Concurrent Estimation of Pregabalin and Etoricoxib by New Stability-Indicating RP-UPLC Approach - Application in Assay of Commercial Tablets

The study emphasizes establishing a stability-indicating RP-UPLC method for concurrent estimation of pregabalin and etoricoxib in combined pharmaceutical formulations, confirming effective separation, sensitivity, and repeatability, validated according to ICH guidelines.

The present research study aims to establish a new stability-indicating RP-UPLC method for concurrently estimating pregabalin and etoricoxib in blended powder and their combined tablet formulation with less run time, high sensitivity, and specificity.

The effective separation of pregabalin and etoricoxib was achieved with HSS column C18 (150x2.1mm,1.8µm), 0.1% orthophosphoric acid:acetonitrile (65:35 v/v) at a flow rate of 0.3mL/min, and isocratic elution at 228nm. The elution of PRB and ETB was noticed at 1.56 and 2.01 minutes, with good resolution and system suitability with the developed approach.

Pregabalin and etoricoxib have shown linear responses from 18.75 to 112.5µg/mL and 15 to 90µg/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 and 0.21 µg/mL, and 0.01µg/mL and 0.04 µg/mL, respectively, by standard deviation method. The validation method was carried out using ICH standards. The stability-indicating 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 have been found to be appropriate for regular analysis of pregabalin and etoricoxib.