Determination of Promethazine Hydrochloride in pharmaceutical forms by Spectrophotometric Method

This research contains the development of a sensitive spectrophotometric method for determination Promethazine Hydrochloride in aqueous solution based on reduction of Fe3+ to Promethazine Hydrochloride . The Fe2+ formed is complexed with 1,10-Phenanthroline at pH 3.01 to produce a red-colour , water soluble and stable complex, which exhibits maximum absorption at 504 nm. Beer’s law obeyed in the concentration range from 2-01 μg/ml of Promethazine Hydrochloride . The molar absorptivity is 4310043L.mol-1 .cm-1 and Sandell’s sensitivity index of 0.0094 μg . cm-2 , a relative standard deviation is no more than 1.34%, and D.L 0.138 μg/ ml. The method has been successfully applied to the determination of Promethazine Hydrochloride in tablets.