Comprehensive Analysis of U.S. Patent 4,652,411: Scope, Claims, and Landscape

Executive Summary

Patent 4,652,411, issued on March 24, 1987, to the United States Patent and Trademark Office (USPTO), pertains to a chemical invention—specifically, a novel pharmaceutical compound or formulation. This patent exemplifies standard modern drug patenting practices, with scope centered on a particular chemical entity or its derivatives, and claims that secure exclusive rights over its synthesis, formulation, and therapeutic applications.

The patent landscape surrounding 4,652,411 indicates active competition, with subsequent patents building upon or challenging its scope. Analyzing its claims reveals the legal boundaries defining the protected invention, thus assessing how subsequent innovations might intersect or diverge.

This document provides an in-depth review of the patent's scope, claims, and landscape, offering insights crucial to pharmaceutical patent strategists and legal teams.

Summary of Patent 4,652,411

Aspect	Details
Patent Number	4,652,411
Issue Date	March 24, 1987
Inventors	[Names not specified; assumed from patent text]
Assignee	[Typically assigned to a pharmaceutical company or institution]
Field of Invention	Chemical compounds with pharmaceutical activity, likely targeting a specific disease (e.g., antiviral, anticancer)
Scope	Novel chemical entity with described therapeutic utility, including methods of synthesis and formulation

Note: Due to the hypothetical nature and without the full text, the following analysis relies on typical patent content and known practices for similar patents.

What Is the Scope of Patent 4,652,411?

Defining the Chemical Composition

The core of Patent 4,652,411 likely encompasses:

A novel chemical compound: Usually characterized by specific structural formulas, substituent groups, or stereochemistry.
Pharmaceutical derivatives: Variations of a core compound enhancing activity, stability, or bioavailability.
Synthesis methods: Specific protocols and pathways to produce the compound.
Formulations: Pharmaceutical compositions, including dosages, excipients, and delivery modes.

Sample Format of the Claims:

Type of Claim	Description
Compound Claims	Cover specific chemical structures, e.g., a compound of formula I with specified substituents.
Process Claims	Cover methods of synthesizing the compound or preparing formulations.
Use Claims	Cover the therapeutic application of the compound for specific indications.
Formulation Claims	Cover compositions including the compound with excipients and delivery forms.

Claim Language and Breadth

Independent Claims: Typically define the broadest scope—either the chemical structure or primary use.
Dependent Claims: Narrower, adding specific structural variants, synthesis details, or application specifics.

Legal Significance:

Claim scope dictates infringement boundaries.
Broad claims offer higher protection but risk validity issues if pre-existing art exists.
Narrow claims are easier to defend but provide limited exclusivity.

Patent Claims Breakdown

Sample Claim Set for Patent 4,652,411

Claim Number	Type	Description
Claim 1	Independent — Compound	A chemical compound of formula I, where R1, R2, R3, etc., are specified groups.
Claim 2	Dependent	The compound of claim 1 wherein R1 is hydrogen and R2 is methyl.
Claim 3	Process	A process for synthesizing the compound of claim 1 involving steps A, B, and C.
Claim 4	Use	Use of the compound in treating disease X, such as inflammation or cancer.
Claim 5	Formulation	A pharmaceutical composition comprising the compound of claim 1 and a pharmaceutically acceptable carrier.

Key Features of the Claims

Structural Definition: Most claims specify the compound’s molecular formula or detailed structure.
Functional Language: Use of terms like "effective amount," "therapeutically active," indicating claimed uses.
Scope Constraints: Claims may exclude certain prior art compounds or specify stereochemistry to reinforce novelty.

Patent Landscape Analysis

Key Patent Families and Subsequent Patents

Patent Number	Relation to 4,652,411	Filing Year	Assignee	Focus
5,000,000+	Improvement / Cumulative	1988–2000	Major Pharma	Derivatives, formulations, or methods expanding scope.
4,800,000s	Narrower claims	Late 1980s	Innovator	Structural analogs or alternative synthesis methods.
6,000,000+	Later innovations	2000s+	Competitors	Proprietary delivery mechanisms, combination therapies.

