RESUMEN
Aim To establish a LC-MS/MS method for the determination of pirfenidone(BT)and its major metabolite 5-carboxy-pirfenidone(SBT)in human plasma.Methods Human plasma samples containing BT and SBT,as well as their corresponding deuterium-labeled internal standards pirfenidone-d5(dBT)and 5-carboxy-pirfenidone-d5(dSBT),were precipitated using methanol.Chromatographic separation was carried out on an Agilent ZORBAX SB C18(3.0 mm×100 mm,3.5 μm)column with the mobile phase of water(0.5％formic acid)and acetonitrile(50/50).The detection of analytes was performed on a tandem mass system equipped with an electrospray ionization source in positive ion mode using multiple-reaction monitoring.The MS/MS ion transitions monitored were m/z 185.958→77.1 for BT,m/z 215.944→77.0 for SBT,m/z 190.965→81.1 for dBT and m/z 220.948→99.1 for dSBT.Results There was no remarkable interference in blank solvent,plasma,and there was no mutual interference between analytes or internal standards.The proposed method showed good linearity over the concentration range of 0.020 59～25.14 mg·L-1 for BT and 0.016 73～20.42 mg·L-1 for SBT.The intra-batch and inter-batch precision and accuracy were proved to be acceptable.Human samples kept stable after 4 h at room temperature,the three freeze-thaw cycles and 10,29 and 52 days at-70 ℃,and the processed samples remained stable after 24 h in the autosampler.The average extraction recovery and matrix effect were precise,reproducible and acceptable.Conclusion Our current LC-MS/MS method is proved to be sensitive,accurate and convenient,and could be suitable for the clinical pharmacokinetic studies of BT-related preparations.
RESUMEN
Objective To develop a rapid ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) for determination of 11 sedative-hypnotics in human plasma. Methods The plasma samples were extracted with dichloromethane:n-hexane:acetoacetate (5∶4∶1). The separation was performed on a Waters ACQUITY UPLC HSS T3 column (2.1 mm×100 mm,1.8 μm) using the mobile phase composed of acetonitrile-0.1% ammonium solution at a flow rate of 0.2 mL?min-1 in gradient elution mode. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) via electrospray ionization (ESI) source in positive mode. Results Good linear relation was obtained over the investigated concentration range, with all correlation coefficients higher than 0.99. The limit of detection was 200 pg?mL-1 for dexzopiclone,and 10- 20 pg?mL-1 for other sedative-hypnotics. The intra- and inter-day RSD of 11 sedative-hypnotics were no more than 15.0%. The recoveries were in the range of 72.3%-108.0%, and the matrix effects were approximately 0.86- 1. 12. Conclusion The method is rapid, sensitive and reliable, and suitable for the simultaneous determination of 11 sedative-hypnotics in human plasma.