Method development and validation for simultaneous estimation of Paracetamol and Etoricoxib in pharmaceutical dosage form by RP-HPLC method

A RP-HPLC method was developed for simultaneous estimation of Paracetamol and Etoricoxib tablet formulation using Phenomenex Luna C18 column (250 mm × 4.6 mm id, 5 μm particle size) and a mobile phase of methanol : water (70:30 v/v), at flow rate 1.0 ml/min with UV detection at 235 nm. The retention time (tR) of Paracetamol and Etoricoxib found to be 3.07 and 5.72 min respectively. The proposed method was validated for system suitability, specificity, linearity, accuracy, precision, LOD, LOQ and robustness. All parameters were found to be within the acceptance limit. Linearity over the concentration range 5-30 μg/ml for both Paracetamol and Etoricoxib with regression coefficient (r2) 0.9998 and 0.9994 respectively. Limit of detection (LOD) found to be 0.10 μg/ml and 0.04 μg/ml whereas limit of quantitation (LOQ) found to be 0.33 μg/ml and 0.13 μg/ml for Paracetamol and Etoricoxib respectively. The accuracy of the proposed method was determined by recovery studies and found to be 99.74%- 101.25% and 99.08%-99.21% for Paracetamol and Etoricoxib respectively.