Concurrent estimation of Pregabalin and Etoricoxib by new stability indicating RP-UPLC approach: application in assay of commercial tablets

The present research aims to establish new stability indicating RP-UPLC method for concurrently estimating Pregabalin and Etoricoxib in blended powder and their combined tablet formulation. The effective separation of Pregabalin and Etoricoxib achieved with HSS column C18 (150 × 2.1 mm, 1.8 µm), 0.1% orthophosphoric acid: acetonitrile in 65:35 v/v) at a flow rate of 0.3 mL/min, and isocratic elution at 228 nm. The elution of PRB and ETB was noticed at 1.56 and 2.01 min, with good resolution and system suitability with the developed approach. PRB and ETB have shown linear responses from 18.75 to 112.5 µg/mL and 15 to 90 µg/mL, respectively. The range of the % RSD for intraday and inter-day precision was 0.33 to 0.81. The LOD and LOQ of Pregabalin and Etoricoxib were computed to be 0.07 µg/mL, 0.21 µg/mL, and 0.01 µg/mL, 0.04 µg/mL, respectively, by standard deviation method. The validation method was carried out using ICH standards. The stability- indicating the feature of the method was confirmed by the forced degradation studies where degradants generated by stress testing were clearly distinguished from the peaks of analytes. The shorter elution period and superior sensitivity of both analytes with this method are appropriate for regular analysis of Pregabalin and Etoricoxib.