Titrimetric determination of some N-substituted phenothiazine derivatives.

An indirect titrimetric method is described for the determination of some N-substituted phenothiazine derivatives. The method involves the use of 1,3-dibromo-5,5-dimethylhydantoin or N-bromosuccinimide as the titrant. A known excess of either reagent is added and, after a specified time, the residual reagent is determined iodimetrically. The proposed method was applied to the analysis of pharmaceutical preparations containing the drugs, and the results obtained compared favourably with those obtained by pharmacopoeial methods.