New Spectrophotometric Methods for the Estimation of Tolterodine Tartarate in Pharmaceutical Formulations

Abstract

Two simple and sensitive visible spectrophotometric methods (methods A and B) have been developed for the estimation of tolterodine tartarate in pure as well as in pharmaceutical formulations. Method A is based on the oxidative coupling reaction with 3-methyl-2-benzothiazolinone hydrazone (MBTH) in the presence of ceric ammonium sulphate (CAS) to form a coloured species with l_max at 555 nm. Method B is based on the oxidation of the drug with ferric chloride followed by complxation with 1,10-phenanthroline (1,10-PTL) to form a blood red coloured chromogen with l_max at 520 nm. Beer’s law is obeyed in the range of 10–50 and 2.5–12.5 μg/mL for Methods A and B respectively. The results obtained are reproducible and statistically validated and also found to be suitable for the assay of tolterodine tartarate in bulk as well as in pharmaceutical formulations.