Delivery Strategies and Clinical Significance of Oral Colon-targeted Drug Delivery Systems

Formulation strategies for colonic delivery offer a unique opportunity for the local delivery of drugs for symptomatic relief in inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and colorectal cancer, as well as for the systemic delivery of peptides and biologics. By releasing active pharmaceutical ingredients (APIs) directly at the site of action within the colon, these systems can achieve higher local exposure with reduced systemic effects. This is achieved by utilizing prodrugs, pH-sensitive polymers, time-dependent systems, pressure, microbiota, and multi-pronged systems. Monolithic delivery systems can deliver drugs to the colon with limitations; however, the multiparticulate drug delivery of pellets has proven to be a superior methodology in meeting targets. This review highlights various techniques to bypass the upper part of the gastrointestinal tract, thereby releasing the active pharmaceutical ingredient specifically in various parts of the intestine and colon, to achieve both local and systemic therapeutic effects.