An Ion-Pair Chromatography Method for Simultaneous Estimation of Tramadol and Paracetamol in Combined Tablet Dosage Form

A simple, fast, and new ion pair chromatographic method was developed and validated, for the simultaneous estimation of Tramadol hydrochloride and paracetamol in pharmaceutical formulations. The developed method uses acetonitrile: 5% sodium lauryl sulphate: methanol in the ratio of 45:15:40 v/v with flow rate of 1mL/minute. The optimum separation was achieved in less than 5 minutes using WATERS Symmetry C18 column (250mm X 4.6mm, 5μm, i.d.) detection was carried out using UV detector, measuring the response at 217nm. Beer's law was obeyed in the concentration range of 20–187.5μg/mL for tramadol and 20–1625 μg/mL for paracetamol, with a detection limit of 4ng/mL for tramadol and 5ng/mL for paracetamol, and a quantitation limit of 15ng/mL for tramadol and 16ng/mL for paracetamol. Intra-day and Inter-day precision and accuracy of the methods have been established according to the current ICH guidelines. The regression co-efficient (r2) value for tramadol and paracetamol was found to be 0.9998 and 0.9996 respectively. The average recovery for tramadol was 100.03% and 100.28% for paracetamol. No interferences were observed from the excipients. The proposed method was found to be accurate, precise and rapid for the simultaneous estimation of tramadol and paracetamol.