Nasal and Pulmonary Drug Delivery System

The widespread interest in intranasal route for therapeutic purposes other than the topically nasal drug delivery arises from the particular anatomical, physiological and histological characteristics of the nasal cavity, which provides potential for rapid systemic drug absorption and quick onset of action. In addition, intranasal absorption avoids the gastrointestinal and hepatic presystemic metabolism, enhancing drug bioavailability in comparison with that obtained after gastrointestinal absorption. Growing attention has been given to the potential of a pulmonary route as an non-invasive administration for systemic delivery of therapeutic agents (mainly peptides and proteins) due to the fact that the lungs could provide a large absorptive surface area (up to 100 m2 ) but extremely thin (0.1 ¿m ¿ 0.2 ¿m) absorptive mucosal membrane and good blood supply. However, recent advances show great promise, but pulmonary delivery of peptides and proteins is complicated by the complexity of the anatomic structure of the human respiratory system and the effect of disposition exerted by the respiration process.