Final assembly of pen injectors / autoinjectors (cartridge insertion + snap-fit closure)

Sanofi markets self-administration drug-delivery devices (e.g. insulin pens and autoinjectors) that are assembled from sub-assemblies combined with a filled drug container at the filling facility. The task involves inserting a filled prefilled syringe or drug cartridge into a device housing, mating dose-mechanism/power-pack subassemblies, compressing actuation springs, and closing snap/press-fit features to a positive engagement. Objects are small, rigid polymer components plus a fragile glass cartridge, with energized springs adding force-sensitive steps. It sits at the downstream end of fill-finish, after the drug container is filled and inspected. It is hard for a robot because success depends on feeling correct seating and full snap engagement rather than seeing it, and because a glass cartridge can crack under excess insertion force. Device makers and filling facilities are noted as having distinct capabilities, so combined final assembly is a recognized integration pain. We identified this through our own research; we have not confirmed the specifics with the customer directly. This page is our researched read — a starting point for that conversation.