The ranking in this dataset covers 100 companies, and it is heavily front-loaded: the leading assignee holds 197 of the 2,164 records in scope, and the top five together hold 863 records, or 39.9% of the field. Past the top ten, which together hold 61.3% of records, filing counts drop off quickly into a long tail of organisations with only a handful of records each. That shape matters for licensing strategy — a handful of names control most of the mechanical claim space around barrel, plunger and needle-shield design.

Filing volume has plateaued rather than grown or collapsed. The last three complete filing years show 189 filings in 2021 against 188 in 2024, a -1% change, after an earlier peak of 218 filings in 2019. Figures for 2025 and 2026 look lower still, but that reflects the roughly 18-month lag between filing and publication rather than a real drop in activity, so they should not be read as a downturn.

The underlying search combines core hardware terms with specific failure modes: silicone oil migration, break loose force, tungsten residue, glass delamination, needle shield interaction and container closure integrity. Device claims (A61M) touch 69.1% of the 2,164 records, more than double the 27.4% share for medicinal-preparation claims (A61K), which means most of the contested ground is the mechanical interface between barrel, stopper and needle rather than the drug formulation itself.

Supporting IPC classes such as C23C coatings (5.9% of records), A61L sterilising (3.5%) and B65B packaging (3.7%) show meaningfully lower filing density than the core A61M device claims. Specific branches worth checking before filing include silicone-free lubricant coatings, delamination-resistant glass treatments, and sterilising methods suited to pre-assembled cartridges — areas where the claim space looks less occupied than the barrel-and-plunger mechanics that dominate the field.

US11331434B2, assigned to Merz Pharma, claims a botulinum toxin prefilled syringe system built around low gliding force and low break loose force, combining a glass barrel, plunger stopper and a closure device such as a tip cap or needle shield with a specific drug payload. It blocks designs that combine that particular force profile with that specific formulation and closure combination, but it does not by itself cover every low-force syringe design — a proper freedom-to-operate read needs to check the granted claim scope against the specific formulation and hardware combination in question.