Nanoparticle-based oral delivery systems for colon targeting: principles and design strategies

Colon-targeted oral delivery is crucial for the treatment of colon-related diseases, as this delivery strategy enables precise drug administration to the diseased site, enhances drug bioavailability, and improves patient compliance. In particular, nanoparticle-based oral formulations shield drugs from the harsh gastrointestinal environment, and selectively increase drug concentration inside diseased colon cells, thus elevating therapeutic efficacy while reducing systemic toxicity. In this review, we elaborate recent progress in this area, with emphasis on the pathophysiological characteristics of colon site and design strategies to take advantage of these characteristics for colon targeting.