DETERMINATION OF NICARDIPINE IN PLASMA BY GC-ECD AND STUDY ON ITS PHARMACOKINETICS IN HEALTHY VOLUNTEERS

AIM　A gas chromatographic method was developed for the determination of nicardipine in human plasma and its pharmacokinetics in healthy volunteers. METHODS　Nicardipine in plasma was extracted with toluene and barnidipine was used as internal standard. Chromatography was performed on a 25 m×0.32 mm ID fused-silica capillary column by splitless injection with an electron-capture detector. RESULTS　The calibration curve was linear in the range of 0.5～100 ng.mL^-1, the minimal detectable concentration in plasma was 0.5 ng.mL^-1. The precisions (RSD) of within-day and between-days were less than 4% and 7% respectively. The extraction recoveries for the concentrations of 0.5, 10 and 50 ng.mL^-1 were 86.0%, 95.7% and 91.2%, respectively. The plasma concentration-time curves and the pharmacokinetic characteristics of nicardipine sustained release capsules after a single and multiple oral doses in 12 healthy volunteers were studied by the GC-ECD method. CONCLUSION　The established method was shown to be sensitive, accurate and simple for the determination of nicardipine levels in human plasma. It is suitable for its pharmacokinetic study and therapeutic drug monitoring.