US Patent 8,491,932: Budesonide Sustained-Release Composition, Claim Scope and Patent Landscape
US Patent 8,491,932 protects a multipart oral budesonide delivery system with two release barriers: an internal sustained-release structure built around an acid-containing layer and alkali-containing ethylcellulose, plus an external delayed-release barrier that postpones exposure until the dosage form reaches the intestine. The patent is strongest against products that reproduce this layered architecture, particularly ammonia-containing ethylcellulose systems. It is materially narrower than a patent covering budesonide, enteric release, or sustained intestinal delivery in general.
The supplied claims do not cover every budesonide extended-release product. Infringement generally requires the accused product to contain each limitation of at least one asserted claim, either literally or under the doctrine of equivalents.
What does US Patent 8,491,932 protect?
The independent claims divide into two categories:
| Claim group |
Claims |
Protected subject matter |
| Composition |
1-8, 14 |
Oral budesonide dosage forms with a defined sustained-release and delayed-release architecture |
| Treatment method |
9-13, 15 |
Administration of the claimed composition for gastrointestinal inflammation, Crohn's disease, ulcerative colitis, glomerulonephritis, or corticosteroid delivery |
Claim 1 is the controlling composition claim. It requires:
- A sustained-release component.
- A core containing budesonide.
- A coating layer containing an acid.
- A further coating layer containing alkali-containing ethylcellulose.
- A delayed-release component that substantially prevents release until the composition reaches the intestine.
The claim is cumulative. A product with budesonide, an enteric coating, and a sustained-release polymer can avoid literal infringement if it does not include the claimed acid layer beneath an alkali-containing ethylcellulose layer.
What is the core technical architecture?
The claimed dosage form has at least two functional release stages:
- The delayed-release component prevents meaningful release in the stomach or earlier gastrointestinal tract.
- After intestinal entry, the sustained-release component releases budesonide over time.
- The acid layer and alkali-containing ethylcellulose layer form the internal controlled-release structure.
The acid-containing layer is not merely an optional excipient. It is a required element of claim 1. The alkali-containing ethylcellulose layer is also mandatory.
The specification is likely to be important in interpreting terms such as "substantially prevents release," "alkali-containing ethylcellulose," and "sustained release." A court would ordinarily assess the intrinsic record, including the claims, specification, and prosecution history, before considering extrinsic technical evidence.[1]
How do the dependent claims narrow the patent?
The dependent claims add formulation, dosage-form, and therapeutic restrictions.
| Claim |
Limitation |
Commercial significance |
| 2 |
Ammonia-containing ethylcellulose |
Targets a specific alkaline modification of ethylcellulose |
| 3 |
Water-soluble additive in the ethylcellulose layer |
Covers selected plasticizers, binders, sugars, and polyols |
| 4 |
Organic acid |
Narrows the acid layer from any acid to an organic acid |
| 5 |
Particles, pellets, granules, or tablets |
Extends coverage across common multiparticulate formats |
| 6 |
Sustained-release component in a capsule |
Covers encapsulated multiparticulate products |
| 7 |
Starch capsule |
Narrows the capsule material |
| 8 |
Capsule coated with delayed-release component |
Covers an enteric-coated capsule implementation |
| 14 |
1% to 10% alkali-containing ethylcellulose by weight |
Adds a quantitative polymer limitation |
| 15 |
Glomerulonephritis treatment with 2-6 hours of release |
Adds a disease and release-duration limitation |
Claims 2, 3, 4, 7, 8, 14, and 15 are narrower than claim 1 and may be easier to avoid through formulation changes. They may also provide stronger positions if laboratory testing confirms that a competing product falls within the added limitations.
Which products are most exposed to infringement risk?
The highest-risk product is an oral budesonide multiparticulate product with:
- Budesonide-containing cores or pellets;
- An acid subcoat;
- An ammonia-containing or otherwise alkaline ethylcellulose release layer;
- An external enteric or delayed-release coating; and
- Intestinal sustained release.
A product using only a conventional enteric coating, such as a pH-dependent methacrylate polymer, does not necessarily meet claim 1. Likewise, a matrix tablet that controls release through a hydrophilic polymer may fall outside the literal scope if it lacks the claimed layered core structure.
