United States Patent 4,830,010: Scope, Claims, Expiration, Litigation, and Urea Breath-Test Patent Landscape

U.S. Patent No. 4,830,010 protected a diagnostic method for detecting upper-gastrointestinal disorders associated with urease-producing bacteria, principally Campylobacter pyloridis, now known as Helicobacter pylori. The patent covered administration of isotope-labeled urea followed by breath analysis for labeled carbon dioxide or ammonia.

The patent issued on May 16, 1989, and, because it was filed before the 1995 patent-term transition, its ordinary term ran for 17 years from issuance. The patent therefore expired on May 16, 2006, absent an earlier terminal disclaimer or unusual term adjustment. It no longer creates an enforceable barrier to urea breath-test products or methods.

What does U.S. Patent 4,830,010 cover?

U.S. Patent 4,830,010, titled “Method for the Diagnosis of Gastrointestinal Disorders,” covers an in vivo diagnostic method based on bacterial urease activity. Public patent records identify David Y. Graham as the inventor and Baylor College of Medicine as the associated assignee.[1]

The claimed diagnostic sequence is:

Administer isotope-labeled urea to a human or lower animal.
Allow urease-producing bacteria in the upper gastrointestinal tract to hydrolyze the urea.
Detect labeled hydrolysis products in the subject’s breath.
Interpret labeled carbon dioxide, labeled ammonia, or both as a positive indication of disease.

The core chemical reaction is:

[ ^{13}CO(NH_2)_2 + H_2O \rightarrow ^{13}CO_2 + 2NH_3 ]

The same principle applies to carbon-14-labeled urea and nitrogen-15-labeled urea. Carbon-labeled urea produces labeled carbon dioxide that can be measured in exhaled breath. Nitrogen-15-labeled urea produces labeled ammonia or downstream nitrogen-containing metabolites that can be detected using an appropriate analytical method.

The patent does not claim urea as a composition of matter. It does not claim an instrument alone, a diagnostic kit alone, an antibiotic regimen, or a treatment method for H. pylori. Its claims are method claims directed to a diagnostic procedure.

How many independent claims does Patent 4,830,010 have?

The supplied claim set contains two independent claims, claims 1 and 2.

Claim	Principal subject matter	Scope
1	Diagnosis of upper-GI disease caused or mediated by Campylobacter pyloridis	Species-focused
2	Diagnosis of upper-GI disease caused or mediated by urease-producing bacteria	Functionally broader
3	Claim 2 limited to labeled carbon dioxide detection	Dependent
4	Claim 3 limited to carbon-14-labeled urea	Dependent
5	Claim 3 limited to carbon-13-labeled urea	Dependent
6	Claim 2 limited to labeled ammonia detection	Dependent
7	Claim 6 limited to nitrogen-15-labeled urea	Dependent

Claim 2 is the principal broad claim. It replaces the named organism in claim 1 with bacteria that cause gastric materials to contain “relatively large quantities of urease.” That language potentially reaches organisms other than H. pylori, provided the bacterial urease activity is present in the upper gastrointestinal tract and produces detectable labeled hydrolysis products.

What is the scope of claim 1?

Claim 1 requires all of the following limitations:

A human or lower-animal subject.
A gastrointestinal disorder of the upper gastrointestinal tract.
A causal or mediating relationship with Campylobacter pyloridis.
Administration of a safe and effective amount of isotope-labeled urea.
Breath analysis.
Detection of isotope-labeled carbon dioxide, isotope-labeled ammonia, or both.
A positive diagnostic interpretation based on detection of either hydrolysis product.

The historical reference to Campylobacter pyloridis is important. The organism was subsequently renamed Helicobacter pylori. Modern use of claim 1 would therefore depend on construing the historical species designation in light of the specification, prosecution history, and scientific nomenclature in existence at filing.

Claim 1 is narrower than claim 2 because it expressly identifies the bacterial species. A method detecting urease activity from a different organism might fall outside claim 1 but still implicate claim 2 if the other limitations were satisfied.

What is the scope of claim 2?

Claim 2 is broader in organismal scope. It covers a diagnostic method for upper-gastrointestinal disease caused or mediated by bacteria that result in gastric materials containing relatively large quantities of urease.

The claim does not require identification of the bacterium by culture, antigen testing, sequencing, or microscopy. Instead, the method relies on a functional characteristic: substantial urease activity in gastric material.

