Nasal Delivery of Micro- and Nano-encapsulated Drugs

Abstract

Publisher Summary Many pharmaceutical products have been developed for the nasal delivery route that now take advantages of the benefits, including convenience and ease of use, rapid onset of action, avoidance of immediate hepatic metabolism, possibilities to minimize systemic exposure, higher bioavailability, and rapid brain access through the nerves that perforate the cribriform plate into the olfactory bulb. Some of the products that have successfully leveraged the benefits of the nasal route are salmon calcitonin, azelastine, desmopressin acetate, and buserelin acetate. These products are usually delivered as a nasal spray, though some offer the options of direct liquid or powder presentation. Recently, the issues associated with this route of administration were thoroughly reviewed. Even though the challenges to develop a successful nasal formulation can be onerous, appropriate use of absorption enhancement, adjuvants, mucosal adhesives, and encapsulation can help ameliorate the problems. Using the controlled-release aspects of the encapsulated drug ensures low concentrations of the drug at the nasal epithelium and is a consistent approach to develop biocompatible and effective nasal formulations. The nasal route has been demonstrated as a safe and promising new needle-free mode of delivering a variety of small-molecule drugs as well as for vaccination against respiratory diseases with DNA-based vaccines. This route of administration also has potential for delivering therapeutics to the brain; therefore, when delivering drugs via the nasal route, only nontoxic mucosal adjuvants are to be used to avoid neurotoxic potential.