United States Patent 4,689,333 (Digestive Ulcers/Gastritis): Claim Scope, Coverage Boundaries, and US Patent Landscape for Formula-Based Drug Compositions
Executive summary: US Patent 4,689,333 claims a US-marketed-relevance chemical class defined by a specific substituted formula (with variable substituents R1-R4 and integer n ∈ {0,1}) for both (i) pharmaceutical compositions and (ii) method-of-treatment for digestive ulcers or gastritis. The claim set is narrow in two key ways: (1) the chemistry is constrained to the enumerated substituent pattern (including a fluorinated C2–C5 alkyl at R4), and (2) the clinical use is limited to “preventing or treating digestive ulcers or gastritis.” The estate’s practical value for clearance analysis is concentrated in whether a candidate competitor product or intermediate uses the same compound(s), the same substituent ranges, and the same n-state, and whether the competitor is trying to steer around by changing R1/R2/R3/R4 or using non-salt forms.
What does US Patent 4,689,333 claim for ulcers and gastritis?
Answer (scope in one line): It claims a pharmaceutical composition and a method of preventing or treating digestive ulcers or gastritis using a compound of a defined substituted formula (R1-R4 and n ∈ {0,1}), including pharmacologically acceptable salts, with standard carriers.
Claim 1: composition coverage
Claim 1 is a formula-dependent composition claim with the structure:
- A “pharmaceutical composition” for preventing or treating digestive ulcers or gastritis
- Contains an “effective amount” of a compound of the formula (as depicted in the patent)
- Constraints on substituents:
- R1 is hydrogen, methoxy, or trifluoromethyl
- R2 and R3 are independently hydrogen or methyl
- R4 is a C2–5 fluorinated alkyl
- n denotes 0 or 1
- Includes pharmacologically acceptable salts
- Includes “pharmacologically acceptable carriers”
Practical meaning: If a product contains one of the formula compounds as an active pharmaceutical ingredient, the presence of standard carriers does not create a meaningful carve-out. The main design-around levers are the substituent set at R1, R2, R3, R4 and the n value.
Claims 2–5: narrowing-dependent composition fallbacks
These claims narrow Claim 1’s generic substituent range into specific subgroups:
- Claim 2 narrows R1 to hydrogen or trifluoromethyl
- Claim 3 narrows R3 to hydrogen
- Claim 4 narrows n to 1
- Claim 5 sets a specific embodiment:
- R1 and R3 are hydrogen
- R2 is methyl
- R4 is 2,2,2-trifluoroethyl
- n is 1
Practical meaning: The patent includes both broad formula coverage (Claim 1) and at least one highly specific “anchor” species (Claim 5). If a competitor picks a compound outside Claim 1’s full range, Claim 5 can still catch that species if it matches the exact parameter combination.
Claim 6: method-of-treatment coverage
Claim 6 is the functional-use mirror of Claim 1:
- A method for preventing or treating digestive ulcers or gastritis
- Administering a compound of the same formula
- Same R1-R4 and n constraints
- Includes pharmacologically acceptable salts and pharmacologically acceptable carriers
Practical meaning: If composition claims are avoided by formulation choices alone (for example, different carrier or dosage form), Claim 6 can still be asserted if the accused method administers the infringing compound for the claimed disease purpose.
Claims 7–10: dependent method-of-treatment fallbacks
- Claim 7: R1 hydrogen or trifluoromethyl
- Claim 8: R3 hydrogen
- Claim 9: n is 1
- Claim 10 sets the same specific embodiment as Claim 5:
- R1 and R3 hydrogen
- R2 methyl
- R4 2,2,2-trifluoroethyl
- n is 1
Practical meaning: These dependent claims strengthen enforcement by giving multiple claim paths depending on which substituent parameters match the competitor’s API.
How broad are the substituent ranges in US 4,689,333?
Answer: Broad on the “R1/R2/R3/R4/n” axis, but still limited to a single formula family and a single therapeutic indication.
R1 breadth
- R1 allowed: hydrogen, methoxy, trifluoromethyl
This is a small set, not a general “alkoxy or halo” definition. Trifluoromethyl is the key electron-withdrawing option.
R2 and R3 breadth
- Each of R2 and R3 allowed: hydrogen or methyl
This yields up to four combinations for R2/R3 pairing in the generic claim, but dependent claims further restrict to R3 hydrogen or R2 methyl.
R4 breadth
- R4: C2–C5 fluorinated alkyl
This is the broadest variable in the claim set and creates real coverage risk for design-arounds. However, it still requires both:
- an alkyl length of 2 to 5 carbons, and
- a fluorinated alkyl identity.
Claim 5/10 show one example: 2,2,2-trifluoroethyl. If an accused compound uses an R4 that is not a fluorinated C2–C5 alkyl, it likely falls outside the formula claim.
n breadth
- n denotes 0 or 1
This means the patent covers two discrete structural “state” possibilities (as defined by the formula). Switching n values can be a meaningful design-around, assuming the competitor uses the alternate state.
Which specific compound embodiments are explicitly called out (and why it matters for infringement)?
Answer: The patent explicitly drills down to a single “2,2,2-trifluoroethyl + R1/R2/R3 pattern + n=1” species, and it uses dependent claims to preserve that coverage even if the broader embodiments are contested.
Explicit embodiment (Claim 5 / Claim 10)
- R1 = hydrogen
- R2 = methyl
- R3 = hydrogen
- R4 = 2,2,2-trifluoroethyl
- n = 1
Enforcement implication: If the accused API is that exact compound, the case does not depend on demonstrating the full “range” of Claim 1. Independent and dependent pathways align around the same species for both composition and method claims.
What does “pharmacologically acceptable salt” add to infringement risk?
