Vargus, F., H. Mendez, E. Tropper, M. Velazquez, and G. Fraile. Studies on the In Vitro Phototoxicity of the Antidiabetes Drug Glipizide. 2000. In Vitro & Molec. Toxicol. 13(1): 17- .

glipizide - 29094-61-9; glutathione - 00070-18-8; ascorbic acid - 00050-81-7; sodium azide - 26628-22-8; superoxide dismutase - 09054-89-1; alpha-tocopherol - 00059-02-9

The phototoxic antidiabetse drug glipizide (1) is photolabile under arobic conditions and UV-B light. Irradiation of a phosphate-buffered solution of 1 under oxygen atmosphere produces 4 photoproducts as well as singlet oxygen, which was detected by trapping it with 2,5-dimethylfuran and by the histidine test. The photochemistry of 1 involves cleavage of the sulfon-amine and the sulfonamine-R bonds. Red blood cell lysis, photosensitized by glipizide and the products of its aerobic photolysis were demonstrated. The photohemolysis rate was lower for 1 than for its photoproducts. Inhibition of this process on addition of 1,4,-diazabicyclo[2.2.2]octane (DABCO), reduced glutathione (GSH), Vitamin C, sodium azide, superoxide dismutase, and alpha-tocopherol confirmed the possibility of singlet oxygen, superoxide ion and free radicals participation. Furthermore, in a lipid-photoperoxidation test with linoleic acid the in vitro phototoxicity of glipizide was also verified. A low decreasing cell viability of lymphocytes and neutrophils was observed.