title: Newer devices and improved formulations of inhaled insulin.
abstract: BACKGROUND
  Delivery of therapeutic insulin via the pulmonary route has been the most investigated non-invasive alternative to the commonly used subcutaneous (SC) route for diabetes management. Despite discontinuation of the first inhalable insulin, Exubera®, due to suboptimal market acceptance, development of orally inhaled insulin delivery systems has been galvanized by the recent approval of Afrezza® and several others awaiting approval.
  
  
  METHODS
  The scope of this review article includes the prospects for and the challenges faced in developing inhaled insulin delivery systems; discussion of orally inhaled therapeutic insulin delivery systems that were discontinued, recently approved or are currently under active investigation; and formulation approaches that have the potential to deliver insulin via the pulmonary route.
  
  
  CONCLUSIONS
  The pulmonary route is the most advantageous route for non-invasive insulin delivery. Inhalable insulin therapeutics have the potential to be successful, provided that the formulations can be made with modified release patterns to substitute for both prandial and basal insulin injections, the delivery devices are convenient and easy to use, and the long-term safety of inhaled insulin is documented through extensive studies.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center , 1300 Coulter St, Amarillo, TX 79106 , USA +1 806 414 9235 ; +1 806 356 4034 ; fakhrul.ahsan@ttuhsc.edu.
authors.forename: Jahidur
authors.initials: J
authors.lastname: Rashid
authors.forename: Shahriar
authors.initials: S
authors.lastname: Absar
authors.forename: Kamrun
authors.initials: K
authors.lastname: Nahar
authors.forename: Nilesh
authors.initials: N
authors.lastname: Gupta
authors.forename: Fakhrul
authors.initials: F
authors.lastname: Ahsan
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D003920:Diabetes Mellitus / Q000188:drug therapy*; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage*
chemical_list: C473734:Exubera; D007004:Hypoglycemic Agents; D007328:Insulin
keywords: diabetes; drug delivery; dry powder insulin formulation; inhaled insulin; insulin device