In this dataset, the term covers liquid biologic formulations, typically monoclonal antibodies, concentrated enough to raise solution viscosity, promote self-association, or cause opalescence during storage. Claims in scope address the excipients, process steps such as ultrafiltration, and stability-testing methods used to make such a formulation viable for subcutaneous injection. The search string used to build this corpus specifically combines high-concentration and viscosity terms with excipient and stability terms, which distinguishes it from broader biologics formulation filings that do not address concentration-driven viscosity.

The ranking covers 100 companies, with the leading assignee holding 150 records, fifth place at 93 records and tenth place at 69 records. The top five filers combined account for 31.1% of the 2,067 records in scope, and the top ten reach 48.3% — meaningful concentration, but with over half the corpus held by companies outside the leading ten. This mix of large pharmaceutical companies and smaller specialist filers suggests the field is still open to new entrants with a focused filing programme.

Filing activity plateaued rather than grew or declined in the most recent complete years: 148 filings in 2021 against 149 in 2024, a flat +1% change. The peak year so far was 2022 at 166 filings. Years after 2024 in the trend chart appear lower, but that reflects the roughly 18-month lag between filing and publication rather than a genuine drop in activity, so those final years should not be read as a slowdown.

US20230279146A1, filed by Merck Patent GmbH and published in September 2023, claims liquid compositions and formulations comprising a protein with reduced viscosity and increased stability, along with methods for achieving that reduction or stability increase in a protein solution. Anyone developing a viscosity-reducing excipient approach for a high-concentration protein formulation should review its specific claim scope directly, since the abstract alone covers both composition and method claims broadly framed around viscosity reduction and stability. Design-around work typically needs to identify a mechanistically distinct route to the same viscosity or stability outcome rather than a minor formulation tweak.

The technology composition data shows heavy claim density in A61K medicinal preparations (74.6% of records) and C07K peptides and proteins (49.9%), meaning excipient and molecule-level chemistry claims are the most crowded. Comparatively thinner classes include A61M devices (5.3%), A61L sterilisation (4.9%) and C12P fermentation and enzymatic synthesis (4.8%), pointing to under-claimed branches such as device-integrated viscosity reduction, sterilisation-compatible high-concentration formats, and fermentation-derived stabilising excipients. A freedom-to-operate search in these thinner classes is a reasonable first step before committing R&D resources there.