Development and Validation of RP-HPLC Method for Simultaneous Estimation of Tapentadol and Paracetamol in Bulk Drug and its Pharmaceutical Dosage Form

A simple, rapid and sensitive isocratic RP-HPLC method was developed for the simultaneous estimation of Tapentadol and Paracetamol in bulk and their Pharmaceutical dosage form using Waters C₁₈ (250 x 4.6 mm i.d, 5 μ particle size) analytical column in an isocratic mode with mobile phase comprising Acetonitrile: Potassium dihydrogen Phosphate pH 6.8 adjusted with orthophosphoric acid in the ratio of 50:50 (% v/v). The flow rate was 1.0 ml/min and effluent was monitored at 215nm. The retention times were found to be 2.38 min for Paracetamol and 4.59 min for Tapentadol. The assay exhibited a linear dynamic range of 350–1050 μg/ml for Paracetamol and 50–150 μg/ml for Tapentadol. The calibration curve was linear (r = 1 for Paracetamol and r = 0.9998 for Tapentadol) over the entire linear range. Recovery was found to be 99.00% ± 0.41 for Paracetamol and 100% ± 0.22 for Tapentadol. The proposed method was statistically evaluated and validated as per ICH guidelines and can be applied for routine quality control analysis of Tapentadol and Paracetamol in Pharmaceutical dosage form.