US Patent 5,093,342: Scope, Claims, Expiration, and Omeprazole Patent Landscape

US Patent 5,093,342 covers a narrow method of treating Campylobacter infections with omeprazole or a pharmaceutically acceptable salt. The patent does not claim omeprazole itself, pharmaceutical compositions generally, proton-pump inhibition, or treatment of gastrointestinal disease broadly. Its legal significance was a disease-specific method-of-use right. The patent has expired, so the claim no longer creates an enforceable U.S. exclusivity barrier.

What does US Patent 5,093,342 cover?

US 5,093,342 covers the administration of omeprazole to a patient suffering from a Campylobacter infection.

The asserted active ingredient is:

Chemical name: 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole
Common name: omeprazole
Drug class: proton-pump inhibitor
Covered forms: omeprazole and pharmaceutically acceptable salts

The sole claim is:

“A method for the treatment of Campylobacter infections comprising administering to a patient suffering therefrom an amount of [omeprazole] or a pharmaceutically acceptable salt thereof sufficient for the treatment of said infection.”

The claim is a method-of-treatment claim rather than a product claim. It requires the combination of:

A patient suffering from a Campylobacter infection.
Administration of omeprazole or a pharmaceutically acceptable salt.
An amount sufficient to treat the infection.

The patent does not require a particular dosage form, route of administration, dosing schedule, treatment duration, or Campylobacter species.

What is the legal scope of the sole claim?

The claim is chemically narrow but operationally broad.

Chemical limitation

The administered substance must be omeprazole or a pharmaceutically acceptable salt of omeprazole. A different proton-pump inhibitor, such as lansoprazole, pantoprazole, rabeprazole, or esomeprazole, would not literally satisfy the active-ingredient limitation.

The claim also does not expressly cover:

Omeprazole metabolites
Omeprazole analogues
Other benzimidazole proton-pump inhibitors
Fixed-dose combinations unless they contain omeprazole
Non-pharmaceutically acceptable salts
A compound that merely produces a similar pharmacological effect

Disease limitation

The treatment must target a Campylobacter infection. Campylobacter jejuni and Campylobacter coli would be the most commercially relevant species, although the claim does not expressly limit the infection to a particular species.

The claim is not limited to:

Enteric or gastrointestinal infection
A particular disease severity
A particular anatomical site
Confirmed laboratory diagnosis
A specified bacterial load
A defined eradication endpoint

The wording “Campylobacter infections” creates the principal disease-scope boundary. Treatment of dyspepsia, peptic ulcer disease, gastroesophageal reflux disease, or Helicobacter pylori infection would not fall within the claim solely because omeprazole is administered.

Administration limitation

“Administering” requires conduct directed to giving the drug to the patient. The claim does not specify whether administration is oral, intravenous, or by another medically suitable route.

A product manufacturer would not ordinarily infringe merely by manufacturing or selling omeprazole without further facts showing that the product is intended for the claimed use. Potential exposure would depend on the product labeling, promotional conduct, instructions, and the applicable inducement standard.

Sufficiency limitation

The amount must be “sufficient for the treatment” of the infection. This language links the claim to therapeutic administration rather than incidental exposure. It does not specify a numerical dose.

The limitation creates two competing effects:

It avoids coverage of trivial or nontherapeutic exposure.
It leaves the claim without a fixed dose threshold, allowing the patent owner to argue that clinically effective dosing falls within the claim.

The phrase would likely be interpreted in light of the specification and ordinary medical understanding. It would not automatically cover every administration of omeprazole to a person who happens to have Campylobacter.

How many claims does US 5,093,342 contain?

The patent contains one independent claim and no apparent dependent claims. The single claim carries the entire substantive scope.

Claim element	Scope
Treatment method	Required
Target patient	Patient suffering from a Campylobacter infection
Active ingredient	Omeprazole
Salt coverage	Pharmaceutically acceptable salts
Dose	Any amount sufficient for treatment
Route	Not expressly limited
Dosage form	Not expressly limited
Duration	Not expressly limited
Campylobacter species	Not expressly limited
Combination therapy	Not excluded by “comprising”

The use of “comprising” is open-ended. Administration of omeprazole with antibiotics, antidiarrheals, fluids, or other medicines could still fall within the claim if the other limitations are met.

When did US Patent 5,093,342 expire?

