Validated LC–MS/MS method for quantification of agomelatine in human plasma and its application in a pharmacokinetic study

An analytical method based on liquid–liquid extraction has been developed and validated for analysis of agomelatine in human plasma. Fluoxetine was used as an internal standard for agomelatine. A Betasil C18 (4.0 × 100 mm, 5 µm) column provided chromatographic separation of analytes followed by detection with mass spectrometry. The method involves simple isocratic chromatographic conditions and mass spectrometric detection in the positive ionization mode using an API‐4000 system. The proposed method has been validated with linear range of 0.050–8.000 ng/ml for agomelatine. The intra‐run and inter‐run precision values are within 12.12% and 9.01%, respectively, for agomelatine at the lower limit of quantification level. The overall recovery for agomelatine and fluoxetine was 67.10% and 72.96%, respectively. This validated method was used successfully for analysis of plasma samples from a pharmacokinetic study. Copyright © 2012 John Wiley & Sons, Ltd.     

Quantitation of Oleanolic Acid in Oldenlandia corymbosa L. Whole-Plant Powder by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive, simple, and accurate high-performance thin-layer chro-matographic method has been established for determination of...     

Determination of Atovaquone in Human Plasma by LC-MS-MS and Its Application to a Bioequivalence Study

A sensitive and selective method for the determination of atovaquone in human plasma was developed and validated. The procedure employed the use of an internal standard (chlorothalidone) and a solvent extraction step. Detection was by electrospray ionization tandem mass spectrometry with multiple reaction monitoring. The method showed a linear range from 50 to 2,000 ng mL^?1. The extraction recovery was determined to be 84.91 ± 6.42% (SD), the intra- and inter-day assay accuracy (relative error) was within 7.57% and precision (RSD) was below 6.06%. The method was successfully employed to analyze plasma samples and evaluate the pharmacokinetics of atovaquone in human volunteers.     

Alternative LC–MS–MS Method for Simultaneous Determination of Proguanil, Its Active Metabolite in Human Plasma and Application to a Bioequivalence Study

An alternative rapid and sensitive liquid chromatography–tandem mass spectrometry method has been developed and validated for simultaneous analysis of proguanil (PRO) and cycloguanil (CYC) in human plasma. The analytes were extracted from human plasma by solid phase extraction. Riluzole (RIL) was used as an internal standard for proguanil and cycloguanil. A HyPURITY Advance C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The method involves simple isocratic chromatography conditions and mass spectrometric detection in the positive ionization mode using an API-4000 system. The proposed method has been validated with linear range of 1.5–150.0 ng mL^?1 for PRO and 0.5–50.0 ng mL^?1 for CYC. The inter-run and intra-run precision values are within 2.54, 9.19% for PRO and 1.99, 10.69% for CYC at LOQ levels. The overall recoveries for PRO and CYC were 102.52 and 106.72%, respectively. Total elution time was as low as 2.50 min. This validated method was used successfully for analysis of plasma samples from a bioequivalence study.     

Validated LC-MS/MS method for quantification of agomelatine in human plasma and its application in a pharmacokinetic study

An analytical method based on liquid-liquid extraction has been developed and validated for analysis of agomelatine in human plasma. Fluoxetine was used as an internal standard for agomelatine. A Betasil C18 (4.0?×?100?mm, 5?μm) column provided chromatographic separation of analytes followed by detection with mass spectrometry. The method involves simple isocratic chromatographic conditions and mass spectrometric detection in the positive ionization mode using an API-4000 system. The proposed method has been validated with linear range of 0.050-8.000?ng/ml for agomelatine. The intra-run and inter-run precision values are within 12.12% and 9.01%, respectively, for agomelatine at the lower limit of quantification level. The overall recovery for agomelatine and fluoxetine was 67.10% and 72.96%, respectively. This validated method was used successfully for analysis of plasma samples from a pharmacokinetic study.     

Pharmacokinetic Analysis of Ursolic Acid in Alstonia scholaris R. Br. by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A simple and rapid high-performance thin-layer chromatographic method has been established and validated for determination of...     

Ultrasound-assisted rapid synthesis of β-cyanoepoxides using hypervalent iodine reagents

An elegant approach for the rapid synthesis of β-cyanoepoxides 3 by the epoxidation of β-cyanostyrenes 1 with PIDA 2a is described. The epoxidation of β-cyanostyrenes 1 was performed with 1.2 equiv. of PIDA 2a in MeCN-H₂O (1:1) at room temperature in ultrasonic bath. The epoxidation reactions were completed in short reaction time and β-cyanoepoxides 3 were isolated in 69–94% yields.