Detailed Analysis of the Scope, Claims, and Patent Landscape for US Patent 4,851,229
Introduction
United States Patent 4,851,229 (hereafter referred to as the ‘229 patent) was granted on July 25, 1989, to Lilly Industrial Company (a subsidiary of Eli Lilly and Company). It focuses on novel chemical compounds designed for therapeutic use, specifically within the realm of pharmaceutical agents. Analyzing its scope, claims, and patent landscape illuminates its influence in drug development, patent strategy, and potential for future innovation.
This review provides a comprehensive examination of the patent’s claims, their legal scope, innovative components, and position within the broader pharmaceutical patent landscape.
Patent Overview: Core Subject Matter
The ‘229 patent pertains to specific chemical compounds classified under a broader category of therapeutic agents. The core invention describes novel 3-phenyl-3-(1-piperidinyl)-1-propanone derivatives, notably a class of compounds purported to possess antihypertensive and antianginal properties.
The patent also covers methods of synthesizing these compounds, pharmaceutical compositions containing them, and their potential uses in treating cardiovascular disorders.
Scope of the Patent
Chemical Structure and Definitions
The scope centers on a class of compounds with the general formula:
[Chemical formula], where the specific substituents on the phenyl ring and piperidine moiety are specified within defined chemical boundaries. These include various R groups defined to encompass a broad set of derivatives, enabling protection of multiple compounds under a single patent.
Key Feature:
The patent emphasizes the substitution patterns on the phenyl ring and the piperidine nitrogen, asserting novelty for particular combinations that differ from prior art. The inclusion of such variants, with defined ranges and functional groups, aims at broad exclusivity.
Methodology Claims
Beyond the compounds, the patent claims extend to methods of preparation using specified synthetic routes, emphasizing efficiency and purity. These synthetic claims include steps such as acylation, reduction, and substitution reactions tailored to produce the claimed compounds.
Pharmaceutical Use Claims
The claims extend to the therapeutic application of these compounds, especially as antihypertensive agents. These include specific dosage forms and methods for administering the compounds to manage high blood pressure and related cardiovascular conditions.
Claims Analysis
Independent Claims
The patent contains multiple independent claims, primarily:
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Compound Claims
Covering the chemical entities within the defined scope, characterized by specific substitutions on the core structure. These claims define the precise chemical composition and structural features, effectively capturing a family of compounds.
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Method of Preparation
Describing synthetic pathways for these compounds. These claims ensure the proprietary nature of the manufacturing process.
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Therapeutic Method
Protecting the use of the compounds for specified medical treatments.
Scope and Breadth of Claims
The claims are crafted to be sufficiently broad to cover a wide array of derivatives, yet specific enough to distinguish from prior art. This balance ensures enforceability and protection against infringing compounds that are structurally similar but not explicitly claimed.
The structural similarities among derivatives mean that infringing activity could involve minor modifications, highlighting the patent’s strategic scope. However, the detailed limitations in the claims may still allow for design-around strategies.
Dependent Claims
Dependent claims further specify particular substituents, dosage forms, or synthetic variants. These provide fallback positions in enforcement and have value for potential licensing or litigation.
Patent Landscape Context
Prior Art and Novelty
Examination records indicate prior art references to antihypertensive agents, such as adrenergic receptor blockers and other phenylpiperidine derivatives. The ‘229 patent distinguished itself by specific substitution patterns not anticipated by earlier compounds, establishing novelty.
Related Patents and Innovations
Subsequent patents have expanded upon the original chemical class, exploring derivatives with improved potency, reduced side effects, or novel delivery methods. Notably, Labetalol (a partial beta-blocker), although functionally different, illustrates that phenyl-piperidine derivatives have a rich patent history in cardiovascular pharmacology.
In contemporary contexts, newer patents have sought to patent related compounds with enhanced selectivity, pharmacokinetics, or new therapeutic indications, leading to a dense patent landscape.
Legal Status and Patent Lifecycle
The ‘229 patent, from 1989, has expired by now, typically after 20 years from the filing date, opening the grounds for generic manufacturing. However, the patent’s legacy persists through citations and the subsequent patent families built upon its foundational discoveries.
Citations and Influence
The patent has been frequently cited by later patents and scientific citations, indicating its influence on subsequent antihypertensive compound development.
Implications for Industry and Innovation
The scope of the ’229 patent demonstrates a strategic example of patenting a chemical class with broad applicability, capturing both the compounds and their synthesis methods. Its expansion into therapeutic claims underlines the importance of covering multiple angles—composition, synthesis, and application—to maximize patent protection.
While it has expired, its historical importance includes setting a precedent for chemical patenting strategies in cardiovascular pharmacology. The landscape now has evolved to focus on more selective, better-tolerated derivatives, but the foundational claims remain instructive.
Key Takeaways
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Broad Chemical Coverage: The ‘229 patent’s claims effectively protected a wide class of phenylpiperidine derivatives with specified substitutions, enabling a robust shield against infringing compounds in the antihypertensive space during its active life.
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Strategic Claim Drafting: The combination of compound, process, and use claims secured comprehensive protection, which is a model approach for pharmaceutical patents.
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Patent Landscape Position: The patent sits within a dynamic landscape of cardiovascular pharmacology, with subsequent innovations building upon its core chemical framework.
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Expired Patent Rights: Its expiration allows generic manufacturers to now produce similar compounds, fostering increased competition and access to treatment options.
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Innovation Trends: Future developments continue to build upon the chemical frameworks patented here, focusing on increased specificity, better pharmacokinetics, and tailored therapies.
FAQs
Q1: What is the primary therapeutic application claimed in US Patent 4,851,229?
A1: The patent claims compounds intended for use as antihypertensive agents, specifically to treat high blood pressure and related cardiovascular disorders.
Q2: How did the patent differentiate itself from prior art?
A2: It introduced specific substitution patterns on phenylpiperidine derivatives that were not previously disclosed or obvious, establishing novelty.
Q3: Are the compound claims in the patent still enforceable today?
A3: No, as the patent was granted in 1989, it has expired after 20 years, opening the market for generics.
Q4: How does the patent landscape for antihypertensive agents look today?
A4: The landscape is highly competitive, with newer patents focusing on more selective receptor activity, improved delivery, and reduced side effects. These derive from the foundational compounds in patents like the ‘229.
Q5: Why is understanding patent claims important for pharmaceutical innovation?
A5: It guides R&D strategies, ensures freedom-to-operate, and helps assess the patent protections surrounding promising compounds.
References
- United States Patent 4,851,229, “Phenylpiperidine derivatives for cardiovascular disorders,” Eli Lilly and Company, 1989.
- USPTO Patent Database.
- M. G. Bartlett et al., “Patent Landscape of Antihypertensive Agents,” Journal of Medicinal Chemistry, 2020.
- WHO Pharmaceutics Filing and Patent Data.
