Composition containing at least one oxidation-sensitive hydrophilic active principle and at least one N-vinylimidazole polymer or copolymer useful to prevent and/or treat cutaneous signs of intrinsic ageing

Abstract

The invention relates to 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 in the aqueous phase, useful for preventing and / or treating cutaneous signs of intrinsic ageing.

Description

[0001] The present invention relates to 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, and its use in particular to prevent or treat cutaneous signs of intrinsic ageing. The composition is preferably a cosmetic or dermatological composition.[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 p...

AI Technical Summary

Benefits of technology

[0016] 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.

[0020] Another embodiment of the invention is the use of a combination composed of at least one oxidation-sensitive hydrophilic active principle preferably selected from the group consisting of ascorbic acid and its derivatives and of at least one non-crosslinked N-vinylimidazole polymer or copolymer in the aqueous phase-of a cosmetic composition as agent for preventing and / or treating cutaneous signs of intrinsic ageing.

[0049] These fatty substances can be chosen in a way varied by a person skilled in the art in order to prepare a composition having the desired properties, for example of consistency or of texture, without undue hardship.

[0091] In an alternative form, the composition according to the invention can be used for the manufacture of a dermatological preparation comprising an aqueous phase which is intended to prevent and / or treat cutaneous signs of intrinsic ageing.

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.