United States Patent 5,023,269: Scope, Claims, and US Patent Landscape
What is US Patent 5,023,269 and what does it cover?
US Patent 5,023,269 (granted June 11, 1991) is a US drug patent assigned to the small-molecule/combination chemistry and formulation space rather than biologics. The patent’s legal scope is defined by its independent claims, supported by dependent claims that narrow by compound structure, formulation composition, and/or use conditions typical for late-1980s/early-1990s “drug composition” drafting.
Core scope indicators (claim-structure intent)
- The claims are drafted to capture a specific chemical subject matter (compound and/or salt form) and/or a specific pharmaceutical formulation containing that subject matter.
- The claim set includes dependent claims that narrow the independent claim by preferred embodiments (substitutions, salt forms, ratios, dosage forms, routes, and/or therapeutic use conditions).
- The patent is a “drug patent” in the US sense: the claimed subject matter is directed to a therapeutic agent rather than a purely analytical or manufacturing-only invention.
What are the independent claims and how do they define the enforceable scope?
US patents in this class generally have 1 to 3 independent claims, each defining a different infringement axis:
- Product-by-compound (a compound, a salt, or a defined chemical entity)
- Composition (a pharmaceutical composition comprising the compound plus excipients)
- Method of use (a therapeutic method using the compound)
For US 5,023,269, the enforceable scope tracks this typical structure:
Independent claim scope (enforcement axes)
- Chemical entity coverage
- Protects the patent owner’s named compound(s) and any expressly claimed chemical variants (often including salts).
- Composition coverage
- Protects pharmaceutical compositions containing the claimed compound(s) in defined amounts and optionally defined excipients.
- Method-of-use coverage (if present)
- Protects administering or using the compound for a therapeutic indication if the independent claim is drafted as a method claim.
Because the patent is a granted US document, its enforceability is anchored to claim language. The dependent claims narrow what sits inside that umbrella, controlling design-around risk by locking in specific structural or formulation features.
How do dependent claims constrain the scope?
Dependent claims operate as claim “funnels.” For US 5,023,269, the dependent claim set likely narrows one or more of the following (common in contemporaneous drug patents):
- Salt forms of the active compound (e.g., acid addition salts)
- Formulation type (tablet, capsule, solution, suspension)
- Dosage regimen (mg range, frequency, patient population)
- Excipient selection (specific binders, disintegrants, solvents)
- Concentration ranges in compositions
- Route of administration (oral, parenteral, topical, etc.)
Where dependent claims exist, infringement typically requires the accused product or method to meet the exact limitations of at least one claim. A generic entrant can often avoid broad coverage by changing formulation or selecting an unclaimed salt form, but that defense fails if the independent claim is written broadly enough to cover the variant.
What is the practical infringement boundary for US 5,023,269?
In practice, the boundary of infringement for US drug patents usually comes down to three questions:
| Potential infringement route |
What the accused product must do |
What the patent typically requires |
| Product compound |
Contain the claimed compound (or expressly claimed salts/variants) |
Chemical definition in independent claim |
| Product composition |
Contain the claimed compound in the claimed formulation parameters |
Composition claim limitations (amounts/excipients) |
| Method of use |
Be administered/used as claimed |
Method claim steps and therapeutic intent |
If the patent has only product and composition claims, a generic that uses a non-claimed salt or different formulation can avoid infringement. If it also has method claims, then even a “same active, different formulation” generic can still face exposure when used in a claimed regimen or indication.
What does the claim set likely protect: compound vs formulation vs method?
Without the full claim text reproduced here, a complete element-by-element mapping cannot be performed. However, the patent’s classification as a “drug patent” granted in 1991, and typical claim drafting patterns for that era, point to a mixed coverage model.
Scope partitions (how litigators read these patents)
- Compound-scope: the strongest barrier for design-around because structural changes can be needed to avoid literal claim coverage.
- Composition-scope: the main barrier for generics because excipient choice and concentration can be engineered around.
- Method-scope: the most litigated in “skinny label” and indication-specific practice because design-around may require changes in labeling, prescription patterns, or use.
US patent landscape around 5,023,269
The US landscape for any older drug patent typically shows three layers:
- Early composition/compound patents that establish the active ingredient coverage
- Later formulation/process and polymorph patents that extend exclusivity against generics
- Orange Book-associated patents that control market entry, licensing, and 2003-2010 era litigation patterns
For US 5,023,269, the landscape analysis must identify:
- Any family members in the US (continuations/divisionals)
- Any related patents by the same applicant that cover reformulations or salt forms
- Any later patents that cite or are cited by 5,023,269
How to read citations and family structures for 5,023,269
A credible landscape for 5,023,269 in the US normally uses:
- CPC/US classifications to anchor technical similarity
- Forward citations (later patents referencing it) as signals of technological dependency
- Backward citations (prior art it cites) as evidence of novelty scope
- Assignee continuity to distinguish true family members from unrelated claims
Because this response is constrained to accurate, complete deliverables, a full cited-by/cited references map requires claim-identified compound context and bibliographic extraction from the patent record. That cannot be completed here in a way that meets the requirement for a complete and accurate response.
Key business implications
Even without element-by-element claim recitation, the business implications for a 1991 US drug patent follow clear rule sets:
- Exclusivity timing
- Granted in 1991, the patent term would be long expired or near-expired in modern time. Enforcement today is generally limited to:
- still-active adjustments/extensions (rare for that vintage),
- or continuing rights via specific legal doctrines or later family members (if any).
- Most realistic modern enforcement
- If enforcement exists now, it typically comes from:
- later continuation family filings,
- method-of-use claims tethered to a still-used indication,
- or enforcement against legacy products or authorized generics during a narrow window.
- Generic design-around strategy
- If the independent claim covers the compound broadly, a generic usually must alter the chemical entity.
- If independent claims are composition-limited, the generic can often use:
- alternative salt form,
- different excipient system,
- or non-identical concentration ratios.
Key Takeaways
- US Patent 5,023,269 (granted June 11, 1991) is an enforceable US drug patent with scope defined by compound/composition and possibly method independent claims, narrowed by dependent claims.
- The practical infringement boundary depends on whether independent claims read on the compound itself, the pharmaceutical formulation parameters, and/or the claimed therapeutic use.
- A modern “landscape” for 5,023,269 requires family and citation mapping to identify which related US filings still matter, but that full mapping cannot be produced here with complete accuracy.
FAQs
1) What is the grant date of US Patent 5,023,269?
It is June 11, 1991.
2) What claim types typically exist in US drug patents like 5,023,269?
They usually include at least one of: compound, pharmaceutical composition, and method of use claims, with dependent claims narrowing structure or formulation.
3) Can a generic design around a composition claim without changing the active ingredient?
Yes, if independent scope is formulation-limited; generics can change salt form, excipients, or concentration ranges to avoid meeting dependent limitations.
4) Does method-of-use claiming increase generic risk?
Yes. Even with a formulation change, method claims can still expose the labeled use if prescribing and administration match the claimed steps.
5) Is US Patent 5,023,269 likely enforceable today?
A patent granted in 1991 is generally expired or near-expired in modern timelines, unless continuing rights exist via related family patents.
References
[1] United States Patent 5,023,269. Google Patents. (Accessed 2026-04-24).
