Determination of pregabalin in human plasma by LC-MS/MS and its application to pharmacokinetics study / 中国药学杂志

ABSTRACT

OBJECTIVE: To establish an LC-MS/MS method for the determination of pregabalin, which was used subsequently to investigate the pharmacokinetics of pregabalin in healthy Chinese volunteers. METHODS: Gabapentin was used as internal standard. The separation was achieved on a Waters Symmetry C18 column (3.9 mm×150 mm, 5 μm) with a mobile phase consisting of acetonitrile -5 mmoL·L-1 ammonium acetate and 0.3% formic acid aqueous solution (8/92, V/V) at a flow rate of 1.0 mL·min-1 within 6.0 min. Pregabalin and the internal standard were measured by a triple-quadrupole mass spectrometer in positive electron atmospheric-pressure chemical ionization (APCI) mode using multiple reaction monitoring (MRM). The extracted ions monitored following MRM transitions were m/z 160.1→142.1 for pregabalin and m/z 172.1→154.1 for the internal standard gabapentin. Plasma samples were pretreated by methanol precipitation. RESULTS: The calibration curve of pregabalin in human plasma was linear over the concentration range of (30-5 000) ng·mL-1. The lower limit of quantitation was 30 ng·mL-1. The intra- and inter-run precisions at three quality control levels were within 2.0%-6.2%, the relative deviation of the assay was within -10.5%-3.0%. The plasma samples were stable at room temperature (25℃) for 6 h, at -30℃ for 27 d and during three freeze-thaw cycles. The determination and the result of incurred sample reanalysis met the requirements. CONCLUSION: The method is proved to be convenient, accurate and sensitive. The method is proved to be suitable for the pharmacokinetics of pregabalin in healthy Chinese volunteers after a single oral dose of 75 mg pregabalin capsule.