Gastroretentive & Colon Targeted Delivery Patents: Leaders 2026
- 41.5% concentration. The top five assignees hold 41.5% of the 720 records in scope, with a single leader at 93 records.
- Filings down 83% since 2021. Annual filings fell from 40 in 2021 to 7 in 2024, the last year the count can be treated as complete.
- 94.7% sits in one IPC class. A61K medicinal preparations covers 94.7% of records, leaving food, veterinary and carbohydrate-carrier branches thin and comparatively open.
Filing growth compares 2021 (40 records) with 2024 (7) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 720 records in scope (CR5), not by the ranked leaders only.
A formulation-mechanism field built on two foundational patents
Gastroretentive and colon-targeted delivery covers dosage forms engineered to control where and when a drug releases in the gastrointestinal tract — held in the stomach by floating or swelling mechanisms, or carried intact to the colon by pH- or time-responsive coatings. The 720 records in this dataset span 2015 through the July 2026 cut-off, and the field’s two oldest citation leaders, US6039975A and US6685962B2, still define the baseline mechanisms that later filings reference or narrow around.
Filing activity peaked in 2018 and has since pulled back sharply through 2024, the last year in this window that can be treated as complete, while ownership has concentrated among a small group of leading assignees. The technology composition is heavily weighted toward core pharmaceutical formulation classes, leaving food-matrix, veterinary and carbohydrate-carrier branches comparatively thin.
Filing concentration, technology mix and where records are filed
720 records dated 2015 to the July 2026 cut-off sit behind this landscape. The filing trend, technology composition and receiving-office spread below are drawn directly from that set.
Filing trend: a sharp pull-back after 2021
Annual filings ran at 81 in 2017 and peaked at 83 in 2018. From 2021 (40) to 2024 (7) — the most recent year that can be treated as complete — filings fell 83%. Publication lags filing by roughly 18 months, so 2025 and 2026 figures are still filling in and should not be read as a continuing decline.
Technology composition: medicinal preparations dominate
A61K (medicinal preparations) appears in 94.7% of the 720 records and A61P (therapeutic activity) in 36.7%, confirming this is overwhelmingly a formulation-chemistry field. Food-related classes (A23L, A23P), veterinary applications (A61D) and carbohydrate carrier chemistry (C07H) each register in the low single digits, marking the field's thinner adjacent branches.
Shares are the percentage of the 720 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Gastroretentive and Colon Targeted Delivery with Eureka
This page is one run against one query. Ask Eureka your own question about gastroretentive and colon targeted delivery and every answer comes back with the patent numbers behind it.
Try EurekaThe prior art everyone in this field designs around
WO2009084040A1 — Once a day formulation of angiotensin receptor blockers
The present invention provides a once a day formulation of angiotensin receptor blockers (ARBs). The present invention further relates to controlled release formulation of ARBs prepared by incorporating pharmaceutically effective amounts of solubilized ARB into a gastroretentive dosage form for once a day administration.Filed by Rubicon Research Private Limited; illustrates how a specific drug class and a specific retention mechanism are claimed together rather than either alone.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US6039975A | Colon targeted delivery system | 1,038 |
| 2 | US6685962B2 | Gastroretentive controlled release pharmaceutical dosage forms | 183 |
| 3 | WO2019032027A1 | Cholestyramine pellets, oral cholestyramine formulations and use thereof | 119 |
| 4 | US20160213702A1 | Glycan therapeutics and related methods thereof | 112 |
| 5 | WO2019032026A1 | Cholestyramine granules, oral cholestyramine formulations and use thereof | 94 |
| 6 | US20120141531A1 | Composition comprising oil drops | 79 |
| 7 | US20050249716A1 | Galenic formulation for colon targeted delivery of active principles | 78 |
| 8 | WO2016172658A2 | Microbiome regulators and related uses thereof | 73 |
| 9 | WO2016172657A2 | Glycan therapeutics and methods of treatment | 73 |
| 10 | US20180296582A1 | Microbiome regulators and related uses thereof | 70 |
Ranked by citation count within the 720-record corpus; older filings accumulate more citations simply by having been available longer.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three signals matter more than the headline record count: how tightly ownership is concentrated, how the historical citation leaders shaped the field, and where the technology composition thins out.
Ownership sits with a small leading group
The leader alone holds 93 records and the top five together hold 41.5% of the 720 records in scope; the top ten extend that to 62.2%. Below that group the ranking runs to 100 companies with a long tail of smaller filers, so the field is concentrated at the top without being a closed market.
Filing pace has pulled back sharply
From a 2018 peak of 83 annual filings, the pace fell to 40 by 2021 and to 7 by 2024, the last year in this window that can be read as complete. Several of the historically most active filers show zero filings in the most recent year, though publication lag means 2025-2026 data is still incomplete.
