A Stability-Indicating RP-HPLC Approach for the Simultaneous Determination of Linagliptin and Dapagliflozin in Bulk and Marketed Formulation

Abstract

A simple, rapid, accurate, precise, and stability-indicating reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous determination of linagliptin (LNG) and dapagliflozin (DPM) in bulk drug and tablet dosage forms. Chromatographic separation was accomplished on a Shimadzu Shimpack C18 (250 mm × 4.6 mm, 5 μm) column with a mobile phase composed of 0.1% orthophosphoric acid and acetonitrile (40:60 v/v) at a flow rate of 1 mL/min, with UV detection at 230 nm. The retention periods for LNG were determined to be 3.651 minutes and for DPM to be 5.989 minutes. The method was validated in accordance with the ICH Q2(R2) guidelines. The concentration ranges of 5–25 μg/mL for LNG (R² = 0.9991) and 10–50 μg/mL for DPM (R² = 0.9990) were used to establish linearity. The limits of quantitation (LOQ) for LNG and DPM were 1.548 μg/mL and 0.669 μg/mL, respectively, while the limits of detection (LOD) were 0.523 μg/mL and 0.220 μg/mL. The mean percentage recoveries for both medications were 99.71 to 100.69, indicating exceptional accuracy. Precision investigations (repeatability, intraday, and interday) produced % RSD values that were significantly lower than 2.0. The method's stability-indicating nature was confirmed by forced degradation experiments conducted under acidic, alkaline, oxidative, thermal, and photolytic stress conditions, which confirmed the efficient resolution of both analytes from their degradation products. The assay that was developed was effectively implemented in the analysis of commercial formulations, demonstrating a high degree of recovery and minimal variability. This technique is appropriate for the routine quality control analysis of combined pharmaceutical formulations.