Utility of Dihaloquinone Chlorimides for the Determination of Phenazopyridine

Abstract

Phenazopyridine was found to react with each of 2, 6-dichloroquinone chlorimide (DCQ) and 2,6-dibromoquinone chlorimide (DBQ) in the presence of sodium acetate to produce a green colour peaking at 700 nm. The produced colour was found to obey Beers law in the range of 2-25 μg/ml. The molar ratio of the reaction could be realized, and a proposal of the reaction pathway was presented. The suggested procedure could be applied successfully to the determination of phenazopyridine HCl in tablets and the results obtained were compared favourably with those given with the official method.