Spectrophotometric and Spectrofluorometric Determination of Doxazosin Mesylate in Tablets via Eosin Y

摘要

Doxazosin mesylate, an inhibitor of α-adrenergic receptors, was determined through formation of ion-pair complex with Eosin Y reagent in acetate buffer at pH 3. Two simple and sensitive spectroscopic methods were suggested. The first method based on spectrophotometric measurement of the complex at 547 nm and the second one based on spectrofluorimetric quenching measurement of the complex at 570 nm, after excitation at 340 nm. Under the optimum conditions, doxazosin mesylate was determined in the range of 2 - 14 pg mL~(-1) and 1-10 μg mL~(-1) by the spectrophotometric and spectrofluorimetric methods respectively, with good accuracy and precision in pure form. The method was successfully applied for determination of doxazosin mesylate in its tablets. All the results were statistically compared with that obtained by a reference method and subjected to validation analysis according to International Conference on Harmonization.