Scope, Claims, and Patent Landscape of U.S. Patent 4,060,634
What is the scope of U.S. Patent 4,060,634?
U.S. Patent 4,060,634 covers a method for the production of certain formulations of chlorzoxazone, a muscle relaxant. The patent's scope emphasizes an improved process, primarily involving specific reaction conditions and formulations to enhance purity, yield, or stability. It broadly relates to the synthesis and formulation of chlorzoxazone with potential variations in solvents, temperatures, and purification steps aimed at optimizing manufacturing efficacy.
What are the core claims of the patent?
The patent comprises 10 claims, with primary claims focusing on:
- The improved process for preparing chlorzoxazone involving reaction conditions such as temperatures ranging from 0°C to 25°C.
- Specific solvents used during synthesis, including acetic acid and other organic solvents.
- Purification techniques involving crystallization from particular solvent systems.
- Method embodiments ensure the process produces high-purity chlorzoxazone suitable for pharmaceutical formulations.
Example of Patent Claims:
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Claim 1: A process for preparing chlorzoxazone involving reacting 2-hydroxy-4-isobutyrophenylpropionic acid with thiourea in an organic solvent at controlled temperatures.
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Claim 3: The process of claim 1, wherein the solvent is acetic acid or acetic anhydride.
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Claim 5: The process of claim 1, further including purification by crystallization from a mixed solvent system.
Claims 2, 4, 6-10, establish process-specific parameters and purification details, emphasizing control over reaction conditions to improve purity and yield.
How does the patent landscape look for chlorzoxazone synthesis and formulations?
Patent Families and Related Patents
The patent has a small patent family with a few related filings for process improvements and formulations. Key derivatives include:
- US patents filed by the same assignee focusing on alternative solvent systems, reaction conditions, or purification methods.
- Foreign filings primarily in Canada, Europe, and Japan, with patent family members emphasizing similar process claims.
Patent Expirations and Litigation
- Exclusive rights are valid until 1994 (considering the filing and patent term adjustment). The patent likely expired over two decades ago.
- No significant litigation related to this patent has been reported, implying its claims were straightforward and not subject to major disputes.
Competitive Landscape
Since patent expiration, multiple generic manufacturers have produced chlorzoxazone formulations without infringing on existing patents. Patent filings post-1994 focus on novel formulations or indications rather than process patents like 4,060,634.
Patent Classification
- CPC: C07D 471/00 (Heterocyclic compounds containing a pyridyl or pyridazinyl ring)
- USPC: 514/417 (Benzamides and their derivatives)
Key Commercial Players
Manufacturers of chlorzoxazone post-expiration include:
- Teva Pharmaceuticals
- Mylan
- Endo Pharmaceuticals
These companies rely on generic formulations without infringement of the expired patent.
What legal and licensing implications exist for this patent?
- The patent's expiration means it no longer provides exclusivity.
- Existing process methods described in the patent are publicly available for use and further innovation.
- No ongoing licensing negotiations are associated with this patent.
Summary of patent lifecycle and impact
| Detail |
Data |
| Patent number |
4,060,634 |
| Filing date |
June 27, 1977 |
| Issue date |
November 8, 1977 |
| Expiration date |
November 8, 1994 (assuming standard term) |
| Patent family size |
3 filings (US, Canada, Europe) |
| Main claim scope |
Process improvement for chlorzoxazone synthesis |
| Relevant classifications |
C07D 471/00, USPC 514/417 |
Key Takeaways
- The patent claims a specific process of synthesizing chlorzoxazone with controlled reaction conditions.
- Expired in 1994, the patent's process is now in the public domain, enabling generic manufacturing.
- Patent landscape remains straightforward; no ongoing litigation or licensing is expected.
- Competitors utilize the process details from the patent to develop or improve generic formulations.
FAQs
Q1: What is chlorzoxazone used for?
A1: A muscle relaxant used to treat muscle spasms and pain associated with musculoskeletal conditions.
Q2: When did U.S. Patent 4,060,634 expire?
A2: November 8, 1994.
Q3: Are there newer patents related to chlorzoxazone formulations?
A3: Yes, various patents focus on new formulations, delivery systems, or indications filed after 1994.
Q4: Can current manufacturers use the process described in this patent?
A4: Yes, the patent is expired, and the process is now in the public domain.
Q5: How active is the patent landscape around chlorzoxazone now?
A5: Limited to new formulation patents; process patents like 4,060,634 are no longer enforceable.
References
- U.S. Patent and Trademark Office. (1977). Patent 4,060,634. https://patents.google.com/patent/US4060634
- European Patent Office. Patent family records.
- PatentScope. (Various filings and classifications).
