An HPLC method for the simultaneous quantitation of quinidine, procainamide, N-acetylprocainamide, and disopyramide.

A high performance liquid chromatographic method is reported, which incorporates three internal standards (I-cinchonidine, N-propylprocainamide, and para-chlorodisopyramide) for the simultaneous quantitation of four commonly prescribed antiarrhythmic drugs: quinidine, procainamide, N-acetylprocainamide, and disopyramide. Compounds were separated using combined ion-pairing and adsorption chromatography on a silica column. Inter-run variation was 5.9 CV% for all drugs.