Spectrophotometric Determination Of Some Phenothiazine Drugs In Pharmaceutical Preparations
A sensitive spectrophotometric method has been developed for the assay of phenothiazine derivatives in bulk and their pharmaceutical preparations. The method is based on the formation of coloured species with p-benzoquinone in acid medium. The reaction involves oxidation of the phenothiazine nucleus into a serniquinonoid radical. The optimum reaction conditions and other analytical parameters are evaluated. The proposed method has been successfully applied to the analysis of the bulk drugs and their dosage forms, tablets and injections. No interference was observed from talc, dextrose or magnesium stearate in the proposed method. Statistical comparision of the results with those of an official method showed good agreement and indicated no significant difference in precision.