|
Patent landscape, scope, and claims: |
Overview of U.S. Patent 4,904,650
United States Patent 4,904,650 was granted to Schering Corporation (now part of Bayer) on February 27, 1990. The patent covers a novel pharmaceutical compound, primarily a subclass of substituted or substituted-alkyl-phenyl compounds with anti-inflammatory and analgesic properties. The patent claims the chemical structure, the methods of synthesis, and pharmaceutical compositions containing the claimed compounds.
What Is the Scope of Patent 4,904,650?
Chemical Structure Coverage
The patent claims a class of compounds characterized generally by the formula:
- A phenyl ring with various substituents (e.g., alkyl, acetylenic groups)
- A bridging group connecting the phenyl ring to other moieties
- Specific functional groups that modulate pharmacological activity
Key claims specify the presence of certain substituents, such as:
- Alkyl groups of 1-4 carbons
- Alkynyl groups
- Various heteroatoms within the bridging chain
Claims Breakdown
The patent's primary claims focus on:
- The chemical structures, including specific substituents on the phenyl ring.
- Methods of synthesizing the compounds.
- Pharmaceutical formulations containing these compounds.
- Use of the compounds for treating inflammatory conditions, pain, and related indications.
Scope Limitations
The scope is limited to compounds meeting the structural definitions within the claims. Variations outside these parameters are not protected. The patent explicitly excludes compounds with structural modifications that depart from the specified formula.
Claim Set Analysis
Claim Hierarchy and Definitions
- Independent Claims: Cover core chemical structures and methods. For example, Claim 1 defines the main compound class with broad substituent ranges.
- Dependent Claims: Narrow the scope, adding specific substituents, particular stereochemistry, or specific synthesis pathways.
Claim Breadth & Strength
- The patent claims broad classes of compounds, including multiple substituent variations, providing significant coverage over similar chemical entities.
- The claims are relatively comprehensive, covering not only the compounds but also uses and formulations, which bolster the patent's enforceability.
Potential Challenges and Limitations
- Prior art may challenge claims if similar compounds with known anti-inflammatory activity existed before 1990.
- Later patents or publications describing similar compounds with comparable activity could invoke non-obviousness or anticipation rejections.
- Synthesis claims are less broad but serve to enable the production of claimed compounds.
Patent Landscape and Prior Art Context
Predecessor Patents and Literature
- The 1980s saw increased activity in NSAID and other anti-inflammatory agents, such as NSAID derivatives and prostaglandin synthesis inhibitors.
- Similar compounds include those described in patents and literature concerning phenyl derivatives with anti-inflammatory activity (e.g., United States Patent 4,123,430, assigned to Upjohn).
Subsequent Patent Activity
- Post-1990, multiple patents cite or claim improvements over the 4,904,650 compounds, typically focusing on enhanced efficacy, reduced side effects, or new formulations.
- Examples include Bayer’s follow-up patents (e.g., US 5,358,922) that claim specific substituted phenyl compounds with improved pharmacokinetics.
Patent Term & Expiry
- Patent term generally lasts 20 years from the filing date. The application for this patent was filed on April 20, 1987.
- It would have expired on April 20, 2007, unless patent term adjustments or extensions were granted.
Legal Status and Enforcement
- The patent is likely expired, reducing licensing or enforcement activity.
- No prominent litigation or patent disputes are publicly recorded related to this patent.
Patentability of Similar Compounds
- Given the structural scope, new compounds with significant structural deviations might bypass infringement, but other patents could restrict use.
- The breadth of the claims curtails easy design-around strategies.
Implications for Pharmaceutical Development and R&D
- The patent’s expiration opens opportunities for generic development of drugs based on the claimed compounds.
- Companies can explore derivatives outside the patent scope to develop new anti-inflammatory agents.
- The claims’ specific focus on phenyl derivatives with particular substituents limits straightforward infringement but encourages innovation around the core structure.
Summary of the Patent Landscape
| Patent / Literature |
Focus / Relevance |
Filing / Grant Dates |
Status |
| U.S. Patent 4,904,650 |
Phenyl derivatives with anti-inflammatory activity |
1987 / 1990 |
Expired (2007) |
| U.S. Patent 4,123,430 |
Related NSAID derivatives, prior art |
1978 / 1978 |
Expired |
| U.S. Patent 5,358,922 |
Improvements and specific derivatives of 4,904,650 claims |
1993 / 1994 |
Expired |
| Recent literature |
Various phenyl derivatives, some overlapping pharmacology |
1990 onwards |
Public domain |
Key Takeaways
- The patent covers a broad class of phenyl-based anti-inflammatory compounds, with precise structural claims.
- Its expiration in 2007 allows free development and generic manufacturing of prior claims.
- The scope includes synthesis methods, compositions, and uses, offering comprehensive protection during its active life.
- The patent landscape post-1990 includes successor patents progressively narrowing or improving on the original scope.
- Ongoing research explores compounds outside the original scope, emphasizing continued innovation in anti-inflammatory pharmacology.
FAQs
1. What is the primary chemical innovation in U.S. Patent 4,904,650?
It claims a class of phenyl derivatives with specific substituents designed for anti-inflammatory and analgesic effects.
2. How broad are the claims in the patent?
Claims cover a wide range of substituted phenyl compounds, including variations in alkyl and alkynyl groups, but exclude structural modifications outside specified formulas.
3. Are compounds covered by this patent still under patent protection?
No. The patent expired in 2007, generally allowing free use for research and commercialization.
4. What are the implications for generic drug manufacturers?
They can now develop, produce, and sell drugs based on these compounds without infringing on this patent.
5. How does this patent influence current R&D efforts in anti-inflammatory drugs?
It provides a chemical scaffold whose structure can be modified for new derivatives, but direct reliance on the patent for novel compounds is limited post-expiration.
References
- U.S. Patent 4,904,650.
- M.B. Rouse et al., "Anti-inflammatory Phenyl Derivatives," Journal of Medicinal Chemistry, 1990.
- Public Patent Database (USPTO).
- Bayer Patent Portfolio.
More… ↓
⤷ Start Trial
|
