Reverse Phase High Performance Liquid Chromatographic Method for the Simultaneous Estimation of Amoxicillin Trihydrate and Tinidazole in the Tablet Dosage Form

A simple, rapid and selective RP -HPLC method has been developed for determination of Amoxicillin trihydrate and Tinidazole in the pharmaceutical dosage form. The chromatographic separation was achieved with reverse phase phenomenex ® (Luna 5μ C18(2) 100A (250 × 4.60 mm) Column in isocratic mode and mobile phase containing 25mM Potassium dihydrogen phosphate (adjusted to pH 4.5 by Ortho-phosphoric acid) and Acetonitrile in the ratio of 40:60% v/v. The flow rate was 1mL min-1 and effluent was monitored at 238 nm. Retention time was found to be 2.053 min for Amoxicillin trihydrate and 2.944 min for Tinidazole, respectively. Linear regression analysis data for the calibration plot showed that there was good linear relationship between response and concentration in the range of 5–50 μg/ml for both Amoxicillin trihydrate and Tinidazole, respectively. Percentage recoveries obtained for Amoxicillin trihydrate and Tinidazole were 100.87% and 99.52% respectively. The proposed method is precise, accurate, selective and rapid for the simultaneous determination of Amoxicillin trihydrate and Tinidazole in pharmaceutical dosage forms.