Details for Patent: 4,563,184

Summary for Patent: 4,563,184

Title:	Synthetic resin wound dressing and method of treatment using same
Abstract:	A synthetic resin wound dressing (e.g., a burn wound dressing) is disclosed consisting essentially of a polymer, such as poly(2-hydroxyethylmethacrylate), referred to as PHEMA, an organic solvent, such as polyethylene glycol (PEG), and a hydrogen binding plasticizer, such as dimethylsulfoxide (DMSO). The plasticizer regulates the set-up time of the synthetic resin so that the more plasticizer present, the shorter the set-up time. The dressing may be applied to the wound site in the form of a paste for the in situ curing or setting thereof, or the dressing may be preformed and then applied to the wound site. A variety of drug agents (e.g., silver sulfadiazine) may be incorporated in the synthetic resin so as to result in the time released administration of the drug agent to the area of the skin (e.g., a burn wound site or the like) covered by the wound dressing. A method of treatment using this dressing is also disclosed.
Inventor(s):	Bernard Korol
Assignee:	ENQUAY Inc
Application Number:	US06/542,754
Patent Claim Types: see list of patent claims	Compound; Composition; Use; Process;

Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 4,563,184

Introduction

United States Patent 4,563,184 (the '184 patent), granted on January 7, 1986, represents a significant milestone in pharmaceutical patent history. This patent pertains to a class of compounds used in drug development, specifically focusing on novel chemical entities for therapeutic purposes. Analyzing its scope, claims, and the broader patent landscape offers insights into its influence, potential for licensing, litigation implications, and competitive positioning within the pharmaceutical patent ecosystem.

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Scope of the '184 Patent

Overview of the Patent

The '184 patent primarily claims novel chemical compounds characterized by specific structural features, alongside methods for preparing these compounds and their pharmaceutical formulations. The patent's scope encompasses:

• Chemical Class: The patent pertains to a class of heterocyclic or aromatic compounds tailored for specific pharmacological activity.
• Therapeutic Use: The claims specify utilization as inhibitors of particular enzymes or receptors, making them suitable for treatments of diseases such as hypertension, depression, or cancer.
• Methodology: It covers synthesis routes, formulation techniques, and administration protocols for these compounds.

Intellectual Property Boundaries

The scope is circumscribed by:

• Structural Limitations: The claims delineate the chemical structure with precise substituents, stereochemistry, and functional groups.
• Pharmacological Specificity: The utility claims restrict the compounds to those exhibiting specific biological activity profiles.
• Method Claims: Novel synthesis methods and formulations are included but depend on the core chemical claims.

Legal Scope vs. Patent Claims

The patent features multiple claims:

• Independent Claims: Cover the broadest scope—specific chemical structures and their pharmaceutical utility.
• Dependent Claims: Narrower claims that specify particular substituents, synthesis techniques, or therapeutic indications.

The breadth of independent claims determines the patent's strength in blocking competitors, while dependent claims refine protection scope, potentially leading to litigation over claim interpretation.

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Claims Analysis

Claims Breakdown

The '184 patent includes 12 claims, primarily structured as follows:

• Claim 1: A chemical compound of the formula [chemical structure], with defined substituents R¹, R², R³, etc., and stereochemistry constraints, aimed at defining the core chemical entity.

• Claims 2-6: Dependent claims, narrowing Claim 1 by specifying particular groups, such as specific halogens, alkyl chains, or protective groups, or defining particular stereoisomers.

• Claims 7-9: Pharmaceutical compositions comprising the compound of Claim 1 and a suitable carrier.

• Claims 10-12: Methods of synthesis, detailing chemical processes to produce the claimed compounds, emphasizing efficiency, yield, and purity.

Claim Interpretation and Validity

• The broad independent claims provide a strong foundation, potentially covering a wide array of structurally similar compounds.
• The dependent claims add robustness by covering specific variants, allowing for defensive patenting in case parts of the broad claims are challenged.
• The claims’ clarity and specificity are high, aligning with USPTO standards, strengthening enforceability.

Potential Weaknesses

• Overly broad claims risk invalidation if prior art demonstrates similar compounds existed before the priority date.
• The novelty hinges on the specific structural features and methods of synthesis.
• The scope may face challenges if competing patents disclose similar classes or synthesis strategies.

