Predicting in vivo performance of fenofibrate amorphous solid dispersions using in vitro non-sink dissolution and dissolution permeation setup

Amorphous solid dispersion (ASD) is emerging as a useful formulation strategy to increase the bioavailability of active pharmaceutical ingredients with poor solubility. In vitro dissolution testing under non-sink conditions has often been used to evaluate the ability of ASDs to generate and maintain supersaturation to predict the in vivo performance. However, such a single compartment dissolution setup can fail to predict the oral bioavailability, due to an interdependence between precipitation and permeation. Hence, the use of two compartment dissolution-permeation setups is emerging. In this study, three ASDs containing fenofibrate as model drug substance were developed using Soluplus®, and Hypromellose Acetate Succinate in two different grades (high and low), respectively. The aim was to compare the use of a small-scale in vitro non-sink dissolution setup and a small-scale in vitro dissolution-permeation setup to predict the in vivo oral exposure of the ASDs in rats. The maximum concentration (C_max) and area under curve (AUC) obtained in the in vitro studies were used to predict the in vivo rank order of the formulations. The results showed that the two in vitro studies resulted in the same rank order based on both C_max and AUC. Interestingly, C_max resulted in a better in vitro/in vivo correlation than the in vitro AUC, and based on the in vitro C_max, the in vivo rank order was predicted.