The present invention relates to cosmetology, body-hygiene, topical dermotherapeutics and, in general, any product intended for the skin, or for surface parts of the human body, in the region of the epidermis, such as nails and hair.[0001]
Traditionally, a cosmetic or dermatological product comprises one or more active principles and an excipient or vehicle in which the active principle(s) is (are) distributed or dispersed, the whole being formulated for topical application, for example in the form of a gel or cream.[0002]
The term “active principle” means any compound, any composition or any product which exerts biomechanical, biophysical, physiological or biological activity on the skin, and in particular on the epidermis, and which has any physicochemical form or nature required for the treatment or action chosen or selected with respect to the skin.[0003]
The active principle(s) selected, of chemical type, is (are) in the great majority foreign to the skin; cf. EP-0,475,851. In certain cases, these active principles are natural products, i.e. products obtained from products or substances of nature, for example in the plant kingdom, cf. EP-0,477,833. In other cases, these active principles are products or constituents found in the skin; cf. WO-94/18945 and EP-0,627,223.[0004]
Moreover, cosmetic or dermopharmaceutical products are known which comprise no excipient or vehicle per se, but in the form of a complex, combining various products; cf EP-0,379,846. In certain examples, one or more components, but not all of them, are natural components; cf. WO-89/05629.[0005]
At the present time, to the Applicant's best knowledge, nobody has been concerned, for cosmetic or therapeutic purposes, in the skin, and in particular the epidermis, considered as an ecological medium or system whose equilibrium should be respected, with the exception of certain studies relating only to the ecology of the cutaneous bacterial flora.[0006]
This is the subject of the present invention.[0007]
In its general aspect, the invention proposes a new generation of cosmetic or corporal hygiene or dermotherapeutic products which comprise, to at least 98% by weight, biodermal constituents, each chosen for their biocompatibility and cytocompatibility with skin cells, and preferably biomimetic with a component of the skin, in particular of the epidermis. These biodermal constituents are chosen and formulated, on the one hand, in order together to express at least one topical biological activity, which is identical to or different from the biological activity of at least one biodermal constituent, and, on the other hand, in order to give the product a composition in topical pharmaceutical form which is stable, as regards the mode of administration considered, for example gel, milk, cream, lotion or make-up remover, for a body hygiene or cosmetic product.[0008]
It results from the above definition, by difference with the traditional cosmetic or dermatological products, that it is no longer possible in particular to distinguish between active principle(s) and excipient or vehicle. In practice, a product according to the present invention behaves both as one or more active principles and as an excipient. Furthermore, each biodermal constituent must be considered equally as a constituent of the skin and/or an active principle and/or a pharmaceutical agent, for example a thickener or a surfactant.[0009]
The composition of a product according to the present invention in practice excludes any non-biodermal excipient other than water or an aqueous phase.[0010]
It results from the above definition that a product according to the present invention cannot be likened to:[0011]
one or more biodermal, including biomimetic, active principles formulated in a stable pharmaceutical form, with a traditional excipient or vehicle[0012]
a complex of natural products, in general without excipient or vehicle per se, since it in practice comprises, as a whole, specific natural products, i.e. biodermal constituents.[0013]
According to the above definition, any product limited to one or more biodermal active principles, distributed in one way or another in water or in an aqueous phase, which is predominant by weight in the total composition of the product is also excluded; this product being, for example, a lotion obtained by dispersing a glycosaminoglycan in an aqueous phase.[0014]
Preferably, biodermal constituents which are cytocompatible with the skin represent the entire weight composition of the product considered.[0015]
Preferably, each biodermal constituent, which is biomimetic with a component of the skin, has a weight content in the said product (expressed as a weight percentage, for example) which is different from that of the said component in the skin.[0016]
By way of example, a product according to the invention comprises two biodermal and biomimetic constituents, the major one of which is a constitutive component of the epidermis and the minor of which is a skin nutrient.[0017]
Advantageously, the biodermal constituent is chosen from the biological, mineral, organic or biochemical species or entities of which the epidermis or the dermis is composed. By way of example, one of the biodermal constituents is chosen from skin nutrients.[0018]
A product in accordance with the invention is two-phase or single-phase or constitutes several emulsion or non-emulsion phases, to obtain any suitable topical form, for example cream, emulsion, lotion, serum, milk, gel, fluid, etc.[0019]
The terms “excipient” and “vehicle” conventionally mean any compound or composition, such as a diluent, dispersant or solvent, which is adapted to form the topical form required, for example a cream, a gel, an oil, a lotion, etc. This composition is completed with various adjuvants that are well known to those skilled in the art, such as wetting agents, astringents, humidifying agents, emollients, etc.[0020]
The term “interactive” refers to the property by which the composition of a product according to the invention maintains all the functional biological equilibria of the skin, without inhibiting or exacerbating them, this being in addition to the topical biological activity of the said composition, resulting from the synergistic or non-synergistic biological activity on the skin of one or more biodermal constituents.[0021]
A product according to the invention thus has three functions. A first function consists in both protecting and maintaining, or even in restoring, the main biological and physiological cutaneous equilibria. A second function consists in creating a suitable stable pharmaceutical form (milk, cream, etc.). A third function consists in treating the skin by providing it with one or more topical benefits, in particular therapeutic or cosmetic benefits.[0022]
The term “pharmaceutical form” means any form or presentation, adapted to the mode of administration selected, which allows the product to exert functional activity on the skin.[0023]
The term “biodermal constituent” means any component or product forming part of the composition of the skin, in particular of the epidermis, it being understood that this constituent is considered in isolated form, in a form identical to its natural form, or modified relative to its natural form, but remaining cytocompatible with the skin, irrespective of the method by which it is obtained or produced, in particular by separation from live skin products, by biosynthesis, by a biotechnology process or by genetic recombination.[0024]
The term “biologically active” refers to the fact that the component or constituent considered itself displays biological activity in the epidermis, or alternatively participates in any biological process, such as metabolism, in the epidermis.[0025]
The term “topical activity” refers to the fact that, globally, the cutaneous interactive base exhibits or manifests, via the topical route, a cosmetic or therapeutic benefit on the skin, for example on the epidermis.[0026]
The expression “cytocompatible with the skin” refers to the property by which the biodermal constituent selected has a cytotoxicity of less than 10% with respect to a cell culture of human keratinocytes, i.e. it remains virtually neutral with respect to the cellular viability and morpho-differentiation of the keratinocytes.[0027]