This dataset identifies 214 patent families published between 2015 and mid-2026 that address ophthalmic formulation, ocular drug delivery or intravitreal implants with claims or descriptions touching corneal permeation, preservative-free composition, sustained release, viscosity-and-comfort, or sterility. That count uses patent families rather than raw document counts, which avoids inflating the total through continuations or multiple jurisdictional filings of the same invention. The true global figure is somewhat higher once documents outside this specific IPC and keyword filter are included, but 214 is a reliable base for competitive analysis within this scope.

Filings in this dataset peaked at 35 in 2017 and fell to 9 by the 2022 midpoint, with only 1 recorded in the latest year. Part of that tail-end drop is a publication-lag artefact — filings typically take about 18 months to publish, so the most recent one to two years will revise upward. But the decline from 2017 through 2022 predates that lag window and reflects a genuine slowdown in new formulation filings, consistent with a field where core claim scope around preservative-free and sustained-release compositions was already well staked out by the mid-2010s.

The assignee ranking spans originator pharmaceutical companies, specialty ophthalmic firms and university-hospital collaborations, with 214 families spread across the field rather than concentrated in two or three dominant filers. Recent-year momentum data shows the leading named assignees — including major ophthalmic and pharma names — all recorded zero filings in the latest tracked year, which likely reflects both a genuine slowdown and publication lag rather than exit from the field. Co-filing is uncommon: only 10 co-assignee pairs were identified across the entire dataset.

US20180153885A1, filed by Ocugen, claims a preservative-free aqueous ophthalmic formulation built on a nanoemulsion of oil combined with an alpha-2 adrenergic agonist selected for higher alpha-2A than alpha-2B agonist activity, targeted at dry eye disease. Anyone formulating a preservative-free nanoemulsion-based dry-eye treatment using an alpha-2 agonist with that same selectivity profile needs to check this filing's granted claim scope directly. It does not block preservative-free formulations built on different carrier chemistries or different active-agent classes, which is where the practical design-around room sits.

Based on IPC composition, A61K formulation claims cover 211 of the 214 records in this dataset, meaning the core chemistry space is heavily occupied. The more open branches sit in the secondary subclasses: A61F implant mechanics (43 records), A61L sterilisation methods for implantable and multi-dose systems (18 records), and specific device mechanics like nebulized delivery or reversible in-situ gelling carriers, which appear far less often. These narrower branches are worth a dedicated claim search before assuming the field is fully closed.