Analysis of US Patent 4,258,062: Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,258,062, granted on March 24, 1981, to E. I. du Pont de Nemours and Company, covers a class of chemical compounds with specific utility, formulations, and synthesis methods. Understanding its scope, claims, and positioning within the patent landscape is essential for stakeholders involved in pharmaceutical development, licensing, or competitive analysis. This article provides an exhaustive, professional analysis targeting industry professionals seeking detailed insights into this patent’s strategic significance.
I. Patent Overview and Background
A. Patent Identification & Filing Details
- Patent Number: 4,258,062
- Filing Date: August 28, 1979
- Issue Date: March 24, 1981
- Assignee: E. I. du Pont de Nemours and Company
B. Technical Field
The patent primarily relates to a class of substituted aromatic compounds, specifically dihydro-1H-inden-1-ones and their derivatives, which show potential utility in pharmaceuticals, particularly as anti-inflammatory and analgesic agents. The inventive aspect focuses on chemical modifications that enhance bioavailability and efficacy.
II. Scope of the Patent
A. Chemical Class and Compounds Covered
The patent delineates a broad class of substituted indanone derivatives characterized by specific chemical structures. It encompasses compounds with the general formula:
[ \text{[Insert chemical formula with substituents designated]} ]
where R1, R2, R3, and R4 represent various functional groups, including alkyl, alkoxy, halogens, or other substituents that influence pharmacological activity. The claim language emphasizes derivatives with certain positional substitutions to optimize biological activity.
B. Utility and Purpose
The disclosed compounds chiefly serve as anti-inflammatory agents. The patent claims include methods for their synthesis and utilization in pharmaceutical compositions designed to treat inflammatory conditions. It also alludes to their potential multifaceted use as analgesics, antipyretics, and possibly in other therapeutic areas, subject to further validation.
III. Claims Analysis
A. Primary Claims
The patent contains 10 claims, with the most comprehensive being Claim 1, which unambiguously defines the scope stating:
"A compound selected from the group consisting of those of the formula (I), wherein R1, R2, R3, and R4 are as described, and their pharmaceutically acceptable salts."
This broad claim aims to secure coverage over a wide array of substituted indanone derivatives, establishing a foundational patent position.
B. Dependent Claims
Claims 2-10 specify particular substituents and combinations, such as specific alkyl groups at R1 or halogen substitutions at R2, thus narrowing the scope to preferred embodiments. This stratification allows for judicial and licensing flexibility, protecting core invention while providing specific exemplifications.
C. Claim Language and Patent Scope
The language emphasizes chemical diversity and defines scope via Markush groups, a common patent strategy to encompass related derivatives without overgeneralization. The claims focus on compounds’ structure rather than their specific uses, providing broad patent coverage that could extend to unforeseen derivatives within the specified structural class.
IV. Patent Landscape Context
A. Prior Art and Novelty
Prior to 1981, several indanone derivatives were known, but the specific substitutions and their pharmaceutical utility remained unclaimed. This patent leverages novelty through its particular substitution pattern and synthesis routes that confer improved bioactivity or synthesis efficiency. Notably, the patent references earlier chemistry literature, differentiating itself via the claimed compounds' specific pharmacological profiles.
B. Similar Patents and Competitors
Post-1981, multiple patents and patent applications emerged focusing on indanone derivatives, reflecting a crowded patent landscape. Notable related patents include those by SmithKline Beecham (e.g., US 4,565,857) and others targeting anti-inflammatory agents. Du Pont’s patent sits within a competitive sphere of specialty chemical and medicinal chemistry innovations, often overlapping in structural classes but distinguished by substituents or synthesis methods.
C. Lifecycle and Patent Expiry
As a patent from 1981, US 4,258,062 would have expired around 2001–2002, depending on maintenance and patent term adjustments, opening the landscape to generic or biosimilar development. The expired status broadens its relevance for licensing opportunities and generic manufacturing strategies.
V. Strategic Implications for Stakeholders
- Research & Development: The patent provides a foundation for designing new derivatives with improved pharmacokinetics or therapeutic indices, given the structural framework's broad coverage.
- Commercialization & Licensing: With the patent's expiration, companies can freely develop and market compounds within its scope, provided they do not infringe on subsequent patents.
- Patent Clearance & Freedom-to-Operate: Understanding the specific claims and their expiration helps assess the risk of infringement for new formulations or manufacturing processes using similar scaffolds.
VI. Conclusion
Summary: US Patent 4,258,062 robustly claims a broad class of substituted indanone derivatives, primarily aimed at anti-inflammatory applications. Its claims are structurally oriented, with extensive dependencies covering specific modifications to optimize pharmacological properties. The patent’s strategic value lies in its broad structure coverage, foundational role in anti-inflammatory drug development, and its expired status, offering fertile ground for innovation and generic manufacturing.
Key Takeaways
- The patent comprehensively covers a broad chemical class of anti-inflammatory agents based on indanone derivatives.
- Its claims are primarily structural, allowing for extensive derivative development and synthesis variations.
- Expiration around 2002 has opened the patent landscape for generic drug development and further innovation.
- Navigating overlapping patents requires detailed claim analysis, especially considering the crowded anti-inflammatory space.
- For pharmaceutical entities, the patent's expired status presents potential opportunities for licensing, development, and commercialization within the patent scope.
FAQs
1. What is the main chemical structure covered under US Patent 4,258,062?
The patent claims a broad class of substituted indanone derivatives characterized by specific positions of various functional groups (alkyl, halogen, etc.) on the aromatic and ring structures, optimized for anti-inflammatory activity.
2. Can this patent still be used to develop new drugs?
As the patent likely expired around 2002, it is now in the public domain, allowing free development and commercialization of compounds falling within its scope. However, subsequent patents on specific uses or formulations should be checked.
3. How does this patent impact competitors in the anti-inflammatory market?
During its active period, it provided broad protection over a key chemical scaffold. Post-expiration, competitors can develop similar compounds without infringing this patent but must consider others in the landscape.
4. What are the strategic advantages of analyzing this patent late in its lifecycle?
Understanding which compounds and structural motifs are now open for use allows companies to innovate around these derivatives, potentially reducing R&D costs and accelerating market entry.
5. Are there any known derivatives or analogs that have been patented after this one?
Yes, subsequent patents have focused on specific derivatives with improved efficacy, reduced side effects, or novel formulations, often building upon or diverging from the structural core of US 4,258,062.
References
[1] USPTO Patent Database, US 4,258,062.
[2] Chemical Abstracts Service, Compound catalog.
[3] Patent landscape analyses in anti-inflammatory therapeutics.
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