[Determination of new anticancer drug, paclitaxel, in biological fluids by high performance liquid chromatography]

A simple and reproducible high performance liquid chromatographic (HPLC) method using an internal standard (I.S.) was developed for the determination of an anticancer drug, paclitaxel, in biological fluids. The sample preparation involves a solid-phase extraction step. HPLC was performed on an ODS column using acetonitrile-2 mM phosphoric acid (45:55) as a mobile phase with detection at 227 nm. A linear relationship was obtained in the range of 0.02-2.0 micrograms/ml in the rat plasma and urine. Since the recovery of the drug was as high as that of I.S. (> 96%), a standard curve generated from the solution of the drug with I.S. in the mobile phase could be used for determination. The method could be applicable for human and dog plasma as well as rat plasma, and the intra- and interday coefficients of variation at 0.05, 2.0 and 10.0 micrograms/ml were less than 7%. This method is useful for pharmacokinetic studies of paclitaxel.