Justification of biowaiver for carbamazepine, a low soluble high permeable compound, in solid dosage forms based on IVIVC and gastrointestinal simulation.

The aim of the present study was to use gastrointestinal simulation technology and in vitro-in vivo correlation (IVIVC) as tools to investigate a possible extension of biowaiver criteria to BCS class II drugs using carbamazepine (CBZ) as a candidate compound. Gastrointestinal simulation based on the advanced compartmental absorption and transit model implemented in GastroPlus was used. Actual in vitro and in vivo data generated in CBZ bioequivalence studies were used for correlation purposes. The simulated plasma profile, based on the CBZ physicochemical and pharmacokinetic properties, was almost identical with that observed in vivo. Parameter sensitivity analysis (PSA) indicated that the percent of drug absorbed is relatively insensitive to the variation of the input parameters. Additionally, plasma concentration-time profiles were simulated based on dissolution profiles observed under the different experimental conditions. Regardless of the differences observed in vitro, the predicted pharmacokinetic profiles were similar in the extent of drug exposure (AUC) while there were certain differences in parameters defining the drug absorption rate (C(max)t(max)). High level A IVIVC was established for the pooled data set (r = 0.9624), indicating that 1% SLS may be considered as the universal biorelevant dissolution medium for both the IR and CR CBZ tablets. The proposed methodology involving gastrointestinal simulation technology and IVIVC suggests that there is a rationale for considering CBZ biowaiver extension and introduction of the wider dissolution specifications for CBZ immediate release tablets.