SENSITIVE DETERMINATION OF DOCETAXEL IN HUMAN PLASMA BY LIQUID-LIQUID-EXTRACTION AND REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A sensitive reversed-phase high-performance liquid chromatographic met hod has been developed and validated for the quantitative determinatio n of docetaxel (I) in human plasma. The concentrations in plasma, for validation procedures spiked with known amounts of I, are read from ca libration curves in the range of 10-20 000 ng/ml. The sample preparati on involved a liquid-liquid extraction of 1000 mu l of sample with a m ixture of acetonitrile-n-butylchloride (1:4, v/v). The related compoun d paclitaxel (II) was used as internal standard. Chromatographic separ ations were performed an Inertsil ODS-80A column, with UV detection pe rformed at 230 nm. The overall extraction recoveries were 84.3 and 90. 0% for I and II, respectively. The lower limit of quantitation was 10 ng/ml, and the accuracy, within-run and between-run precisions at thre e tested concentrations fell within the generally accepted criteria fo r bioanalytical assays.