Gellan gum-based microbeads for Colon-targeted drug delivery: A promising polysaccharide for controlled and site-specific release

Targeting drug delivery to the colon presents significant challenges due to unfavorable pH conditions and enzymatic activity in the upper gastrointestinal tract. This obstacle can be overcome with colon-targeted microbeads, which have led to significant advancements in treating colonic diseases such as inflammatory bowel disease and colorectal cancer, as well as in achieving sustained delivery of macromolecules like peptides and proteins. Polysaccharide-based microbeads (MBs) formulated with gellan gum (GLG) offer a robust platform for controlled and site-specific drug release. GLG, a natural anionic polysaccharide, is renowned for its gelation properties in the presence of divalent cations, biocompatibility, and enzymatic degradability, making it ideal for colon-specific applications. In this review, we explored the potential of GLG-MBs for colon-targeted drug delivery and their physicochemical properties, drug release mechanisms, formulation strategies, therapeutic applications, methods for analytical characterizations, highlighting their advantages over conventional drug delivery, and target specificity towards the colonic disease. Furthermore, we discussed the significant limitations of GLG-MBs, such as burst release, processing, scaling up production, regulatory challenges, and clinical uniformity towards colonic environments. We explored the strategies to overcome key limitations in clinical translation, such as uniformity and regulatory hurdles. The review concludes by outlining the direction of advancing GLG-MBs, emphasizing their potential in achieving efficient and targeted drug delivery towards the colon.