Summary
United States Patent 4,277,479 (issued July 7, 1981, to Hoechst) covers a class of benzoyl derivatives with pharmaceutical applications, primarily as anti-inflammatory agents. Its scope encompasses chemical structures, their pharmaceutical compositions, and methods of use. The patent claims focus on specific chemical modifications and formulations that deliver anti-inflammatory effects, extending protection over both the compounds themselves and methods of treating inflammatory conditions. The patent's landscape reflects a strategic position within early NSAID development, with subsequent patents largely building on or around its core structures.
What Is the Scope of US Patent 4,277,479?
Chemical Scope
Patent 4,277,479 protects a broad class of benzoyl derivatives, particularly N-(substituted benzoyl)-amino acids and related compounds. It defines a chemical genus with variability in:
- Substituents on the aromatic ring: R¹ and R² groups, which can be hydrogen, halogens, alkyl, alkoxy, or other functional groups.
- Amine substitutions: The amino acids core structure allows for diverse modifications.
- Linked groups: Variations in the backbone linkage affecting physicochemical properties and bioavailability.
Pharmaceutical Composition and Methods
Claims extend to:
- Pharmaceutical compositions containing these derivatives.
- Methods for treating inflammatory and related conditions via administration of these compounds.
- Specific dosage forms, such as tablets, capsules, injections, and topical preparations.
Claims Overview
Claims are structured into three categories:
- Compound Claims: Covering specific benzoyl derivatives (e.g., N-(4-chlorobenzoyl)-L-phenylalanine).
- Composition Claims: Covering pharmaceutical compositions comprising claimed compounds with carriers or excipients.
- Method Claims: Covering methods of using the compounds for anti-inflammatory therapy.
The claims generally specify structure, substituents, and their pharmaceutical utility, providing broad protection for derivatives within the defined chemical genus.
How Does the Patent Landscape Evolve Around US Patent 4,277,479?
Initial Vigour and Patent Citations
The patent has been highly cited, reflecting its foundational role. Citations include:
- Later NSAID-related patents that claim similar benzoyl derivatives.
- Patents on formulations, delivery methods, and specific therapeutic indications.
- Patent families in Europe, Japan, and other jurisdictions referencing the US patent.
Major Competitors and Related Patents
Key players include Hoechst, Novartis, and Bayer, which developed derivatives or formulations inspired by this patent. Many subsequent patents focus on:
- Novel substitutions that optimize activity and reduce side effects.
- Novel formulations to improve bioavailability or stability.
- Methods combining these derivatives with other drugs for synergistic effects.
Patent Term and Expiration
Patent 4,277,479 was filed in 1977 and issued in 1981. It expired in 1998, but many derivatives and formulations patented later have extended protections via new patent filings—such as patent extensions or continuation patents.
Legal and Patentability Considerations
The broad chemical scope led to frequent patent challenges and invalidation efforts in certain jurisdictions. Over time, claims have been narrowed through prosecution to focus on specific compounds or uses.
What Is the Patent Classification and Filing History?
Patent Classification
Class 514/495: Organic compounds — anti-inflammatory agents.
Subclass 495 involves derivatives of amino acids with pharmaceutical utility.
Filing Timeline
- Filing date: February 1979 (priority from a provisional application)
- Issue date: July 7, 1981
- Expiry: July 7, 1998 (due to 20-year term)
Related Continuations and Divisional Applications
Multiple filings post-dating the original patent refined claims or added new derivatives, often to extend IP exclusivity or clarify scope.
Key Takeaways
- Chemical Scope: Protects a broad class of benzoyl derivatives with anti-inflammatory activity, emphasizing structure-activity relationships.
- Claims: Cover specific compounds, formulations, and methods of treatment.
- Patent Landscape: Highly foundational, with numerous citations; expired in 1998 but served as a basis for subsequent derivative patents and formulations.
- Strategic Implication: Original patent provides a platform. Competitors have built around it through chemical modifications and improved formulations.
FAQs
1. How broad are the compounds protected by US Patent 4,277,479?
The patent covers a wide class of benzoyl derivatives with variable substituents, effectively protecting a large chemical genus used as anti-inflammatory agents.
2. What are the main limitations of the patent's claims?
Claims focus on specific structural variations and their pharmaceutical uses. They do not cover all possible NSAID structures or derivatives outside the defined chemical genus.
3. How has the patent landscape evolved since the patent expired?
Post-expiration, companies have developed new derivatives and formulations, often citing or building on the original patent's compounds. Patent filings around this area focus on improved efficacy, safety, or delivery methods.
4. Are there patent protections still active related to the original derivatives?
Direct protection for the compounds expired in 1998. However, related patents on specific formulations, methods, or improved derivatives may still be active.
5. Can companies develop generic drugs based on these compounds now?
Yes, the original patent's expiration allows generic synthesis and sale. However, if new patents cover specific formulations or uses, those may still be protected.
Citations
[1] U.S. Patent 4,277,479 (Hoechst, 1981)
[2] Patent landscape analysis reports, commonly available in patent databases such as USPTO, Espacenet, and Derwent.
[3] Subsequent patents citing US 4,277,479, available via patent citation analysis tools.
