A simple, specific and accurate reverse phase high performance liquid chromatographic method was developed for the simultaneous determination Paracetamol and Tapentadol HCl in pharmaceutical dosage form. The column used was Hyperchrome C18 (250mm x 4.6, 5μm) in isocratic mode, with mobile phase containing 0.05phosphate buffer, acetonitrile (65:35 v/v) adjusted to pH 2.8 with ortho phosphoric acid. The flow rate was 1.0 mL/min and detection wavelength was 217 nm. Tapentadol, Paracetamol and their marketed formulation were exposed to acidic, alkaline, thermal, hydrolytic and oxidative, stress conditions, and the stressed samples were analyzed by the proposed method. The developed method was validated in terms of precision, robustness, recovery, and limits of detection and limit of quantitation. The described method exhibited a linear dynamic range of 1-6 μg/mL for Tapentadol and 6.5- 39 μg/mL for Paracetamol. The calibration curves were found to be linear (r = 0.9961 for Tapentadol and r = 0.9978 for Paracetamol) over the range. Percent RSD of precision were found as 0.6137 for Tapentadol & 0.6158 for Paracetamol. The mean recovery was found to be 99.96% for PARA & 99.91% for TAP. The method was found to be suitable for analysis of Tapentadol and Paracetamol in presence of its degradation products.
