Determination of lercanidipine in human plasma by an improved UPLC-MS/MS method for a bioequivalence study$

An improved and reliable ultra-performance liquid chromatography/tandem mass spectrometry (UPLC–MS/MS) method has been developed and validated for the determination of lercanidipine in human plasma. Plasma samples with lercanidipine-d3 as an internal standard (IS) were prepared by solid phase extraction on Phenomenex Strata-X cartridges using 100 mL of human plasma. Chromatographic analysis was performed on UPLC BEH C18 (50 mm ? 2.1 mm, 1.7 mm) column under isocratic conditions. Linear calibration curves were obtained over a wide dynamic concentration range of 0.010–20.0 ng/mL. Matrix effect was assessed by post-column infusion, post-extraction spiking and standard-line slope methods. The mean extraction recovery was 4 94%for the analyte and IS. Inter-batch and intra-batch precision (%CV) across five quality controls was o 5.8%. Bioequivalence study was performed with 36 healthy sub-jects after oral administration of 10 mg of lercanidipine and the assay reproducibility was evaluated by reanalysis of 133 incurred samples.