Indirect Spectroscopic Determination of Carvedilol and Propranolol Hydrochloride in Its Pure Form Using Methyl Orange Dye and Applying to Their Pharmaceutical Preparations

Abstract

An easy, rapid, and indirect, selective spectroscopic method was developed for estimating Carvedilol and Propranolol in their pure form and in their pharmaceutical preparations, as the method relies on oxidation and reduction with a known increase (excess) of the oxidizing agent cerium sulfate ( in medium of sulfuric acid 5 molar) and estimation of the remaining of the oxidizing agent (surplus excess) by its reaction with methyl orange to form a pink color complex, the maximum absorption was given at the wavelength of 507 nm. The relationship was linear with in the ranges of concentration (0.5 - 24.5 and 0.5 - 24.0) μg / ml for carvedilol and propranolol respectively with molar absorptivity of 2.88 × 104 and 2.076 x 104 l. mol-1 . cm-1 and recovery rate of 99.54% and 99.42% respectively standard deviation value amounted to less than 0.37% for each one of the Carvedilol and Propranolol respectively in such a way that indicates good accuracy and compatibility. The method was successfully applied to the pharmaceutical preparations of the two drugs under study on the form of tablets, The results of the method are compatible with the original content of the pharmaceutical preparations and with the results of the standard addition method, there is no noticeable overlap of the excipient materials, that proves the efficiency of the proposed method.