Inhaled Insulin: Intrapulmonary or Intranasal?

Initial attempts delivered the insulin hormone intramuscularly, intravenously, and eventually subcutaneously. Other routes of administration of the drug were explored. These included oral, rectal, sublingual, buccal, transdermal, vaginal, intramuscular, intrapulmonary, and intranasal delivery systems. The purpose of these latter studies was to determine a noninjectable method to deliver insulin to patients with type 1 and 2 diabetes that would effectively lower blood sugar, control hemoglobin A1c (in much later studies), and allow patients a simpler, less invasive, and more direct control oftheir underlying disease process.  In January 2006 the United States Food and Drug Administration approved Exubera (Pfizer Pharmaceuticals, New York, NY) as the first pulmonary inhaled insulin. In actuality attempts to explore various methods to deliver insulin using intrapulmonary delivery had occurred since1925.