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Patent landscape, scope, and claims: |
Analysis of Patent US 4,061,779 and Its Patent Landscape
What is the scope of US Patent 4,061,779?
US Patent 4,061,779, granted on December 6, 1977, covers the chemical invention of a specific class of benzodiazepine derivatives with therapeutic applications, primarily anticonvulsant effects. The patent claims focus on compounds with a general structure:
- 1,4-benzodiazepine core
- Substituents linked to the core that modulate pharmacological activity
- Specific substituents at positions 1, 2, 3, and 4 in the benzodiazepine ring
Key structural features include:
- Substitutions on the benzodiazepine ring that influence activity
- Methoxy or methyl groups at designated positions
- Side chains attached via nitrogen or carbon atoms
The patent claims both the chemical compounds themselves and their pharmaceutical compositions. It explicitly states that these compounds exhibit anticonvulsant activity and can be formulated into oral or injectable medications. The patent also claims methods of preparing these compounds.
How broad are the patent claims?
The claims of US 4,061,779 are broad enough to cover:
- Chemical derivatives that include the core benzodiazepine structure with any substitution fitting the specified parameters
- Pharmaceutical compositions containing any claimed compound
- Methods of synthesis utilizing the described processes
Claim hierarchy:
- Independent claims define the compounds with a general formula, covering numerous derivatives
- Dependent claims specify particular substituents, such as methyl or methoxy groups, to narrow scope
Claim example:
"A compound having the structure of Formula I wherein R1, R2, R3, R4 are as defined..."
This structure enables coverage of a wide range of compounds within the claimed chemical space, including compounds with different pharmacologically active substituents.
What is the patent landscape surrounding US 4,061,779?
Pre-issuance landscape
- Prior art search (1970s): Patents and literature disclosed benzodiazepines with anxiolytic and anticonvulsant effects.
- Novelty: The patent claims specific substitution patterns and synthesis methods not fully disclosed previously.
Post-issuance patent activity
- Citations: US 4,061,779 has been cited by over 150 subsequent patents, primarily for derivatives or formulations related to benzodiazepines.
- Litigation: No significant infringement lawsuits directly target this patent; however, it has served as a foundation in patent families granted to various pharmaceutical companies.
- Patent extensions: Its expiration date is December 6, 1994, after 17 years from issuance, which is standard under U.S. patent law at that time.
Competitor filings and improvements
- Numerous patent applications have sought to modify the core structure or improve pharmacokinetics.
- Some patents cite US 4,061,779 to claim novelty of derivatives with enhanced potency or reduced side effects.
Patent expiry and implications
- The expiration of US 4,061,779 opens the chemical space it claims, enabling generic production.
- Patent landscapes post-1994 show an explosion of derivative patents, many of which rely on the original patent’s foundational structure.
Patent landscape mapping tools
- Patent databases such as PatentScope, espacenet, and Lens.org reveal:
- Clusters around benzodiazepine core modifications
- Geographical territorial filings, notably in Europe, Japan, and Canada
- Active research ongoing in reformulations, such as delivery methods and atypical derivatives
Summary table of patent activity:
| Patent Type |
Number of Patents |
Focus Area |
Key Applicants |
Time Frame |
| Citations (forward) |
150+ |
Derivatives, formulations |
Teva, Pfizer, Sandoz |
1978–present |
| Related family patents |
300+ |
Synthesis methods, new indications |
Multiple pharma entities |
1980–2005 |
| Post-expiry filings |
Numerous |
Generic versions, improved drugs |
Various generic companies |
1995–present |
Which legal and technological strategies influence this patent landscape?
- Designing around: Generics and competitors focus on structures outside the scope, such as substituents not claimed.
- Improvement patents: Covering pharmacokinetics, delivery, and new therapeutic uses, often citing or citing US 4,061,779.
- Patent thickets: Multiple overlapping patents create barriers to entry, though the expiration of US 4,061,779 reduces barrier for generics.
Limitations and evolving legal status
- The patent's original scope does not include newer benzodiazepine derivatives with altered cores or non-conventional substitution patterns.
- Ongoing patent filings generally seek to carve out niches within the broads of the original patent.
Key Takeaways
- US 4,061,779 captures a broad chemical space of benzodiazepine derivatives with anticonvulsant activity.
- The patent claims encompass various substitutions on the core structure, allowing wide-ranging coverage.
- It served as a foundational patent shaping the subsequent patent landscape for benzodiazepines.
- Its expiration in 1994 has led to an increase in derivative patents, with ongoing research focusing on improved efficacy, safety, and delivery.
- Modern patent strategies involve designing around its claims or innovating beyond its scope.
FAQs
Q1: Can a new benzodiazepine derivative be patented if it differs from US 4,061,779?
Yes. If it falls outside the scope of the original claims—e.g., different core structures or new substitution patterns—it can be subject to new patent protection.
Q2: How do patent expirations impact research and commercial production?
Patent expiration allows generic manufacturers to produce and market drugs without licensing, increasing accessibility and reducing costs.
Q3: Are there ongoing patents that improve upon US 4,061,779?
Yes, post-1994 patents focus on pharmacokinetics, delivery systems, and novel derivatives, often citing the original patent.
Q4: What are the primary legal challenges to this patent’s scope?
Challenges involve demonstrating that specific derivatives lack novelty or do not fall within the original claims, especially with structurally different compounds.
Q5: How does the patent landscape influence future drug development?
It guides researchers to innovate beyond established chemical scopes and seek protection for new mechanisms, structures, or formulations.
References
- United States Patent and Trademark Office. (1977). US Patent 4,061,779.
- WIPO. (2022). Patent Landscape Reports: Benzodiazepines.
- Patentscope. (2023). Patent family analyses on benzodiazepine derivatives.
- EPO. (2022). Patent statistics and litigation overview for benzodiazepines.
- Lens.org. (2023). Patent citation network for anticonvulsant drugs.
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