HPTLC- Densitometric method for assay of chlorthalidone, metoprolol succinate and telmisartan in combined pharmaceutical formulation

: The present study shows the compilation of the results obtained for a very simple, fast and precise high-performance thin-layer chromatography (HPTLC) - densitometric determination of chlorthalidone (CHL), metoprolol succinate ( MET) and telmisartan ( TEL) in bulk drugs as well as the commercially available formulation. The chromatographic separation of samples was performed on Silica Gel 60 F254 aluminum sheets using Toluene: Methanol: Ethyl acetate: Tri-ethylamine as the mobile phase in the volume ratio 4:0.8:1: 1.2. The densitometric scanning was performed at 225 nm wavelength using CAMAG TLC Scanner- IV. The mentioned chromatographic system showed the compact band and symmetrical peaks of CHL, MET and TEL with 0.40 (±0.2), 0.69 (±0.2) and 0.27 (±0.2) retardation factor (Rf) respectively. The reported method is linear in the concentration range of 500-2000 ng/band, 1000-4000 ng/band and 1600-6400 ng/band while the recovery was found in the range of 98.94-99.62%, 98.26-98.41% and 99.86-100.28% for CHL, MET and TEL respectively. The method assayed the marketed formulation with 99.89 (±0.91) for CHL, 98.92 (±1.07) for MET and 100.12 (±0.65) for TEL concerning the label claim. All the results suggested the agreement of the developed method to the ICH Q2(R1) guidelines and its applicability for day-to-day analysis of these drugs in combined pharmaceutical formulations.