Application of Stability Indicating HPLC Method for Quantitative Determination of Etoricoxib and Paracetamol in Pharmaceutical Dosage Form

A stability indicating reversed-phase HPLC method has been developed and subsequently validated for simultaneous estimation of etoricoxib (ETX) and paracetamol (PCT) from their combination product. The proposed RP-HPLC method utilizes a Phenomenex® C18, 5μm, 250mm X 4.6mm i.d. column, mobile phase consisting of acetonitrile, methanol and water in the proportion of 60:15:25 (v/v/v) and UV detection at 236.0 nm using a UV detector. Separation was completed within 10 minutes. ETX, PCT and their combination drug product were exposed to thermal (60C), humidity (75% RH), hydrolytic (acidic 1 N HCl for 24 h at 50 °C, alkaline 1 N NaOH kept for 24 h at 50°C) and oxidative stress conditions (3% H2O2 for 24h at 50°C), the stressed samples were analyzed by the proposed method. The described method was linear over a range of 8.3-41.5 μg mL^-1 for PCT and 1-5 μg mL^-1 for ETX with correlation coefficients values of 0.9999 and 0.9993, respectively. The mean recoveries were 99.69±0.52 and 99.66±1.29 for PCT and ETX, respectively. The proposed method can be useful in the quality control of combination drug products.