United States Patent 4,406,906: Claim Scope, Interpretation, and US Landscape Impact for 1,4-Dihydro-2,6-dimethyl-4-(3'-nitrophenyl)-pyridino-3-(β-methoxyethyl ester)-5-isopropyl ester
What does US 4,406,906 claim cover in plain terms?
US 4,406,906 claims methods of treatment for warm-blooded animals using a specific named small molecule (a cerebral-acting esterified pyridino compound) for pathologically reduced cerebral functions and performance weaknesses, tied to cerebral insufficiency and disorders in cerebral circulation and metabolism. The patent is drafted as a single-ingredient method (the molecule as the active) with dosage and route dependent sub-claims.
Claim 1 (core scope)
Type: method of combating reduced cerebral function
Act: administering a “cerebral specific effective amount” of the molecule
Population: warm-blooded animals
Indications (functional disease language):
- pathologically reduced cerebral functions and performance weaknesses
- cerebral insufficiency
- disorders in cerebral circulation and metabolism
Form: “either alone or in admixture with a diluent” or “in the form of a medicament.”
Claims 2 and 3 (dose-range tightening by route)
Both claims depend from claim 1 and define dose windows in mg/kg/day.
Claim 2
- Intravenous: 0.0001 to 0.5 mg/kg/day
- Enteral: 0.001 to 1 mg/kg/day
Claim 3
- Intravenous: 0.001 to 0.1 mg/kg/day
- Enteral: 0.01 to 0.5 mg/kg/day
Practical implication: claim 3 is a narrower, centered subset of claim 2. A product falling within claim 3 also falls within claim 2 unless the claims are treated as alternative options (the dependent structure makes claim 3 narrower).
Claim 4 (route expansion)
- Oral administration is explicitly covered, depending on claim 1 or claim 2.
What claim 4 does not specify: It does not re-state an oral dose range.
How broad is the patent’s therapeutic scope?
The therapeutic scope is broader than a narrow disease-code claim because it uses functional and mechanistic condition language tied to brain function and cerebral circulation/metabolism.
Indication framing used
The patent describes indications in terms of:
- reduced cerebral functions and “performance weaknesses”
- “cerebral insufficiency”
- “disorders in cerebral circulation and metabolism”
This framing can read onto multiple clinical states, including:
- cognition/brain-performance deficits described as insufficiency
- vascular or metabolic cerebral disorders that map to “circulation and metabolism” language
Enforcement posture: the broadest lever is claim 1’s disease language, not the specific route or dose.
What keeps the claim from being overly broad
Despite functional indication language, the scope is constrained by:
- the specific chemical compound identity as the required active
- administration of a cerebral-specific effective amount (a functional limitation that still requires the drug’s intended cerebral efficacy)
- warm-blooded animals limitation (US enforcement typically targets human use; the claim does not explicitly list humans, but humans are warm-blooded)
What is the claim scope for the compound itself?
The patent claims a single active compound with a long structural name:
“1,4dihydro-2,6dimethyl-4-(3'-nitrophenyl)-pyridino-3-(β-methoxyethyl ester)-5-isopropyl ester.”
Consequence for design-around strategy
Because the independent claim requires administration of that particular named compound, competitors generally avoid literal infringement by:
- using a different salt, ester, or stereoisomer unless the claimed name covers it by definition in the specification (not provided in your excerpt)
- using a different chemical entity
- arguing non-equivalence if they use close analogs
However, if the specification defines salts, hydrates, or tautomer/ester variations under the umbrella of the same compound name, scope can expand. With only the claim text provided, the safest reading is literal identity requirement.
How do route limitations change enforceability?
Route is central only in the dependent claims.
Route coverage by claim
- Claim 1: does not constrain route (it says administer “either alone or in admixture … or in the form of a medicament”).
- Claim 2: constrains route-specific dose ranges for IV and enteral.
- Claim 3: further constrains to tighter IV and enteral dose bands.
- Claim 4: adds oral administration (but no oral mg/kg/day range).
Enforcement logic
- If a competitor uses the compound by any route with a “cerebral specific effective amount,” claim 1 can be asserted.
- If dosage is known and matches the claimed ranges, claims 2 or 3 can narrow the target product profile.
- Oral dosing creates additional coverage through claim 4 even where IV/enteral dose ranges might not be applicable.
What do the dosage windows practically mean?
The patent specifies mg/kg/day windows. Claims 2 and 3 are the strongest quantitative boundaries.
Dosage matrix (as claimed)
| Claim |
Route |
Amount (mg/kg/day) |
Scope band |
| 2 |
IV |
0.0001 to 0.5 |
broad |
| 2 |
Enteral |
0.001 to 1 |
broad |
| 3 |
IV |
0.001 to 0.1 |
narrower |
| 3 |
Enteral |
0.01 to 0.5 |
narrower |
Relationship between claim 2 and claim 3
- IV: claim 3 (0.001–0.1) is fully inside claim 2 (0.0001–0.5).
- Enteral: claim 3 (0.01–0.5) is fully inside claim 2 (0.001–1).
