United States Patent 5,599,794 (Omeprazole + Clarithromycin): Claim Scope and US Patent Landscape
What does US Patent 5,599,794 claim?
US Patent 5,599,794 is directed to a fixed synergistic oral combination of:
- Omeprazole: about 1 to 200 mg (or a pharmaceutically acceptable salt)
- Clarithromycin: about 250 mg to 10 mg
- Intended for treatment of gastritis and peptic ulcer
The patent also includes a method claim tied to increasing bioavailability of an acid-degradable antibiotic via oral administration of the combination.
How broad is claim 1 (composition) in practice?
Claim 1 text (scope-defining elements)
“A synergistic combination comprising from about 1-200 mg omeprazole or a pharmaceutically acceptable salt thereof and from about 250 mg to 10 mg clarithromycin for the treatment of gastritis and peptic ulcer.”
This claim contains three main scope drivers:
1) Core actives and pairing requirement
The claim is limited to a pair:
- Omeprazole (including salts)
- Clarithromycin (dose-range specified)
A product must include both actives to land inside claim 1. Substitution of one active (for example, swapping another PPI for omeprazole or another macrolide for clarithromycin) falls outside claim 1.
2) Dose ranges (numeric claim boundaries)
The dose structure is asymmetric:
| Component |
Dose range in claim 1 |
Practical implication |
| Omeprazole |
about 1–200 mg |
Broad; covers typical oral PPI strengths |
| Clarithromycin |
about 250 mg to 10 mg |
Dose range is written inversely (upper bound “250 mg” down to “10 mg”); still implies acceptable embodiments between those endpoints |
From a freedom-to-operate perspective, most clinically used clarithromycin regimens (commonly 250 mg) sit near the high end of the stated clarithromycin range. If a competitor uses clarithromycin outside the 10–250 mg window per unit, it can attempt to position outside the numeric element.
3) Therapeutic use
The claim is tied to “for the treatment of gastritis and peptic ulcer.” Therapeutic indication language can limit infringement to use in those disease contexts, depending on claim construction and enforcement posture (especially for product claims).
Synergy as a structural requirement
Claim 1 uses the term “synergistic combination.” In claim interpretation, synergy often becomes a functional/entitlement requirement rather than a mere marketing label. In enforcement, the patentee typically does not need to prove “synergy” after-the-fact for every accused dose if the formulation falls within the defined numeric and composition requirements, but the patent record can influence what evidence is persuasive for validity and infringement.
How broad is claim 2 (method/bioavailability) relative to claim 1?
Claim 2 text
“A method of orally administering an acid degradable antibiotic so as to increase its bioavailability comprising an effective amount of the synergistic combination of claim 1 to a human.”
Claim 2 adds two constraints beyond claim 1:
1) Oral administration
2) Acid degradable antibiotic bioavailability increase
3) Uses “effective amount of the synergistic combination of claim 1” as the operative ingredient
Claim 2 depends on claim 1
Claim 2 incorporates claim 1 by reference (“effective amount of the synergistic combination of claim 1”). That means the method claim also requires the same omeprazole + clarithromycin combination within the defined boundaries of claim 1, plus the administration context.
Method claims catch dosing approaches that may not match a rigid label
Even if a competitor packages actives separately, a method claim can still cover conduct where:
- the clinician or pharmacy administers both actives orally as part of a regimen
- the regimen uses an effective amount that corresponds to claim 1’s combination
That said, for claim 2, the “acid degradable antibiotic” element matters for scope. Clarithromycin is commonly treated as acid-sensitive in formulation contexts, but the enforcement record and claim construction control how broadly that element is interpreted.
What exactly is the claim “shape” for competitive products?
Accused product likely falls inside if it meets all of these
- Contains omeprazole and clarithromycin as the antibiotics and acid suppressor
- Doses fall within claim 1 ranges
- Administration is oral
- Used for gastritis or peptic ulcer treatment
- Method claim also targets increased bioavailability of the antibiotic after oral administration
Accused product likely falls outside if it breaks any one element
- Omit omeprazole or omit clarithromycin
- Use a different PPI (instead of omeprazole)
- Use a different macrolide (instead of clarithromycin)
- Dose clarithromycin outside 10–250 mg range (as claimed)
- Administer in a way not covered by “orally administering” (for example, non-oral routes)
- Treat indications outside “gastritis and peptic ulcer,” depending on how the claim is construed and enforced
What does this imply for the US patent landscape (positioning vs. likely prior art and follow-on filings)?
Core landscape theme
The patent sits in a well-defined technology cluster:
- PPI + macrolide combinations
- acid suppression to improve oral antibiotic performance
- H. pylori and peptic disease therapeutic regimens (even when the claim text names “gastritis and peptic ulcer,” the competitive science cluster tends to include H. pylori treatment settings)
In the US, this theme typically produces:
- early foundational composition claims (like claim 1)
- method claims about administration and bioavailability (like claim 2)
- follow-on patenting around:
- fixed-dose ratios
- alternative dosing schedules
- additional components (for example, other antibiotics and bismuth)
- salt forms, formulations, and controlled-release approaches
Practical landscape inference
Given the specificity of claim 1 (named actives and numeric dose ranges) and claim 2 (bioavailability for an acid-degradable antibiotic via oral administration), the most relevant landscape questions for business decisions are usually not “is there any PPI+clarithromycin combination anywhere,” but:
- Is the competitor’s regimen a close numeric match to the stated ranges
- Is it omeprazole specifically, or a different PPI
- Is clarithromycin specifically, or a different macrolide
- Does the competitor’s product bundle and dosing schedule map to an “effective amount” under claim 2
Where freedom-to-operate typically tightens
- Fixed-dose combination products using omeprazole + clarithromycin in overlapping dose ranges tend to face the highest risk.
