Square Wave Voltammetric Behavior of N,N-DiethyI-P-Nitroso Aniline an Indirect Method for Determination of Chlorpheniramin Maleate, Application of Pharmaceutical Formulations

The electrochemical behavior of N,N-diethyl-p-nitroso aniline was carried out using SWV (square wave voltammetric) at HMDE. A well defined reduction peak was observed at (-0.214) volt versus the reference electrode (Ag/AgCl/sat. KCl), calibration curve was constructed in phosphate buffer (pH = 7.0), the relationship is linear within the concentration range 1.283 × 10 -5 M - 3.66 × 10 -5 M with the correlation (R = 0.9923). The serial addition of CPM (chlorpheniramine maleate) leads to the decrease in the reduction current peak (Ip), quantitatively, the plot of ∆Ip (Ip - Ip) where, Ip: Peak current of N, N-diethyl-p-nitroso aniline alone, Ip: peak current of N,N-diethyl-p-nitroso aniline in the presence of CPM, versus concentration is linear within the concentration range 0.984 × 10 -6 M - 9.756 × 10 -6 M, the correlation coefficient was 0.9954. The method was successfully applied to determine CPM in different types of pharmaceutical formulations, and compared with standard method from British Pharmacopeia (1). N, N-diethyl-p-nitroso aniline is a green solid insoluble in water. It considers a nitrated amine stable under ordinary conditions, air and light sensitive, posses a strong reduction behavior through nitroso group. CPM (chlorpheniramin maleate) chemically 3-(4-chloro, phenyl)-n, n-dimethyl-3-pyridin-2-yl- propan-1-amine is an antihistamine drug that is widely used in pharmaceutical preparations for symptomatic relief of common cold and allergic diseases (2). The structure of CPM is shown in Fig. 1. Several methods have been described for the direct