Claim 1 dose-independent constraint
Claim 1 uses “cerebral specific effective amount,” which is not numerically limited in the excerpt. That means claim 1 can potentially cover doses outside claims 2/3 if “effective amount” is satisfied.
What does the patent landscape look like for US practice around this compound?
With only the claim excerpt provided, a complete US patent landscape cannot be reconstructed reliably because the answer must be grounded in:
- bibliographic data (filing date, publication, assignee)
- related continuation/divisional patents
- prosecution history affecting claim interpretation
- citations in the US file wrapper
- potential later patents on improved salts, formulations, methods, or uses
Your prompt asks for “Detailed analysis of the scope and claims and patent landscape,” but the landscape portion requires external record access (USPTO/Google Patents/INPADOC) and cannot be produced accurately from the claim text alone.
Given the constraint that no incomplete or speculative landscape analysis can be delivered, the landscape section below focuses strictly on scope-based “attack and defend” implications that follow directly from the claim structure you provided.
What are the main patent “pressure points” for competitors (based on claim drafting)?
1) Literal infringement hinges on using the exact claimed molecule
Because claim 1 is tied to administration of a specific named chemical entity, competitors can target:
- different chemical entities (core design-around)
- different ester/salt forms only if they are not encompassed by the claimed compound name under the patent’s definitions (not assessable from your excerpt)
2) Dose bands provide quantitative constraints for method claims with known dosing
If a competitor replicates the compound and route, claims 2 and 3 become a measurable infringement grid:
- IV doses in 0.0001–0.5 mg/kg/day could land in claim 2
- IV doses in 0.001–0.1 mg/kg/day could land in claim 3
- Enteral doses in 0.001–1 mg/kg/day could land in claim 2
- Enteral doses in 0.01–0.5 mg/kg/day could land in claim 3
A product with dosing outside these windows may still be vulnerable under claim 1’s “effective amount,” depending on how the “effective amount” is proven.
3) Oral coverage is explicitly present
Even if IV/enteral dosing is chosen to avoid claims 2/3, oral administration can still trigger claim 4 if the oral dose is within “effective amount” for the claimed condition.
4) “Cerebral-specific effective amount” and functional conditions increase evidence burden
In US litigation, the functional language can shift the evidentiary focus to:
- whether the administered amount is “cerebral specific effective”
- whether the patient population fits “pathologically reduced cerebral functions,” “cerebral insufficiency,” and “disorders in cerebral circulation and metabolism”
This does not weaken the claim; it defines the proof contours.
What claims would likely be most valuable in licensing or defense?
Best leverage: Claim 1
- It captures broad routes and uses a “cerebral specific effective amount” standard.
- It covers the core therapeutic purpose.
Best litigation tool when dosing is documented: Claims 2 and 3
- They provide clear mg/kg/day windows for IV and enteral dosing.
- They let licensors target specific label or protocol ranges.
Route-specific coverage: Claim 4
- It makes oral use a direct infringement target for method activity (even without stated oral dose windows in the excerpt).
Can later patents expand or contract scope beyond this set of claims?
A complete answer requires the full patent record, but scope mechanics are standard:
- Continuation filings can add narrower species, additional routes, new dosing windows, or new indication language.
- Divisional filings can segregate method claims from other categories.
- Formulation or salt patents can create adjacent IP around the same active without touching method claims directly.
From your excerpt alone, we know this patent is written as a method-of-treatment patent tied to the compound and cerebral insufficiency/circulation/metabolism functional disease framing.
Key Takeaways
- US 4,406,906 claims methods of treating cerebral insufficiency and cerebral circulation/metabolism disorders in warm-blooded animals by administering a specific named pyridino ester compound.
- Claim 1 is the broadest: it requires only a “cerebral specific effective amount” and does not fix route or numerical dosing.
- Claims 2 and 3 provide measurable dose windows for IV and enteral dosing (claim 3 is nested inside claim 2).
- Claim 4 explicitly covers oral administration, creating a direct route hook beyond IV/enteral.
- Without the full bibliographic and prosecution record, a true US “patent landscape” cannot be stated from claims alone; scope-based infringement/defense pressure points follow directly from the claim structure.
FAQs
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Does US 4,406,906 cover humans explicitly?
The claims cover “warm-blooded animals.” Humans are warm-blooded, and enforcement can target human use, but the claim language itself does not list “human” explicitly.
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Is oral dosing covered even though IV/enteral doses have numeric ranges?
Yes. Claim 4 covers oral administration, but the excerpt does not provide an oral mg/kg/day range.
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What is the narrowest dosage claim in the excerpt?
Claim 3: IV 0.001 to 0.1 mg/kg/day and enteral 0.01 to 0.5 mg/kg/day.
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If a dosing regimen falls outside the mg/kg ranges in claims 2 and 3, is the method claim still at risk?
Yes in principle, because claim 1 does not impose a numeric dose window and uses “cerebral specific effective amount.”
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Can competitors avoid infringement by changing formulation (diluent/medicament) only?
Claim 1 allows administration “alone or in admixture with a diluent” or as a medicament, so formulation packaging alone does not avoid infringement if the same named compound is administered.
References
[1] United States Patent 4,406,906 (claim text provided in prompt).
