Determination of 3'-deamino-3'-[2(S)-methoxy-4-morpholinyl]doxorubicin, a new morpholinyl anthracycline, in plasma by high-performance liquid chromatography with fluorescence detection.

A sensitive and selective high-performance liquid chromatographic method for the determination of 3'-deamino-3'-[2(S)-methoxy-4-morpholinyl]doxorubicin and its possible 13-dihydro metabolite in human plasma has been developed. The plasma samples were buffered and the drugs and internal standard (doxorubicin) were extracted with diethyl ether-n-butanol, back-extracted into 0.3 M phosphoric acid, then analysed by reversed-phase liquid chromatography. Quantitation was achieved by fluorescence detection of the eluate. The linearity, precision and accuracy of the method were evaluated. No interference from blank plasma sample was observed. The suitability of the method for in vivo samples was checked by analysis of plasma samples drawn from female rats that had received repeated intravenous doses of the test compound.