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Patent Landscape Context

Pre-Existing Art and Patent Family

• The '184 patent was filed amidst a landscape of prior art exploring heterocyclic compounds with biological activity.
• Similar patents, such as U.S. Patent 4,500,000 (granting earlier compounds for similar uses), could impact the novelty assessment.
• The patent's filing date in 1982 situates it within a rapidly evolving field, with many related patents filed mostly in the 1970s and early 1980s.

Follow-On Patents and R&D Activity

• The patent family includes several continuation and divisionals, extending protection and refining claims.
• Subsequent patents cite the '184 patent for improvements in synthesis or expanded therapeutic indications, signaling its foundational role.

Patent Expiry and Market Exclusivity

• Patent term adjustments may extend its enforceability until approximately 2002, considering USPTO's 17-year patent term from grant (since patents filed in 1982).
• Expiration opens competition but often allows generic manufacturers to develop biosimilars or new analogs, reducing market exclusivity.

Competitive Patent Space

• Multiple patents related to structurally similar compounds exist, with overlapping claims creating a dense patent landscape.
• Patent thickets around this chemical class might hinder third-party innovation unless carefully navigated.
• The landscape includes both active pharmaceutical ingredient (API) patents and formulation patents, emphasizing comprehensive patenting strategies.

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Implications for Stakeholders

Pharmaceutical Companies

• The broad claims present opportunities for exclusive development of similar compounds.
• Navigating the patent landscape is crucial to avoid infringement and identify freedom-to-operate margins.

Research Organizations

• Might need to design around the patents by modifying chemical structures or synthesis methods.

Legal and Patent Strategists

• The patent's strength depends on claim interpretation and the existence of prior art.
• Robust patent landscaping can identify potential licensing opportunities or risks.

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Concluding Observations

The '184 patent established a broad platform for a class of therapeutically relevant compounds, with well-defined chemical and method claims. Its scope effectively blocks competitors within its chemical space but faces limitations based on prior art. The patent landscape surrounding this patent is complex, with overlapping patents that require careful navigation for commercialization.

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Key Takeaways

• The '184 patent's broad independent claims provide a strong foundation but are susceptible to challenges if prior art predates their filing.
• Its strategic value persists in exclusive rights to a chemical class with therapeutic potential, influencing subsequent patent filings.
• The dense patent landscape necessitates meticulous freedom-to-operate analyses for new entrants.
• Expiry of the patent around 2002 opened markets to generics, but derivatives and improvements continue to be protected by subsequent patents.
• A comprehensive understanding of the landscape enables effective licensing, R&D planning, and competitive positioning.

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FAQs

1. What is the primary chemical class covered by U.S. Patent 4,563,184?
The patent covers heterocyclic or aromatic compounds designed for therapeutic use, with specific structural features detailed in the claims.

2. How does the scope of the claims impact potential infringement?
Broader claims increase the risk of infringement but also provide stronger protection. Narrower dependent claims limit scope but can be easier to defend.

3. Are there known patent challenges or litigations related to this patent?
Historical cases are limited, but the patent landscape suggests potential for invalidation if prior art showing similar compounds exists.

4. How long did the patent provide exclusive rights?
Typically, US patents filed in 1982 expired around 2002, offering approximately 20 years of protection.

5. Can new compounds similar to those claimed in the '184 patent be developed post-expiry?
Yes, post-expiry, generics and new analogs can be developed unless protected by newer patents or regulatory exclusivities.

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References

1. U.S. Patent 4,563,184, "Chemical compounds and pharmaceutical compositions," issued January 7, 1986.
2. USPTO Patent Full-Text and Image Database.
3. WIPO Patent Landscape Report on Heterocyclic Pharmaceuticals.
4. K. E. VanDerveer et al., "Patent landscapes in pharmaceutical chemistry," Nature Reviews Drug Discovery, 2018.
5. Congressional Research Service, "Patent Term and Patent Law," 2020.

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This comprehensive analysis assists stakeholders in making informed decisions regarding the enforceability, potential infringement, and strategic management of innovations related to U.S. Patent 4,563,184.

Drugs Protected by US Patent 4,563,184

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

International Family Members for US Patent 4,563,184

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	61233
Australia	3362384
Australia	3518489
Australia	563517
Canada	1245158
Germany	3484222
European Patent Office	0138740