US 5,093,342 issued on March 3, 1992. Public patent records identify the application as filed in 1989 and the patent as assigned to Aktiebolaget Hässle, an Astra group company.[1]

For a U.S. utility patent filed before June 8, 1995, the term generally runs for 17 years from issuance, subject to applicable patent-term adjustments, disclaimers, and other statutory rules. On that basis, the patent term reached its end in 2009. Patent records commonly identify March 3, 2009 as the expiration date.[1]

The patent is therefore expired and cannot presently support an enforceable U.S. infringement action.

Event	Date
U.S. application filing	1989
Patent issuance	March 3, 1992
Expected 17-year term from issuance	March 3, 2009
Current status	Expired
Current enforceable exclusivity	None

Patent expiration does not erase the historical scope of the claim. It removes the right to exclude others during the remaining term.

What patents protect omeprazole and its formulations?

US 5,093,342 is one part of the broader omeprazole estate. The main patent categories are composition-of-matter, formulation, manufacturing, and method-of-use rights.

Omeprazole composition-of-matter patent

US Patent 4,255,431 covered omeprazole and related substituted benzimidazole compounds. It was an earlier Astra/Hässle patent and expired well before US 5,093,342.[2]

That patent was materially broader from a product perspective because it addressed the compound class and pharmaceutical use of the compounds. US 5,093,342 did not extend the basic chemical monopoly. It added a disease-specific use involving Campylobacter.

Formulation patents

Omeprazole is acid-labile. Commercial oral products therefore use enteric protection or other delivery measures designed to prevent degradation in the stomach and permit release in the intestine.

Relevant formulation protection historically included patents directed to:

Enteric-coated omeprazole dosage forms
Alkaline stabilizing agents
Tablet and capsule structures
Layered pharmaceutical compositions
Delayed-release delivery
Manufacturing processes for stable omeprazole products

A well-known Astra formulation patent is US 5,045,321, which concerned pharmaceutical preparations containing omeprazole and protective formulation technology.[3] Formulation claims could create a separate infringement risk even after the compound patent expired, depending on claim scope and the specific product architecture. Those formulation rights also expired or became commercially irrelevant over time as generic delayed-release omeprazole products entered the market.

Method-of-use patents

US 5,093,342 is a method-of-use patent focused on Campylobacter infection. Other omeprazole uses included acid-related disorders and Helicobacter pylori eradication regimens.

The Campylobacter claim should not be conflated with:

Treatment of gastric acid disorders
Treatment of H. pylori
Prevention of NSAID-associated ulcers
Maintenance therapy for reflux disease
General antibacterial use

A patent claim must be analyzed according to its express limitations. Pharmacological activity against one organism does not automatically expand the claim to other infections.

What was the FDA status of omeprazole and the Orange Book position?

FDA approval of omeprazole was directed to acid-related indications, not to the Campylobacter method claimed in US 5,093,342.

The FDA approved Prilosec, Astra’s omeprazole product, for indications including duodenal ulcer, gastric ulcer, gastroesophageal reflux disease, erosive esophagitis, and pathological hypersecretory conditions. Later products and labels included combination regimens for H. pylori eradication.[4]

The FDA Orange Book identifies patents submitted by sponsors for approved drug products. Orange Book listing is tied to an approved product and its labeled uses, formulation, or other listed characteristics. A method patent directed to Campylobacter treatment would not automatically be listed merely because the active ingredient is omeprazole.

US 5,093,342 should therefore be distinguished from Orange Book-listed Prilosec patents. Its claim concerns a use that was not the principal FDA-approved omeprazole labeling basis. The patent’s historical relevance was primarily patent-law and licensing-related, not an enduring regulatory exclusivity right.

Issue	US 5,093,342
FDA approval of omeprazole	Yes
FDA approval specifically for Campylobacter treatment	Not established by the patent
Orange Book product patent status today	No current enforceable protection
Patent type	Method of treatment
Approved indication required for patent validity	No
FDA approval required to enforce a patent during its term	No, although regulatory and labeling facts affect infringement analysis

A patent does not itself establish FDA approval. Conversely, absence of a Campylobacter indication from the FDA label does not by itself invalidate a patent claim.

Were Paragraph IV challenges or ANDA disputes relevant?

A Paragraph IV certification is an ANDA applicant’s assertion that a listed patent is invalid, unenforceable, or not infringed. It is relevant only when the patent is listed for the reference product in the Orange Book and remains within the relevant regulatory framework.

US 5,093,342 is expired. It therefore does not create a current Paragraph IV barrier to generic omeprazole approval.

