PhD defence A. (Annemarie) Broesder

Ileo-colonic drug delivery

Delivering drugs to the ileo-colonic region of the intestinal tract might improve therapy for patients with diseases within their large intestines. The pH variations in the gastrointestinal tract can be used to achieve the targeted delivery. The pH rises from the stomach to the end of the small intestine, where the highest value is found. An example of a system that uses this pH profile is the ColoPulse coating. In this thesis, research is described in which the ColoPulse coating was applied to develop several novel ileo-colonic targeting formulations.Celecoxib, which has a poor water solubility, is a drug of interest for the treatment and prevention of colon cancer. We were able to create a celecoxib formulation that improves its solubility as well as targets the ileo-colonic region. When a single unit dosage form is damaged, then there is a risk that the entire dose is released in higher regions of the intestinal tract instead of the ileo-colonic region. Therefore, a multi-particulate formulation is preferred. To that end, we developed a pellet formulation that releases its contents in the ileo-colonic region. Sulfasalazine and caffeine were incorporated in these pellets, since these compounds can be used to verify ileo-colonic drug delivery. Since the colon has a low free water content, we also developed a formulation that was able to deliver an aqueous drug solution to the ileo-colonic region. With this work, we hope that in the future, therapy of patients can be improved.

Promotores Prof.dr. H.W. Frijlink and Dr. W.L.J. Hinrichs