Rapid and sensitive determination of vinorelbine in human plasma by liquid chromatography–tandem mass spectrometry and its pharmacokinetic application

Vinorelbine is a semi-synthetic vinca alkaloid with demonstrated high activities against various types of advanced cancer. To support a clinical pharmacokinetic study, a simple, rapid and sensitive method to determine vinorelbine in human plasma was developed using reversed phase liquid chromatography (LC) coupled with electrospray ionization mass spectrometry/mass spectrometry (ESI-MS/MS). Vinorelbine and vinblastine (the internal standard) were extracted from human plasma by one-step liquid–liquid extraction (LLE) with methyl-t-butyl ether. The chromatographic separation was achieved on a Spursil polar-modified C18 column (50 mm × 2.1 mm, 3 μm, Dikma Technologies) with an isocratic mobile phase of a 75:25 (v/v) acetonitrile–4 mmol/L ammonium formate (pH 3.0) mixture at a flow-rate of 0.4 mL/min. The MS/MS detection was performed in the positive ion multiple reaction monitoring (MRM) mode by monitoring the precursor → product ion transitions at m/z 779.4 → 122.0 and m/z 811.3 → 224.2 for vinorelbine and the internal standard, respectively. The assay was validated in the range 0.1–200 ng/mL (r > 0.997), the lowest level of this range being the lower limit of quantification (LLOQ) based on 50 μL of plasma. The intra- and inter-day precisions were within 6.0%, while the accuracy was within ±4.7% of nominal values. Detection and quantification of both analytes within 2 min make this method suitable for high-throughput analyses. The method was successfully applied to evaluate the systemic pharmacokinetics of vinorelbine after a 20-min intravenous infusion of 25 mg/m2 of vinorelbine to patients with metastatic breast cancer.