Non-coated multiparticulate matrix systems for colon targeting.

Background: Colon specific drug delivery can significantly improve the efficacy of local treatments of inflammatory bowel diseases. Film coatings containing the starch derivative Nutriose have recently been reported to minimize 5-ASA release in media simulating the upper gastro intestinal tract (GIT), while releasing the drug in a time-controlled manner upon contact with feces from Crohn's Disease and Ulcerative Colitis patients. It was the aim of this study to prepare Nutriose-containing matrix pellets and mini tablets in order to avoid a film coating step.

Methods: Highly dosed matrix pellets were prepared by extrusion-spheronization, highly dosed mini tablets by compression. Various types of lipids were added and drug release measured in 0.1 N HCl and phosphate buffer pH 6.8, optionally containing pepsin and pancreatin.

Results: The type of added lipid and the preparation technique, in particular the curing conditions, significantly affected the resulting drug release kinetics. Glyceryl palmitostearate containing pellets and mini tablets showed the most promising results upon appropriate curing, minimizing premature drug release in media simulating the upper GIT.

Conclusion: The proposed novel multiparticulates do not require a film coating step and show an interesting potential for site-specific drug delivery to the colon of inflammatory bowel disease patients.