Abstract
OBJECTIVE—To comprehensively review the progress to date on the development of alternative routes for insulin delivery. RESEARCH DESIGN AND METHODS—Study data were collected through a Medline review. RESULTS—Proof of principle has been established for many routes of administration including dermal, nasal, oral, buccal, and pulmonary insulin delivery. CONCLUSIONS—Of all the approaches to date, pulmonary delivery appears to be most feasible. Ongoing phase III studies will ultimately determine safety, tolerability, and efficacy before approval for clinical use.