Hydrophilic interaction liquid chromatography-tandem mass spectrometry for the determination of adefovir in human plasma and its application to a pharmacokinetic study.

A selective, rapid and sensitive hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method was developed for the first time to determine adefovir in human plasma and applied to a pharmacokinetic study. Plasma samples were prepared by protein precipitation with methanol followed by a further cleaning using dichloromethane. The chromatographic separation was carried out on an ACQUITY UPLC BEH HILIC column with the mobile phase of methanol-water-formic acid (85:15:0.2, v/v/v). The detection was performed on a triple-quadrupole tandem mass spectrometer with multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The method was rapid with a run time of 3 min per sample. The linear calibration curves were obtained in the concentration range of 1.02-102 ng/mL (r(2)> or =0.99) with the lower limit of quantification (LLOQ) of 1.02 ng/mL. The intra- and inter-day precision (relative standard deviation, R.S.D.) values were below 12% and the accuracy (relative error, R.E.) was from 0.6% to 3.2% at all quality control (QC) levels. The method was applicable to clinical pharmacokinetic study of adefovir in healthy volunteers after oral administration of adefovir dipivoxil tablet.

Xiong Z ，Zhang Y ，Qin F ，Qin T ，Yang S ，Li F ... -  《-》

High-performance liquid chromatography-tandem mass spectrometry for the determination of pidotimod in human plasma and its application to a pharmacokinetic study.

Zhang Y ，Xiong Z ，Qin F ，Lu S ，Liu W ，Li F ... -  《-》

Development and validation of a liquid chromatography/tandem mass spectrometry procedure for the quantification of adefovir in human plasma.

To investigate the pharmacokinetics of adefovir as an anti-hepatitis B virus drug, a sensitive and specific liquid chromatography/tandem mass spectrometry method was developed and validated. After a simple protein precipitation using methanol, the post-treatment samples were analyzed on a C(18) column interfaced with a triple-quadrupole tandem mass spectrometer using positive electrospray ionization. A structural analogue, PMPA, was used as the internal standard. The method was linear in the concentration range 0.25-100 ng/mL. The lower limit of quantification was 0.25 ng/mL. The intra- and inter-day relative standard deviation over the entire concentration range was 5.7% or less. The accuracy determined at three concentrations (0.75, 10 and 80 ng/mL for adefovir) was within +/-2.5% relative error. The method described here was successfully applied for the evaluation of pharmacokinetic profiles of adefovir after single oral administration doses of 5, 10 and 20 mg adefovir dipivoxil to ten healthy volunteers.

Chen X ，Liu D ，Zhu L ，Zhong D ... -  《RAPID COMMUNICATIONS IN MASS SPECTROMETRY》

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

A rapid, sensitive and selective ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the determination of palonosetron (PALO) in human plasma. Verapamil was used as the internal standard (I.S.). Sample pretreatment involved liquid-liquid extraction with diethyl ether under alkaline condition. Chromatographic separation was carried out on an ACQUITY UPLC™ HSS T(3) column with mobile phase consisting of methanol-water containing 0.1% formic acid (80:20, v/v) at a flow-rate of 0.20mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The ion transitions of PALO and I.S. were m/z 297.3→109.8 and m/z 455.1→164.9, respectively. Each plasma sample was chromatographed within 1.2min. The linear calibration curves were obtained in the concentration range of 0.0190-3.80ng/mL (r(2)≥0.99) with a lower limit of quantification (LLOQ) of 0.0190ng/mL. The intra- and inter-day precision (relative standard deviation, R.S.D.) values were all less than 11% and accuracy (relative error, R.E.) was from 4.3% to 6.1% at all quality control (QC) levels. The method has been successfully applied to determine the plasma concentration of PALO in healthy Chinese volunteers after intravenous administration of a single dose of 0.125mg palonosetron hydrochloride.

Yang S ，Qin F ，Wang D ，Li N ，Li F ，Xiong Z ... -  《-》

Simultaneous quantification of enalapril and enalaprilat in human plasma by high-performance liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study.

Lu S ，Jiang K ，Qin F ，Lu X ，Li F ... -  《JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS》