Determination and pharmacokinetic study of chiisanogenin in rat plasma by ultra performance liquid chromatography-tandem mass spectrometry.

Chiisanogenin existing in many Acanthopanax species has been reported to possess anti-inflammatory, antibacterial and antiplatelet aggregatory activities. To develop and validate a rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry method for the determination of chiisanogenin in rat plasma and to investigate its pharmacokinetics after oral administration of chiisanogenin or the extract of Acanthopanax sessiliflorus fruits. The sample pretreatment involved a one-step extraction of 0.2 mL plasma with diethyl ether. Acetaminophen was used as the internal standard. The separation was carried out on an ACQUITY UPLC™ BEH C₁₈ column with a mobile phase of acetonitrile-5 mM ammonium acetate (90:10, v/v) at a flow rate of 0.2 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. A high sample throughput was achieved with an analysis time of 1.1 min per sample. The calibration curve was linear (r² ≥ 0.99) over the concentration range of 5-500 ng/mL with a lower limit of quantification (LLOQ) of 5 ng/mL. The intra-day and inter-day precision (relative standard deviation, R.S.D.) values were below 11% and the accuracy (relative error, R.E.) was within 8% at all three quality control (QC) levels. The method was successfully applied to the pharmacokinetic study of chiisanogenin in rat after oral administration of chiisanogenin and the extract of Acanthopanax sessiliflorus fruits. Other constituents in the extract affected the pharmacokinetic behavior of chiisanogenin.

Yang C ，Yu K ，Song Y ，Qin F ，Li F ... -  《-》

Determination of nifedipine in human plasma by ultra performance liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study.

A fast, sensitive and selective ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the determination of nifedipine in human plasma. Nitrendipine was used as the internal standard. The sample preparation employed liquid-liquid extraction with a mixture of n-hexane-diethyl ether (1:3, v/v). Chromatographic separation was performed on an ACQUITY UPLC™ BEH C(18) column. The mobile phase was composed of acetonitrile-10 mmol/L ammonium acetate (75:25, v/v) with a flow rate of 0.20 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. A high throughput was achieved with a run time of 1.4 min per sample. The linear calibration curves were obtained in the concentration range of 0.104-52.0 ng/mL (r(2)≥ 0.99) with a lower limit of quantification (LLOQ) of 0.104 ng/mL. The intra- and inter-day precision (relative standard deviation, RSD) values were below 15% and the accuracy (relative error, RE) was -4.0% to 6.2% at three quality control levels. The method was fully validated and successfully applied to a clinical pharmacokinetic study of nifedipine sustained-release tablet in healthy male volunteers.

Wang D ，Jiang K ，Yang S ，Qin F ，Lu X ，Li F ... -  《-》

Determination of lovastatin in human plasma by ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry.

A fast and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of lovastatin in human plasma. With simvastatin as internal standard, sample pretreatment involved one-step extraction with n-hexane-methylene dichloride-isopropanol (20:10:1, v/v/v) of 0.5 mL plasma. Chromatographic separation was carried out on an Acquity UPLC BEH C(18) column with mobile phase consisting of acetonitrile-water (containing 5 mmol/L ammonium acetate; 85:15, v/v) at a flow-rate of 0.35 mL/min. The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) via electrospray ionization source with positive mode. The analysis time was shorter than 1.7 min per sample. The standard curve was linear (r2>or=0.99) over the concentration range 0.025-50.0 ng/mL with a lower limit of quantification of 0.025 ng/mL. The intra- and inter-day precision values were below 11% and the accuracy (relative error) was within 6.0% at three quality control levels. This is the first method of MS with MRM coupled to UPLC for the determination of lovastatin, which showed great advantages of high sensitivity, selectivity and high sample throughput. It was fully validated and successfully applied to the pharmacokinetic study of lovastatin tablets in healthy Chinese male volunteers after oral administration.

Wang D ，Wang D ，Qin F ，Chen L ，Li F ... -  《BIOMEDICAL CHROMATOGRAPHY》

Simultaneous determination of three bufadienolides in rat plasma after intravenous administration of bufadienolides extract by ultra performance liquid chromatography electrospray ionization tandem mass spectrometry.

Zhang Y ，Tang X ，Liu X ，Li F ，Lin X ... -  《-》

Simultaneous quantification of venlafaxine and O-desmethylvenlafaxine in human plasma by ultra performance liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study.

A rapid, selective and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneously determine venlafaxine (VEN) and O-desmethylvenlafaxine (ODV) in human plasma. Sample pretreatment involved a one-step extraction with diethyl ether of 0.5 mL plasma. The separation was carried out on an ACQUITY UPLC BEH C(18) column with 10 mmol/L ammonium acetate and methanol as the mobile phase at a flow rate of 0.30 mL/min. The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The linear calibration curves for VEN and ODV were both obtained in the concentration range of 0.200-200 ng/mL (r(2)> or =0.99) with the lower limit of quantification (LLOQ) of 0.200 ng/mL. The intra- and inter-day precision (relative standard deviation, R.S.D.) values were less than 13% and the accuracy (relative error, R.E.) was within +/-5.3% and +/-3.6% for VEN and ODV. The method herein described was superior to previous methods in sensitivity and sample throughput and successfully applied to clinical pharmacokinetic study of venlafaxine sustained-release capsule in healthy male volunteers after oral administration.

Qin F ，Li N ，Qin T ，Zhang Y ，Li F ... -  《-》