Determination of vinflunine in rat plasma by liquid chromatography–electrospray ionization mass spectrometry for a pharmacokinetic study

A rapid, simple and sensitive high-performance liquid chromatography–electrospray ionization mass spectrometry (LC–ESI-MS) method for the quantification of vinflunine in rat plasma was developed and validated. After making alkaline with NaOH, plasma was extracted with ethyl acetate and determined by LC–MS. The analysis was carried out on a Shimadzu VP-ODS column (150 mm × 4.6 mm ID, packed with 5 μm C18 Silica RP particle). The mobile phase consisted of methanol–10 mM ammonium acetate buffer (80:20, v/v) with the flow rate of 1.0 ml/min. LC–MS was performed in the selected ion monitoring (SIM) mode using target ions at m/z: 817.3 for vinflunine and m/z: 373.2 for finasteride (IS). Chromatographic separation was achieved in less than 6 min and the calibration curve was linear over a concentration range of 0.025–6.25 μg/ml. The intra-assay and inter-assay variability values were less than 8.6%. The accuracy ranged from 91.5 to 105.6%. The established method has been successfully applied to a pharmacokinetic study of vinflunine in rats.