A sensitive and simple high-performance liquid chromatographic method for the determination of doxorubicin and its metabolites in plasma.

A sensitive high-performance liquid chromatographic (HPLC) method for the measurement of doxorubicin and its metabolites in plasma is described. After precipitation with zinc sulphate and methanol, samples are resolved by isocratic elution from a C18 reverse phase support within 20 min and quantified by endogenous fluorescence. Recoveries over a concentration range from 5 to 1,000 nM of doxorubicin, doxorubicinol, doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinolone were 80-110%, while recovery for 7-deoxydoxorubicinone was approximately 60%. At concentrations of 5 nM, within-run and between-day coefficients of variation for each compound were < 8 and < 16%, respectively. Limits of detection for the compounds were 1-2 nM and standard curves were linear up to at least 1,000 nM. The drug and its metabolites are stable in deproteinized plasma samples at room temperature and in the dark for at least 24 h. The method requires few manipulations and is readily adaptable to automated analysis of large series of samples.