SIMPLE AND RAPID ANALYSIS OF LAMOTRIGINE, A NOVEL ANTIEPILEPTIC, IN HUMAN SERUM BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY USING A SOLID-PHASE EXTRACTION TECHNIQUE

A simple and rapid method for the quantitation of concentrations of la motrigine, a novel antiepileptic, in human serum was developed with hi gh-performance liquid chromatography, using a solid-phase extraction t echnique. The mobile phase was composed of acetonitrile-10 mM phosphat e buffer (pH 3.5) containing 5 mM sodium octanesulphonate (27:73, v/v) , and components were detected at 265 nm. Retention times of acetanili de as an internal standard and lamotrigine were 3.4 and 10.3 min, resp ectively. The coefficients of variation were 3.1-4.5% and 4.4-9.8% for the within-day and between-day precision estimates, respectively. The extraction recovery of lamotrigine added to blank serum was 85-107%. The quantitation limit of lamotrigine was ca. 0.2 mu g/ml in 100 mu l of serum. These results suggest that the method employed in this study is useful for the routine monitoring of sereum concentrations of lamo trigine in epileptic patients.