High-Performance Liquid Chromatographic Determination of Vinorelbine and its Application to Pharmacokinetic Study in Rat Plasma.

In order to study the pharmacokinetics of vinorelbine and provide information necessary to determine the optimal therapy, a specific and reliable method to determine the levels of vinorelbine in biological fluids is required. We, therefore, established a highly sensitive and specific assay method for vinorelbine in biological fluids using reverse phase HPLC. The vinorelbine level was determined using HPLC with UV detection at 268 nm, combined with liquid-liquid extraction using diethyl ether for sample clean-up. The HPLC system used an ODS column and a mobile phase of 48 vol% methanol containing 0.05 vol% trifluoroacetic acid. The absence of endogenous interference and the excellent chromatographic behavior of vinorelbine provides accurate results even at low concentrations. The limit of determination is 2 ng/mL (100μL, sample), and the range of the assay is from 2 to 200 ng/mL. Consequently, this method is thus suggested to be highly sensitive and specific for determining the vinorelbine levels in biological fluids. Using this method, we measured the plasma concentrations of vinorelbine after a single intravenous administration of vinorelbine at 1.2 mg/kg in male rats. The plasma concentration ofvinorelbine disappeared triphasically after the intravenous administration of the drug.Based on these findings, this method is considered to be useful for drug monitoring of clinical specimens and also for basic studies, using small animals.