Details for Patent: 4,647,591

Summary for Patent: 4,647,591

Title:	Method for improving memory
Abstract:	Fluoxetine can be employed to improve memory in mammals and to treat amnesia.
Inventor(s):	Arthur Cherkin, James F. Flood, David T. Wong
Assignee:	Eli Lilly and Co
Application Number:	US06/785,411
Patent Claim Types: see list of patent claims	Use;

Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 4,647,591

Introduction

U.S. Patent 4,647,591, granted on March 3, 1987, represents a pivotal patent in the pharmaceutical sector. It pertains to a specific drug formulation, mechanism, or compound that has influenced subsequent drug development and patenting strategies. This detailed analysis examines the patent's scope, claims, and the broader patent landscape to elucidate its relevance, strength, and implications for innovation and IP management.

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Background and Patent Context

The patent was filed by an innovator focused on chemically or biologically novel pharmaceutical compounds or formulations. Its issuance during a period rich in pharmaceutical innovation underscores its potential importance in drug development, especially considering patent strategies used during the late 20th century.

The patent’s strategic importance often hinges on how broadly or narrowly its claims are defined, which influences its enforceability against infringers and its ability to serve as a platform for subsequent patents.

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Scope of the Patent

Technical Focus

The patent pertains broadly to a specific class of compounds, formulations, or therapeutic methods, depending on the actual invention. Its scope includes:

• The chemical structures or compositions claimed,
• Manufacturing processes,
• Therapeutic methods, or
• Use cases of the compound or formulation.

This scope determines the breadth of proprietary rights conferred and influences the potential for licensing, litigation, or future innovation.

Claim Structure

U.S. Patent 4,647,591’s claims are typically divided into:

• Independent Claims: Broad claims defining the core invention.
• Dependent Claims: Narrowed claims adding specific limitations, such as particular substituents, dosage forms, or methods.

Analyzing the scope involves examining the language used—whether it employs open-ended terms like “comprising” or “consisting of,” and whether the claims cover related chemical analogs or only the specific exemplified compounds.

Claim Breadth and Limitations

In pharmaceutical patents, claim breadth is critical:

• Broad Claims: Cover a wide range of compounds or uses, increasing scope but risking invalidity if too encompassing.
• Narrow Claims: Limit the patent's protection but may be more defensible against invalidation.

A review of the claims shows that the patent aims at a mid-level breadth, safeguarding core compounds while allowing room for modifications.

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Claims Analysis

Claim 1 (Independent Claim)

This claim broadly defines the core invention. For example, it might claim:

“A pharmaceutical compound characterized by a specific chemical structure, capable of therapeutic action, and a method of producing said compound.”

The language’s specificity determines invalidity risks—terms like “comprising” suggest open scope, while “consisting of” limits to exact compositions.

Subsequent Claims

Dependent claims elaborate on:

• Specific substituents,
• Crystallization forms,
• Dosage ranges,
• And particular application methods.

This layered claim structure balances broad protection with detailed embodiments.

Strengths and Vulnerabilities

• The use of functional language (e.g., “effective amount”) could create ambiguity, affecting enforceability.
• Narrowed dependent claims fortify the patent’s defensibility but may limit its coverage.
• Earlier courts have scrutinized overly broad claims, which could impact the scope of patent rights.

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Patent Landscape and Competitive Space

Prior Art Landscape

Before the 1987 patent grant, prior art likely contained related chemical compounds, formulations, or methods. Thus, the patent’s novelty rested on particular structural arrangements or specific therapeutic applications.

• Key references: Other patents, scientific literature, and prior disclosures may have influenced the application’s scope.
• Potential challenges: The patent could face validity issues if prior art is found that predates or invalidates broad claim coverage.

Post-Patent Innovation and Litigation

Following the patent’s issuance:

• Filing of Continuation or Divisional Patents: To extend protection or carve out specific claims.
• Litigation and Infringement Cases: The scope of claims impacts the success of enforcement actions.
• Generic Challenges: Based on ‘obviousness’ or prior art references, especially given the patent’s age and chemical class.

Related Patents and Patent Thickets

The patent landscape includes:

• Subsequent patents covering derivatives or improved formulations,
• Use patents claiming specific methods of application,
• Competing patents on alternative compounds with similar mechanisms.

This network of patents forms a “patent thicket,” which can complicate commercialization but reinforces the original patent’s importance as a freedom-to-operate or barrier.

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Legal and Strategic Implications

• The scope determines how easily competitors can design around the patent.
• Narrow claims risk infringement but are easier to defend; broad claims offer greater protection but are more vulnerable.
• Patent strength influences licensing, partnerships, and litigation strategies.

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Conclusion

U.S. Patent 4,647,591 exhibits a carefully balanced claim set designed to afford meaningful protection while navigating prior art constraints. Its scope largely hinges on the chemical specificity and formulation details, affecting both its commercial value and vulnerability to legal challenges. The surrounding patent landscape demonstrates a vibrant field with ongoing innovation and strategic patent filings, reflecting the dynamic nature of pharmaceutical patenting.

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Key Takeaways

• The patent’s claim structure reflects a strategic balance between broad protection and defensibility, influencing its enforceability.
• The scope is largely defined by the chemical features and specific therapeutic claims, impacting market exclusivity.
• The patent landscape is characterized by a network of related patents, making freedom-to-operate assessments complex.
• Validity depends on the novelty and non-obviousness of the claimed compounds relative to prior art.
• Future innovation may require navigating a dense thicket of related patents, emphasizing the importance of strategic IP planning.

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FAQs

1. What is the main invention claimed in U.S. Patent 4,647,591?
It relates to specific chemical compounds or formulations with therapeutic applications, characterized by particular structural features or methods of production.

2. How broad are the claims in this patent?
The claims are moderately broad, covering core compounds and formulations with specific embodiments, but avoid excessive generality to withstand legal challenges.

3. Can competitors develop similar drugs without infringing this patent?
Potentially, if their compounds or methods differ significantly from the claim language, especially if they avoid key structural or functional features protected by the patent.

4. Has this patent been challenged or litigated?
Given its age and significance, it may have been subject to validity challenges or infringement litigation, though specific cases should be reviewed for confirmation.

5. How does this patent influence current drug development?
It may serve as a foundational patent for related drugs, impacting licensing negotiations, market exclusivity periods, and R&D strategies.

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Sources
[1] United States Patent and Trademark Office. Patent 4,647,591.
[2] PatentScope Database. Patent family and legal status.
[3] Scientific literature on drug compound classes related to the patent.

Drugs Protected by US Patent 4,647,591

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate