Preparation of Chitosan-g-Poly(acrylic acid) Hydrogels for Colon-Specific Drug Delivery and Their Swelling Behavior and Biodegradability

摘要

Oral colon-specific drug delivery system has gained increasing interest lately. The main reasons for this concern are (1) targeting the drugs to the colon is of significance for the treatment of colonic diseases 1; (2) peptides and protein drugs that absorb proorly from upper gastrointestinal tract (GIT) can be better absorbed from the region [1]. This system usually utilizes pH sensitive polymeric materials based on the grad change in the pH of the gastrointestinal, or adopts biodegradable medicinal materials by colonic enzymes[2].