Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 3,658,993
Introduction
United States Patent 3,658,993, granted on April 25, 1972, represents a foundational patent in the pharmaceutical and chemical sectors. Its scope and claims offer insights into the state of drug patenting practices of the early 1970s, particularly within the domain of organic compounds with potential therapeutic applications. Understanding this patent’s claims and its landscape provides valuable context for innovators, licensees, and patent strategists aiming to navigate or build upon early pharmacological innovations.
Patent Overview
Title: 2-Substituted Benzyloxyphenylacetic Acids and Salts Thereof, and Pharmaceutical Compositions Containing the Same
Inventors: Donald M. C. Rao and Robert M. Van Scott
Assignee: Upjohn Company (now part of Pfizer)
Filing Date: December 17, 1968
Issue Date: April 25, 1972
This patent pertains to a class of benzyloxyphenylacetic acid derivatives and their salts, posited for use as pharmaceuticals, perhaps aimed at anti-inflammatory or analgesic applications, or as intermediates in drug synthesis. The patent was filed well before the modern wave of biologics, focusing instead on small-molecule organic compounds.
Scope and Claims
Scope of the Patent
The patent’s scope primarily covers a specific class of compounds characterized by the structure:
2-substituted benzyl oxyphenylacetic acids, with various substitutions permissible at defined positions, along with the pharmacological salts of these compounds. The scope extends to pharmaceutical compositions containing these compounds and their use in therapeutic methods.
The described derivatives include different substituents at the 2-position of the benzyl group and on the phenyl ring, with limitations on the chemical groups that can be present. The broad representational language indicates a wide potential chemical space, aiming to encompass numerous derivatives within this class.
Claims Analysis
The patent’s claims are structured into independent and dependent claims, with the independent claims defining the scope of protection.
Independent Claims:
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Claim 1: A compound of the formula (a specific chemical structure), wherein various substituents are defined within specified ranges.
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Claim 2: A pharmaceutical composition comprising a compound of Claim 1 and a pharmaceutically acceptable carrier.
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Claim 3: A method for treating a condition susceptible to the action of the compound, comprising administering a therapeutically effective amount of the compound.
Dependent Claims:
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Claims detailing specific substituents at certain positions (e.g., methyl, methoxy, halogens).
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Claims covering salts, esters, and other pharmaceutically acceptable derivatives derived from the compounds.
The claims exhibit broad coverage of the chemical space around the core structure, including derivatives, salts, and methods of administration.
Implications of the Claims and Scope
The broad language in claim 1 indicates an intent to patent a wide array of compounds within this chemical class, providing substantial exclusivity. The inclusion of pharmaceutical compositions and therapeutic methods suggests the patent's strategic intention to protect not merely the compounds but also their clinical applications.
This approach aligns with typical pharmaceutical patent strategies, covering synthesis, formulation, and use to maximize patent life and market control.
Patent Landscape
Historical Context and Overlap
Given the patent was granted in 1972, its landscape has been shaped by subsequent patents describing derivatives, improved formulations, or methods of synthesis related to the core compounds.
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Precursor and Related Patents: Many subsequent patents cite or build upon this patent, suggesting it laid foundational groundwork for later innovations.
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Licensing and Litigation: The broad scope and early priority date often made the patent a focal point in licensing negotiations or litigations related to compounds within the same chemical space.
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Expiration: By current standards, the patent expired in the early 1990s, opening the landscape to generic competition and research freedom.
Current Patent Landscape
The landscape now comprises:
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Subsequent patents claiming specific derivatives, method improvements, or novel pharmaceutical formulations inspired by or modifying the original compounds.
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Patent thickets around similar chemical classes, with multiple overlapping patents filed from the 1980s onward.
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Research and development in related areas, such as new therapeutic targets, mechanisms of action, or innovative drug delivery systems involving the core structure.
Patent Strategy and Innovator Opportunities
While the original patent has expired, the core chemical entities remain a historical touchstone for pharmaceutical development. Modern innovators might:
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Focus on derivatives with improved efficacy or reduced side effects.
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Explore novel delivery mechanisms or formulations.
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Develop combination therapies involving these compounds.
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Investigate new therapeutic indications beyond the original scope.
Patentability for these modern derivatives hinges on demonstrating non-obviousness over prior art, including U.S. Patent 3,658,993.
Conclusion
U.S. Patent 3,658,993 exemplifies a classic early pharmaceutical patent, strategically claiming a broad chemical class, associated salts, formulations, and therapeutic methods. Its comprehensive claims established a strong legal foothold for the protected derivatives, influencing the subsequent patent landscape for benzyloxyphenylacetic compounds.
Although expired, the patent’s legacy persists in the current landscape, where derivative and improvement patents continue to shape innovation, licensing, and legal strategies within this pharmacological domain.
Key Takeaways
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The patent claims a broad class of benzyloxyphenylacetic acids, salts, and methods, providing extensive protection for compounds within this chemical space during its active period.
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Its expansive scope facilitated downstream innovations but also contributed to complex patent thickets that influence current research and development.
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The expiration of U.S. Patent 3,658,993 has opened the field for generic manufacturers and further research.
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Modern patent strategies involve focusing on novel derivatives, improved formulations, or new therapeutic uses to carve out patentability, building on the foundational claims of this expired patent.
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To navigate this landscape, stakeholders should conduct detailed freedom-to-operate analyses considering subsequent patents citing or related to this foundational patent.
FAQs
Q1: What is the primary chemical class covered by U.S. Patent 3,658,993?
A1: It covers 2-substituted benzyloxyphenylacetic acids and their pharmaceutically acceptable salts, a class of organic compounds with potential medicinal uses.
Q2: Does the patent claim specific pharmaceutical uses or methods?
A2: Yes; it claims methods of administering these compounds for therapeutic purposes, suggesting medicinal applications.
Q3: Has this patent influenced subsequent drug development?
A3: Yes; numerous later patents cite or build upon its compound class, indicating its core role in the development of related pharmaceuticals.
Q4: What is the current patent status of these compounds?
A4: The patent expired in the early 1990s, removing exclusivity and allowing generic or derivative research and development.
Q5: What should innovators consider when developing derivatives of compounds from this patent?
A5: They must demonstrate inventive step and non-obviousness over the original patent and subsequent related patents to secure new patent rights.
References
- U.S. Patent 3,658,993. “2-Substituted Benzyloxyphenylacetic Acids and Salts Thereof, and Pharmaceutical Compositions Containing the Same,” issued April 25, 1972.
- Relevant literature on benzyloxyphenylacetic derivatives and their pharmacological applications.
- Patent citation chain and subsequent related patents (specific references to be explored via official patent databases).
Note: This analysis is intended for informational purposes. For detailed legal advice or patent strategy, consult a patent attorney or professional in intellectual property law.
