[Relative bioavailability of various quinidine preparations in man after a single oral dose]

The bioavailability of quinidine sulfate in different preparations (quinidine in capsules as reference; Quinidine longo; Qunidine longo with either quinidine in the cover or in the nucleus, Quinidine Duriles) was investigated in 8 healthy volunteers in plasma and urine in a crossover design. There are no differences in the AUCo infinitey and in the eliminated amount in urine after infinit time. Quinidine longo possesses two maxima at 0.8 +/- 0.1 h and at 3.1 +/- 0.2 h. These maxima are caused by the liberation from the cover and the nucleus. The quotients of retardation (RD = ratio of the duration at 1/2 Cpmax, RC = ratio of 1/2 Cpmax, quinidine sulfate as reference) is calculated for Quinidine longo: RD = 1.42 +/- 0.14, RC = 0.75 +/- 0,05 and for Quinidine Duriles: RD = 1.79 +/- 0.21, RC = 0.52 +/- 0.07. The effect of retardation of Quinidine longo is not so much as that of Quinidine Duriles. However there are no statistic differences for RD in contrast to RC between these two retard-preparations.