Dissolution and relative bioavailability of two carbamazepine preparations for children with epilepsy

The in-vitro dissolution profiles of two carbamazepine formulations (Tegretol and a generic carbamazepine) have been assessed and the bioavailability of carbamazepine compared in 12 epileptic children at steady-state. Dissolution from the generic formulation (100 and 200 mg tablets) tended to be greater than for the proprietary tablets. However, the bioavailability and pharmacokinetics of carbamazepine when assessed at steady-state were similar for the two formulations. It appears, therefore, that the breakthrough seizures and higher incidence of neurological side-effects observed when children were given generic carbamazepine in place of the proprietary formulation cannot be accounted for by differences in bioavailability or pharmacokinetics.