Development of HPLC Method for Quantification of Orphenadrine, Paracetamol, and Caffeine in Pharmaceutical Formulations

A method for the determination of orphenadrine (ORPH), paracetamol (PAR) and caffeine (CAF) using HPLC was developed. The proposed method provides an easy sample preparation and low cost using a mobile phase consisting of 80% of water with direct determination of the active principles present in pharmaceutical formulations. The separation of ORPH, PAR and CAF was accomplished on a C-18 column at 25 degrees C at a flow rate of 1.2 mL min(-1) using acetonitrile/water (pH 2.5) as mobile phase (20:80, v/v). The method exhibits linear responses for ORPH, PAR and CAF in the concentration ranges of 0 - 150 mg L-1, 0 - 200 mg L-1 and 0 - 200 mg L-1, respectively. The detection limits and quantification determined according to IUPAC recommendation were found to be 1.14 and 3.79 mg LA(-1) for ORPH, 0.05 and 0.17 mg L-1 for PAR and 0.02 and 0.07 mg L-1 for CAF. Recoveries varying from 98.02 up to 101.81% for two pharmaceutical formulations spiked with these analytes were achieved assuring the accuracy of the proposed method.