What formulation changes could design around claim 1?
Potential design-around paths include:
| Design-around approach |
Claim limitation potentially avoided |
| Use a hydrophilic matrix tablet |
Coated core and ethylcellulose-layer limitations |
| Use an enteric polymer without an internal acid layer |
Acid-containing layer |
| Use neutral ethylcellulose without an alkali-containing component |
Alkali-containing ethylcellulose |
| Use a pH-dependent methacrylate polymer as the sustained-release membrane |
Ethylcellulose limitation |
| Place the acid in the core rather than in a separate coating layer |
Required acid-containing layer |
| Use an osmotic delivery system |
Claimed coating architecture |
| Release budesonide in the colon through a site-specific system |
Claimed delayed and sustained-release configuration |
These approaches require product-specific testing. The location of excipients, polymer chemistry, coating sequence, and release profile would be critical.
What do the method-of-use claims cover?
Claims 9 through 13 are method claims dependent on administering the composition of claim 1.
Claim 9 covers treatment of inflammatory disease in the gastrointestinal tract. Claims 10 and 11 identify Crohn's disease and ulcerative colitis. Claim 12 addresses glomerulonephritis, while claim 13 covers sustained release of a corticosteroid drug.
Because these claims incorporate "the composition of claim 1," a method defendant would generally face the same formulation limitations as a composition defendant. A company that sells a product outside claim 1 may avoid claims 9-13 even if physicians use that product for the same diseases.
Claim 15 adds a 2-to-6-hour release duration to the glomerulonephritis method. The claim therefore requires proof of both the claimed composition and the specified release duration. In vitro dissolution data, gastrointestinal transit assumptions, and the meaning of "duration of drug release" could become important in litigation.
When does US Patent 8,491,932 lose exclusivity?
US Patent 8,491,932 is a granted utility patent issued in 2013. Its nominal patent term is generally measured from the applicable nonprovisional or international filing date, not from the issue date, under the Uruguay Round Agreements Act and 35 U.S.C. §154.[2]
The patent's practical exclusivity period therefore depends on:
- The earliest effective nonprovisional or PCT filing date;
- Any continuation or divisional relationship;
- Patent term adjustment;
- Terminal disclaimers;
- Patent term extension, if applicable; and
- Whether individual claims survived post-grant proceedings.
The supplied claim text alone does not establish the exact expiration date or the existence of a terminal disclaimer. A definitive expiration analysis must use the USPTO patent record and the patent's continuity data.[3]
The patent cannot receive Hatch-Waxman patent term extension merely because it covers a formulation used with an FDA-approved drug unless the statutory requirements for the approved product and regulatory review period are met.[4]
What is the FDA and Orange Book status?
FDA approval and patent enforceability are separate questions. A patent may protect a formulation without being listed in the Orange Book, and Orange Book listing does not determine whether every claim is valid or infringed.
For budesonide, the relevant FDA product categories include:
| Product |
Dosage form |
Principal release concept |
| Entocort EC |
Delayed-release capsules |
Ileum and ascending-colon delivery |
| Uceris/Cortiment |
Extended-release tablets |
Colonic delivery using a multimatrix approach |
| Generic budesonide products |
Capsules or tablets, depending on product |
Product-specific delayed or extended release |
The Orange Book identifies patents submitted by NDA holders for approved drug products. A patent number should not be treated as an Orange Book barrier unless it appears in the relevant FDA listing for the specific reference product and dosage form.[5]
US 8,491,932 should therefore be evaluated in three separate ways:
- Whether it is listed against an approved budesonide product;
- Whether the accused generic product is required to address it in an ANDA Paragraph IV certification; and
- Whether the patent claims cover the generic's actual formulation.
A patent that is not Orange Book-listed can still support a conventional patent infringement action, but it may not create the same automatic 30-month stay associated with an ANDA Paragraph IV notice for a listed patent.
Are there Paragraph IV challenges involving this patent?
A Paragraph IV certification applies to a patent listed in the Orange Book for the relevant reference-listed drug. The certification asserts that the patent is invalid, unenforceable, or will not be infringed by the ANDA product.[6]
The supplied materials do not identify an ANDA notice letter, district-court complaint, or Paragraph IV litigation directed specifically to US 8,491,932. The patent number should not be described as a known Paragraph IV barrier without matching it to:
- The reference-listed drug;
- The ANDA product;
- The Orange Book patent listing;
- The notice-letter date; and
- Any resulting complaint under 21 U.S.C. §355(j).
