Spectrophotometric Estimation of Lamotrigine in Tablets

Simple and accurate spectrophotometric methods have been developed for the determination of lamotrigine in tablet formulation. The method A was based on the diazotization of lamotrigine followed by coupling with 4-(dimethylamino)benzaldehyde in acid medium to give greenish yellow product with a λmax of 410 nm. The method B also was based on the diazotization of drug and conversion of phenol into nitrosophenol with excess nitrous acid in acid medium to give brown color with a λmax of 448 nm. Thus, methods A and B were used to determine lamotrigine in the range of 1-10 μg/ml and 2.5-12 μg/ml, respectively in the final measured solution. There was no interference from the ingredients commonly found in lamotrigine tablets with these methods. The results compared favorably with those of reported methods and related analytical parameters were calculated.