Gas chromatography nitrogen phosphorous detection (GC-NPD) assay of tofisopam in human plasma for pharmacokinetic evaluation.

Tofisopam (1-(3,4-dimethoxyphenyl)-4-methyl-5-ethyl-7,8-dimethoxy-5H-2,3-benzodiazepine) has been shown to be an effective anxiolytic agent in the wide-ranging clinical practice. A high sensitive gas chromatography nitrogen phosphorous detection (GC-NPD) bioanalytical method was developed and validated for the purpose of pharmacokinetic study of tofisopam. A liquid-liquid extraction method was used for the sample preparation.

Detection of N-monomethyl-lysine generated by metabolic transmethylation.

Administration of radiolabelled deprenyl to rats resulted in the urinary elimination of a (14)C-labelled N(epsilon)-monomethyl-lysine. An increased level of N(epsilon)-monomethyl-lysine was found following an oral dose of another drug, also containing an N-methyl group. The urine sample was treated with 9-fluorenylmethoxycarbonyl chloride and then subjected to high-performance liquid chromatography (HPLC); the radioactive fraction was identified as N(epsilon)-monomethyl-lysine by using HPLC-MS in electrospray mode.

High-performance liquid chromatographic-tandem mass spectrometric method for the determination of clemastine in human plasma.

A highly sensitive high-performance liquid chromatographic-tandem mass spectrometric method (HPLC-MS-MS) has been developed to quantitate clemastine in human plasma for the purpose of pharmacokinetic studies. Sample preparation was carried out by liquid-liquid extraction using deuterated clemastine as an internal standard. Chromatographic separation used a C18 reversed phase polymer column giving an extremely fast total run time of 2 min.

Influence of food on the oral bioavailability of deramciclane from film-coated tablet in healthy male volunteers.

The effect of a high-fat meal on the oral bioavailability of deramciclane 30 mg tablet was evaluated in 18 healthy male volunteers in a randomised, single dose, two-way crossover study. The drug was administered following an overnight fast or a standardised high-fat breakfast. The plasma concentrations of deramciclane and N-desmethylderamciclane were determined by using a validated HPLC-MS -MS/MS method.