Simultaneous Estimation of Paracetamol and Tramadol in Tablet Formulation by Reverse Phase HPLC Method

A simple, fast, precise and accurate liquid chromatographic method was developed for the simultaneous estimation of paracetamol and tramadol in combined dosage forms. This combination is used as analgesic in dental and postsurgical pain. Drugs are chromatographed on a reverse phase Kromasil C18 column using a mobile phase, 0.1M Potassium dihyrdogen phosphate buffer (pH 6.8) and Methanol in the ratio of 40:60%v/v. Valdecoxib was used as an internal standard. The retention time of paracetamol, tramadol, and valdecoxib was 3.15, 5.65, 8.22 min, respectively. The validation of the proposed method was also carried out. The method was found to be linear (r>0.99), precise (%RSD: 0.49% for paracetamol and 0.89% for domperidone), accurate (overall average recovery yields: paracetamol 99.81% and domperidone 98.98%) and selective. Due to its simplicity and accuracy the proposed method can be used for routine quality control analysis of these drugs in combined dosage form.