Photodegradation of benzydamine: Phototoxicity of an isolated photoproduct on erythrocytes

Article abstract of DOI:10.1002/jps.2600820407

Benzydamine hydrochloride (Tantum, 1) is a photoallergic and phototoxic anti-inflammatory and analgesic agent. This drug is photolabile under aerobic and anaerobic conditions. Irradiation of a methanol solution of benzydamine under oxygen or argon at 300 nm affords 5-hydroxybenzydamine (2) and 2-β- dimethylaminopropyl-1-benzylindalolin-3-one (3) as the main isolated and spectroscopically identified photoproducts. A radical intermediate was evidenced by thiobarbituric acid that was used as a radical sonde, as well as by the dimerization of cysteine. Erythrocyte lysis phososensitized by 1, 2, and 3 was investigated.