Determination of felodipine concentration in human plasma by GC-ECD and study of its pharmacokinetics
Yang, L.; Yuan, Y.; Dai, X.
Yao Xue Xue Bao 33(6): 461-464
1998
ISSN/ISBN: 0513-4870 PMID: 12016918 Document Number: 496122
A rapid, accurate and sensitive gas chromatographic method using electron-capture detector (GC-ECD) was developed for the determination of felodipine concentration in human plasma. Nimodipine was used as internal standard. The plasma samples were extracted using a mixture of ethyl ether and n-hexane (2:1) to give mean recoveries of 97.3% of felodipine. The extracts were separated by a 5% SE-30 glass packed column (2 m x 3 mm). The detection limits for felodipine was 0.25 ng.ml-1. The precisions (RSD%, n = 5) of within-day and day-to-day were less than 5.09% and 8.62%, respectively. The pharmacokinetic parameters of felodipine in ten men were investigated by this method. The concentration-time curve was fitted to a two-compartment model. Its main pharmacokinetic parameters were: T1/2 alpha = 0.76 h, T1/2 beta = 16.09 h, Cmax = 4.78 ng.ml-1, Tmax = 2.01 h, AUC = 45.2 h.ng.ml-1.