ABSTRACT
The absorption from the gastrointestinal (GI) tract is a complex process, which includes dissolution, permeation, degradation and intestinal and/or hepatic metabolism. These processes are often inuenced by physiological mechanisms of gastric emptying, intestinal motility and the action of inux and efux proteins. Furthermore, the rate and extent of absorption from the GI tract depends on the physicochemical properties of the administered compound and its functioning in different environments of the GI tract. The absorption into the systemic circulation entails the permeation of the compound from the lumen to gut wall and subsequent diffusion through capillary wall into the blood stream. A summary of the factors inuencing the absorption from the GI tract is presented in Figure 8.1.
