Method of selecting antioxidants for use in topically applied compositions

Abstract

Antioxidant-containing compositions and methods for confirming antioxidant activity of a composition formulated for topical application to skin. Methods for testing a composition for ability to inhibit both ultraviolet radiation-induced lipid peroxidation on skin and ultraviolet radiation-induced reactive oxygen species formation in the stratum corneum. Compositions and methods for treating and preventing photodamage to skin.

Description

[0001]This application claims priority to U.S. Provisional Application Nos. 61 / 023,713, filed Jan. 25, 2008, and 61 / 114,758, filed Nov. 14, 2008.FIELD OF THE INVENTION[0002]This invention relates generally to compositions applied topically to skin and hair for protection against ultraviolet radiation. The invention also relates to methods of selecting antioxidants for inclusion in such compositions.BACKGROUND OF THE INVENTION[0003]Exposure of skin to ultraviolet radiation (UVR) induces formation of free radicals and oxidants (singlet oxygen, hydroxy radical, hydrogen peroxide, peroxynitrite, superoxide anions, etc.) collectively referred to as reactive oxygen species (ROS) (Hanson K M, Clegg R M. Photochemistry and Photobiology, 2002, 76(1): 57-63; Black H S. Photochem. Photobiol. 1987, 46, 213-221). Formation of UV-induced ROS causes oxidative damage to lipids, proteins and DNA (Vile G F and Tyrrell R M. Free Radic. Biol. Med, 1995, 18, 721-722; Chen Q, et al. Proc. Natl. Acad. Sci...

AI Technical Summary

Benefits of technology

[0011]The invention further provides for a composition for topical application, wherein the composition comprises at least one antioxidant compound that substantially inhibits ultraviolet radiation-induced reactive oxygen species formation in the upper layers of the epidermis and at least one antioxidant compound that substantially inhibits ultraviolet radiation-induced reactive oxygen species formation in the lower layers of the epidermis.

Problems solved by technology

However, research has shown that even sub-erythemal doses of UVR generates such an abundance of ROS that skin's own antioxidant defenses become overwhelmed, resulting in a build up of ROS that are free to cause oxidation, which contributes to acute (immunosuppression and photosensitivity disorders) and chronic (photoaging and skin cancer) forms of skin damage (Thiele J J, et al.

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