Oral administration is widely used for drug delivery and nutrition, but its bioavailability is limited by gastrointestinal instability, enzymatic degradation, poor solubility, and interindividual variation. Reliable in vitro, ex vivo, and in vivo models are required to predict intestinal absorption. While Caco‑2 cells are standard, they lack tissue complexity; animal studies are costly and ethically limited. The ex vivo porcine intestine–Ussing chamber system preserves physiological structure and transporter activity, making it highly translational.

This PhD further developed this model to explore intestinal absorption mechanisms. It clarified the dual active–passive transport of thiamine, evaluated thiamine biofortified rice coupled with in vitro digestion, and assessed Gum Arabic–based formulations for lipophilic antioxidants. Results confirmed the model’s versatility for mechanistic, nutritional, and formulation studies. This work supports the Ussing chamber/ex vivo porcine intestine as a robust, physiologically relevant tool for oral bioavailability research.