5 - Composites of hydrogels and nanoparticles: A potential solution to current challenges in buccal drug delivery

Abstract

The buccal mucosa has emerged as an attractive route for local and systemic drug delivery. Owing to its unique anatomical and physiological features, the buccal mucosa offers advantages over more traditional routes. Its relative permeability and high degree of vascularization combined with the lack of keratinization lead to the rapid absorption of drugs, bypassing the hepatic first-pass metabolism and hydrolysis in the gastrointestinal tract. Conventional small molecule drugs and biologics have been administered through this route. However, the technological requirements and challenges associated with the buccal route have restricted the number of formulations available on the market or under clinical evaluation. In this chapter, nanoparticle hydrogel composites are presented as an innovative buccal drug delivery (BDD) system to overcome biopharmaceutical limitations related to the physiology and anatomy of the buccal route. The main developments in hydrogels, nanoparticles, and hybrid composites, as well as the formulation strategies, are reviewed here. In particular, we have focused on aspects related to permeability, mucoadhesion, and delivery of drugs with low solubility and poor bioavailability. New knowledge and directions to resolve challenges in BDD are summarized.