A schematic overview of the population pharmacokinetic model for 10,11-dihydro-10-hydroxy-carbamazepine (MHD) describing the pharmacokinetics in plasma and brain simultaneously. The model consists of a central compartment with combined zero- and first-order absorption with lag time and biophase distribution (V, volume of distribution; ka, absorption rate constant; k, elimination rate constant; k23, k32, transfer rate constants between central and effect compartment).