The prime aim of the present investigation was to develop and validate a novel, precise, accurate, specific, rapid and economical stability- indicating isocratic reverse phase liquid chromatography method for the quantitative simultaneous estimation of valsartan and hydrochlorothiazide in bulk and marketed formulations. Estimation of drugs in this combination was achieved with a C18 column [Kromasil 100-5 C18 column, P134 250 × 4.6 mm] kept at ambient temperature, isocratic mode using mobile phase of composition acetonitrile and phosphate buffer (40:60 V/V, pH 4). The flow rate was 0.8 ml/min and the effluents were monitored at 235 nm, using variable wavelength UV detector. The retention time of valsartan and hydrochlorothiazide were 2.65 min and 3.97 min, respectively. Validation of the method was done according to the ICH guidelines for different analytical parameters. The method was found to be linear over a range of 50-250 μg/mL for valsartan and hydrochlorothiazide. The established method was as reproducible with a %RSD value of less than 2 and having robustness and accuracy within the specified limits. Assay of marketed formulation was determined and was 99.04% and 99.8% respectively. The stressed samples were analyzed. The proposed method was found to be specific and stability indicating as no interfering peaks of degradation compounds and excipients were noticed. The proposed method can be successfully employed in the estimation of commercial formulations.
Development and validation of a stability indicating HPLC method to determine diltiazem hydrochloride in tablets and compounded capsules
