This document discusses nasal and pulmonary drug delivery systems. It begins by providing an introduction to nasal drug delivery and its advantages such as avoiding first-pass metabolism. It then discusses the anatomy and physiology of the nasal cavity along with the mechanisms of drug absorption. Various formulation approaches for nasal delivery are described including nasal gels, drops, sprays, powders, liposomes and microspheres. Strategies to improve nasal absorption involving permeation enhancers, prodrug approaches, particulate systems and enzyme inhibitors are also summarized. The document concludes by outlining evaluation tests for nasal gels involving mucoadhesive testing and in vitro drug diffusion studies.