Abstract
A capillary electrophoretic method coupled to a diode array detector (CE-DAD) was developed and validated for the simultaneous determination of metformin hydrochloride (MET), the dipeptidyl peptidase-4 (DPP-4) inhibitor saxagliptin hydrochloride (SAX), and the sodium glucose co-transporter (SGLT 2) inhibitor dapagliflozin (DAP). The proposed method was used for the determination of these drugs in binary antidiabetic combinations namely, SAX/MET, combination I, DAP/MET, combination II, and SAX/DAP, combination III. CE separation was performed on a fused silica capillary with background electrolyte consisting of 30 mM phosphate buffer (pH 6.0) with a high voltage of 30 kV, a pressure of 20 mbar, and an injection time of 40 s. The compounds were detected at 203 nm for SAX/DAP and 250 nm for MET. The method was linear in the concentration range of 10-200 µ g/mL (SAX), 1.25-50 µ g/mL (DAP), and 7.5-1000 µ g/mL (MET). Full validation of the proposed method was performed as per the ICH guidelines. The obtained errors and deviation values did not exceed 2% assessing good accuracy and precision, respectively. The stability-indicating potential of the proposed method was proved under different stress-degradation conditions. The proposed method was successfully applied to the analysis of the three binary combinations in their tablets.