Comparable steady-state bioavailability between two preparations of conventional-release procainamide hydrochloride

The pharmacy and therapeutics committee-based clinical evaluation can be a useful tool in the economic and functional effectiveness of a restrictive formulary system. We utilized this concept to evaluate a generic formulation of procainamide hydrochloride (PA) for admission to our formularies. The study performed was a randomized, single-blind, crossover comparison of the serum-concentration profiles of two preparations (Squibb vs. Ascot) of conventional-release PA. Ten outpatients requiring chronic PA therapy for the control of ventricular dysrhythmias were evaluated. The resultant dose-adjusted data showed no significant difference between mean serum PA concentrations at any sample time, area under the serum concentration-time curves, mean peak serum PA concentrations achieved, or peak-trough fluctuations. Relative bioavailability was calculated to be 0.972 +/- 0.59. The Ascot preparation demonstrated a delay of 15 minutes before the onset of absorption; however, it also showed an earlier tmax in comparison to the Squibb formulation. Generic substitution of Ascot PA in place of Squibb PA may be implemented with significant cost savings.