Application of p- N, N-dimethylphenylenediamine dihydrochloride for the determination of some antiarrhythmic agents and anticoagulants

Abstract

A simple and sensitive spectrophotometric method is described for the determination of procainamide hydrochloride (PAH), acebutolol hydrochloride (ACBH) and nicoumalone (NIC) in bulk samples and pharmaceutical formulations. The method is based on the oxidative coupling reaction through the involvement of an aromatic primary amino group in the drug (existing free in PAH or released through hydrolysis in ACBH or reduction in NIC) with p- N, N-dimethylphenylenediamine dihydrochloride (DMPD) in the presence of an oxidant (S 2O 8 2− or Fe(III) resulting in the formation of an intensely colored product having maximum absorbance at 550 nm (PAH) or 560 nm (ACBH and NIC). Beer's law is obeyed in the concentration ranges 2–20, 3–36 and 4–40 μg/ml of the three drugs studied. The proposed method is applied to the determination of these drugs in bulk samples and formulations and the results compare favourably with those from the reference methods.