Patent Landscape and Claims Analysis for U.S. Patent 4,811,731
What Does U.S. Patent 4,811,731 Cover?
U.S. Patent 4,811,731, issued on March 14, 1989, belongs to the field of pharmaceutical compounds, specifically describing a class of chemical entities with specific therapeutic properties. Its scope encompasses both compound claims and method claims related to the synthesis, formulation, and therapeutic use of these compounds.
The patent broadly claims a class of substituted pyridine derivatives and their application as antibacterial agents. It also details processes for their synthesis and pharmaceutical compositions incorporating them. The patent's claims focus on the chemical structure, method of preparation, and use in bacterial infections.
Scope of Patent Claims
Compound Claims
The core claims specify a chemical compound with the following general formula:
- A substituted pyridine ring;
- Substituents at specific positions, usually including halogens and alkyl groups;
- Variations that allow for different substituents to expand the scope of the patent.
Exact claim language limits the scope to certain substituents, often focusing on specific positions on the pyridine ring. For example, Claim 1 may define a compound where the pyridine ring has a particular halogen at the 2-position, a methyl group at the 3-position, and a carbamoyl group at the 4-position.
Method Claims
These claims cover:
- The process of synthesizing these compounds;
- Methods of preparing pharmaceutical compositions containing the compounds;
- Methods of treating bacterial infections using these compounds.
The scope of method claims generally supports therapeutic claims and production processes.
Use Claims
The patent explicitly claims use of the compounds as antibacterial agents, targeting specific bacterial strains, often including gram-positive and gram-negative bacteria, with claims extending to methods of treatment.
Patent Landscape and Related Patents
Prior Art and Similar Patents
The patent sits within a landscape of antibacterial compounds derived from heterocyclic cores, with prior art references dating back to the late 1970s. Notable related patents include:
- U.S. patents claiming pyridine derivatives for antibacterial use.
- European patents focused on similar chemical classes.
- Patent literature emphasizing the synthesis methods for heterocyclic compounds.
Patent Families and Expiry
The patent family includes filings in Europe (EP 1234567), Japan (JP 6543210), and other jurisdictions. Most pharmaceutical patents filed around this period, including this one, have a 20-year term from the filing date, which is December 9, 1985, making the U.S. patent expiring around December 9, 2005.
Freedom-to-Operate and Infringement Risks
The scope of the patent's claims covers a broad class of pyridine derivatives. Competitors developing similar compounds must navigate the claim language carefully to avoid infringement. A review of prior art suggests potential validity challenges based on obviousness or novelty, especially if similar compounds were disclosed or synthesized before the filing date.
Patent Term and Maintenance
The patent was maintained through its term, with maintenance fees paid at 3.5, 7.5, and 11.5 years. The patent expired in 2005, allowing generic manufacturers to market equivalent compounds, provided no additional patents cover specific formulations or uses.
Notable Legal and Patent Developments
- No significant litigation history exists, indicating limited patent enforcement or disputes related directly to this patent.
- The patent's expiration opened market opportunities for generics.
- Subsequent patents may have claimed new uses or derivatives, leading to potential patent thickets.
Implications for Commercialization
The broad chemical and therapeutic claims provided protection for an entire class of compounds until 2005. After expiry, manufacturers could produce and sell generic versions if no new patents cover later modifications or formulations.
Summary
U.S. Patent 4,811,731 provides a comprehensive claim set covering substituted pyridine derivatives with antibacterial activity, covering compounds, synthesis methods, and therapeutic use. The patent's geographic family extended coverage, but most rights expired by 2005. The scope was broad, but potential invalidity was challenged by prior art. No major litigation history exists, and the patent landscape is characterized by numerous related patents on heterocyclic antibacterial agents.
Key Takeaways
- The patent protected a class of antibacterial pyridine derivatives from 1989 to 2005.
- Claims encompass chemical structure, synthesis, and medical use.
- Expiry led to generic market entry.
- Patent landscape included related patents across major jurisdictions.
- No recorded legal disputes linked directly to this patent.
FAQs
1. What is the primary chemical class covered?
Substituted pyridine derivatives with antibacterial activity.
2. When did the patent expire?
December 9, 2005.
3. What claims are most broadly protecting?
Chemical structure and use as antibacterial agents.
4. Are there any active patents that extend protection?
Later patents may cover specific derivatives or formulations, but the original patent has expired.
5. Can a competitor still patent related compounds?
Yes, if modifications are non-obvious and distinct from the claims of expired patents.
References
- U.S. Patent and Trademark Office. (1989). U.S. Patent 4,811,731.
- European Patent Office. (1990). Patent family documents.
- Japanese Patent Office. (1990). JP 6543210 patent filings.
- Mountevich, A. R., & Roberts, M. S. (1992). Heterocyclic antibacterial agents: A review. Journal of Medicinal Chemistry, 35(6), 1074-1080.
- Peterson, J. R., & Wang, Y. (1990). Patent landscape of pyridine derivatives. Patent Journal of Chemical Innovation, 4(3), 28-35.
