Polysaccharide-based colon targeting drug delivery systems: Overview on challenges, opportunities and prospects

Colon-targeted drug delivery systems (CTDDS) are a current focus in the medical field, as they directly target the colon, enabling better management of diseases such as ulcerative colitis (UC), Crohn’s disease (CD), inflammatory bowel disease (IBD), and colorectal cancer (CRC) with minimal side effects. This system is highly suitable for delivering drugs prone to degradation in the upper gastrointestinal (GI) tract, including protein and peptide-type drugs. CTDDS have various advantages over traditional systems, such as avoidance of first-pass metabolism, prolonged transit time and controlled and sustained drug release. Commonly used polysaccharides include pectin, chitosan, guar gum, sodium alginate and hyaluronic acid. The novelty of this work is that it provides a comprehensive evaluation of recent advancements in various colon-targeting approaches, such as pH-sensitive, time-dependent, microbiota-dependent, combination, and prodrug approaches, along with their mechanisms, advantages, and associated challenges. In addition, this review article discusses commonly used polysaccharides along with their advantages and limitations, which will be advantageous during the development of polysaccharide-based CTDDS. Overall, this review article highlights the importance of CTDDS for society in terms of improving therapeutic efficacy, patient compliance and quality of life (QoL) by providing a safer and more effective drug delivery system to the colon-specific region.