For commercial diligence, a Paragraph IV risk assessment should distinguish the patent from the better-known budesonide formulation patents associated with Entocort EC and Uceris/Cortiment.
How does this patent compare with other budesonide patent estates?
The principal competing budesonide patent estates have different technical centers.
| Patent estate or product |
Primary protection |
Relationship to US 8,491,932 |
| Entocort EC-related patents |
Delayed release to the ileum and colon; budesonide capsule technology |
May overlap in intestinal targeting but does not necessarily require the claimed acid/alkali ethylcellulose sequence |
| Uceris/Cortiment-related patents |
Multimatrix extended-release tablets and colonic delivery |
Technically distinct from a coated multiparticulate acid/ethylcellulose structure |
| Generic budesonide capsule patents |
Product-specific release profiles and formulation features |
Risk depends on the generic's exact coating and excipient arrangement |
| US 8,491,932 |
Acid layer plus alkali-containing ethylcellulose sustained-release component inside an intestinal delayed-release system |
Narrow architecture with potentially strong product-testing relevance |
The patent is therefore best viewed as a formulation-layer patent rather than a broad budesonide patent. Its value is highest where a competitor has copied the coating sequence or used a closely related aqueous ethylcellulose process.
How strong is the patent estate?
Claim breadth
Claim 1 is moderately narrow. It covers multiple dosage forms but requires a specific internal structure. Claims 5 and 6 broaden physical presentation by covering coated particles, pellets, granules, tablets, and capsules. The polymer and acid requirements remain limiting.
The method claims are narrower in enforcement terms because they depend on the composition claim. They may be useful against a manufacturer promoting a product for the specified diseases, but they are less likely to expand protection beyond the formulation architecture.
Validity exposure
The principal validity risks are:
- Anticipation by earlier budesonide multiparticulate formulations;
- Obviousness based on combining enteric coating technology with ethylcellulose sustained-release membranes;
- Lack of written description for broad interpretations of "alkali-containing ethylcellulose";
- Indefiniteness disputes over "substantially prevents release"; and
- Enablement challenges if the claim is applied across polymers, acids, dosage forms, and release profiles not adequately supported by the specification.
The strongest validity defense would usually depend on evidence that the acid layer and alkaline ethylcellulose layer produce an unexpected release profile or solve a formulation problem not addressed by the prior art.
Infringement proof
The likely evidence set includes:
- ANDA or product-development records;
- Coating-process documents;
- Excipient specifications;
- Microscopy and cross-sectional analysis;
- FTIR, elemental, or chemical testing;
- Polymer composition records;
- Dissolution testing across staged pH conditions; and
- Samples of commercial capsules, pellets, or tablets.
An accused manufacturer may argue that ammonia is a process residual rather than a claimed component, that the ethylcellulose is not alkaline, or that the acid is not present as a discrete coating layer.
What manufacturing and geographic barriers exist?
The patent is territorial. A US claim reaches manufacture, use, sale, offer for sale, or importation into the United States under 35 U.S.C. §271.[7] It does not independently prevent manufacture and sale outside the United States.
International exposure requires corresponding patents in the relevant jurisdictions. The key diligence points are:
- PCT publication and national-phase filings;
- European, Canadian, Japanese, and Australian counterparts;
- Grant and lapse status in each country;
- Claim amendments during prosecution;
- Supplementary protection certificates in Europe;
- Local patent-term calculations; and
- Importation of finished dosage forms into the United States.
Manufacturing can create infringement risk even when the finished product is supplied by a third party. A contract manufacturer using the claimed coating sequence may be exposed under direct or contributory infringement theories, depending on its activities and knowledge.
What generic launch scenarios are possible?
Scenario 1: Same formulation architecture
A generic using an acid-coated budesonide core, ammonia-containing ethylcellulose, and an intestinal delayed-release coating faces the highest risk. A Paragraph IV challenge, if the patent is listed, would likely focus on validity and claim construction.
