A reversed-phase high-performance liquid chromatographic method was developed and validated for the simultaneous estimation of Metformin and Canagliflozin in the presence of their degradation products. Analytes were separated on Hypersil C18, 250x4.6 mm, 5?m column using an isocratic elution mode having a mobile phase composition of 50 mM potassium dihydrogen phosphate buffer (pH 3.0): methanol (50:50 v/v). Analytes were detected at a wavelength of 225 nm. A 20?L fixed-loop injector was used for the injection of samples at a flow rate of 1.0 mL min?1. The optimized method was validated as per ICH Q2 guidelines. The retention times of Metformin and Canagliflozin were 3.47 min and 5.28 min respectively. The linearity was assessed by analysis of a combined standard solution in the range of 5-20 ?g/ml for each of Metformin and Canagliflozin respectively. The correlation coefficient for calibration curves of Metformin and Canagliflozin were 0.999 and 0.999 respectively. Accuracy was calculated in terms of percentage recovery and was within the limits of 98-102%. Inter and Intra-day precisions were calculated as percentage relative standard deviation and were less than two percent. Limit of detection and limit of quantitation were within the limits of ICH-Q2 guidelines. Method was robust with % RSD values <2% with the deliberate changes in the composition of mobile phase, changes in the pH or change in the flow rate. Significant degradation was observed in the presence of acidic, basic, neutral, oxidative and photolytic stress conditions. The proposed RP-HPLC method is simple, precise, accurate, robust and reproducible and was successfully able to separate, identify and quantify the Metformin and Canagliflozin in the presence of their degradation products implies the stability indicating nature and specificity of the method.
