In vitro assessment of the phototoxicity of anti-inflammatory 2-arylpropionic acids.

We have combined photochemical and physicochemical studies with in vitro testing on human fibroblasts and erythrocytes to investigate the photobiological risk of four non-steroidal anti-inflammatory drugs (NSAID)-ibuprofen, butibufen, flurbiprofen and naproxen. Under aerobic conditions these compounds undergo photodecarboxylation, mainly to benzylic alcohols and aromatic ketones. The photoproducts have been purified and chemically identified. While parent compounds showed very little or no phototoxicity, the most toxic photoproducts were systematically the benzylic alcohols, which showed lytic activity to erythrocytes and cytotoxicity to cultured fibroblasts. The results partly explain the in vivo phototoxicity of this family of drugs.