Development and validation of a rapid high-performance liquid chromatography-tandem mass spectrometry method for the determination of WJ-38, a novel aldose reductase inhibitor, in rat plasma and its application to a pharmacokinetic study.

WJ-38 is an aldose reductase inhibitor that is being developed for the treatment of diabetic complications. The present paper describes a sensitive and specific liquid chromatography-tandem mass spectrometry method for the determination of WJ-38 in rat plasma. Partial denaturation of plasma proteins with methanol followed by liquid-liquid extraction using ethyl acetate was used to extract strongly protein-bound WJ-38 from rat plasma. Chromatographic separation was performed on an Inertsil ODS-3 column with an isocratic mobile phase consisting of acetonitrile, water and formic acid (75:25:0.125, v/v/v). Mass spectrometric detection was achieved by a triple-quadrupole mass spectrometer equipped with an ESI interface operating in positive ionization mode. Quantitation was performed using selected reaction monitoring of precursor-product ion transitions at m/z 392→246 for WJ-38 and m/z 446→321 for glipizide (internal standard). A linear calibration curve was obtained over the concentration range of 10.0-10,000 ng/mL for WJ-38 in rat plasma. The intra- and inter-day precisions were less than 13.6% and the accuracy was within ± 5.3%. The extraction recovery of WJ-38 from rat plasma was over 66.0%. The validated method has been successfully applied to a pharmacokinetic study in rats after intragastrical administration of WJ-38.

Lu J ，Liu Y ，Wang X ，Wang S ，Di X ... -  《-》

Highly sensitive method for the determination of a novel triple kinase inhibitor with anti-cancer activity, JI-101, in rat plasma by liquid chromatography-electrospray ionization tandem mass spectrometry: application to a pharmacokinetic study.

A highly sensitive, rapid assay method has been developed and validated for the estimation of JI-101 in rat plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive-ion mode. The assay procedure involves extraction of JI-101 and phenacetin (internal standard, IS) from rat plasma with a solid-phase extraction process. Chromatographic separation was achieved using a binary gradient using mobile phase A (acetonitrile) and B (0.2% formic acid in water) at a flow rate of 0.30 mL/min on a Prodigy ODS column with a total run time of 4.0 min. The MS/MS ion transitions monitored were 466.1 → 265 for JI-101 and 180.1 → 110.1 for IS. Method validation and sample analysis were performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 5.03 ng/mL and the linearity range extended from 5.03 to 2014 ng/mL. The intra-day and inter-day precisions were in the ranges of 1.17-19.6 and 3.09-10.4%, respectively. This method has been applied to a pharmacokinetic study of JI-101 in rats.

Gurav SD ，Gilibili RR ，Jeniffer S ，Giri S ，Srinivas NR ，Mullangi R ... -  《-》

Determination of p-aminohippuric acid in rat plasma by liquid chromatography-tandem mass spectrometry.

A rapid, simple and sensitive method was developed for the determination of para-aminohippuric acid (PAH) in rat plasma using liquid chromatography tandem mass spectrometry (LC-MS-MS). Acetaminophen was used as the internal standard. Chromatographic separation was performed using a Symmetry C18 column and the mobile phase was composed of A: 2 mM ammonium formate and 0.1% formic acid in water and B: 2 mM ammonium formate and 0.1% formic acid in acetonitrile (ACN) (A:B, 30:70, v/v). Detection was performed on a triple-quadrupole tandem mass spectrometer using positive ion mode electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. The MS/MS ion transitions monitored were m/z 195.2-->120.2 and 152.1-->110.1 for PAH and acetaminophen, respectively. Good linearity is observed over the concentration range of 0.1-500 microg/ml. The method was proved to be accurate and reliable and was applied to a pharmacokinetic study in rat.

Fan HY ，Lin CC ，Pao LH 《-》

Determination of chamaechromone in rat plasma by liquid chromatography-tandem mass spectrometry: application to pharmacokinetic study.

A rapid, simple and accurate method was developed for the determination of chamaechromone in rat plasma using liquid chromatography tandem mass spectrometry (LC-MS-MS). Rosuvastatin was used as the internal standard. The plasma samples were extracted by liquid-liquid extraction with ethyl acetate. Chromatographic separation was performed on Xbridge™ C(18) column (2.1mm×50mm, 3.5μm) with linear gradient elution using water and methanol, both of which were acidified with 0.1% aqueous formic acid. The flow rate was 0.4mL/min and the total run time was 6min. Detection was performed on a triple-quadrupole tandem mass spectrometer using positive ion mode electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. The MS/MS ion transitions monitored were m/z 543.3→198.9 and 481.9→258.3 for chamaechromone and rosuvastatin, respectively. Good linearity was observed over the concentration range of 8-6400ng/mL in 0.1mL of rat plasma. The lowest concentration (8ng/mL) in the calibration curve was estimated as LLOQ with both deviation of accuracy and RSD of precision <20% (n=6). Intra-assay and inter-assay variability were less than 11% in plasma. This method was successfully applied to a pharmacokinetic study of chamaechromone in rats after intravenous (5mg/kg) and oral (100mg/kg) administration. Following oral administration the concentration-time curve of chamaechromone exhibited a biphasic absorption profile. The maximum mean concentration in plasma (C(max), 795.9±14.6ng/L) was achieved at 11.3±0.8h (T(max)) and the area under curve (AUC(0-60)) was 6976.7±1026.9ngh/L. After single intravenously administration of chamaechromone, the essential pharmacokinetic parameters C(max), AUC(0-48) were 4300.7±113.6ng/L and 3672.1±225.4ngh/L, respectively. The result showed that the compound was poorly absorbed with an absolute bioavailability being approximately 8.9%.

Lou Y ，Hu H ，Liu Y ，Yu Q ，Li L ，Ping L ，Yu L ，Jiang H ，Zeng S ... -  《-》

Development of a liquid chromatography/tandem mass spectrometry assay for the determination of bestatin in rat plasma and its application to a pharmacokinetic study.

Wang C ，Fan G ，Lin M ，Chen Y ，Zhao W ，Wu Y ... -  《JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES》