Analysis of tofisopam in human serum by column‐switching semi‐micro high‐performance liquid chromatography and evaluation of tofisopam bioequivalency

Publisher Website
Google Scholar
Abstract
A rapid and sensitive column‐switching semi‐micro HPLC method is described for the direct analysis of tofisopam in human serum. The sample (100 µL) was directly injected onto the precolumn (Capcell Pak MF Ph‐1), where unretained proteins were eluted to waste. Tofisopam was then eluted into an enrichment column using 13% acetonitrile in 50 mM phosphate buffer (pH 7.0) containing 5 mM sodium octanesulfonate and subsequently into the analytical column using 43% acetonitrile in 0.1% phosphoric acid containing 5 mM sodium octanesulfonate. The detection limit (2 ng/mL), good precision (CV ≤ 4.2%) and speed (total analysis time 24 min) of the present method were sufficient for drug monitoring. This method was successfully applied to a bioequivalence test of two commercial tofisopam tablets. Copyright © 2002 John Wiley & Sons, Ltd.