Measurement of Lamotrigine Under Conditions Measuring Phenobarbitonecomma; Phenytoincomma; and Carbamazepine Using Reversedhyphen;Phase Highhyphen;Performance Liquid Chromatography at Dual Wavelengths

摘要

SummaryA reversed-phase high-performance liquid chromatographic (HPLC) method for the measurement of lamotrigine (LTG) simultaneously with phenobarbitone (PB), phenytoin (PHT), and carbamazepine (CBZ) is described using hexobarbital as the internal standard. The method uses the chromophore at 307 nm to detect LTG in the presence of interfering CBZ-10, 11-epoxide detected at 220 nm, the wavelength used to measure the other drugs. This method requires 10 min/sample for completion. Simultaneous monitoring of the chromatographs at 220 and 310 nm with a simple calculation allows LTG to be measured virtually identically to a routine method for monitoring of the other anticonvulsants. Between-batch precisions for LTG at 2 and 6 mg/L were 5percnt;. Accuracy of LTG estimation was assessed by comparison with known values of samples supplied by an external quality assessment scheme.