Insert prefilled glass syringe into autoinjector and seat snap-fit closures

Several Novartis biologics are delivered via pen/autoinjector formats (e.g. Kesimpta Sensoready pen, Cosentyx), which require assembling a fragile prefilled glass syringe (PFS) into a plastic autoinjector housing, placing spring/plunger components, snapping the housing closed, and capping. The PFS is fragile glass with inherently variable shoulder/flange geometry — the syringe shoulder is formed over a tungsten pin, producing variable nominal geometries even within ISO tolerances, which creates unpredictable offsets at the device interface. The task involves force-controlled insertion of a fragile component into a tight housing, then confirming full snap engagement of mating parts. It is hard because a force-blind insert can crack the glass or jam, and a partially-seated snap yields a leaking or defective combination product. This is a multi-step rigid/press/snap assembly where seating must be felt, not just seen. 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.