Insert prefilled syringe into autoinjector and snap-close final assembly

Roche's biologics are increasingly delivered via autoinjectors built around a prefilled glass syringe (PFS). Final device assembly involves loading a filled, stoppered PFS into a syringe holder/housing, then plugging a spring-loaded power-pack module into the housing and pushing until it locks into a non-separable snap-fit position, with plunger-rod and needle-shield subassemblies engaged. The objects mix fragile glass (with a highly variable shoulder/flange geometry formed over a tungsten pin) with springs and plastic snap features. It is the last step before a drug-loaded, patient-administered device, downstream of fill-finish and inspection. It is hard for a robot because the PFS glass shoulder geometry varies unit-to-unit, stoppering offsets are referenced to the flange creating unpredictable variability, the syringe can crack under misaligned insertion force, and a snap-fit that is not fully engaged is a latent device failure that vision cannot confirm. 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.