Historical generic disputes involving omeprazole focused more directly on:

The original compound patent
Delayed-release formulation patents
The composition and structure of generic omeprazole capsules and tablets
FDA patent listings for Prilosec and successor products

The commercial generic launch risk associated with US 5,093,342 was limited by its narrow indication. A generic omeprazole applicant could generally seek approval for non-Campylobacter indications without adopting the patented use. Under the Hatch-Waxman framework, a generic applicant may also use labeling strategies that omit patented indications where legally permissible, subject to the scope of the proposed label and the induced-infringement analysis.[5]

Because the patent expired in 2009, there is no present Paragraph IV challenge required to remove it as a blocking patent.

Did US 5,093,342 affect generic launch scenarios?

During its term, the patent could have affected a product marketed or labeled for Campylobacter treatment. It would have posed less risk to a generic omeprazole product labeled solely for approved acid-related indications.

Scenario analysis

Generic conduct	Historical risk during patent term	Current risk
Sell omeprazole for reflux disease	Low from this patent	None
Sell omeprazole for ulcer treatment	Low from this patent	None
Sell omeprazole for H. pylori therapy	Low from this patent unless Campylobacter use was promoted	None
Label omeprazole for Campylobacter infection	Potentially high	None because patent expired
Promote omeprazole specifically to treat Campylobacter	Potential inducement theory during term	None from this patent
Use omeprazole in a combination regimen including antibiotics for Campylobacter	Potentially within “comprising”	None because patent expired
Manufacture bulk omeprazole without disease-specific promotion	Generally outside the method claim	None

The claim’s commercial value was constrained by the rarity of omeprazole’s use as a recognized Campylobacter therapy and by the absence of a corresponding mainstream FDA-approved indication.

How strong was the patent estate for Campylobacter treatment?

The Campylobacter estate represented by US 5,093,342 was narrow and commercially specialized.

Strengths

It identified a specific pharmaceutical compound.
It covered omeprazole salts.
It did not limit the claim to one Campylobacter species.
It did not impose a fixed dose, route, or formulation.
The open “comprising” language permitted combination treatment.

Limitations

The patent had only one claim.
It did not cover omeprazole as a product.
It did not cover all anti-Campylobacter agents.
It did not expressly cover prevention of infection.
It required treatment of a patient already suffering from a Campylobacter infection.
It lacked a defined dose and regimen.
Its commercial value depended on recognition and adoption of an unconventional antibacterial use.
It expired in 2009.

From a litigation perspective, the claim would have turned on proof of the infection, the purpose of administration, the identity of the administered compound, and the therapeutic sufficiency of the amount. From a market perspective, the patent could not prevent competitors from selling omeprazole for its established acid-suppression indications.

What companies held or commercialized the relevant rights?

The patent records identify Aktiebolaget Hässle as the original assignee.[1] Hässle was part of the Astra organization and was associated with the development and commercialization of omeprazole under the Prilosec brand.

The relevant commercial participants included:

Aktiebolaget Hässle, original patent assignee
Astra and later AstraZeneca, originator and commercial sponsor
Generic manufacturers of omeprazole delayed-release capsules and tablets
Contract manufacturers supplying omeprazole active pharmaceutical ingredient and finished dosage forms

No current licensing or settlement arrangement is necessary to commercialize generic omeprazole based on this expired patent. Historical assignments, licenses, or Astra-related corporate transactions may affect chain-of-title analysis, but they do not restore exclusivity after expiration.

What manufacturing and intellectual-property barriers remain?

US 5,093,342 imposes no current manufacturing barrier. It never claimed a manufacturing process.

Historical manufacturing barriers for omeprazole included:

Protecting omeprazole from acidic degradation
Producing stable enteric-coated dosage forms
Controlling polymorphic or crystalline characteristics
Achieving consistent dissolution and bioavailability
Formulating omeprazole with alkaline excipients
Demonstrating pharmaceutical equivalence to the reference product

Modern manufacturers can address these issues through established delayed-release capsule, tablet, pellet, granule, or layered dosage-form technologies. Any surviving patent risk would have to come from a separate, unexpired patent covering the specific process, formulation, crystalline form, or delivery system.

How does US 5,093,342 compare with competing drug patents?

Patent category	Example subject matter	Commercial effect
Composition patent	Omeprazole molecule and related compounds	Broadest historical product exclusion
Formulation patent	Enteric protection and stabilization	Product-specific launch barrier
Method-of-use patent	Omeprazole for Campylobacter infection	Indication-specific exclusion
Manufacturing patent	Processes for making or formulating omeprazole	Process and supply-chain risk
Regulatory exclusivity	FDA approval-based exclusivity	Separate from patent rights

US 5,093,342 was weaker than a composition patent because it could not block all omeprazole sales. It was potentially stronger than a narrow formulation patent for the specific Campylobacter treatment conduct because it did not depend on a particular dosage form.