The claim has several potentially limiting features:

The disease must involve the upper gastrointestinal tract.
The condition must be caused or mediated by bacteria.
The bacteria must cause gastric material to contain relatively large quantities of urease.
The patient must receive isotope-labeled urea.
The labeled hydrolysis product must be detected in breath.
Detection must be used as a positive disease indication.

The phrase “relatively large quantities” is qualitative rather than numerically defined in the claim. Its meaning would likely be assessed against the specification, examples, ordinary technical meaning, and evidence concerning background urease activity. That limitation could have created claim-construction and infringement disputes while the patent was enforceable.

What do claims 3 through 7 add?

Claims 3 through 7 narrow claim 2 by specifying the detected product and isotope.

Claim 3: labeled carbon dioxide

Claim 3 requires analysis for isotope-labeled carbon dioxide, the carbon-containing hydrolysis product of labeled urea. This is the basis of most modern carbon-13 urea breath tests.

Claim 4: carbon-14-labeled urea

Claim 4 specifies carbon-14-labeled urea. Carbon-14 testing is highly sensitive but involves radioactive material and corresponding radiation-safety controls.

Claim 5: carbon-13-labeled urea

Claim 5 specifies carbon-13-labeled urea. Carbon-13 is stable and nonradioactive. Modern commercial breath tests commonly use carbon-13 urea with infrared spectroscopy, isotope-ratio mass spectrometry, or related analytical systems.

Claim 6: labeled ammonia

Claim 6 requires detecting isotope-labeled ammonia rather than labeled carbon dioxide. It depends from claim 2 and therefore retains claim 2’s bacterial and upper-gastrointestinal limitations.

Claim 7: nitrogen-15-labeled urea

Claim 7 limits claim 6 to nitrogen-15-labeled urea. It is the narrowest isotope-specific branch in the claim set.

What diagnostic products could have implicated Patent 4,830,010?

A product or laboratory procedure could have implicated the patent if it directed users to perform the claimed sequence. Relevant products included:

Carbon-13 urea breath-test kits.
Carbon-14 urea breath-test products.
Nitrogen-15 urea breath-test methods.
Breath collection systems used with labeled urea.
Instruments that measure labeled carbon dioxide or ammonia.
Clinical protocols that interpret the detected isotope as evidence of H. pylori infection or related upper-GI disease.

The patent’s method claims could potentially have reached coordinated product use even when the kit itself did not contain every claimed element. In particular, liability analysis would have depended on who administered the urea, who performed the breath analysis, who made the positive diagnostic interpretation, and whether a supplier induced or contributed to the claimed method.

The patent did not prevent all H. pylori diagnostics. A test based solely on stool antigen, serology, endoscopy, histology, culture, nucleic acid amplification, or an unconnected non-urease mechanism would not practice the claimed isotope-urea breath method.

When did U.S. Patent 4,830,010 lose exclusivity?

The patent expired on May 16, 2006, based on the 17-year term applicable to patents filed before June 8, 1995.[1,2]

Event	Date
U.S. patent filing	December 17, 1985
Patent issued	May 16, 1989
Standard term	17 years from issue
Expected expiration	May 16, 2006
Current enforceability	Expired

The expiration eliminated the patent’s ability to block commercial practice of the claimed diagnostic method in the United States. A later patent could still cover a specific kit, reagent formulation, sample-handling protocol, instrument, calibration method, or workflow. Such a later patent could not restore exclusivity over the expired foundational method itself.

What is the Orange Book status of Patent 4,830,010?

Patent 4,830,010 is not a current Orange Book exclusivity barrier.

The Orange Book primarily records patents and regulatory exclusivities associated with approved drug products. A diagnostic urea breath test may involve a drug component, a device, and a diagnostic use. A method patent may be listed only if the applicable product sponsor submits it and the FDA accepts the listing under the Orange Book rules.[3]

Even if the patent was historically submitted in connection with an approved product, its expiration in 2006 means it cannot support a current Paragraph IV-based market-exclusivity dispute. Current commercial barriers would instead arise from:

Later unexpired patents.
FDA approval requirements.
Device clearance or approval requirements.
Manufacturing controls.
Radioisotope handling for carbon-14 products.
Proprietary breath-analysis systems.
Trademarks and commercial distribution agreements.

What was the FDA regulatory status of urea breath tests?

The FDA has authorized urea breath-test products for detection of H. pylori. Commercial examples have included carbon-13 and carbon-14 systems, with some products combining labeled urea, a test substrate, breath collection, and an analytical instrument.

