct-C ₇ alkyl group, a cycloalkyl group, a heterocycle, a C ₂ alkenyl group -C, an aryl group, an aralkyl group, an aryloxylalkyl group or a heteroaryl group or R1 and R2 taken together represent a C ₂ -C ₇ alkylene which may contain one or more heteroatoms and the group R3 represents a primary, secondary or tertiary or its cosmetically acceptable salt with the exception of the compound of formula

as an anti-aging and restructuring active ingredient for the epidermis and papillary dermis.

2. Use according to claim 1 for increasing the production of type III collagen in the papillary dermis, for stimulating the proliferation of keratinocytes in the epidermis and / or for increasing the thickness of the epidemic.

3. Use according to any one of the preceding claims for preventing, reducing and / or eliminating the appearance of wrinkles on the skin.

4. Use according to any one of the preceding claims for its tightening and / or firming effect on the skin.

5. Use according to any one of the preceding claims, characterized in that the groups R1 and R2 represent, independently of one another, a hydrogen atom or a CC ₇ alkyl group.

6. Use according to any one of the preceding claims, characterized in that the group R3 represents NH ₂ .

7. Use according to claim δcharacterized in that the biguanide derivative is metformin, advantageously in the form of a hydrochloride.

8. Use according to any one of the preceding claims taken separately, characterized in that the biguanide derivative is in the form of a cosmetic composition for local use.

9. Use according to claim 8 characterized in that the composition contains from 0.02 to 2% by weight of the biguanide derivative or of its cosmetically acceptable salt and an appropriate excipient.

10. Use according to any one of the preceding claims, characterized in that the biguanide derivative or its cosmetically acceptable salt is combined with at least one other active principle.

11. Method for cosmetic treatment of aging of the skin by application of a composition comprising a biguanide derivative of general formula I below:

R1. NH NH ^• s II II _/ NCNC-R3 R2 IH (I) in which: the groups R1 and R2 represent, independently of one another, a hydrogen atom, a C ₁ -C ₇ alkyl group, a cycloalkyl group, a heterocycle, a C ₂ -C ₇ alkenyl group, a aryl group, an aralkyl group, an aryloxylalkyl group or a heteroaryl group or R1 and R2 taken together represent a C ₂ -C7 alkylene which may contain one or more heteroatoms and the group R3 represents a primary, secondary or tertiary amine or its salt cosmetically acceptable with the exception of the compound of formula