The ranking covers 100 companies, with the leading assignee holding 220 of the 2,834 records in scope. The gap to the field is steep: fifth place holds 76 records and tenth place holds 52, so the top five together account for 22.8% of all records while the top ten reach 33.3%. That leaves a long tail of assignees with only a handful of filings each, meaning the field is concentrated at the top but still has substantial room for new entrants outside the leading group.

Filing peaked at 195 records in 2020 and had fallen to 90 by 2024, a -38% move from 2021’s 144 filings over that three-year span. That is the most reliable read because 2024 is the last year with largely complete publication data. Figures for 2025 and 2026 are still incomplete due to the roughly 18-month lag between filing and publication, so they should not yet be read as confirmation of a continued decline.

Separation processes under IPC class B01D appear in 30.6% of the 2,834 records, making membrane and filtration applications the single largest claim area. Polymer composition claims (C08L) follow at 24.6%, with additive use, condensation polymer chemistry and polymer processing each around 13.5%. Sterilising-specific claims (A61L) are comparatively rare at 5.6%, which suggests most hydrolysis-resistance and steam-sterilization language is being claimed through membrane or molding property claims rather than as standalone sterilising methods.