Polysaccharide and Chitosan-Based Colon Drug Delivery System: An Advanced Approach for IBD Therapy

Inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease, is a chronic inflammatory disease of the gastrointestinal system that continues to affect millions of people every day all over the globe. Current therapies (amino salicylates, corticosteroids, immunosuppressing agents, and biologic medications) can provide symptomatic relief; however, they also have systemic side effects and poor bioavailability and are limited in the targeting of the inflamed tissue. Colon-targeted drug delivery systems (CDDS) were created to address these issues with newer drug delivery approaches that deliver the drug directly to the disease site of IBD—this designed targeting mechanism explains better therapeutic outcomes and fewer adverse effects. Chitosan and natural polysaccharides are among some of the most suitable drug carriers for CDDS systems because of a variety of reasons, such as biocompatibility, biodegradability, and their ability to respond to colonic biosystem parameters (pH, microbial enzymes, and oxidative stress). Polysaccharides such as pectin, dextran, alginate, inulin, and guar gum provide selective microbial degradation and therefore release the active pharmaceutical ingredients for controlled drug delivery. Since chitosan derivatives provide improved mucoadhesion and epithelial permeability. The more advanced formulations deliver nanoparticles, hydrogels, microspheres, and prodrug systems. This review summarizes the latest developments in CDDS based on polysaccharides and chitosan, as well as more recent methods such as pH-sensitive, time-controlled, and providing the capacity for colonic time-molecularly controlled drug absorption.