Spectrophotometric Determination of Phenothiazine Drugs with N-iodosuccinimide

Abstract

A simple and rapid spectrophotometric method for the determination

of seven phenothiazine derivatives, based on the colour

reaction with N-iodosuccinimide is described. The reaction proceeds

via oxidation of phenothiazine nucleus into a semiquinonoid

radical. The optimum reaction condition and other analytical parameters

are evaluated. A study of the effect of commonly associated

excipients revealed that they did not cause interference. The new

method has been applied for the assay of phenothiazine drugs in

pure and dosage form. Statistical comparison of the results with

those of an official method shows excellent agreement and indicates

no significant difference in precision.