Spectrophotometric determination of hydrochlorothiazide using charge transfer interactions with alizarin red s reagent

Abstract

The present work included using transferred charge complex reaction in the assay of Hydrochlorothiazide using Alizarin Red S as an electron acceptor. The method is based on direct spectrophotometric estimation of hydrochlorothiazide by its reaction with Alizarin Red –S in absolute methanol media through forming a red charge transfer complex solution that gives a maximum absorption at 537 nm. The relation between concentration and absorbance was linear within the concentration range of 0.1-2.5 μg / ml with the molar absorption coefficient equal to 1.2774 × 10⁵ l. mol^-1. cm^-1. The method was successfully applied to estimate hydrochlorothiazide in its pharmaceutical preparations (tablets).