Research progress and interfacial adhesion mechanisms of oral delivery systems based on natural polymers

Oral mucoadhesive delivery is a significant strategy for drug administration due to its capacity to bypass hepatic first-pass metabolism and enhance drug bioavailability. However, the highly moist environment and frequent mechanical stresses in the mouth present substantial challenges to delivery systems. In this review, the oral environment and principal challenges of delivery systems and mechanisms of oral adhesion are discussed. Then, the oral drug delivery systems based on natural polymers with good biocompatibility as well as their adhesive mechanisms are analyzed. Moreover, the application areas of these systems in prevention and treatment of oral diseases, local targeted therapy of oral cancer, and dental care are summarized. The emerging role of artificial intelligence technologies in the design of delivery systems and diagnostic assistance is also discussed to put forward the intelligent development trend for oral drug administration. This review can provide a theoretical basis and design insights for oral mucoadhesive delivery systems.