Extractive Visible Spectrophotometric Determination of Lamotrigine in Pure and Pharmaceutical Formulations

Abstract

Two simple, sensitive, accurate and economical spectrophotometric methods (A & B) for the determination of lamotrigine (LMT) in pure and pharmaceutical formulations (tablets) are described in the present work. Method A is based on the formation of coloured ion-association complex between lamotrigine and tropaeolineo-oo (TPooo) with absorption maximum at 485 nm and obeys Beer's law in the concentration range of 5-25 µg/mL. Formation of ion-association complex between lamotrigine and alizarine Red S (ARS) to yield a coloured chromogen exhibiting absorption maximum at 440 nm (Method B) obeying Beer's law in the concentration range of 5-25 µg/mL forms the basis of Method B. The two methods have been validated statistically through recovery studies. The results are compared with those obtained using UV spectrophotometric method (Reference method) in chloroform at 260 nm.