Compared with antibiotic patents, the claim was also unusual. Conventional Campylobacter treatment has generally relied on antibacterial agents such as azithromycin, with treatment decisions affected by resistance patterns and clinical severity.[6] The patent claimed an acid-suppression drug for an anti-infective purpose, creating a specialized use right rather than a conventional antibiotic product monopoly.

What is the current patent and litigation status?

US 5,093,342 is expired. No current U.S. patent litigation can be based on an expired claim for prospective infringement. Any historical dispute would require analysis of the conduct during the patent term, applicable damages limitations, standing, assignment history, and the relevant litigation record.

The patent does not create:

Current U.S. exclusivity for omeprazole
Current biosimilar risk
Current generic entry restrictions
A current Orange Book block
A current manufacturing injunction risk
A present Paragraph IV filing requirement

Biosimilar analysis is not applicable because omeprazole is a chemically synthesized small molecule, not a biological product. Generic-drug analysis under ANDA rules is the relevant regulatory framework.

Key Takeaways

US 5,093,342 claims one method: treating a Campylobacter infection with omeprazole or a pharmaceutically acceptable salt.
The claim does not cover omeprazole itself, general proton-pump inhibition, or all gastrointestinal infections.
“Comprising” permits combination therapy, while “sufficient for the treatment” requires a therapeutic amount.
The patent does not specify dose, route, dosage form, treatment duration, or Campylobacter species.
The patent issued March 3, 1992 and expired in 2009.
It has no current enforceable U.S. exclusivity or generic-entry blocking effect.
Historical omeprazole risk was concentrated in composition and formulation patents, not this Campylobacter method claim.
FDA approval of omeprazole did not establish FDA approval for the patented Campylobacter indication.
Paragraph IV and Orange Book issues were more relevant to Prilosec product and formulation patents.
Biosimilar risk is not applicable; omeprazole is a small-molecule drug subject to generic competition.
The patent’s current business value is historical and freedom-to-operate related, not exclusionary.

FAQs

Does US 5,093,342 cover treatment of Helicobacter pylori?

No. The claim expressly targets Campylobacter infections. H. pylori treatment would not fall within the claim solely because omeprazole is used.

Does the patent cover omeprazole magnesium?

Only if omeprazole magnesium qualifies as a pharmaceutically acceptable salt of omeprazole under the claim and the remaining treatment limitations are met. The patent is expired in any event.

Could the patent cover a combination of omeprazole and azithromycin?

Historically, potentially yes. The open “comprising” language does not exclude additional drugs, provided omeprazole is administered to a patient suffering from Campylobacter infection in a therapeutically sufficient amount.

Was Campylobacter treatment an FDA-approved omeprazole indication?

The patent itself does not establish FDA approval. FDA-approved omeprazole labeling centered on acid-related disorders and, in later products, H. pylori eradication regimens, rather than a Campylobacter treatment indication.

Can a company now sue a generic manufacturer under US 5,093,342?

No. The patent expired in 2009, eliminating current enforceable patent rights under the claim.

References

U.S. Patent No. 5,093,342. (1992). Treatment of Campylobacter infections with omeprazole. U.S. Patent and Trademark Office.
U.S. Patent No. 4,255,431. (1981). Substituted benzimidazoles. U.S. Patent and Trademark Office.
U.S. Patent No. 5,045,321. (1991). Pharmaceutical preparation containing omeprazole. U.S. Patent and Trademark Office.
U.S. Food and Drug Administration. (2023). Drugs@FDA: Prilosec and omeprazole product information.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations.
Shane, A. L., Mody, R. K., Crump, J. A., Tarr, P. I., Steiner, T. S., Kotloff, K., Langley, J. M., Wanke, C., Warren, C. A., Cheng, A. C., Cantey, J., Pickering, L. K., & others. (2017). 2017 infectious diseases society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clinical Infectious Diseases, 65(12), e45-e80.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Japan	1-30311	Feb 09, 1989

PCT Information
PCT Filed	February 02, 1990	PCT Application Number:	PCT/SE90/00070
PCT Publication Date:	August 23, 1990	PCT Publication Number:	WO90/09175

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	94063	⤷ Start Trial
Australia	5038190	⤷ Start Trial
Australia	626641	⤷ Start Trial
Canada	2025668	⤷ Start Trial
Cyprus	1909	⤷ Start Trial
Germany	69003207	⤷ Start Trial
Denmark	0414847	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,093,342

Summary for Patent: 5,093,342