Comparative Liquid Chromatographic Study for Concurrent Determination of Canagliflozin and Metformin in Combined Tablets.

New HPLC-UV method (method A), for simultaneous determination of metformin (MET) and canagliflozin (CANA), was developed and compared to another novel UPLC-UV method (method B) in their tablet combination. Concerning method A, isocratic separation was done by C18 column (100 mm × 2.1 mm, 3 μm) using methanol and 0.03 M phosphate buffer (75 : 25, v/v) at pH 3.2 as a mobile phase. Meanwhile, chromatographic separation in method B was achieved via Hypersil® gold (50 mm × 2.1 mm, 1.9 μm). Mobile phase was methanol and 0.03 M phosphate buffer at ratio of 80 : 20  v/v. In both, detection was done at wavelength of 240 nm. Method A showed satisfactory linearity results over 1-50 μg·mL-1 and 0.5-100 μg·mL-1, while method B linearity was at 0.1-50 μg·mL-1 and 0.25-100 μg·mL-1 for CANA and MET, respectively. In terms of accuracy and precision, method A accuracy was 99.81 ± 0.73 and 99.37 ± 0.54, while method B gave accuracy of 99.47 ± 1.03 and 99.73 ± 0.89 for CANA and MET, respectively. For precision, the % RSD was found to be less than 2% for three concentrations analyzed three times. The two methods are convenient for quality laboratories, yet the UPLC method offered the advantage of shorter run times and higher sensitivity.