Beyond the Needle: Reimagining Insulin Delivery and the Evolution of Inhaled Insulins

Insulin has been around for a century since its discovery and has seen multiple innovations to improve its pharmacokinetic profile, thus impacting its efficacy, safety, and patient compliance. Despite its powerful glycemic efficacy, the use of insulin has remained sub-optimal owing mainly to the invasive route of administration and associated barriers. Non-invasive insulin development has been one of the highly researched fields in diabetes management. Amongst the various non-invasive routes investigated for insulin delivery, the pulmonary route has been among the most evaluated ones - a route that has yielded the only existing non-invasive option, inhaled insulin. Technosphere® insulin (Afrezza®; Mannkind Corporation, Danbury, CT, USA) is the only available inhaled insulin that has regulatory approval for the treatment of adult individuals with diabetes mellitus and has been available for more than a decade. This review article provides an overview of the pulmonary route of administration and charts the developmental journey of inhaled insulins, with a focus on Technosphere® insulin.