Abstract
Spectrophotometric Determination Of Promethazine Hydrochloride In Pharmaceutical Formulations
A simple, rapid and selective spectrophotometric method has been proposed for the assay of promethazine hydrochloride in pure and pharmaceutical formulations. The method is based on the formation of a chloroform-soluble red coloured product having an absorption maximum at 516 nm with o-toluidine in presence of N-bromosuccinimide. The reaction conditions were optimized. Beer's law is valid in the concentration range 2-15 μg/ml (r=0.9993) having molar absorptivity of 4.64X103 I/mol.cm. The results obtained by the proposed method were compared by means of Student t- test and by the F-test with those of official method and were found to be in good agreement. No interference was observed from common excipients. Moreover, the method is specific for C-2 unsubstituted phenothiazines.
