Polymer mixtures as colon targeted drug delivery systems

For the development of colon delivery systems (CDS) formulations have to be gastric resistant. The advantage of the CDS is the ability for a local treatment for colon diseases but also its systemic action. CDS can also increase the bioavailability of poorly water soluble drugs e.g. resveratrol, which can be degraded in the upper gastrointestinal tract or by the First-Pass-Effect. In this project the coating technique with different polymer mixtures containing Kollicoat MAE-30DP, Eudragit-NM, Eudragit-L, and Eudragit-NE was investigated. Resveratrol was used as a model drug and all formulations were coated with a polymer mixture in a small scale fluidized bed apparatus. Morphology, roughness and film thickness of the coated tablets were determined by a scanning electron microscope and a 3D light microscope. Drug amount was determined by UV-spectrometry. Release studies were performed in a dissolution apparatus type II. Kinetic profiles of drug release were demonstrated. Results exhibit the advantages of polymer mixtures for CDS in comparison with results of pure Kollicoat MAE-30DP which were published in one of our latest publications.