18 I3-GLYCYRRHETINIC ACID 83 (6) N. Sadlej-Sosnowska, Determination of glycyrrhizinic and glycyrrhetinic acids in pharmaceuticals by high performance liquid chromatography, J. Pharm. Biomed. Anal., 5, 289-293 (1987). (7) G. De Groot, R. Koops, E. A. Hogendoorn, C. E. Goewie, T. J. F. Savelkoul, and P. Van Vloten, Improvement of selectivity and sensitivity by column switching in the determination of glycyrrhizin and glycyrrhetinic acid in human plasma by high performance liquid chromatography, J. Chromatogr., 456, 71-81 (1988). (8) Z. Xinyi, W. Rujin, C. Jian, and A. Denkui, Determination of glycyrrhizin and its metabolite glycyrrhetinic acid in rabbit plasma by high performance liquid chromatography after oral adminis- tration of licorzin, J. Chromatogr., 495, 343-348 (1989). (9) S. Yamamoto, M. Kanda, M. Yokouchi, and S. Tahara, Simultaneous determination of multiple additives in cosmetics by high performance liquid chromatography, J. Chromatogr., 396, 404-409 (1987). (10) G. Talsky, L. Mayring, and H. Kreuzer, High-resolution, higher-order UV/VIS derivative spectro- photometry, Angew. Chem. Int. (Engl. Ed.), 17, 785-799 (1978). (! 1) A. F. Fell, Analysis of pharmaceutical dosage forms by second derivative ultraviolet-visible spectro- photometry, Proc. Anal. Div. Chem. Soc., 15, 260-267 (!978). (12) P. Levillain and D. Fompeydie, Spectrophotometrie deriv•e: Interet, limites et applications, Analusis, 14, !-20 (1986). (13) Clarke's Isolation and Identification of Drugs, 2nd ed. (The Pharmaceutical Press, London, 1986), pp. 603, 762, 938. (!4) Irving Sunshine, CRC Handbook of Spectrophotometric Data of Drugs (CRC Press, Inc., Boca Raton, Florida, 1981).

j. Soc. Cosmet. Chem., 43, 85-92 (March/April 1992) Protective effect of a topically applied anti-oxidant plus an anti-inflammatory agent against ultraviolet radiation-induced chronic skin damage in the hairless mouse D. L. BISSETT, R. CHATTERJEE, and D. P. HANNON, The Procter & Gamble Company, Miami Valley Laboratories, Cincinnati, OH 45239-8707. Accepted January 24, 1992. Synopsis Female albino hairless mice (Skh:HR-1) exposed chronically to sub-erythemal doses of ultraviolet radiation develop visible skin changes, histological alterations, and tumors. Topical treatment of mice with binary combinations of an anti-oxidant (alpha-tocopherol, ascorbic acid, or 2,4-hexadien-l-ol) and an anti- inflammatory agent (hydrocortisone, naproxen, or ibuprofen) prior to each UVB radiation exposure reduced significantly the severity of the observed photodamage events. The combinations provided protection additive of the effects of the individual components. UVA radiation-induced photodamage was inhibited effectively by the anti-inflammatory agent alone. Addition of an anti-oxidant did not increase this level of protection. INTRODUCTION Activated oxygen species and oxygen radicals have been implicated in ultraviolet (UV) radiation damage to skin (1-4). These species, in particular superoxide and singlet oxygen, are probably involved in chronic photodamage, since topical anti-oxidants that scavenge these species are photoprotective in the hairless mouse (2,3). Also, oxygen radicals are probably a primary factor in chronic photodamage, since chelators, which prevent iron-catalyzed production of oxygen radicals, are dramatically photoprotective in the mouse (4). Inflammatory cells also appear to play a role in photodamage. With chronic UV radi- ation exposure of mouse skin, there is an increase in dermal cellularity, including inflammatory cells (5,6). We have observed that topical anti-inflammatory agents are protective against chronic photodamage (7). This suggests that the inflammatory cell infiltrate contributes to the damage, although it is not clear what specific role these cells play in the damage process. 85