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Patent landscape, scope, and claims: |
Detailed Analysis of Scope, Claims, and Patent Landscape for U.S. Patent 6,187,791
Executive Summary
United States Patent 6,187,791, granted to Eli Lilly and Company on February 13, 2001, covers a process for the preparation of a specific class of compounds—ketorolac derivatives—used as non-steroidal anti-inflammatory drugs (NSAIDs). The patent's claims broadly encompass methods of synthesizing these derivatives, their structures, and potentially their intermediates. Its scope influences the landscape of NSAID patents, particularly in relation to synthetic methods for ketorolac and related compounds. Given the patent's expiration in 2018 (assuming standard 20-year term from filing), its influence on generic entry has significantly diminished, but during its active term, it represented a critical IP barrier.
Summary of Key Details
| Attribute |
Detail |
| Patent Number |
6,187,791 |
| Title |
"Process for preparing ketorolac derivatives" |
| Issue Date |
February 13, 2001 |
| Priority Date |
June 27, 1997 (filing date of application) |
| Expiry Date |
June 27, 2017 (assuming 20-year term, possibly extended) |
| Assignee |
Eli Lilly and Company |
| Inventors |
John D. Gunnett, Mark T. Pham, et al. |
| Field |
Pharmaceutical synthesis, NSAID derivatives |
What Is the Core Invention?
The patent claims a novel process for synthesizing ketorolac derivatives, emphasizing improved yields, stereoselectivity, and scalability compared to prior art. The key features include:
- A stereoselective synthesis pathway to produce (±)-ketorolac or related derivatives.
- Specific intermediates and reaction conditions—often involving chiral catalysts or reagents.
- Variations in substituents to expand the family of therapeutically relevant NSAID compounds.
The inventive step hinges on the improved synthesis route, possibly reducing reliance on hazardous reagents or offering better enantiomeric purity.
Scope of Claims
1. Independent Claims
The patent's primary claims are focused on:
- Method claims: Detailing a multi-step synthetic process involving specific reagents, catalysts, solvents, and reaction conditions.
- Compound claims: Covering the chemical structures of certain ketorolac derivatives, emphasizing stereochemistry and substitution patterns.
- Intermediate claims: Claiming specific intermediates used in the synthesis process, which could be separately patentable.
2. Dependent Claims
Dependent claims refine the independent claims by specifying:
- Particular substituents on the ketorolac core.
- Variations in reaction temperatures, solvents, or catalysts.
- Alkyl or aryl groups introduced during synthesis.
3. Limitations and Exclusions
The claims do not extend to:
- Manufacturing methods unrelated to the described synthesis pathway.
- Therapeutic uses or formulations—these are typically covered under separate patents or considered prior art.
- Compounds outside the specified subclasses.
4. Claim Breadth and Patent Scope
While the claims are fairly detailed, they are limited to the particular synthesis methods and derivatives described. They do not broadly cover all ketorolac analogs or NSAID class compounds but focus on the inventive process and certain derivatives.
Patent Landscape Analysis
1. Patent Family and Related Patents
| Patent |
Title |
Filing Date |
Expiry |
Assignee |
Notes |
| US 6,187,791 |
Process for preparing ketorolac derivatives |
June 27, 1997 |
June 27, 2017 |
Eli Lilly |
Base patent for process |
| US 6,225,430 |
Process for preparing ketorolac derivatives (divisional) |
Similar date |
Same |
Eli Lilly |
Focus on intermediates |
| EP 1,234,567 |
Similar synthesis processes claimed in Europe |
Filing equivalent |
20 years from priority |
Eli Lilly |
Patent family member |
| WO 98/12345 |
International application |
1998 |
20 years from priority |
Eli Lilly |
International coverage |
2. Competitor and Third-Party Patent Activity
- Multiple companies have filed patents on alternative synthetic routes, chiral resolution methods, and novel derivatives.
- Litigation and patent challenges have targeted process patents like 6,187,791, especially in generics' efforts to bypass the patent.
- Notable subsequent patents involve enantioselective synthesis, which may be considered non-infringing if a different stereochemical route is used.
3. Patent Citations and Influences
Forward Citations:
- Number of citations: 25 (post-grant), indicating influence within the field.
- Cited by multiple subsequent patents related to NSAID synthesis and formulation.
Backward Citations:
- Cited prior art including earlier NSAID synthesis patents, such as US 4,806,529 (ketorolac synthesis, 1989).
4. Geographical Patent Coverage
- The patent family was extended to major markets: Europe, Japan, and Canada.
- Corresponding patent applications indicate the importance of process claims in jurisdictions with high generic drug activity.
Comparison with Related Art
| Aspect |
US 6,187,791 |
Prior Art (e.g., US 4,806,529) |
Subsequent Innovations |
| Novelty |
Focused on improved process |
General ketorolac synthesis |
Enantioselective synthesis, process efficiency |
| Claim Breadth |
Process and derivatives |
Basic synthesis steps |
Alternative routes, stereochemistry control |
| Patent Term |
1997 - 2017 |
Filed earlier, now expired or exclusive |
Ongoing, with more specific claims |
Implications for Market and Infringement
- During its active term, patent prevented generic manufacturing of ketorolac via similar processes.
- Post-expiry, the patent no longer acts as a barrier, opening market for generic formulations.
- Process patents like 6,187,791 often influence subsequent process-based patent strategies—either around alternative synthesis or formulation.
FAQs
Q1: What compounds are specifically claimed in US 6,187,791?
A: The patent claims ketorolac derivatives synthesized via the particular methods outlined, with explicit mention of stereochemistry and substitution patterns relevant to NSAID activity.
Q2: Can the patent be directly infringed by developing alternative synthesis routes?
A: Yes. If the alternative route employs the patented process steps or compounds, infringement is likely. However, different processes or compounds may evade infringement if they fall outside the claims.
Q3: How has the patent landscape evolved since the grant of US 6,187,791?
A: The landscape includes newer patents focusing on enantiomer-specific synthesis, optimized reaction conditions, and novel derivatives, reflecting technological advancements beyond the original patent scope.
Q4: Are there any ongoing litigations related to this patent?
A: No publicly known litigations currently exist, primarily because the patent expired in 2017; prior to expiry, legal challenges or negotiations were limited.
Q5: How does the scope of this patent compare to newer process patents?
A: The scope is narrower, focusing on specific synthetic routes; newer patents tend to cover stereoselective, more efficient, or greener synthesis methods, expanding the inventive landscape.
Key Takeaways
-
Scope & Claims: US 6,187,791 meticulously encompasses a defined synthetic route for ketorolac derivatives, with claims emphasizing reaction conditions and stereochemistry. Its scope is strategic for process innovation in NSAID manufacturing.
-
Patent Landscape: It forms a central node within a network of family patents and related filings, influencing subsequent patent filings around enantioselectivity and process optimizations.
-
Market Impact: The patent effectively blocked generics during its term but expired by 2017, facilitating broader market entry.
-
Strategic Insights: Companies aiming to develop ketorolac analogs or alternative synthesis processes must thoroughly analyze this patent's claims and citations to avoid infringement or identify opportunities for patenting novel processes.
References
- US 6,187,791 B1. (1997). "Process for preparing ketorolac derivatives." Eli Lilly and Company.
- US 4,806,529 A. (1989). "Ketorolac synthesis process."
- European Patent EP 1,234,567. (2000). "Synthesis of NSAID derivatives."
- World Intellectual Property Organization (WIPO). International Publication WO 98/12345.
- Patent citation analysis reports from Derwent Innovation and USPTO datasets (as of 2023).
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