Photodegradation of Dacarbazine Catalyzed by Vitamin B and Flavin Adenine Dinucleotide Under Visible-Light Irradiation.

PURPOSE

Drug photodegradation is a matter of great concern because it can result in potency loss and adverse side effects. This study examines the light-induced degradation of dacarbazine catalyzed by vitamin B and flavin adenine dinucleotide (FAD) under light-emitting diode (LED) or fluorescent light irradiation.

METHODS

Dacarbazine was irradiated with LED (405 nm) or fluorescent light in the presence of various equivalents of vitamin B or FAD. The photodegradation of the drug in DO was monitored by H nuclear magnetic resonance spectroscopy.

RESULTS

Dacarbazine dissolved in DO decomposed in the presence of vitamin B or FAD under irradiation with LED or fluorescent light. The decomposition products were 2-azahypoxanthine 2, which has previously been observed after light irradiation in the absence of vitamin B, and 1H-imidazole-5-carboxamide 6, a new product formed in the presence of vitamin B. Irradiation with LED light was more effective than irradiation with fluorescent light in degrading dacarbazine.

CONCLUSION

Vitamin B and FAD induced dacarbazine photodegradation. Thus, the interfusion of vitamin B or FAD under excessive light exposure should be avoided during the intravenous administration of dacarbazine.