Visible spectrophotometric methods for the determination oftrimetazidine dihydrochloride in pharmaceutical formulations

Two simple and sensitive visible spectrophotometric methods (A&B) have been described for the assay of trimetazidine dihydrochloride (TMZ) either in pure form or in pharmaceutical formulations. Method A is based on the oxidative coupling between the TMZ and 3-methyl-2- benzothiazolinone hydrazone hydrochloride (MBTH) in presence of ceric ammonium sulphate to form a coloured product with λ m a x at 520 nm. Method B is based on the oxidation/reduction reaction between the TMZ and Folin-Ciocalteu reagent to form a blue coloured chromogen having λ m a x at 745 nm. All the variables have been optimized and the reaction sequence is presented. The concentration measurements are reproducible within a relative standard deviation of 1.0% Recoveries are 97.9-101.75%.