The field is formulation-chemistry heavy
A61K (medicinal preparations) appears in 94.7% of records and A61P (therapeutic activity) in 36.7%. Food, veterinary and carbohydrate-carrier classes each sit in the low single digits, marking clear but narrow adjacent branches rather than a broad, evenly-spread technology base.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to gastroretentive and colon targeted delivery, with the prior art for and against each one.
A concentrated leading group over a long tail
The assignee ranking covers 100 companies drawn from the 720 records in scope. Ownership is top-heavy but not closed: a handful of leaders hold the bulk of the claim space while dozens of smaller filers hold one or two records each.
One assignee well ahead of the field
The ranked leader holds 93 records, more than any other single assignee in the dataset, though it sits well below the fifth-place figure of 48 and tenth-place figure of 27 that define the rest of the leading group.
Ten assignees cover most of the concentrated share
The top ten assignees together account for 62.2% of the 720 records in scope, up from 41.5% for the top five, showing that concentration extends meaningfully beyond the single leader into a defined leading cohort.
Historical leaders have gone quiet recently
Several of the most historically active assignees show zero filings in the latest year captured, though the 18-month publication lag means recent-year counts across the board are still incomplete and should be read cautiously.
Collaboration is limited and clustered
Only 10 co-assignee pairs appear in the dataset, and the strongest pairing recurs across several filings with the same core assignee, suggesting most patenting here happens within a single owning entity rather than through joint filings.
| Assignee | Recent year | YoY |
|---|---|---|
| Kaleido Biosciences Inc. | 0 | — |
| Intec Pharma | 0 | — |
| OSMOTICA KERESKEDELMI ES SZOLGALTATO KFT | 0 | — |
| Thiogenesis Therapeutics Inc. | 0 | — |
| Amneal Complex Products Research LLC | 0 | — |
| Rubicon Research Private Limited | 0 | — |
| Sigmoid Pharma Limited | 0 | — |
| Albireo | 0 | — |
Turning this landscape into a filing decision
The figures above show where claim space is dense and where it is not. Translating that into a specific filing or licensing decision means checking your own formulation against the leading portfolios and the thinner branches directly.
Check a specific formulation against the leaders
Run your retention mechanism and drug class combination against the top assignees' portfolios to see how closely it maps to existing claims before drafting.
Search assignee portfolios in EurekaExplore the under-claimed branches
Food-matrix, veterinary and carbohydrate-carrier sub-areas show low filing density in this dataset — worth a closer look before assuming a formulation route is blocked.
Explore white space in EurekaTrack filing momentum going forward
Because 2025-2026 records are still incomplete due to publication lag, set up ongoing monitoring rather than relying on a single snapshot.
Set up monitoring in EurekaFrequently asked questions
A gastroretentive dosage form is designed to stay in the stomach for an extended period, usually through a floating, swelling or high-density mechanism, so a drug releases over a longer window than a standard tablet allows. It matters for patents because the retention mechanism itself — not just the active ingredient — is what gets claimed, which is why floating-system and swelling-polymer patents dominate the citation leaders in this dataset. A new entrant typically has to either license or design around the specific retention mechanism, not just formulate a new drug.
Ownership is meaningfully concentrated: the top five assignees account for 41.5% of the 720 records in scope, and the top ten account for 62.2%. The single ranked leader holds 93 records, well ahead of the rest of the field. That said, the ranking runs to 100 companies total, so beyond the leading group there is a long tail of smaller and single-filing entrants, meaning the field is not a two-player market even if it looks top-heavy.
Recent-year filing counts show a decline through the most recent complete year, with annual filings dropping from 40 in 2021 to 7 in 2024, an 83% fall over that span. However, publication typically lags actual filing by around 18 months, so 2025 and 2026 figures in any dataset are structurally incomplete and should not be read as proof the field has stopped moving — they simply have not caught up yet. The 2017-2018 period, by contrast, was the historical peak with filings in the low 80s per year.
US6039975A, titled "Colon targeted delivery system," is cited 1,038 times in this dataset and is by far the most influential reference, followed by US6685962B2 on gastroretentive controlled-release dosage forms at 183 citations. Two related cholestyramine-formulation applications, WO2019032027A1 and WO2019032026A1, and a glycan-therapeutics filing, US20160213702A1, round out the most-cited group. Citation counts favour older filings simply because they have had more time to accumulate references, so treat these as foundational rather than as the current state of the art.
The IPC composition points to several thinner branches sitting alongside the dominant A61K/A61P core: food-based delivery matrices (A23L, 6.0% of records), food-shaping or forming processes applied to a delivery matrix (A23P, 2.5%), veterinary-specific applications (A61D, 2.5%), and saccharide or nucleic-acid carrier chemistry (C07H, 1.3%). None of these approach the filing density of the core pharmaceutical classes, which suggests more room to establish a first claim without colliding with an entrenched blocking patent.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.