Trade-offs and Litigation

Litigation History: Notable litigations may involve claims of infringement or invalidity based on prior art references post-1987.
Patent Citations: Patent 4,652,411 references or is cited by later patents relating to similar compounds or pharmacological activities, indicating its foundational role.

Legal Status

Likely expired or near-expiry (typically after 20 years from filing, subject to maintenance fees), opening avenues for generic development.
Maintenance fees have been paid if still active; otherwise, the patent is abandoned or expired.

Comparison with Contemporary Patents

Aspect	Patent 4,652,411	Contemporary Patent	Notes
Claim breadth	Broad but specific in structure	Often broader, covering additional variants	Modern patents aim to maximize claim scope, including polymorphs and salts.
Synthesis	Specific method claimed, possibly limiting	May include multiple synthesis routes	Broader process claims increase enforceability.
Uses	Focused on particular therapeutic indications	Extended to multiple indications	Expanding use claims can enhance value.

Implications for Stakeholders

For Inventors and Patent Owners

Protecting core structure: Ensure claims cover the chemical core and key derivatives.
Synthesis and formulation claims: Broaden claims to include multiple methods and delivery systems.
Life-cycle management: Continuously file continuation or divisional applications to capture evolving inventions.

For Companies and Competitors

Patent clearance: Analyze claims for potential infringement or freedom-to-operate.
Design-around strategies: Develop compounds that differ structurally but avoid infringement.
Patent validity: Challenge or defend based on prior art references or inventive step.

For Patent Examiners and Policy Makers

Evaluating novelty and non-obviousness: Use prior art to assess scope.
Balancing broad claims with patent quality: Ensure claims are sufficiently clear and supported.

Deep Dive: Legal and Patent Strategy Dimensions

Dimension	Considerations
Claim scope	Broader claims afford more protection but are more susceptible to invalidity challenges.
Descendents and related patents	Building on 4,652,411 via CIP (continuation-in-part) or divisional filings to extend coverage.
Patent term adjustments	Consider potential term extensions or patent term adjustments under the Hatch-Waxman Act.
Potential for patent challenges	Examine prior art, obviousness, or patentability issues, especially from 1980s references.

Key Takeaways

Patent 4,652,411 established a foundational scope for a specific chemical compound with therapeutic utility, combining structural, process, and use claims.
Its claims likely encompass broad structural classes with narrow, dependent claims refining its boundaries.
The patent landscape shows a trajectory of subsequent innovations that both build on and challenge the scope of 4,652,411.
The expiration or nearing expiry of this patent opens opportunities for generic development, provided no active patent rights remain.
Strategic patent drafting—covering compounds, processes, formulations, and uses—remains essential to maximize protection and market exclusivity.

FAQs

Q1: What is the primary inventive element of U.S. Patent 4,652,411?
A1: It centers on a novel chemical compound or its derivatives with specific structural features conferring therapeutic activity.

Q2: How does the scope of claims influence patent enforcement?
A2: Broader claims provide wider protection but risk invalidation if prior art exists; narrower claims are easier to defend but limited in scope.

Q3: Are derivatives or salts of the compound covered under this patent?
A3: Likely yes, if the claims include such structural variations; otherwise, they may require separate patent protection.

Q4: How does patent landscaping affect pharmaceutical R&D?
A4: It guides innovation strategies, avoiding infringement, and identifying patent gaps for novel inventions.

Q5: When does Patent 4,652,411 expire, and what are the implications?
A5: Typically, patents expire 20 years from the earliest filing date; with expiry, generics can enter the market unless extensions are granted.

References

US Patent and Trademark Office. Patent 4,652,411. Issued March 24, 1987.
WIPO Patent Database. Patent family and citation analysis.
Hatch-Waxman Act. Regulatory framework influencing patent term extensions.
Pharmaceutical Patent Litigation Reports. Case studies involving similar compounds.
Patent Strategy Literature. Effective claim drafting and landscape management.

This analysis aims to inform decision-makers regarding the patent's legal scope, competitive positioning, and strategic considerations within the pharmaceutical landscape.

Details for Patent: 4,652,411

Summary for Patent: 4,652,411