Simultaneous estimation of tramadol hydrochloride, paracetamol and domperidone by RP-HPLC in tablet formulation

A new high performance liquid chromatography method was developed and validated for the quantitation of tramadol, paracetamol, and domperidone in pharmaceutical formulations. Determination was performed using a Inertsil-ODS-3 (C-18) column (5 μm, 250 mm × 4.60 mm), a mobile phase containing methanol–phosphate buffer (pH 4.0; 40 + 60, v/v), in gradient flow rate 1.2 mL. The method was validated with respect to linearity, precision, robustness, and accuracy. The calibration graphs ranged from 250 to 1500 mg/mL for paracetamol, 25 to 150 mg/mL for tramadol, and 5 to 30 mg/mL for domperidone. Intra- and interday relative standard deviation values for the standard solutions were 0.077%, 0.98%, and 1.04%, respectively. Repeatability of relative standard deviation values was 0.115%, 0.494%, and 1.97% respectively. Total recoveries of paracetamol, tramadol, and domperidone from the laboratory prepared mixtures were 100.4, 100.06, and 100.2%, respectively.