Monitoring clorazepate dipotassium as desmethyldiazepam in plasma by electron-capture gas--liquid chromatography.
We describe a procedure for determing clorazepate dipotassium as its decarboxylated, pharmacologically active metabolite, desmethyldiazepam, in 100 microL of plasma, with use of electron-capture gas--liquid chromatography and with methylnitrazepam as the internal standard. The procedure is a one-tube, one-step extraction without derivative formation and is accurate, reproducible, and rapid. The sensitivity limit is 20 micrograms/L. Within-run and between-run CV's (concentration, 3.5 mg/L) were 2.9 and 3.5%, respectively. Within-run CV's 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.
D014151:Anti-Anxiety Agents / Q000097:blood*; D002849:Chromatography, Gas / Q000379:methods; D003009:Clorazepate Dipotassium / Q000097:blood*; D003975:Diazepam / Q000031:analogs & derivatives*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D003708:Nordazepam / Q000097:blood*
D014151:Anti-Anxiety Agents; D003009:Clorazepate Dipotassium; D003708:Nordazepam; D003975:Diazepam