Development of Ion-Association Methods for Spectrophotometric Assay of Imipramine HydrochlorideAuthor(s): G. Nagarjuna Reddy, C. Ramesh, T. V. Narayana, K. V. S. Prasada Rao and B. Ganga Rao
Three simple and sensitive spectrophotometric methods (M 1 -M 3 ) for the assay of imipramine in pure and dosage forms based on the formation of chloroform soluble ion-as sociates under specified experimental conditions are described. Three acidic dyes, namely, azocarmine G (ACG, M 1 ), naphthalene blue 12BR (NB 12BR, M 2 ) and woolfast blue BL (WFB BL, M 3 ) are utilized. The extracts of the ion- associates exhibit absorption maxima at 550, 620 and 590 nm for methods M 1 , M 2 and M 3 , respectively. Regression analysis of Beer’s law plots showed good correlation in the concentration ranges 2.0-12.0, 4.0- 16.0 and 1.0-12.0 μ g/mL for methods M 1 , M 2 and M 3 , respectively. These methods are found to be suitable for the assay of imipramine in pharmaceutical formulations. All the variables have been optimized and the reaction mechanisms presented. The concen tration measurements ar e reproducible within a relative standard deviation of 1.0%.