QBD-BASED STABILITY-INDICATING RP-HPLC METHOD OF BEMPEDOIC ACID AND EZETIMIBE IN PHARMACEUTICAL DOSAGE FORMS

Abstract

The present study highlights a systematic Quality by Design–assisted development of an efficient analytical method for the estimation of Bempedoic acid and Ezetimibe in tablet dosage form. Daclatasvir was selected as the internal standard due to its suitable chromatographic behavior, good peak symmetry, and adequate resolution from the analytes. It showed no interference with the drug peaks and provided a consistent response, thereby improving method precision and reliability. Response surface methodology based on design of experiments was employed to identify critical method parameters influencing the critical analytical attributes. Chromatographic separation was achieved on a Sunfire C18 column (250 × 4.6 mm, 5 µm). The effects of acetonitrile content (v/v), flow rate, and column temperature on retention time, resolution, and number of theoretical plates were systematically investigated and optimized. The optimum chromatographic conditions within the design space consisted of an isocratic mobile phase of buffer and acetonitrile (60:40, v/v) at a flow rate of 1.0 mL/min with a run time of 6 min. Both drugs exhibited significant degradation under acidic, alkaline, and oxidative stress conditions, while minor degradation was observed under thermal and photolytic stress. Overall degradation ranged from approximately 6–17% under the applied stress conditions, and degradation products were well resolved from the main analyte peaks, confirming the stability-indicating nature of the method. The retention times of Bempedoic acid and Ezetimibe were 2.36 and 3.00 min, respectively. Method validation was performed in accordance with ICH and FDA guidelines. Central composite design was applied for optimization, yielding an overall desirability of 1.0 and establishing a Method Operable Design Region that ensured robust chromatographic performance.