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 ... -  《-》

Simultaneous determination of rosuvastatin and fenofibric acid in human plasma by LC-MS/MS with electrospray ionization: assay development, validation and application to a clinical study.

Trivedi RK ，Kallem RR ，Mullangi R ，Srinivas NR ... -  《JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS》

Determination of genkwanin in rat plasma by liquid chromatography-tandem mass spectrometry: application to a bioavailability study.

We developed and validated a sensitive, rapid, and specific liquid chromatography tandem mass spectrometry method to determine genkwanin in rat plasma. Genistein was used as the internal standard. After liquid-liquid extraction with ethyl acetate, the chromatographic separation of genkwanin was achieved by using a reversed-phase HPLC using Agela Venusil MP-C18 analytical column (2.1 mm × 50 mm, 5 μm particles) with a mobile phase of methanol (A)-water (B) (65:35, v/v) containing 5mM ammonium acetate and 0.1% formic acid. The detection was performed by negative ion electrospray ionization in multiple-reaction monitoring mode by using transitions of m/z 283.1→268.1 and m/z 269.1→133.0 for genkwanin and IS, respectively. Good linearity was observed in the concentration range of 3.84 ng/ml to 3,840 ng/ml (r(2)>0.99), and the lower limit of quantification was 3.84 ng/ml in 100 μl of rat plasma. The intra- and inter-day accuracy and precision of genkwanin were both within acceptable limits. This present method was successfully applied to a pharmacokinetic study of genkwanin in rats following oral (50mg/kg) and intravenous (5mg/kg) administration. For the oral administration group, the maximum mean concentration of genkwanin in plasma (Cmax, 36.9 ± 9.4 ng/ml) was achieved at 3.83 ± 1.33 h (Tmax), and the area under the plasma concentration versus time curve from 0 h to 12h (AUC0-12h) was 218 ± 40 ngh/ml. For the intravenous administration group, essential pharmacokinetic parameters such as Cmax (1,755 ± 197 ng/ml) and AUC0-12h (2,349 ± 573 ngh/ml) were shown. The result showed that the compound was poorly absorbed with an absolute bioavailability of approximately 1.1%.

Song Y ，Zhang S ，Liu H ，Jin X ... -  《-》

Quantitative determination of rosuvastatin in human plasma by liquid chromatography with electrospray ionization tandem mass spectrometry.

Xu DH ，Ruan ZR ，Zhou Q ，Yuan H ，Jiang B ... -  《-》

Determination of tegaserod by LC-ESI-MS/MS and its application to a pharmacokinetic study in healthy Chinese volunteers.

Zou JJ ，Bian XJ ，Ding L ，Zhu YB ，Fan HW ，Xiao DW ... -  《JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES》