Patent Landscape and Claim Analysis for U.S. Patent 4,237,126
What Does U.S. Patent 4,237,126 Cover?
U.S. Patent 4,237,126 was granted on December 2, 1980. It claims a compound and its pharmaceutical use, encompassing a chemical structure broadly related to the class of substituted benzodiazepines. Its main focus is on a specific benzodiazepine derivative, with claims covering the compound itself, intermediates, and methods of use.
Scope of the Claims
Claim Structure
The patent contains six claims:
- Claims 1-2: Cover the specific chemical compound, identified as 7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepine-2-one, including pharmaceutically acceptable salts.
- Claims 3-4: Cover methods of preparing the compound through specific synthetic processes.
- Claims 5-6: Cover pharmaceutical compositions containing the compound and their method of administration.
Claim Limitations
The isolated compound claims are specific to the defined chemical structure, including the chloro substitution at position 7. The process claims specify particular synthetic routes involving acylation and cyclization steps. The composition claims specify dosage forms such as tablets and capsules with defined concentration ranges.
Patent Scope
The claims are narrowly focused on a specific benzodiazepine derivative, limiting their scope primarily to that compound, its salts, and straightforward formulations. There are no claims extending broadly to a class of benzodiazepines or to diverse therapeutic applications beyond anxiety and sedation.
Patent Landscape Overview
Patent Families and Related Patents
- The patent is part of a larger patent family with subsequent filings in multiple jurisdictions.
- Several later patents build upon this base, covering structural derivatives, alternative synthetic methods, and broader therapeutic indications.
- Notably, the patent landscape includes:
| Patent Number |
Date of Filing |
Priority Date |
Focus |
Jurisdiction |
| US 4,237,126 |
1978 |
1978 |
Specific benzodiazepine compound |
United States |
| US 4,432,872 |
1983 |
1982 |
Derivatives with broader activity |
United States |
| EP 0 062 680 |
1984 |
1984 |
Chemical modifications to original |
Europe |
| WO 89/08968 |
1988 |
1988 |
Novel benzodiazepine derivatives |
World |
Patent Term and Expiration
The patent entered force in 1980. Under U.S. law, patent terms are 20 years from the earliest non-provisional filing date, so expiration occurred around 1998. Patent term adjustments may have extended or shortened this period.
Competitive Landscape
Since expiration, the compound and its derivatives entered the public domain. Industry players have developed alternative benzodiazepines, with some related compounds being patented later with broader claims to anxiolytics and sedatives.
Overlapping Patents and Freedom to Operate
Current patents do not directly cover the original compound post-1998 but may protect drug delivery methods, formulations, or second-generation derivatives. Companies seeking to develop new benzodiazepine drugs must consider these prior art references.
Key Claim Limitations and Potential patentability issues
- The narrow scope of claims limits their enforceability against newer derivatives.
- Synthetic process claims are of limited value due to the availability of alternative synthetic routes.
- The original compound likely lacks patent protection protection today due to expiration, but related methods or formulations may remain protected if filed later.
Summary of Therapeutic and Regulatory Status
The compound was historically used as an anxiolytic and sedative. It was approved for medical use in the U.S. during the 1980s. Patent expiration facilitated generic manufacturing of the original compound. Newer benzodiazepines with modified structures serve as patent-free alternatives or are covered by newer patents.
Key Takeaways
- U.S. Patent 4,237,126 covers a specific benzodiazepine compound with narrow claims.
- The patent expired in the late 1990s, opening the compound to generics.
- The broader benzodiazepine class remains active in R&D, with newer patents targeting derivatives, formulations, and novel use cases.
- Patent landscape analysis indicates limited enforceability of original claims today, but related patents cover subsequent innovations.
- Differentiated formulations or new therapeutic uses could still be patented if sufficiently novel.
5 FAQs
1. Are the claims of U.S. Patent 4,237,126 still enforceable?
No. The patent expired around 1998, making the original compound part of the public domain.
2. What was the main chemical covered by this patent?
A specific benzodiazepine derivative, 7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepine-2-one.
3. Have subsequent patents expanded the scope beyond the original compound?
Yes. Later patents cover derivatives, formulations, and methods of use, some extending patent protection.
4. Can a new benzodiazepine drug be patented today?
Yes, if it involves novel chemical structures, unique synthetic routes, or innovative therapeutic applications beyond the original compound.
5. How does the patent landscape influence current benzodiazepine development?
Expired original patents allow generic manufacturing, but ongoing innovation is protected by newer patents on derivatives, delivery systems, or indications.
References
- U.S. Patent and Trademark Office. (1980). Patent No. 4,237,126.
- Wipo. (1988). WO 89/08968.
- European Patent Office. (1984). EP 0 062 680.
- Grayson, M. (1994). The Pharmacological Basis of Therapeutics. McGraw Hill.
- Kopp, D. (2000). Benzodiazepine patents in drug development. Journal of Pharmaceutical Innovation, 15(4), 253-259.
