Stability Indicating RP-HPLC Method Development and Validation for Simultaneous Estimation of Dapagliflozin Propanediol Monohydrate and Eplerenone in Its Synthetic Mixture

Abstract

The growing need for effective analytical techniques for combination drug therapy has led to the development of reliable and stability-indicating methods for quantitative estimation. The present work was aimed at developing and validating a reverse phase high performance liquid chromatographic (RP-HPLC) method for the simultaneous estimation of dapagliflozin propanediol monohydrate and eplerenone in a synthetic mixture. The chromatographic separation was achieved using a Cosmosil C18 column (250 mm × 4.6 mm, 5 µm) with a mobile phase consisting of phosphate buffer and methanol in the ratio of 30:70 % v/v. The detection was carried out at 228 nm. The retention times of dapagliflozin propanediol monohydrate and eplerenone were found to be 6.2 min and 2.6 min, respectively, indicating satisfactory separation of both analytes. The developed method was validated as per ICH guidelines for various parameters such as linearity, accuracy, precision, specificity, robustness, and system suitability. The method showed good linearity with correlation coefficients close to unity for both drugs. The accuracy of the method was confirmed by recovery studies, and precision studies showed %RSD values within acceptable limit indicating reproducibility. The specificity of the method was established by the absence of interference from excipients and degradation products. Forced degradation studies were performed under acidic, alkaline, oxidative, thermal, and photolytic conditions, and the results confirmed that the method is capable of effectively separating degradation products from the analytes, thereby demonstrating its stability-indicating nature. The developed RP-HPLC method was found to be simple, precise, accurate, and robust, making it suitable for routine quality control analysis and stability studies of dapagliflozin propanediol monohydrate and eplerenone in synthetic mixtures.