Photodegradation of doxorubicin, daunorubicin and epirubicin measured by high-performance liquid chromatography.

The degradation kinetics of doxorubicin, daunorubicin and epirubicin in aqueous solution under fluorescent light and sunlight were studied using high-performance liquid chromatographic (HPLC) methods. The rates of photodegradation of all three drugs were similar, they were inversely proportional to the drug concentration and were accelerated by an increase in the pH of the vehicle. Photodegradation followed first-order kinetics. At concentrations greater than or equal to 500 micrograms/ml no special precautions appeared to be necessary to protect freshly prepared solutions of these agents from light. Photolysis was very rapid, however, at concentrations in the low microgram range therefore, when these solutions are used for in-vitro work or stability studies, they should be protected from light at all times. In addition, adsorptive losses, which may also be pronounced in low concentration solutions, should be prevented by storage in polypropylene containers.