Simultaneous Analysis of Losartan Potassium, Atenolol and Hydrochlorothiazide in Bulk and in Tablets by High-performance Thin-

A simple high-performance thin-layer chromatographic (HPTLC) method for separation and quantitative analysis of losartan potassium, atenolol, and hydrochlorothiazide in bulk and in pharmaceutical formulations has been established and validated. After extraction with methanol, sample and standard solutions were applied to prewashed silica gel plates and developed with toluene–methanol–triethylamine 6.5:4:0.5 (v/v) as mobile phase. Zones were scanned densitometrically at 274 nm. The RF values of losartan potassium, atenolol, and hydrochlorothiazide were 0.60, 0.43, and 0.29 respectively. Calibration plots were linear in the ranges 1000–5000 ng per band for losartan potassium and atenolol and 250–1250 ng per band for hydrochlorothiazide; the correlation coefficients, r, were 0.9994, 0.9993, and 0.9994, respectively. The suitability of this method for quantitative determination of these compounds was proved by validation in accordance with the requirements of pharmaceutical regulatory standards. The method was used for routine analysis of these drugs in bulk and in a formulation.