Phototransformation and ecotoxicity of the drug Naproxen-Na

The phototransformation of naproxen Na in aqueous medium has been investigated. Irradiation of the drug in drinking water affords seven photoproducts. Three of them are dimeric photoproducts isolated for the first time. The compounds, isolated by chromatographic processes, have been identified by spectroscopic means. The toxicity of the photoproducts and the parent drug has been assayed on Daphnia magna and Vibrio fischeri. The results indicate that some photoproducts are more toxic than naproxen.