title: Utility of diphenylamine and N-bromosuccinimide for colorimetric determination of certain phenothiazine drugs.
abstract: A sensitive colorimetric method for the quantitative estimation of 11 phenothiazine drugs was developed. The method was based on the interaction of phenothiazine compounds with diphenylamine in presence of N-bromosuccinimide and sulfuric acid. Most of studied phenothiazines yielded bluish green products with two absorption maxima, one in the range of 392-396 nm with higher molar absorptivity and the other in the range of 770-780 nm with lower molar absorptivity. Phenothiazine base, mepazine HCl and pericyazine yielded blue products with only one maximum at 655, 775 and 778 nm, respectively. The color was stable for at least 1 h. The reproducibility and recovery of the method were excellent. The method was applied successfully to the determination of some commercially available phenothiazines in different dosage forms. Results were comparable to those obtained by official and reported methods.
authors.affiliation: Department of Analytical Pharmaceutical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt.
authors.forename: A
authors.initials: A
authors.lastname: El-Maaboud
authors.forename: I
authors.initials: I
authors.lastname: Mohamed