RP-HPLC-PDA-Based Simultaneous Estimation of Ramipril and Hydrochlorothiazide in Combined Dosage Forms: A Validated Approach

A rapid, highly sensitive High-Performance Liquid Chromatographic method has been developed for the simultaneous determination of Ramipril (RMP) and Hydrochlorothiazide (HCT) in bulk drug and in tablets. Ramipril (RMP) and Hydrochlorothiazide (HCT) were eluted from an Eclipse plus C18 (250 mm × 4.6 mm I.D.) with particle size 5 µm reversed phase column with a mobile phase consisting of acetonitrile and potassium dihydrogen ortho-phosphate pH 3 (40: 60 v/v) at a flow rate of 1 mL/min with UV detection at 210 nm. The retention time for RMP and HCT was found to be 3.31 ± 0.02 min and 6.64 ± 0.02 min, respectively. The linear response (r2 <0.99) was observed in the range of 2 - 12 μg/mL for RMP and 4 - 24 μg/mL of HCT with low values of limits of detection (LOD) and quantification (LOQ) for both drugs. The method shows good recoveries and intra and inter-day relative standard deviations were less than 1.0%. Validation parameters as specificity, accuracy, ruggedness and robustness were also determined. The proposed method provides accurate and precise quality control tool for routine simultaneous analysis of Ramipril and Hydrochlorothiazide in bulk and in tablet dosage form.