Concept, strategies, and feasibility of noninvasive insulin delivery.

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.