Scope and Claims Analysis of U.S. Patent 5,061,722
Patent Overview
U.S. Patent 5,061,722, granted on October 29, 1991, covers a benzodiazepine derivative with therapeutic applications, particularly focusing on its use as an anxiolytic, sedative, or muscle relaxant. The patent is assigned primarily to Hoffmann-La Roche Inc., emphasizing its relevance to pharmaceutical compositions involving benzodiazepine compounds.
Claims Breakdown
The patent contains 16 claims, with the core claims establishing the chemical compound's structure, its pharmaceutical composition, and methods of use.
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Claim 1: Defines a chemical compound with a benzodiazepine core, specifically characterized by a substituted phenyl group at the N1 position and a methyl group at the 2-position of the diazepine ring. It broadly covers compounds where various substituents can be attached to the phenyl ring, including halogens and alkyl groups.
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Claims 2-4: Specify particular derivatives within the scope of Claim 1, such as 1-methyl-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepine-2-one.
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Claims 5-8: Address pharmaceutical compositions incorporating the compounds and their methods for treating anxiety, tension, or sleep disturbances.
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Claims 9-16: Cover the methods of synthesizing the compounds and their intermediates.
Scope Analysis
The patent's claims encompass a class of benzodiazepine derivatives characterized by structural features including a phenyl substituent at the N1 position and methyl substitution at the 2-position. The broad language in Claim 1 provides protection over multiple derivatives, potentially covering compounds with various phenyl substituents, as long as the core benzodiazepine structure is maintained. However, the claims exclude compounds with significant modifications outside the specified substitution pattern.
The focus on specific substituents limits the scope regarding derivatives outside the phenyl group or with structural modifications that fall outside the enumerated claims. The patent primarily emphasizes compounds with anxiolytic and sedative activity, reflected in claims directed at therapeutic uses.
Patent Landscape Context
This patent fits into the broader benzodiazepine patent landscape, which includes multiple patents filed from the 1960s through the 1990s. Notable adjacent patents include:
- U.S. Patent 3,652,761: Covering early benzodiazepine compounds like diazepam.
- U.S. Patent 4,088,607: Covering substituted benzodiazepines with anxiolytic applications.
The scope of 5,061,722 overlaps with other patents claiming specific derivatives, but its unique aspect resides in the substituted phenyl design, which was a focus of several subsequent patents aiming to develop new benzodiazepine analogs.
Legal Status and Lifespan
The patent's enforceability expired in 2009, given its 17-year patent term from the grant date, subject to maintenance fee payments. With expiration, this opens the prior art landscape and generic development within the scope of the claims.
Implications for Competitors
Merck, Teva, and other generic companies could potentially enter the market now that the patent has expired, provided they do not infringe on other active patents covering benzodiazepine formulations or synthesis methods.
Comparison with Contemporary Patents
Compared to more recent filings, the claims of 5,061,722 are relatively broad but centered on classical benzodiazepine structures. Newer patents tend to include novel substitution patterns, asymmetric compounds, or unique synthesis methods to extend patent life or carve out specific niches.
Conclusion
U.S. Patent 5,061,722 claims a specific class of benzodiazepine derivatives with industrial relevance for anxiolytic and sedative indications. Its expiration creates space for generic competition and further development within its structural scope.
Key Takeaways
- The patent claims a class of benzodiazepine derivatives with phenyl substitution at N1 and methyl group at the 2-position.
- Its scope covers compounds with various phenyl substitutions, aligned with anxiolytic/sedative uses.
- The patent expired in 2009, opening the market for generics.
- The landscape includes overlapping patents but with distinct claims focusing on specific derivatives.
- The patent's structure set the foundation for subsequent modifications and analog development in benzodiazepine research.
FAQs
1. What are the main chemical features covered by the claims?
The core features include a benzodiazepine ring with a phenyl group at the N1 position and a methyl group at the 2-position, with various phenyl substitutions incorporated.
2. How does this patent compare to earlier benzodiazepine patents?
It expands upon earlier patents like U.S. Patent 3,652,761 by claiming specific substitution patterns, focusing on benzodiazepine derivatives with altered phenyl groups.
3. Does the patent cover all benzodiazepines?
No, it specifically covers a subclass with phenyl substitution at N1 and methyl at 2-position, not all benzodiazepine compounds.
4. Can a company develop new benzodiazepines without infringing this patent now?
Yes, since the patent has expired, new benzodiazepine derivatives outside its claims do not infringe, though one should assess other active patents.
5. What therapeutic applications are covered by the patent claims?
Primarily anxiolytic, sedative, and muscle relaxant indications.
Citations
- U.S. Patent 5,061,722.
- Prior art references including U.S. Patent 3,652,761.
- Patent landscape analyses reports on benzodiazepines.
