In-vitro simulation of drug intestinal absorption

In this work, a simple set-up was designed, realized and tested to evaluate the effect of intestinal absorption on the in vitro drug release studies. The conventional USP-approved dissolution apparatus 2 was equipped with an hollow fibers filter, along with the necessary tubing and pumps, to simulate the two-fluids real behavior (the gastro intestinal lumen and the gastro intestinal circulatory system). The realized set-up was characterized in term of mass exchange characteristic, using the theophylline as the model drug, also with the aid of a simple mathematical model; then the release kinetics of a controlled release tablet was evaluated in the conventional test as well as in the novel simulator. The concentration of drug in the release compartment (which simulates the gastric lumen) was found lower in the novel simulator than in the traditional one