Recent trends in design and evaluation of chitosan-based colon targeted drug delivery systems: Update 2020

Colon-targeted drug delivery systems is an active area of research that is designed to selectively release the drug in the colonic environment to enhance the oral delivery of active drug moieties which are vulnerable to the acidic environment in the upper gastrointestinal tract. It is continuing to progress and address the needs of the diseases affecting the colon especially owing to the design and development of novel colon-targeted delivery systems based on natural biodegradable polymers. Chitosan is a key biopolymer that has been widely exploited for the delivery of drugs, peptides, protein, and genes to the colon. In the current review, the emphasis has been placed on the role of chitosan in the design of colon targeting drugs and a comprehensive overview of chitosan-based colon-specific formulations and recent developments are captured. This review will provide a brief overview of previous applications, current trends, and the recent developments that have emerged in the chitosan-based colon targeted delivery system. We anticipate the future developments and new research areas surrounding the chitosan-based delivery systems that can strengthen the applicability of this polymer in new drug modalities.