Auto-Injector
A spring-loaded or motorised device for self-administration of injectable peptide drugs that automates needle insertion, drug delivery, and needle retraction. Modern auto-injector pens for semaglutide, dulaglutide, and other GLP-1 receptor agonists have simplified self-injection and supported widespread patient adoption.
Technical Context
Modern peptide auto-injectors include multi-dose pen devices (FlexPen/FlexTouch for semaglutide Ozempic, with dose dial; KwikPen for dulaglutide Trulicity, single dose per pen) and single-use auto-injectors (spring-loaded devices that automatically insert the needle, inject, and retract). Design considerations: needle gauge (29-32G for minimal pain), injection depth (4-6mm for SC), dose accuracy (±5% for pens), and human factors (usability studies with patients who have limited dexterity, vision, or cognitive function). The pen injector format has been critical to GLP-1 RA commercial success — patient surveys consistently report that pen-based injection is the most preferred delivery method for self-administered peptide drugs.