- Separate-ingredient regimens can still create method-infringement exposure if the accused conduct can be characterized as the claimed oral method using the claimed combination.
Where design-around typically loosens
- Switching omeprazole to another PPI reduces direct hit probability for claim 1 and claim 2.
- Switching clarithromycin to another macrolide reduces direct hit probability for claim 1 and claim 2.
- Moving outside the clarithromycin numeric range, if feasible, can reduce direct literal coverage.
Does the claim language suggest vulnerability to narrow construction or interpretive limits?
Numeric ranges invite precision disputes
Claim 1 uses “about” and spans wide intervals, but the endpoints still act as measurable anchors. Enforcement and invalidity arguments often turn on:
- whether an accused dose is “about” a boundary
- whether the claimed range supports the formulation actually practiced
“Synergistic” can become evidentiary friction
“Synergistic” can raise questions of:
- whether the claimed synergy is an inherent property of the actives at those doses
- whether it is a functional limitation that may limit claim scope or affect validity
In practice, this can matter most when a competitor uses the same ingredients but different dosing ratios, because the patentee may need to justify the synergy framework tied to the specific amounts.
Therapeutic indication language can help and can complicate
“for the treatment of gastritis and peptic ulcer” can narrow the relevant “use” category. But method claims about oral administration and bioavailability may still be argued in a way that overlaps common clinical uses.
Actionable claim-to-product mapping (risk checklist)
| Competitive approach |
Claim 1 risk |
Claim 2 risk |
Main reason |
| Fixed-dose omeprazole + clarithromycin |
High |
High |
Meets actives + composition + oral regimen pathways |
| Separate omeprazole and clarithromycin, co-prescribed |
Medium to High |
Medium to High |
Product-level may dodge literal composition, method exposure depends on “effective amount” and conduct framing |
| Omeprazole + another macrolide (e.g., azithromycin) |
Low |
Low to Medium |
Breaks clarithromycin element |
| Another PPI + clarithromycin |
Low |
Low to Medium |
Breaks omeprazole element |
| Omeprazole + clarithromycin with clarithromycin dose outside 10–250 mg |
Medium |
Medium |
Numeric element may be argued off-range depending on claim construction for “about” |
| Non-oral route administration |
Low for claim 2; composition claim may remain |
Low |
Claim 2 requires oral administration |
What parts of claim 2 should business teams focus on in diligence?
Claim 2 contains three elements teams can convert into contracting and product design requirements:
1) Oral administration constraint
- route of administration matters for method claims
2) “Acid degradable antibiotic” element
- clarithromycin form and physiology tie into argumentation about acid degradability and bioavailability
3) “Increase its bioavailability”
- efficacy and pharmacokinetics evidence can become central in both infringement and validity narratives
- dossier-level differences in formulation (for example, dissolution, enteric coating, excipients) can shift how “bioavailability increase” is characterized
Key Takeaways
- US Patent 5,599,794 claim 1 is a composition claim limited to a synergistic combination of omeprazole (about 1–200 mg) plus clarithromycin (about 10–250 mg) for gastritis and peptic ulcer treatment.
- Claim 2 is a method-of-use claim that covers oral administration of an acid-degradable antibiotic where the regimen uses an effective amount of the claim 1 combination to increase antibiotic bioavailability.
- Freedom-to-operate risk concentrates on products that are fixed-dose or co-administered regimens containing both omeprazole and clarithromycin within the claimed dose bands, and where clinical use aligns with the claimed indications.
- Design-around usually comes from breaking one of the protected variables: switch PPI, switch macrolide, move dose out of range, or change route away from oral.
FAQs
1. Does the patent cover omeprazole plus clarithromycin even if the combination is not fixed-dose?
Claim 2 can cover oral administration methods using an “effective amount” of the claim 1 combination, which can reach co-administration scenarios. Claim 1, as drafted, is still limited to the synergistic combination comprising the two actives within the specified dose ranges.
2. Can a competitor avoid infringement by using a different PPI than omeprazole?
Yes. Claim 1 requires omeprazole (or a salt) specifically, and claim 2 incorporates claim 1. Replacing omeprazole with another PPI breaks an essential element.
3. Can a competitor avoid infringement by using a different macrolide than clarithromycin?
Yes. Claim 1 requires clarithromycin within the specified dose range, and claim 2 incorporates that same combination. Swapping the macrolide breaks an essential element.
4. How important is the “about” qualifier in the dose ranges?
It preserves flexibility around boundary values but does not eliminate numeric anchors. Claim construction will govern how close an accused dose must be to land within the “about” band.
5. What is the main risk difference between composition and method exposure?
Composition exposure tracks product composition and labeled regimen, while method exposure tracks conduct: oral administration tied to acid-degradable antibiotic bioavailability increase using the claim 1 combination.
References
- US Patent 5,599,794.
