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Patent landscape, scope, and claims: |
US Patent 4,387,103: Scope, claim map, and US patent landscape for rapidly inactivated IV β‑blocking ester treatment of cardiac disorders
Executive summary: US Patent 4,387,103 claims a specific class of IV-administered β‑blocking ester compounds used to rapidly establish β‑blockade during critical cardiac illness and then recover quickly by terminating infusion because the compound is rapidly inactivated in vivo. The claim set is drafted as a method-of-treatment/prophylaxis with tight medicinal-chemistry constraints (parameterized structures for aryl substitution, ester/β‑blocking motif, and IV infusion termination), and then layered with narrow dependent claims to particular aryl positions and substitution patterns (ortho/para arrangements, no ring substituents, specific R/R1 options, and numeric infusion-rate ranges).
What does US 4,387,103 claim, and what is the technical scope of the β‑blocking ester “rapid recovery” method?
Core claim (Claim 1) is a method claim:
A method for treatment or prophylaxis of cardiac disorders in a mammal by IV infusion into a mammal having a critical cardiac illness, using a β‑blocking ester compound of a parameterized formula with defined substituent variables, where the β‑blocking ester is rapidly inactivated in vivo; infusion is given at a rate sufficient to establish effective β‑blockade and is then terminated to effect rapid recovery from β‑blocking effects.
Claim-construct elements (Claim 1)
The claim is built from six enforceable elements:
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Patient condition / timing context
- Mammal with critical cardiac illness.
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Route and dosing architecture
- Intravenous infusion (not bolus; “infused at a rate” then “infusion is then terminated”).
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Mechanistic pharmacology
- Drug class requires β‑blocking ester compound.
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Medicinal-chemistry boundary (formula constraints)
- The β‑blocking ester compound must match:
- R = lower alkyl or alkenyl (1 to ~5 carbons)
- n = 0 to ~3
- x = 1 or 2 (and if x=2, the two instances of a structural group can be same or different)
- R1 = lower alkyl or aralkyl
- Ar = phenyl or naphthyl optionally substituted with a specified set of substituents (lower alkyl/alkenyl/alkynyl/alkoxy, halogen, acetamido, amino, nitro, alkylamino, hydroxy, lower hydroxyalkyl, cyano)
- The claim also covers pharmaceutically acceptable salts.
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Rapid inactivation premise
- The β‑blocking ester compound is rapidly inactivated in vivo.
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Infusion termination requirement tied to pharmacokinetics
- Infusion rate establishes β‑blockade.
- Infusion is terminated to produce rapid recovery from β‑blocking effects.
Practical meaning for scope
- The claim does not merely cover “IV β‑blockers.” It requires a rapid-inactivation ester class and a treat-and-stop infusion strategy to obtain controlled exposure.
- The medicinal-chemistry constraints on R, R1, and Ar substitution patterns narrow the claim beyond generic β‑blocker structures.
Which specific sub-genus of the formula is carved out by dependent claims?
Dependent claims incrementally narrow Claim 1 through aryl identity, ring substitution pattern, specific numeric parameters, and selected alkyl/aralkyl substituents.
Ar identity and ring substitution positioning
- Claim 2: Ar is phenyl.
- Claim 3: Ar is phenyl; x=1; specific orientation requirement:
- The substituted group pattern includes an ortho position relationship between two listed functional groups (the claim uses structured placeholders; the key point is ortho placement when x=1).
- Claim 4: Ar is phenyl; n=2, x=1; para position relationship between the same two groups.
n parameter narrowing
- Claim 5: dependent on Claim 3: n=0.
R choices (lower alkyl/alkenyl)
- Claim 6: dependent on Claim 5/4/6 chain:
- R = lower alkyl/alkenyl with 1 to ~3 carbons
- Optional aromatic substituents limited to lower alkoxy (1–5 carbons), lower alkyl (1–5), halogen, or cyano.
- Claim 7: halogen = fluorine.
- Claim 8: R is methyl or ethyl.
- Claim 9: R = methyl.
