DEVELOPMENT AND VALIDATION OF A STABILITY INDICATING RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF PREGABALIN AND ETORICOXIB IN PHARMACEUTICAL DOSAGE FORM

The present study was carried out to develop and validate a stability-indicating Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method for simultaneous estimation of Pregabalin and Etoricoxib in pharmaceutical dosage forms. The method was developed by optimizing the detection wavelength, chromatographic column, mobile phase, flow rate, column temperature and other chromatographic conditions. An Inertsil ODS-3 C18 column (250 × 4.6 mm, 5 µm) was used for separation. The optimized mobile phase consisted of potassium dihydrogen phosphate buffer adjusted to pH 3.0 ± 0.05 with orthophosphoric acid and acetonitrile (60:40, v/v), with a flow rate of 1.0 mL/min and detection at 234 nm. The method was validated according to ICH guidelines for specificity, linearity, accuracy, precision, sensitivity, robustness and solution stability. The method showed good linearity for Pregabalin and Etoricoxib over the selected concentration ranges, with correlation coefficients of 0.9998 and 0.9999, respectively. Mean recoveries were within the acceptable range, and precision studies showed low variability. Forced degradation studies were performed under acidic, alkaline, oxidative, thermal, photolytic and neutral conditions. The degradation products were adequately separated from the main drug peaks, confirming the stability-indicating nature of the method. The method was also successfully applied to a marketed tablet formulation, giving assay values of 99.49% for Pregabalin and 99.52% for Etoricoxib. The developed method is simple, accurate, precise and suitable for routine quality control analysis of Pregabalin and Etoricoxib combination formulations.