High electrolyte content W/O emulsions for treating irritated/sensitive skins

Abstract

Stable, topically applicable water-in-oil emulsions, well suited for therapeutically treating irritated / sensitive skins and having high electrolyte content, comprise (a) at least 2% by weight of at least one water-soluble metal salt, (b) at least one hydrophobic gelling agent, (c) less than 5% by weight of at least one emulsifying agent, and, advantageously, at least one biologically active agent, for example an active agent that modulates skin differentiation and / or proliferation and / or pigmentation, an anti-inflammatory, an antibacterial, an antifungal, etc., and / or at least one keratolytic active agent, neuropeptide antagonist and / or inflammation-mediator antagonist.

Description

[0001] This application is a divisional of U.S. application Ser. No. 08 / 943,191, filed Oct. 3, 1997, incorporated by reference herein in its entirety and relied upon.[0002] 1. Technical Field of the Invention[0003] The present invention relates to stable water-in-oil emulsions having a high electrolyte content, comprising at least 2% by weight, relative to the total weight of the composition, of a water-soluble metal salt, at least one hydrophobic gelling agent and an amount of a suitable emulsifying system effective to provide a stable composition, particularly a stable topically applicable composition.[0004] This invention also relates to dermocosmetic compositions comprising the above stable w / o emulsions, for treating pathological and / or physiological disorders associated with the release of substance P and / or of TNF-alpha (Tumor Necrosis Factor-alpha) and, in particular, for treating sensitive skin and skin disorders and diseases in which pruritus, acne rosacea and / or discreet ...

AI Technical Summary

Problems solved by technology

The symptoms of sensitive skin were hitherto poorly characterized and the problem of these skin types was consequently poorly defined since it was unknown exactly what process was involved in skin sensitivity / nonallergic hyperreactivity of the skin.

However, these tests did not permit the characterization of sensitive skin, which was likened to allergic skin.

Pruritus is a common symptom of dermatitis, which often causes considerable inconvenience to the patient.

When the pruritus is very severe, the inconvenience may be such that the patient cannot continue his or her usual activity.

In addition, pruritus may be a source of complications: excoriations which may become overinfected, lichenification of the pruriginous regions, the consequence of which is to position the patient in a veritable vicious circle.

Since the characteristics of sensitive skin are poorly understood, it was hitherto very difficult to treat it, and it was treated indirectly, for example by limiting the use of products irritant in nature, such as surfactants, preservatives or fragrances, as well as certain active agents, in cosmetic or dermatological compositions.

Local corticoids are, admittedly, very effective for alleviating the symptoms, but their effect is, unfortunately, not immediate.

Too, they often elicit very severe side effects such as atrophy, and expose the patient to risks of mycosal and / or bacterial infections.

This technique presents the major drawback of photoaging which may result in skin cancers.

Further, this treatment is not ambulatory, thus obliging patients to regularly visit a specialized center throughout the treatment period, which is very restrictive and limits their professional activity.

Emollients elicit a very modest anti-pruriginous effect and are of poor efficacy when the pruritus is considerable.

Moreover, antihistamines are not of constant efficacy and must be administered orally.

Thus, serious need continues to exist in this art for improved treatment of the above skin afflictions which does present the above drawbacks.

These emulsions often have stability problems, which makes them difficult to formulate.

However, it is known that emulsifiers used in large amounts can elicit irritant effects on certain skin types.

Moreover, as above, the creams obtained are often compact and heavy.

It will readily be appreciated that such compositions are not suitable for application to sensitive skin, given the difficulties indicated above.

These compositions comprising a high emulsifier content and a limited amount of water are not suitable for application to sensitive skin either.