R1 parameter narrowing
- Claim 10: R1 = lower alkyl (1–~5 carbons) or aralkyl where:
- alkyl portion 1–~5 carbons
- aryl portion 6–10 carbons
- Claim 12: R1 in limited set: isopropyl, t‑butyl, or 3,4‑dimethoxyphenethyl.
- Claims 15 and 18-19 further pin down R1 and R:
- Claim 15: R1 = isopropyl (with Claim 14 dependency).
- Claim 18: R = methyl, R1 = isopropyl.
- Claim 19: R = methyl, R1 = t‑butyl.
Compound substitution pattern restrictions on Ar ring
- Claim 14: (dependent on Claim 13): no optional substituents on phenyl group.
x=2 branch
- Claim 16: x=2, R=methyl or ethyl; R1 is isopropyl, t‑butyl, or 3,4‑dimethoxyphenethyl.
- Claim 17: R is lower alkyl/alkenyl (1–~3 carbons); R1 is isopropyl, t‑butyl, or 3,4‑dimethoxyphenethyl.
Infusion rate limitations (numeric ranges)
These are key because they create measurable infringement boundaries tied to dosing practice:
- Claim 20: infusion rate 0.001 to 100 mg/kg/hour, for the dependent-claim group “1, 4, 5, 6, 8, 9, 10, 11, 15 or 16” (i.e., only when the compound is within those specific sub-genus limitations).
- Claim 21: infusion rate 0.01 to 10 mg/kg/hour, for the dependent-claim group “1, 4, 5, 6, 8, 9, 10, 11, 15 or 36” (note: “36” appears in the user-provided list; it is likely a numbering reference in the patent, but only the excerpted dependent claim list is provided here).
What is the practical claim landscape for enforcement: what an IV β‑blocker must do to infringe?
Based on the claim structure, infringement requires meeting both the chemical definition and the clinical administration logic. The claim is method-of-use/instructional.
Infringement checklist for Claim 1
A generic or competitor IV β‑blocker would need to show, in a US method-of-treatment context:
- The active is an ester β‑blocker matching the formula constraints for R, n, x, R1, and Ar substitution; and
- The ester is rapidly inactivated in vivo; and
- Administration is IV infusion in a patient with critical cardiac illness with infusion rate sufficient for effective β‑blockade; and
- The infusion is terminated to achieve rapid recovery from β‑blocking effects.
High-friction elements
- Rapid inactivation in vivo: not merely “short half-life,” but a condition stated in the claim.
- Infusion termination to drive rapid recovery: method-step language can be harder for generics to avoid if labels or practice patterns match.
- Formula constraints: broad enough to capture a class, but narrow enough to exclude many known β‑blockers not formulated as rapid-inactivating esters.
How does the claim narrow the chemical universe vs. broader β‑blocker patents?
Within the β‑blocker landscape, many patents cover:
- specific β‑blocker molecules,
- solid forms,
- general IV formulations,
- general uses in cardiac disorders.
US 4,387,103 differentiates itself by combining:
- esterified β‑blocker scaffold with parameterized substitution variables, plus
- rapid inactivation and infusion-stop recovery as claim-defining features.
That drafting approach typically reduces the chance that a competitor can argue “we use a β‑blocker IV” without matching the rapid recovery and specific ester sub-genus.
Patent landscape context: what other US patents commonly compete with or complement this type of rapidly inactivated IV β‑blocker?
Because only the excerpt of the claims is provided, the full landscape (related family members, continuation patents, citation set, and examiner references) cannot be exhaustively enumerated here from the provided materials.
What can be stated from the claim itself is the likely adjacent IP buckets that would exist around this kind of therapy:
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Chemical compound patents
- Ester β‑blockers with rapid hydrolysis or enzymatic inactivation.
- Substituent variants around the same scaffold (R/R1/Ar substitution).
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Method-of-use patents
- Acute coronary syndrome, perioperative cardiac management, arrhythmia prophylaxis, shock/MI settings.
- IV infusion protocols with titration or stop-and-recover dosing.
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Formulation and delivery patents
- IV infusion stability, solubilizers, emulsions, pH-adjustment.
- Use of pharmaceutically acceptable salts to improve stability/solubility.
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Dosing regimen patents
- Rate ranges, titration schedules, and specific start-stop timing.
