A Rapid Procedure for the Simultaneous Estimation of the Anticonvulsant Drugs, Ethosuximide, Phenobarbitone, Phenytoin, and Carbamazepine in Serum Using High-Pressure Liquid Chromatography

Abstract

A rapid isocratic high-pressure liquid chromatography procedure for the analysis of ethosuximide, phenobarbitone, phenytoin, and carbamazepine in serum is described. The method employs a single extraction from serum; alumina treatment of this extract eliminates interference from fast-eluting compounds, allowing rapid chromatography. A linear response is obtained for drug concentrations up to three times the upper limit of the therapeutic ranges. Within-batch and between-batch precisions for the means of these ranges varied from 2·2 to 5·5% and from 3·1 to 7·5%, respectively.