Overview of U.S. Patent 4,233,285
U.S. Patent 4,233,285, granted on November 11, 1980, to Hoechst AG (now part of Sanofi), covers a class of compounds known as 4-aminoquinoline derivatives, primarily related to chloroquine and its derivatives. The patent claims focus on novel chemical structures with potential applications as antimalarial agents.
What is the Scope of Patent 4,233,285?
Chemical Class and Basic Structure
- The patent claims a specific subset of 4-aminoquinoline compounds.
- Central to the invention are substituted 4-aminoquinolines with variations at the 4-position and side chains, influencing activity and pharmacokinetics.
Claims Summary
- The patent includes 15 claims, mainly covering compounds with specific substitutions:
- A 4-aminoquinoline core with at least one side chain substituent.
- Variations include different alkyl, cycloalkyl, and aryl groups attached to the amino or other positions.
- Claims extend to methods of synthesis, pharmaceutical compositions containing these compounds, and their use as antimalarial agents.
Limitations and Exclusions
- Claims explicitly exclude prior known chloroquine derivatives, focusing on compounds with novel substitutions.
- The patent emphasizes compounds with improved efficacy, reduced toxicity, or altered pharmacokinetics compared to known antimalarials.
Chemical and Pharmacological Claims
- The core compounds are described by a general formula (not numerically specified here) with variable groups that influence activity.
- The patent also claims their salts and methods of preparing these compounds.
- The intended use is as antimalarial agents, with potential application in treating other diseases such as rheumatoid arthritis.
Patent Landscape and Patentability
Prior Art Landscape
- The patent builds on prior art, notably early 4-aminoquinoline compounds like chloroquine (U.S. Patent 2,668,160, 1954).
- The novelty lies in specific substituents and their pharmaceutical properties, aiming to overcome resistance or toxicity issues associated with earlier compounds.
Patent Validity and Patent Term
- The patent issued in 1980, with a standard 17-year term ending in 1997 (patent term calculation beginning from the grant date).
- The patent is in the public domain now; no longer enforceable.
Citations and Family
- The patent has been cited by subsequent patents related to antimalarial compounds and derivatives, indicating its influence.
- It forms part of a patent family covering related compounds and synthesis methods, with filings in Europe, Japan, and other jurisdictions.
Patent Challenges and Litigation
- No publicly documented litigations or patent reexaminations targeting this patent.
- Given its age, it has not faced major legal challenges in recent times.
Innovation and Research Implications
- The patent was foundational in the development of chloroquine analogs.
- It guided the synthesis of derivatives designed to address resistance and toxicity issues.
- Subsequent patents cited this invention in the context of compounds with improved pharmacological profiles.
Current Status
- The patent's claims are expired, opening opportunities for research and generic development.
- Modern drug development has shifted focus towards other class derivatives due to resistance issues.
Summary of Key Patent Data
| Aspect |
Details |
| Patent Number |
4,233,285 |
| Issue Date |
November 11, 1980 |
| Expiry Date |
November 11, 1997 (patent term) |
| Assignee |
Hoechst AG (now Sanofi) |
| Claims |
Approximately 15 claims covering compounds and methods |
| Patent Family |
Extended in Europe (EP), Japan, Canada, others |
| Cited Patents |
Multiple, related to antimalarial agents |
Key Takeaways
- U.S. Patent 4,233,285 covers chemical derivatives of 4-aminoquinoline with potential antimalarial use.
- Its claims encompass specific substitutions and synthesis methods, while focusing on efficacy improvements.
- The patent landscape reflects ongoing research to optimize chloroquine derivatives, though the patent is now expired.
- Modern development efforts pivot toward new classes due to resistance emergence.
- The patent's expiration allows unrestricted research and potential generic formulation.
FAQs
1. Are compounds covered by this patent still under patent protection?
No. The patent expired in 1997, making its claims part of the public domain.
2. Can modern drugs use the derivatives described in this patent?
Yes. Since the patent is expired, these compounds can be freely researched, synthesized, and developed further.
3. Did this patent contribute to the development of new antimalarial therapies?
Yes. It provided a foundation for modifications of chloroquine aimed at overcoming resistance and toxicity.
4. Were there any major legal disputes related to this patent?
No publicly documented litigation or oppositions have arisen concerning this patent.
5. How does this patent influence current antimalarial research?
It offers insights into chemical modifications of 4-aminoquinolines, but current research primarily focuses on newer derivatives and entirely different compound classes due to resistance issues.
References
- U.S. Patent 4,233,285.
- Patent family records (EPO, JPO, CIPO).
- Literature on chloroquine resistance and derivative development [1].
[1] References to the development and resistance challenges related to chloroquine derivatives are based on publicly available scientific literature.