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Device or administration patents
- Infusion pump control schemes tied to time-to-recovery or pharmacodynamic targets.
In practice, US 4,387,103’s enforceability against a competitor depends on whether the competitor’s product uses:
- the same or very close ester sub-genus, and
- a clinically similar “establish β‑blockade then terminate infusion to recover quickly” protocol.
What is the US exclusivity timeline risk profile for US 4,387,103 (filing to expiration, including potential extensions)?
The patent term mechanics depend on:
- application filing date (for 20-year term),
- whether any adjustments under 35 U.S.C. §154 (patent term adjustment) apply, and
- maintenance status.
Those inputs are not provided in the prompt; therefore a defensible, date-specific exclusivity timeline cannot be produced from the given information.
What generic entry risks exist for an IV rapidly inactivated β‑blocking ester method?
Given the claim language, generic risk depends on the generic’s ability to match all claim limitations. The biggest practical risk categories are:
- Chemical match risk: If the generic uses the same rapid-inactivating ester β‑blocker sub-genus captured by the formula variables.
- Method match risk: If the generic product labeling or practice patterns instruct IV infusion at clinically relevant rates and recommend stopping infusion to restore baseline quickly.
- Evidence risk: If clinical practice and pharmacokinetic/pharmacodynamic data show “rapid recovery” consistent with the claim’s “rapidly inactivated in vivo” requirement.
Because Claim 1 is broad at the “Ar optionally substituted” level and “R lower alkyl/alkenyl,” a sufficiently similar ester chemistry could still fall inside scope even if the exact named compound differs.
Key claim-to-product mapping: which dependent claims likely align with commercial dosing and substitution variants?
Sub-genus likely to be commercially pursued (based on claim specificity)
- R=methyl (Claims 8-9 and those downstream).
- R1=isopropyl or t‑butyl (Claims 12, 15, 18-19).
- Selected ring substitution includes “no optional substituents” (Claim 14) and “3,4‑dimethoxyphenethyl” (Claim 12).
Dosing likely used in protocol claims
- Rate windows in Claim 20 and Claim 21 are the most litigation-relevant numbers:
- Broad: 0.001–100 mg/kg/hour (Claim 20).
- More targeted: 0.01–10 mg/kg/hour (Claim 21).
These ranges create bright-line parameters that are often central in method-of-use infringement arguments because they align to infusion pump programming and clinical protocol documents.
Key Takeaways
- US 4,387,103 claims a method-of-treatment/prophylaxis using a rapidly inactivated IV β‑blocking ester with an infusion then termination strategy to obtain rapid recovery.
- Claim 1 is defined by a parameterized chemical formula (R, n, x, R1, Ar substitution scope), plus explicit requirements for rapid inactivation and infusion-stop recovery.
- Dependent claims narrow to Ar=phenyl, specific ortho/para relationships when x=1, specific n values, and concrete R/R1 selections (notably R=methyl and R1=isopropyl/t‑butyl/3,4‑dimethoxyphenethyl).
- Numeric infusion-rate ranges in dependent claims (notably 0.001–100 mg/kg/hour and 0.01–10 mg/kg/hour) are the clearest measurable boundaries for infringement analysis.
FAQs
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Does US 4,387,103 cover IV bolus dosing or only infusion?
The independent claim language requires intravenous infusion with infusion termination to drive rapid recovery.
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Can a different β‑blocker ester scaffold infringe if it also shows rapid inactivation in vivo?
Infringement requires matching the formula-constrained β‑blocking ester definition in Claim 1, not only the pharmacokinetic outcome.
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What makes the “rapid recovery” limitation litigation-relevant?
It requires both rapid inactivation in vivo and that infusion is terminated to effect rapid recovery from β‑blocking effects, which can be tied to pharmacodynamic reversal timing.
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Which claim elements create the strongest “non-infringement” defenses for generics?
A competitor can focus defenses on failure to meet the ester chemical definition and failure to follow the infusion-stop recovery dosing method.
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How do the infusion-rate dependent claims change infringement analysis?
They provide concrete dosing windows that can be matched (or avoided) against infusion pump settings and protocol ranges used during treatment.
References (APA)
- US Patent No. 4,387,103.
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