Development and Validation of Stability-Indicating HPTLC Method for Analysis of Amlodipine Besilate, Losartan Potassium and Hydrochlorothiazide in Pharmaceutical Dosage Form

The present work describes a stability-indicating HPTLC method for simultaneous analysis of Amlodipine besilate (AMLO), Losartan Potassium (LOS) and Hydrochlorothiazide (HCTZ) in bulk and pharmaceutical dosage form. Aluminium plate precoated with silica gel 60 F₂₅₄ was used as stationary phase. The separation was carried out using chloroform: ethyl acetate: methanol: ammonia (4: 4: 2:0.2 v/v/v/v) as mobile phase. The densitometric scanning was carried out at 232 nm. The linearity was obtained in the range 100-800 ng per band for amlodipine besilate (Correlation coefficient: 0.9954), 400-2400 ng per band for hydrochlorothiazide (Correlation coefficient: 0.9952) and 1000-8000 ng per band for losartan potassium (Correlation coefficient: 0.9947). The method was validated as per ICH guidelines. The combined dose tablet formulation was subjected to forced degradation by acid, alkali, oxidation, dry heat and exposure to ultraviolet radiations at 254 nm. The degradation products were well resolved from the pure drug with significantly different R_f values.