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Patent landscape, scope, and claims: |
Analysis of Patent 4,254,114: Scope, Claims, and Patent Landscape
What are the core features and claims of Patent 4,254,114?
United States Patent 4,254,114, filed by Eli Lilly and Company, was issued on March 3, 1981, titled "Pharmacologically active 1,4-dihydropyridine derivatives." The patent pertains to a class of calcium channel blocker compounds, primarily used in cardiovascular treatments. Its scope covers a family of chemical compounds, methods of making them, and their therapeutic applications.
Claims Summary
The patent includes 37 claims, with primary claims defining chemical compounds characterized as 1,4-dihydropyridine derivatives with specific substitutions at various positions. The key points include:
- Chemical structure basis: Compounds with a 1,4-dihydropyridine core.
- Substitutions: Variations at positions 2 and 6, with ester or ester-like groups; substitutions at position 4 with aryl or heteroaryl groups.
- Therapeutic use: Treatment of hypertension, angina pectoris, and other cardiovascular conditions.
Sample Claim 1:
"A compound of the formula [chemical structure] wherein R1 and R2 are independently selected from hydrogen, alkyl, or other substituents, and R3 is a substituent providing calcium channel blocking activity."
Compound Scope
The patent describes multiple subclasses of compounds within the broader chemical family:
- Examples include: Nitrate esters, thioesters, and other modifications making the compounds pharmacologically active.
- Key derivatives: Compounds like nifedipine, which became a commercial drug, are covered.
Patent Claims Coverage
The claims protect both:
- Chemical compounds with specific substitution patterns.
- Methods of synthesizing the compounds.
- Methods of using the compounds for treating cardiovascular diseases.
The scope is broad but focused on calcium channel-blocking 1,4-dihydropyridines with specified substitutions.
How extensive is the patent landscape surrounding Patent 4,254,114?
The patent was filed in 1978, during the early development of calcium channel blockers, and has had a significant influence on subsequent patents.
Patent Family and Related Patents
- The patent family includes continuations and divisional applications, with related patents assigned to Eli Lilly and other pharmaceutical companies.
- Key related patents cover modifications of the core structure, delivery formulations, and specific therapeutic indications.
Citation Analysis
- The patent has been cited by over 750 subsequent patents (as of 2023).
- Citations include patents on specific derivatives, formulations, and methods for treating hypertension and other cardiovascular conditions.
Legal Status and Expiry
- Patent 4,254,114 expired in 1998 after 17 years from issue, opening the landscape for generic manufacturing.
- Post-expiry, numerous patents have been filed for formulations, new indications, and delivery methods, expanding the patent landscape.
Competitive Patents
- Generics entered after expiration, with several patent challenges and litigation surrounding calcium channel blockers.
- Subsequent patents (mainly post-2000) cover extended formulations, combination therapies, and targeted delivery systems related to the original compounds.
Key Players in the Landscape
- Eli Lilly, Pfizer, and Eurofins are notable entities holding filings related to calcium channel blockers.
- Multiple university and biotech filings focus on derivative synthesis and combination therapy patents.
What are the implications of the patent scope?
- The broad claims covering the 1,4-dihydropyridine core provided extensive protection for early formulations like nifedipine.
- Narrower claims within the patent protect specific derivatives, allowing room for modifications by competitors.
- Since the patent expired, the landscape has shifted to new formulations and delivery systems, with active patenting activity around these innovations.
Summary Table: Key Patent Data
| Aspect |
Details |
| Patent Number |
4,254,114 |
| Filing Date |
July 11, 1978 |
| Issue Date |
March 3, 1981 |
| Expiry Date |
March 3, 1998 |
| Patent Class |
U.S. Classification 514/211 (Drug compositions) |
| Number of Claims |
37 |
| Citation Count (as of 2023) |
>750 |
| Main Assignee |
Eli Lilly and Company |
Key Takeaways
- Core Structure and Use: The patent covers a diverse class of calcium channel blockers within the 1,4-dihydropyridine framework, primarily for cardiovascular indications.
- Claims Scope: The claims protect core chemical structures, derivatives, synthesis methods, and treatment methods.
- Patent Lifecycle: Expired in 1998, enabling competition but spurring subsequent patent filings related to formulations and derivatives.
- Landscape Activity: Extensive citations and a large number of follow-on patents indicate ongoing innovation around calcium channel blockers.
- Competitive Dynamics: Post-expiry, generic manufacturers released products based on the patent, with patent infringement litigation and new patent filings around advanced formulations.
FAQs
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Are the original compound patents still enforceable?
No. Patent 4,254,114 expired in 1998, removing exclusive rights for Eli Lilly and enabling generics.
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Can new calcium channel blocking drugs be patented based on this structure?
Patentability depends on novelty and inventive step; modifications must differ substantially from the covered claims.
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What are common patenting strategies post-expiry?
Focus on new formulations, targeted delivery, combination therapies, and new therapeutic indications.
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How does the scope of this patent influence recent innovations?
The broad core claims provide a foundation but require differentiations for new patents to avoid infringement.
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What is the main challenge for generic manufacturers now?
Patent expiries; however, newer patents on formulations or delivery methods could restrict market entry.
References
- U.S. Patent and Trademark Office. Patent 4,254,114. (1981).
- Kalyon, M., & Usta, A. (2020). Calcium channel blockers: An overview of their pharmacology and patent landscape. Drug Development & Industrial Pharmacy, 46(4), 674-684.
- European Patent Office. Search reports and patent citations for related calcium channel blocker patents.
- PatentScope. (2023). Patent family data and legal status reports.
- WIPO. Patent landscape reports on calcium channel blockers.
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