Estimation of Olmesartan and Hydrochlorthiazide in Bulk and Tablet by Simultaneous Equation and Multi-component UV-Spectrophotometric Methods

Abstract

Olmesartan and hydrochlorthiazide are estimated simultaneously in bulk and tablets by two simple and rapid UV-spectrophotometric methods. The first method employs simultaneous equation for analysis, using methanol, as a solvent. The two wavelengths 255 nm (λ_max of olmesartan) and 270 nm (λ_max of hydrochlorthiazide) were selected for formation of simultaneous equations. Linearity was observed in the concentration range of 3 - 24 μg/mL for olmesartan and 2 - 16 μg/mL for hydrochlorthiazide. Statistical analysis and recovery studies validated the method. Multi-component method utilizes six mixed standards and two sampling wavelengths, as 255 and 270 nm. Six mixed standard solutions of both the drugs were prepared and concentrations were determined by the multi-component mode.