SPECTROPHOTOMETRIC DETERMINATION OF PROPRANOLOL HYDROCHLORIDE AND METOPROLOL TARTRATE IN PHARMACEUTICAL DOSAGE FORMS, SPIKED WATER AND BIOLOGICAL FLUIDS

Objective: A new spectrophotometric method for the determination of propranolol hydrochloride (PRO) and metoprolol tartrate (MTP), beta blocker drugs, has been developed for their analysis in pharmaceutical dosage forms for the purpose of quality control and water samples for monitoring impact on environmental water quality of natural sources and in biological fluids for ascertaining their physiological performance.Methods: The method is based on the derivatization of the amino function present in these drugs to the corresponding yellow copper (I) drug dithiocarbamate derivative through reaction with carbon disulphide, pyridine and copper (I) perchlorate in aqueous acetonitrile and measuring absorbance at 406 nm for propranolol and 400 nm for metoprolol. The different experimental parameters affecting the development and stability of the colour were carefully studied and optimized.Results: The Beer's law is obeyed in the range of 1.0-40.0 μg/ml of each drug solution with a correlation coefficient 0.999. The maximum relative standard deviations (RSDs) in the analysis of pure PRO and MTP were 1.01 and 1.52 % respectively. The recoveries of the drugs from pharmaceutical formulations, spiked water samples and biological fluids were in the range 98.0-100.5 % with RSDs in the range 0.23-1.94% indicating good accuracy and precision of the method.Conclusion: The instantaneous development of colour and its stability, well-established stoichiometry of the reaction and above simplicity and rapidity of procedures are some special attributes of the proposed method