Development and Validation of a New RP-HPLC method for the Simultaneous Estimation of Dapagliflozin Propanediol Monohydrate and Metformin Hydrochloride in Bulk and Film-Coated Tablets

This study presents a newly developed reversed phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of dapagliflozin (DAPA) and metformin hydrochloride (MET HCl) in both bulk drug form and film-coated tablets. The separation was achieved using an InertSustain C18 column (4.6 mm I.D. × 150 mm, 3 μm) maintained at 30 °C. Detection was carried out with a photodiode array detector, measuring DAPA at 223 nm and MET HCl at 270 nm. The mobile phase consisted of acetonitrile and phosphate buffer (pH adjusted to 3.0 with orthophosphoric acid) in a 45:55 (v/v) ratio, delivered at a flow rate of 1 mL/min with an injection volume of 60 μL. MET HCl and DAPA eluted at retention times of 1.366 min and 3.678 min, respectively. Calibration curves were linear within the ranges of 1.0–10.0 μg/mL for DAPA and 0.17–1.70 mg/mL for MET HCl. Method validation demonstrated satisfactory results for linearity, specificity, accuracy, precision, robustness, and system suitability. These outcomes confirm the method's reliability and its compliance with ICH Q2(R1) guidelines.