Determination and pharmacokinetic study of hydrocodone in human plasma by liquid chromatography coupled with tandem mass spectrometry.

A rapid, highly sensitive and specific high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS-MS) quantitation method was developed and validated for the determination of hydrocodone in human plasma. Sample was extracted from 0.5mL heparinized plasma by a simple liquid-liquid extraction method and analyzed on a C18 column with a mobile phase of acetonitrile-water (78:22,v/v,0.1% acetic acid). Detection was carried out by positive elevtrospray ionization (ESI) in multiple reactions monitoring (MRM) mode of 300.3-->199.2 (m/z) for hydrocodone and 341.2-->107.2 (m/z) for canrenone (I.S.), respectively. A good linearity was obtained from 0.5 to 60 ng x mL(-1) and the lower limit of quantification (LLOQ) was 0.1 ng x mL(-1). Compared to an existing method, the extraction method, internal standard and chromatographic conditions were modified and the cost of a large amount of samples determination was decreased obviously. The method was successfully applied to the pharmacokinetic and bioequivalence studies in healthy Chinese volunteers.