UV-induces formation of hydrogen peroxide based on the photochemistry of ketoprofen

Ketoprofen (KP) is a potent nonsteroidal anti-inflammatory drug, However, a pplication to the skin is problematic because the photosensitizing properti es of the benzophenone moiety may cause phototoxic effects when the treated skin region is exposed to UVA light. Using capillary electrophoresis with electrochemical detection we are able to differentiate the peroxides formed during illumination of KP-containing solutions of linoleic acid. Contrary to other profens a high amount of hydrogen peroxide was found among the rea ction products. For investigation of the skin damaging effect human keratin ocytes were used as models. Cell viability, DNA synthesis efficiency and in tracellular concentration of peroxides were determined, Viability and proli feration behavior was not altered under the influence of KP, While lower co ncentrations of KP (10-100 nM) led to a protection against the UVA-induced (8 J/cm(2)) cell proliferation damage, higher concentrations (10-100 muM) l ed to an amplification of the proliferation decrease. With UVB irradiation at relevant doses the effects were lower than using UVA, Furthermore, intra cellular peroxide content was increased after UV irradiation and KP additio n, In conclusion some efforts have to be done to avoid these side effects i n the use of KP for topical or transdermal application.