Stability Indicating RP-HPLC Method for Simultaneous Estimation of Hydrochlorothiazide, Amlodipine Besylate and Losartan Potassium in Bulk and Tablet Dosage Form

The present study describes a simple, accurate and precise stability indicating RP-HPLC technique for the simultaneous determination of hydrochlorothiazide, amlodipine besylate and losartan potassium in the tablet dosage form. The method involves an isocratic elution of the drug in a stationary phase of phenomenex ODS 2, C18 (150 mm × 4.6 mm, 5 μm) column using a mobile phase composition of methanol and 0.1% (v/v) orthophosphoric acid in the composition ratio of 65:35 v/v with a flow rate of 0.8 mL/min at 254 nm of detection. The injection volume is 20 μL. The method has been validated for specificity, linearity, range, precision, accuracy, limit of detection, limit of quantification and robustness. The retention times for hydrochlorothiazide, amlodipine besylate and losartan potassium are about 2.30, 3.52 and 5.09 min, respectively. Quantitative linearity was observed over the concentration range of 5.12 to 49.60 μg/mL for hydrochlorothiazide, 2.52 to 25.24 μg/mL for amlodipine besylate and 10.02 to 250.44 μg/mL for Losartan potassium, respectively. The regression equations of concentration for hydrochlorothiazide was found to be y = 207189.9x + 176236.2, it is y = 179464.9x + 2658.2 for amlodipine besylate and it is y = 47400x + 34309.7 for Losartan potassium where y is the peak area and x is the concentration of drug (μg/mL). All the validation parameters are within the acceptance range.