[Multiple dose pharmacokinetic and bioavailability studies of oral sustained release and conventional formulations of isosorbide-5-mononitrate in healthy volunteers].

The pharmacokinetics of a new sustained release tablets (40 mg, qd) of isosorbide-5-mononitrate (IS-5-MN) was investigated together with a conventional preparation (20 mg, bid) after multiple oral administration in ten healthy human subjects using an open, randomized two-way crossover experimental design. Based on three statistical analyses of the area under the plasma concentration-time curve (AUC), the two tablet formulations are judged to be bioequivalent (P > 0.1), with a relative bioavailability of 108.95% for the IS-5-MN sustained release formulation. Pharmacokinetic data showed that the sustained release formulation reached mean peak plasma levels significantly later and lower minimum plasma concentration (Cmin), compared with the conventional preparation. But no statistically significant difference was found for other pharmacokinetic parameters including peak plasma levels (Cmax), AUC, elimination constant (Ke), elimination half-life (T1/2) and fluctuation index (FI) between the two preparations (P > 0.05).