Otsuka America Pharmaceutical’s BreathTek UBT system is a prominent carbon-13 product authorized for detection of H. pylori infection. The product uses nonradioactive carbon-13 urea and measures labeled carbon dioxide in exhaled breath.[4]

Historically, carbon-14 products such as Pytest used radioactive urea and required a different regulatory and safety profile. The commercial status of particular legacy products has changed over time, but FDA authorization of a product does not depend on the continuing enforceability of Patent 4,830,010.

A modern product may therefore remain FDA-authorized while relying on technology that is no longer patent-blocked by the 1989 patent.

Were there Paragraph IV challenges to Patent 4,830,010?

Patent 4,830,010 has no current Paragraph IV significance because it expired in 2006.

Paragraph IV litigation generally arises when an ANDA applicant states that an Orange Book-listed patent is invalid, unenforceable, or not infringed. Urea breath tests do not fit neatly into the ordinary small-molecule generic-drug model because the commercial product can combine:

A diagnostic drug component.
A breath-collection device.
A dedicated analyzer.
A clinical interpretation protocol.

Publicly available patent records do not identify a current Paragraph IV challenge that could delay entry based on Patent 4,830,010. Any historical challenge would now have no forward-looking exclusionary effect from this patent.

What patent litigation affects the urea breath-test market?

Patent 4,830,010 is not an active litigation asset. Its expiration removes the principal legal issue that would have concerned direct practice of the claimed isotope-urea breath-test method.

Litigation risk in the current market would be more likely to involve later rights covering:

Specific carbon-13 urea formulations.
Citric-acid or other gastric-retention formulations.
Breath-sampling timing.
Isotope-ratio measurement.
Infrared spectroscopy.
Analyzer calibration.
Automated result thresholds.
Integrated collection tubes and sample logistics.
Labeling and software-controlled interpretation.

No current infringement exposure can arise solely from practicing the expired claims of Patent 4,830,010.

What formulations are protected by the patent?

Patent 4,830,010 does not contain a conventional formulation claim. It does not claim:

A tablet or capsule composition.
A liquid urea formulation.
A citric-acid excipient system.
A preservative system.
A specific dose.
A breath-collection container.
A carbon dioxide analyzer.

The patent requires administration of a “safe and effective amount” of isotope-labeled urea, but that phrase functions as a method limitation. It does not independently reserve a particular dosage form or formulation.

Later patents could protect formulation characteristics that improve gastric contact, accelerate urease access, stabilize labeled urea, or standardize the breath signal. Those rights would need separate claim-by-claim analysis.

How does Patent 4,830,010 compare with later urea breath-test patents?

Issue	Patent 4,830,010	Later urea breath-test patents
Core concept	Labeled urea hydrolysis in the stomach	Often optimization of the same concept
Disease target	Upper-GI bacterial disorder, principally H. pylori	Usually H. pylori detection
Isotopes	Carbon-14, carbon-13, nitrogen-15	Often carbon-13
Detection	Labeled carbon dioxide or ammonia	Frequently instrument-specific carbon dioxide analysis
Formulation claims	No clear composition claim in supplied claims	May claim tablets, solutions, acids, buffers, or excipients
Device claims	None in supplied claims	May cover analyzers or collection systems
Legal status	Expired May 16, 2006	Depends on filing date and prosecution history
Current market impact	Foundational technology only	Potentially relevant to product-specific freedom to operate

The commercial market therefore shifted from a foundational biological concept to narrower product and workflow patents. A competitor can practice the expired core method but must still evaluate unexpired rights around the complete product architecture.

Is there biosimilar risk associated with Patent 4,830,010?

No. Biosimilar risk is not relevant to this patent.

The patent concerns a diagnostic method and labeled urea reagent, not a therapeutic biologic. Competitive entry would involve generic diagnostic products, competing laboratory-developed tests, device-based systems, or alternative H. pylori diagnostic technologies rather than biosimilars.

Which companies and technologies compete with urea breath tests?

The competitive field includes:

Branded carbon-13 breath-test systems.
Legacy carbon-14 breath-test products.
Stool antigen assays.
Serology.
Endoscopic biopsy-based urease tests.
Histology and culture.
Molecular tests.
Laboratory-developed breath assays.

Breath tests compete on sensitivity, specificity, patient convenience, reimbursement, instrument availability, isotope cost, and test-of-cure utility. Carbon-13 systems have a commercial advantage where nonradioactive testing simplifies logistics and patient acceptance.

The most important competitive distinction is between the reagent and the analyzer. A supplier may control the full workflow through proprietary instrumentation even when the underlying isotope-urea diagnostic concept is in the public domain.

What generic launch risks exist after patent expiration?

