LC-MS/MS determination of pantoprazole content in human plasma

Objective:To develop an LC-MS/MS method for determination of pantoprazole in human plasma.Methods:After protein precipitation with acetonitrile,the analyte and internal standard,lansoprazole,were separated on a Zorbax SB-C18 Narrow-Bore analytical column(150 mm×2.1 mm,5 μm) with the mobile phase of methanol and 10 mmol·L-1 ammonium acetate(65∶ 35) at a flow rate of 0.40 mL·min-1.Detection was carried out by electrospray positive ionization mass spectrometry in the multiple reaction monitoring(MRM) mode.The MRM transitions of m/z 384.1→m/z 200.2 and m/z 370.1→m/z 252.0 were used to quantify pantoprazole and IS,respectively.Results:Pantoprazole and internal standard were eluted at 1.75 and 2.36 min,respectively.The calibration curve was linear over the concentration range of 0.0100-6.00 mg·L-1 with the lower limit of quantitation(LLOQ) 0.0100 mg·L-1.Intra-day and inter-day relative standard deviations were both less than 5%,and the relative errors were within±4%.The mean extract recoveries were(97.2±5.4)%.In the stability studies,pantoprazole in plasma was found to be stable under various storage conditions.Conclusion:It is a rapid,sensitive,selective and reliable method for the determination of pantoprazole in human plasma.The method was successfully applied to a bioequivalence study of pantoprazole sodium enteric-coated tablet in healthy volunteers.