Process of making and using composition containing oxidation-sensitive hydrophilic active principle and maleic anhydride copolymer

Abstract

The invention relates to the use of a composition for, e.g., promoting the synthesis of the epidermal ceramides and / or for improving the barrier function of the skin, the composition containing at least one oxidation-sensitive hydrophilic active principle selected from the group consisting of ascorbic acid and its compounds and at least one maleic anhydride copolymer. The invention also relates to a cosmetic process for moisturizing the skin comprising the application to the skin of a composition as defined above.

Description

REFERENCE TO PRIOR APPLICATIONS[0001] This application claims priority to U.S. provisional application No. 60 / 394,255, filed Jul. 9, 2002, and to French patent application 0207638, filed Jun. 20, 2002, both of which are incorporated herein by reference.[0002] The present invention relates to the use, preferably the cosmetic and / or dermatological use, of a composition comprising at least one oxidation-sensitive hydrophilic active principle and at least one maleic anhydride copolymer in a physiologically acceptable medium comprising an aqueous phase. The invention compositions are especially useful for, e.g., promoting the synthesis of the epidermal ceramides and / or for improving the barrier function of the skin, for combating roughness of the skin and / or maintaining and / or improving the radiance of the complexion, and for moisturizing the skin.DISCUSSION OF THE BACKGROUND[0003] It is known to introduce, into cosmetic compositions, various active principles intended to contribute spec...

AI Technical Summary

Benefits of technology

The patent text describes a composition that uses a combination of a hydrophilic active principle and a maleic anhydride copolymer to stabilize ascorbic acid and other unstable active principles in cosmetic and dermatological products. This composition has been found to be effective in promoting skin health, reducing skin roughness, improving skin barrier function, and moisturizing the skin. The use of maleic anhydride copolymer has been shown to reduce the decomposition of ascorbic acid and other unstable active principles in the presence of oxygen, light, or metal ions. The composition is comfortable to apply, does not cause skin irritation, and is compatible with industrial manufacturing processes. The use of ascorbic acid and other unstable active principles in the composition helps to maintain the integrity of the lipids in the skin, improve skin barrier function, and reduce moisturizing issues.

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.