The legal risk from Patent 4,830,010 is zero as an expired patent. Commercial launch risks remain.

Risk category	Current relevance
Patent infringement under 4,830,010	None after expiration
Later formulation patents	Product-specific risk
Analyzer patents	Product-specific risk
FDA authorization	Material
Radioactive-material controls	Material for carbon-14 products
Manufacturing quality	Material
Reimbursement and coding	Material
Brand and distribution	Material
Clinical validation	Material
Trade secrets	Potentially material

A generic or competing product would not need to invent around the broad biological method. It would need to establish regulatory compliance, analytical performance, manufacturing reliability, and freedom to operate against later patent families.

What geographic coverage did Patent 4,830,010 provide?

The patent provided rights only in the United States. Any corresponding foreign applications or granted patents would have required separate analysis by country.

U.S. expiration did not automatically determine the status of foreign counterparts. European, Australian, Canadian, Japanese, or other national rights could have different filing dates, examination outcomes, patent terms, and expiration dates. Because the supplied information identifies only the U.S. patent and claims, the enforceability conclusion applies to the United States.

How strong was the patent estate?

The patent was strategically strong as an early foundational method patent because it claimed the biological relationship between bacterial urease, isotope-labeled urea, and exhaled labeled products. Its broadest practical value came from claim 2, which extended beyond the named organism to urease-producing bacteria.

Its weaknesses included:

Functional and qualitative language such as “relatively large quantities.”
Dependence on proof that the detected signal indicated an upper-GI bacterial disorder.
Potential claim-construction issues concerning the historical name Campylobacter pyloridis.
Method-claim enforcement challenges involving physicians, laboratories, kit suppliers, and analyzers.
Limited protection for formulation, device, software, and manufacturing assets.
Eventual statutory expiration.

The patent’s present strength is historical and technical rather than legal. It remains relevant for prior-art analysis, patentability, and freedom-to-operate mapping, but it cannot support an injunction or damages claim for current U.S. practice.

Key Takeaways

U.S. Patent 4,830,010 claimed isotope-labeled urea breath testing for urease-producing upper-GI bacteria.
Claim 1 focused on Campylobacter pyloridis, the historical name for H. pylori.
Claim 2 was broader and covered bacteria that generate substantial gastric urease activity.
Claims 3 through 7 narrowed the method to labeled carbon dioxide, carbon-14, carbon-13, labeled ammonia, and nitrogen-15.
The patent was issued May 16, 1989, and expired May 16, 2006.
It is not a current Orange Book or Paragraph IV barrier.
It did not claim a formulation, analyzer, kit, treatment, or composition of matter.
Biosimilar analysis is inapplicable.
Current freedom-to-operate risk would arise from later patents covering formulations, analyzers, breath collection, software, manufacturing, or regulatory-linked product configurations.
The foundational isotope-urea breath-test method is now in the public domain in the United States.

FAQs About U.S. Patent 4,830,010

Can a company sell a carbon-13 urea breath test in the United States without licensing Patent 4,830,010?

Yes. Patent 4,830,010 expired on May 16, 2006. A company does not need a license under that patent to practice its expired claims, although later patents may require separate review.

Does Patent 4,830,010 cover BreathTek UBT?

The patent covers the general diagnostic method reflected in the supplied claims. BreathTek UBT may practice that public-domain method, but its commercial product can also involve later patents, regulatory rights, trademarks, proprietary instrumentation, and manufacturing know-how.

Does the patent cover stool antigen testing for H. pylori?

No. The supplied claims require administering isotope-labeled urea and analyzing breath for labeled carbon dioxide, labeled ammonia, or both.

Could Patent 4,830,010 block a laboratory-developed test?

No, because the patent has expired. A laboratory-developed test remains subject to applicable FDA, CLIA, state, quality, and reimbursement requirements, as well as any later patent rights.

Does the patent cover treatment of H. pylori infection?

No. The claims are directed to diagnosis. They do not claim antibiotic treatment, acid suppression, eradication therapy, or a treatment regimen.

References

U.S. Patent No. 4,830,010. (1989). Method for the diagnosis of gastrointestinal disorders. U.S. Patent and Trademark Office.
U.S. Patent and Trademark Office. (n.d.). Patent term adjustment and patent term provisions. https://www.uspto.gov
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book
U.S. Food and Drug Administration. (2003). BreathTek UBT for Helicobacter pylori detection: Prescribing information. Otsuka America Pharmaceutical, Inc.

Details for Patent: 4,830,010

Summary for Patent: 4,830,010