MONITORING CLORAZEPATE DIPOTASSIUM AS DESMETHYLDIAZEPAM IN PLASMA BY ELECTRON-CAPTURE GAS-LIQUID-CHROMATOGRAPHY

  • 1 January 1980
    • journal article
    • research article
    • Vol. 26  (1) , 142-144
Abstract
A procedure for determining clorazepate dipotassium as its decarboxylated, pharmacologically active metabolite, desmethyldiazepam [central depressant], in 100 .mu.l of plasma, with use of electron-capture GLC and with methylnitrazepam as the internal standard was described. The procedure is 1-tube, 1-step extraction without derivative formation and is accurate, reproducible and rapid. The sensitivity limit is 20 .mu./l. Within-run and between-run CV [coefficient of variation] (concentration, 3.5 mg/l) were 2.9 and 3.5%, respectively. Within-run CV for 1.5 and 1.0 mg/l concentrations were 3.9 and 4.3%, respectively. For a 1.0 mg/kg per day dose of clorazepate dipotassium, the mean steady-state concentration of desmethyldiazepam in plasma was 1.037 mg/l.