Development and validation of an RP-HPLC method for simultaneous analysis of drotaverine and omeprazole in a tablet dosage form

A simple, rapid reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous estimation of drotaverine and omeprazole in a tablet dosage form. A C18 column was used with a 60:40 (v/v) mixture of methanol and ammonium acetate (0.1 m, pH 5, adjusted with orthophosphoric acid) as mobile phase at a flow rate of 1.5 mL min−1. UV detection was performed at 319 nm. The method was validated for accuracy, precision, linearity, specificity and sensitivity in accordance with International Conference on Harmonisation guidelines. The method was successfully used for quantitative analysis of Ranipas-DV tablets. Total run time was 10 min, drotaverine and omeprazole were eluted with retention times of 7.969 and 6.538 min respectively. Validation revealed that the method is specific, accurate, precise, reliable and reproducible. Calibration plots were linear over the concentration ranges 5–40 μg mL−1 for drotaverine and 5–50 μg mL−1 for omeprazole, respectively. Limits of detection were 16.2 and 4.8 ng mL−1 and limits of quantification were 49.0 and 14.5 ng mL−1 for drotaverine and omeprazole, respectively. Recovery was in the range 100.66–100.94% and 102.42–102.89% for drotaverine and omeprazole, respectively, and the coefficient of variance was <2.0% for both. The high percentage recovery and low co-efficient of variation confirm the suitability of the method for simultaneous analysis of drotaverine and omeprazole in tablets.