Simultaneous Densitometric TLC Analysis of Olmesartan Medoxomil and Hydrochlorothiazide in the Tablet Dosage Form

A simple, rapid, and selective densitometric thin-layer chromatographic (TLC) method has been established and validated for simultaneous quantitative analysis of olmesartan medoxomil and hydro-chlorothiaziide in the presence of olmesartan medoxomil degradation products. Chromatography was performed on aluminum foil-backed HPTLC plates coated with 0.2 mm layers of nano-silica gel 60 F-254 as stationary phase. R-F values of olmesartan medoxomil, its degradation products, and hydrochlorothiazide were significantly different when chloroform methanol formic acid 8:1.5:0.5 (v/v) was used as mobile phase. Detection was performed at 260 nm and 272 nm for olmesartan medoxomil and hydrochlorothiazide, respectively. Regression plots revealed good linear relationships in the concentration range 0.05-1 mg mL(-1). Accuracy was checked by conducting recovery studies; average recovery was 100.35 +/- 1.060 and 99.91 +/- 1.154 for olmesartan medoxomil and hydrochlorothiazide, respectively. The amounts of the drugs in the dosage formulation were 102.78 +/- 1.525% of the label claim for olmesartan medoxomil and 103.09 +/- 1.259 for hydrochlorothiazide. Method validation was performed in accordance with USP guidelines.