Analysis of tofisopam in human serum by column-switching semi-micro high-performance liquid chromatography and evaluation of tofisopam bioequivalency.
A rapid and sensitive column-switching semi-micro HPLC method is described for the direct analysis of tofisopam in human serum. The sample (100 microL) 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 < or = 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.
Baek
Soo Kyoung
SK
Medicinal Resources Research Center, College of Pharmacy, Wonkwang University, Shinyongdong, Iksan 570-749, Korea.
Choi
Sung Jin
SJ
Kim
Jeong Soo
JS
Park
Eun Jeon
EJ
Sohn
Dong Hwan
DH
Lee
Hee-Yong
HY
Lee
Hye Suk
HS
D000328:Adult; D014151:Anti-Anxiety Agents / Q000097:blood* / Q000493:pharmacokinetics; D001569:Benzodiazepines; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004353:Drug Evaluation, Preclinical; D006801:Humans; D008297:Male; D015203:Reproducibility of Results
D014151:Anti-Anxiety Agents; D001569:Benzodiazepines; C012582:tofisopam