Abstract
Nanoformulations have become increasingly useful as drug delivery technologies in recent decades. As therapeutics, oral administration is the most common delivery method, although it is not always the most effective route because of challenges with swallowing, gastrointestinal discomfort, low solubility, and poor absorption. One of the most significant barriers that medications must overcome to exert a therapeutic effect is the impact of the first hepatic transit. Studies have shown that controlled-release systems using nanoparticles composed of biodegradable natural polymers significantly improve oral administration, which is why these materials have attracted significant attention. Chitosan possesses a wide variety of properties and functions in the pharmaceutical as well as healthcare industries. Drug encapsulation and transport within the body are two of its most important features. Moreover, chitosan can enhance drug efficacy by facilitating drug interaction with target cells. Based on its physicochemical properties, chitosan can potentially be synthesized into nanoparticles, and this review summarizes recent advances and applications of orally delivered chitosan nanoparticle interventions.