Liquid chromatography/positive ion electrospray tandem mass spectrometry method for the quantification of hydrochloride meptazinol in human plasma: application to a pharmacokinetic study.

A robust and validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with positive electrospray ionization (ESI) was developed for the determination of hydrochloride meptazinol in human plasma. After liquid-liquid extraction of 200mul of human plasma, HPLC separation was achieved on a Thermo Hypurity Cyano column, using acetonitrile:ammonium formate (50mM, aq) (70:30, v/v) as the mobile phase. The mass spectrometer was operated in multiple reaction monitoring (MRM) mode using the transition m/z 234-->234 for meptazinol and m/z 152-->110 for the IS (acetaminophen), respectively. The calibration curves were linear over the range of 0.2925-292.5ng/ml, with the limit of quantification (LOQ) 0.2925ng/ml. The mean absolute recovery of hydrochloride meptazinol was more than 70.21%. Intra- and inter-day precisions were less than 9.05% and 12.89%, respectively. And the accuracy was within -2.99% to 4.96%. This method was applied to a pharmacokinetic study of hydrochloride meptazinol tablets in healthy Chinese volunteers.