Scenario 2: Same therapeutic profile, different technology
A generic may reproduce intestinal sustained release with a hydrophilic matrix, methacrylate polymer, osmotic system, or alternative coating sequence. This scenario reduces literal infringement risk but may create separate patent issues under other budesonide estates.
Scenario 3: Different release site
A product releasing in the ileum, colon, or throughout the gastrointestinal tract through a different mechanism may avoid the patent's structural limitations. FDA bioequivalence requirements would still apply to the relevant reference product.
Scenario 4: Post-expiration launch
After expiration, the patent no longer blocks commercial entry, although unexpired continuation patents, separate formulation patents, regulatory exclusivity, trade secrets, and manufacturing rights may remain relevant.
What licensing or settlement issues matter?
No licensing agreement or settlement involving US 8,491,932 is established by the supplied claim text. A commercial review should distinguish:
- Patent licenses;
- Technology-transfer agreements;
- Co-development arrangements;
- Authorized generic agreements;
- ANDA litigation settlements;
- Covenants not to sue; and
- Royalty-bearing supply agreements.
A settlement concerning a related budesonide patent does not necessarily grant freedom to operate under US 8,491,932. The covered patent numbers, licensed fields, dosage forms, territories, and launch dates control.
Key Takeaways
- US 8,491,932 is directed to a specific budesonide intestinal sustained-release architecture.
- Claim 1 requires an acid-containing layer beneath an alkali-containing ethylcellulose layer, plus a delayed-release component.
- Ammonia-containing ethylcellulose is expressly covered by claim 2.
- The patent does not broadly cover every budesonide delayed-release or extended-release product.
- Claims 9-15 are dependent treatment claims and inherit the composition limitations of claim 1.
- The principal design-around routes involve changing the release polymer, removing the separate acid layer, or using a matrix, osmotic, or alternative multiparticulate system.
- Orange Book relevance depends on listing against a specific approved budesonide product, not on the patent number alone.
- A definitive expiration date requires the patent's continuity, filing-date, PTA, and terminal-disclaimer records.
- The main validity questions concern prior art, obviousness, claim construction, and the technical significance of the acid/alkali ethylcellulose sequence.
- Generic exposure is highest when the competitor's coating process reproduces the claimed layer order and polymer chemistry.
FAQs
Does US 8,491,932 cover all budesonide capsules?
No. It covers capsules only when the capsule contains the claimed sustained-release component and delayed-release structure. Claim 6 adds the capsule format, while claim 7 narrows the coverage to starch capsules.
Can a product infringe if it uses an alkaline polymer other than ethylcellulose?
Literal infringement of claim 1 is less likely because the claim requires alkali-containing ethylcellulose. A doctrine-of-equivalents analysis could remain relevant, depending on the substituted polymer and the prosecution history.
Does an enteric-coated budesonide tablet necessarily infringe?
No. An enteric coating alone does not satisfy the full claim. The product also requires the budesonide core, acid-containing layer, alkali-containing ethylcellulose layer, and delayed-release function specified in claim 1.
Is claim 15 commercially important for Crohn's disease products?
Usually not. Claim 15 is limited to glomerulonephritis and a 2-to-6-hour release duration. Crohn's disease products would be analyzed primarily under claims 1, 9, and 10, subject to the product's actual formulation.
Can a patent outside the Orange Book still block a generic launch?
Yes. An unlisted patent may support a patent infringement action, although it may not trigger the same ANDA certification and automatic stay mechanisms that apply to a properly listed Orange Book patent.
References
- U.S. Patent No. 8,491,932, claims 1-15 (2013). https://patents.google.com/patent/US8491932B2/en
- 35 U.S.C. §154. Patent term. https://www.law.cornell.edu/uscode/text/35/154
- United States Patent and Trademark Office. (n.d.). Patent Center. https://patentcenter.uspto.gov/
- 35 U.S.C. §156. Extension of patent term. https://www.law.cornell.edu/uscode/text/35/156
- U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
- 21 U.S.C. §355(j). Abbreviated applications and patent certifications. https://www.law.cornell.edu/uscode/text/21/355
- 35 U.S.C. §271. Infringement of patent. https://www.law.cornell.edu/uscode/text/35/271
