APPLICATION OF P-N,N-DIMETHYLPHENYLENEDIAMINE DIHYDROCHLORIDE FOR THEDETERMINATION OF SOME ANTIARRHYTHMIC AGENTS AND ANTICOAGULANTS

A simple and sensitive spectrophotometric method is described for the determination of procainamide hydrochloride (PAH), acebutolol hydrochl oride (ACBH) and nicoumalone (NIC) in bulk samples and pharmaceutical formulations. The method is based on the oxidative coupling reaction t hrough the involvement of an aromatic primary amino group in the drug (existing free in PAH or released through hydrolysis in ACBH or reduct ion in NIC) with p-N,N-dimethylphenylenediamine dihydrochloride (DMPD) in the presence of an oxidant (S2O82- or Fe(III)) resulting in the fo rmation of an intensely colored product having maximum absorbance at 5 50 nm (PAH) or 560 nm (ACBH and NIC). Beer's law is obeyed in the conc entration ranges 2-20, 3-36 and 4-40 mug/ml of the three drugs studied . The proposed method is applied to the determination of these drugs i n bulk samples and formulations and the results compare favourably wit h those from the reference methods.