Contemporary Detection Of 4-Demeth-Oxydaunorubicin And Its Metabolites 13-Dihydro-4-Demethoxydaunorubicin And4-Demethoxydaunorubicinone By Reverse Phase High-Performance Liquid Chromatography

Abstract

The aim of this work was to optimize a simple analytical method for a complete pharmacological and toxicological follow up of patients treated with a new orally active daunorubicin analog, the 4-demethoxydaunorubicin. For this reason the Chromatographic properties of the unchanged drug, its reduced metabolite 13-dihydro-4-demethoxydaunorubicin and its aglicone metabolite 4-demethoxydaunorubicinone have been investigated. Extraction of these compounds from biological fluids has been carried out using ethyl acetate and buthanol. Separation has been achieved in a C₁₈ reverse phase column by iso-cratic eluition with a mobil phase consisting of acetonitrile:methanol :phosphate buffer 40:10:50, pH 4.7. Drug and metabolites can be quantitated at nanogram level by fluorescence detection.

The appearance of a further compound, identified as the 13-dihydro-4-deme-thoxydaunorubicinone, was noted when whole blood instead of plasma was utilized while developing the assay. Aldo-cheto reductases of red blood cells could be responsible for the reduction of the 4-demethoxydaunorubicinone in its 13-dihydroderivative.