Screening of different polysaccharides in a composite film based on Eudragit RS for subsequent use as a coating for delivery of 5-ASA to colon.

This study aims at identifying the more suitable polysaccharide in a composite film based on Eudragit RS for 5-ASA delivery to the colon. Different polysaccharides (pectin, chitosan, guar, inulin, and dextran) were examined. The mechanical properties, swelling index, loss of film mass and permeability of films to 5-ASA were recorded at simulating gastric (SGF), intestinal (SIF) and colonic fluids (SCF). Films containing inulin or dextran were more flexible and showed better mechanical properties. Films containing chitosan, pectin or guar exhibited extensive swelling in SGF and SIF. Loss of film mass and drug permeation was more pronounced in SCF than SIF for all samples indicating their sensitivity to colonic bacteria. However, films containing inulin or dextran showed minimum swelling index in SGF and SIF and the highest ratio of permeability in SCF to SIF. Accordingly, inulin and dextran are suggested as appropriate polysaccharides in a film based on Eudragit RS for colon delivery of 5-ASA.