Answer: It expands coverage to salt forms of the same defined API, meaning salt switching is not a strong design-around strategy.
How salt coverage typically plays out
- If the competitor sells a salt form of the same compound (same cation/anion around the same core), Claim 1 and Claim 6 can be asserted as long as the active compound falls within the formula constraints.
- Salt choice affects formulation and stability, but not the “compound of the formula” requirement.
What barriers exist to generic or “follow-on” entry under this claim scope?
Answer: For a generic to avoid infringement, it must avoid both: (i) using a compound that falls within the claimed formula limits and (ii) the method-of-use administering that compound for ulcers/gastritis.
Design-around pathways
- Change R1/R2/R3 to land outside the allowed set
Example: substituting R1 with a group other than hydrogen, methoxy, or trifluoromethyl can be a route out of Claim 1/2/7.
- Change R4 so it is not a fluorinated C2–C5 alkyl
Example: moving to a non-fluorinated alkyl, changing carbon count outside C2–C5, or using a fluorinated group that does not meet “alkyl” characterization.
- Change n to the other state
If the competitor uses n = 0 when the accused compound matches n = 1 (or vice versa), it can exit the literal scope.
- Use a non-salt isomer or derivative that is not captured by the formula definition
This depends on whether the competitor’s structure matches the formula depiction in the patent drawings.
Limits of formulation-only workarounds
- Because Claims 1 and 6 are not limited by dosage form, delivery system, or excipient composition beyond “pharmacologically acceptable carriers,” formulation changes alone will not avoid the “compound of formula” requirement.
How does method-of-use scope (Claim 6) change litigation leverage vs. composition-only challenges?
Answer: It creates an additional infringement theory independent of product composition.
Scenario structure
- Even if a party tries to litigate only about composition infringement (Claim 1), the patent also claims an administration method for the same compound formula and same ulcer/gastritis purpose.
- For generics, “carve-out labels” or restricted indications may reduce exposure if a method claim is asserted based on label instructions and actual use evidence.
What is likely the strongest claim target for an accused product?
Answer: The strongest claim target is the specific embodiment matching Claim 5/10, because it aligns independent constraints (formula inclusion) with the narrow dependent fallback.
Litigation posture
- If the accused API matches the Claim 5 compound parameters, the defense has fewer escape routes because Claim 1 and Claim 6 already cover the broader class and the dependent claims already map directly.
- If the accused API differs, the case turns on the exact R1/R2/R3/R4/n mapping to the formula.
What does a US “patent landscape” look like for US 4,689,333 (how to map risk)?
Answer: The landscape for this type of patent typically clusters around: (i) the original chemistry family, (ii) salt/formulation follow-ons, (iii) process patents for manufacturing the same scaffold, and (iv) later indication or combination patents. For US 4,689,333, the claim text you provided indicates the core asset is the formula-based compound class with both composition and method-of-treatment hooks.
Landscape buckets to search (US)
- Family members: continuations, divisionals, and related filings with the same scaffold
- Salt patents: compositions claiming specific salt forms of the same API
- Formulation patents: dosage forms using that API (if any)
- Process patents: manufacturing methods for producing the scaffold
- Indication or treatment refinements: other ulcer/gastritis-related endpoints that might be tied to the same scaffold
How you would use the claim scope in a landscape map
- Start with the exact “R1/R2/R3/R4/n” constrained scaffold.
- Identify any other US patents naming the same scaffold or overlapping variable sets.
- Prioritize those that also include either:
- pharmaceutical compositions for ulcers/gastritis, or
- method-of-use administration claims.
(No further patent numbers or prosecution data are included here because your prompt provides only the claim set text, not the bibliographic record needed to anchor a complete US landscape.)
Key Takeaways
- US 4,689,333 claims a defined substituted formula chemical class for both pharmaceutical compositions and methods of preventing or treating digestive ulcers or gastritis.
- Coverage is driven by the enumerated substituent set: R1 ∈ {H, methoxy, CF3}, R2/R3 ∈ {H, methyl}, R4 = fluorinated C2–C5 alkyl, n ∈ {0,1}, plus pharmacologically acceptable salts.
- Dependent claims (2–5 and 7–10) provide multiple infringement paths, including a specific embodiment: R1 H, R2 methyl, R3 H, R4 2,2,2-trifluoroethyl, n=1.
- Formulation changes and carrier substitutions do not materially mitigate risk because the independent claims are not limited by dosage form or excipient composition.
- The method-of-use claim adds leverage beyond composition infringement, creating exposure even where product-formulation arguments arise.
FAQs
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Does US 4,689,333 cover both composition and treatment methods?
Yes. Claims 1 and 6 cover pharmaceutical compositions and methods of preventing or treating digestive ulcers or gastritis, respectively, using the same formula-constrained compound set.
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Can a competitor avoid infringement by switching from a free base to a salt?
No. The claims include pharmacologically acceptable salts, so salt switching alone does not remove coverage if the underlying compound matches the formula parameters.
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Which substituent is the most design-around sensitive: R1, R2/R3, R4, or n?
The most leverage usually sits with R4 (fluorinated C2–C5 alkyl requirement) and n (discrete 0 or 1), while R1 is limited to only three options and R2/R3 each have only two options.
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Is the patent limited to a specific dosage form or formulation technology?
No. The claims require only “pharmacologically acceptable carriers,” leaving dosage form and excipient technology largely unconstrained.
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If a product targets gastritis but uses a compound outside the R4 fluorinated C2–C5 alkyl range, is it still at risk?
Risk depends on whether the API still fits the exact formula constraints. If R4 does not meet the fluorinated C2–C5 alkyl requirement, the formula-based claim element is not satisfied.
References
- US Patent 4,689,333. Claims provided in the prompt text.
