Cosmetic and/or dermatological use of a composition containing at least one oxidation-sensitive hydrophilic active principle and at least one N-vinylimidazole polymer or copolymer

Abstract

The invention relates to the use of a composition containing, preferably in a physiologically acceptable medium comprising an aqueous phase, at least one oxidation-sensitive hydrophilic active principle selected from the group consisting of ascorbic acid and its derivatives and at least one non-crosslinked N-vinylimidazole polymer or copolymer, the active principle and the polymer or copolymer both being present in the aqueous phase, for promoting the synthesis of epidermal ceramides and / or for improving the barrier function of the skin, among other uses.

Description

[0001] The present invention relates to the cosmetic and / or dermatological use of a composition comprising at least one oxidation-sensitive hydrophilic active principle and at least one N-vinylimidazole polymer or copolymer in a physiologically acceptable medium comprising an aqueous phase.[0002] It is known to introduce, into cosmetic compositions, various active principles intended to contribute specific treatments to the skin and / or hair. However, some of these active principles exhibit the disadvantage of being unstable in an aqueous medium and of easily decomposing on contact with water, in particular because of oxidation phenomena. They thus rapidly lose their activity over time and this instability conflicts with the desired effectiveness.[0003] Attempts have thus been made for a long time to formulate ascorbic acid or vitamin C because of its numerous beneficial properties. In particular, ascorbic acid stimulates the synthesis of the connective tissue and in particular of co...

AI Technical Summary

Benefits of technology

[0014] One object of the present invention is to provide a composition comprising an oxidation-sensitive active principle preferably selected from the group consisting of ascorbic acid and its derivatives, which exhibits good cosmetic properties, both with regard to touch and with regard to tolerance, the preservation of which over time does not require specific precautions, and which retains the activity of the said active principle in improving the synthesis of ceramides and the barrier function of the skin and in improving the differentiation of keratinocytes, among other benefits and attributes.

[0015] The inventors have discovered that the use of non-crosslinked N-vinylimidazole polymers or copolymers in compositions in which the aqueous phase includes an oxidation-sensitive active principle, such as ascorbic acid or one of its derivatives, makes it possible to achieve the abovementioned aim.

Problems solved by technology

However, some of these active principles exhibit the disadvantage of being unstable in an aqueous medium and of easily decomposing on contact with water, in particular because of oxidation phenomena.

They thus rapidly lose their activity over time and this instability conflicts with the desired effectiveness.

Unfortunately, because of its chemical structure (of .alpha.-ketolactone), ascorbic acid is highly sensitive to certain environmental parameters and in particular to oxidation phenomena.

These solutions have disadvantages with regard to the cost and the complexity of the manufacturing operations and significant restrictions with regard to use.

However, these solutions exhibit the disadvantage of resulting in sticky formulations, the cosmetic quality of which is difficult to improve.

Furthermore, the presence of a high concentration of these compounds can lead to phenomena of irritation.

A major disadvantage of such solutions results from the lack of freshness on application.