DETERMINATION OF DOXORUBICIN AND METABOLITES IN MURINE SPECIMENS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A sensitive and selective reversed-phase high-performance Liquid chrom atographic method for the quantification of doxorubicin and its metabo lites doxorubicinol, 7-deoxydoxorubicinone and 7-deoxydoxorubicinolone was developed and validated for a variety of murine specimens. Daunor ubicin was used as internal standard. Sample pretreatment involved liq uid-liquid extraction of 200 mu l sample with 1 ml of chloroform-1-pro panol (4.1, v/v). Chromatographic separation was achieved isocraticall y on a LiChrosorb RP-8 analytical column at ambient temperature. The m obile phase consisted of acidified water (pH 2.05)-acetonitrile-tetrah ydrofuran (80:30:1, v/v/v). The column effluent was monitored fluorime trically at an excitation wavelength of 460 nm and an emission wavelen gth of 550 nm. The lower limits of quantitation were in the range 1.8- 2.4 nM. Spiked murine specimens and samples from treated mice were sub jected to stability studies. The results demonstrated the importance o f validation in all relevant specimens, since the accuracy and precisi on were highly matrix-dependent. Accuracies and precisions of measured drug concentrations in liver, spleen, muscle, gastrointestinal tissue s, diluted bile, feces and urine were lower than in the other matrices . Doxorubicin was unstable in diluted bile, but not in the other speci mens. The method is suitable for studying the pharmacokinetics of doxo rubicin and its metabolites in mice. (C) 1998 Elsevier Science B.V. Al l rights reserved.