Bioavailability of four different pharmaceutical preparations of carbamazepine.

The bioavailabilities of two tablet brands carbamazepine (CBZ) (Tegretol, A; Neurotol, B) were compared with two new experimental preparations (C,D). Formulation A showed a more sustained release nature than did the other formulations. The AUCs0 leads to infinity gave no significant differences between treatment A and three other treatments. However, if AUC0 leads to 72 was calculated instead of AUC0 leads to infinity, the preparation A gave the significantly lower bioavailability than the other compounds. Formulations A and B are marketed as generically equivalent preparations in Finland. However, their pharmacokinetic parameters after a single dose were different.