United States Patent 4,260,769: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,260,769, titled "5,5-Diphenylhydantoins," is a significant patent in the field of pharmaceuticals, particularly concerning anticonvulsant compounds. This analysis will delve into the scope, claims, and the broader patent landscape surrounding this patent.
Background and Invention
The patent, issued to Warner-Lambert Co., pertains to the synthesis and use of 5,5-diphenylhydantoin compounds as anticonvulsants. These compounds are derivatives of hydantoin, a class of drugs known for their efficacy in treating epilepsy and other seizure disorders[5].
Scope of the Patent
Claims
The patent includes several claims that define the scope of the invention. Here are the key aspects:
- Chemical Structure: The patent claims compounds having the 5,5-diphenylhydantoin structure, which are modified to include various acyloxymethyl groups. These modifications enhance the anticonvulsant properties of the base compound[5].
- Synthesis: The claims also cover the methods of synthesizing these compounds, which involve specific chemical reactions to introduce the acyloxymethyl groups.
- Use: The primary use claimed is as anticonvulsants, indicating their therapeutic application in treating seizure disorders.
Independent and Dependent Claims
The patent includes both independent and dependent claims. Independent claims stand alone and define the invention broadly, while dependent claims build upon the independent claims and provide more specific details. For example, an independent claim might cover the general structure of the 5,5-diphenylhydantoin compounds, while a dependent claim might specify a particular acyloxymethyl group attached to the hydantoin ring[5].
Patent Landscape
Regulatory Review and Patent Term Restoration
The approval of a drug product like the one described in this patent involves a significant regulatory review period. Under the Drug Price Competition and Patent Term Restoration Act of 1984, a patent may be extended for up to five years if the product was subject to FDA regulatory review before being marketed. This was relevant for the patent in question, as it underwent a regulatory review period that included both a testing phase and an approval phase[1].
Related Patents and Applications
The patent landscape around 5,5-diphenylhydantoins includes other related patents and applications. For instance, U.S. Pat. No. 3,595,862 is cited as prior art and discusses the potential usefulness of similar compounds as anticonvulsants. This indicates a continuum of research and development in the field of hydantoin derivatives[5].
International Patent Landscape
The global patent landscape for similar compounds is extensive. Databases such as those provided by the European Patent Office (EPO), Japan Patent Office (JPO), and World Intellectual Property Organization (WIPO) offer insights into international patent filings and grants related to anticonvulsant compounds. These resources are crucial for understanding the global scope and potential overlaps or conflicts with other patents[4].
Metrics for Measuring Patent Scope
Claim Length and Count
Research has shown that metrics such as independent claim length and independent claim count can be useful in measuring patent scope. Patents with narrower claims, as indicated by shorter independent claim lengths and fewer independent claims, tend to have a higher probability of grant and a shorter examination process. This suggests that the scope of U.S. Patent 4,260,769, with its specific claims on chemical structure and synthesis, is well-defined and likely to be enforceable[3].
Impact on Innovation and Litigation
The scope and claims of this patent can influence innovation and litigation in the pharmaceutical industry. Patents with clear and narrow claims, like U.S. Patent 4,260,769, can reduce licensing and litigation costs by providing a clear understanding of what is protected. However, overly broad patents can stifle innovation by creating barriers to entry for other researchers and companies[3].
Expiration and Current Status
The patent has expired, as indicated by its legal status. This means that the protected compounds and methods are now in the public domain, allowing other companies to manufacture and use these anticonvulsants without infringing on the original patent[5].
Key Takeaways
- Specific Claims: U.S. Patent 4,260,769 includes specific claims on the chemical structure and synthesis of 5,5-diphenylhydantoin compounds.
- Regulatory Review: The patent underwent a regulatory review period, which could have led to a patent term extension.
- Global Landscape: The global patent landscape for anticonvulsant compounds is extensive, with various international patents and applications.
- Metrics for Scope: The patent's scope can be measured using metrics like independent claim length and count.
- Impact on Innovation: Clear and narrow claims can reduce litigation costs and promote innovation.
FAQs
What is the main subject of U.S. Patent 4,260,769?
The main subject of U.S. Patent 4,260,769 is the synthesis and use of 5,5-diphenylhydantoin compounds as anticonvulsants.
What are the key claims of this patent?
The key claims include the chemical structure of the compounds, methods of synthesis, and their use as anticonvulsants.
Has the patent undergone regulatory review?
Yes, the patent underwent a regulatory review period, which included both a testing phase and an approval phase.
How can the scope of this patent be measured?
The scope can be measured using metrics such as independent claim length and independent claim count.
What is the current status of the patent?
The patent has expired and is no longer in force.
How does this patent impact innovation in the pharmaceutical industry?
The patent's clear and narrow claims can reduce licensing and litigation costs, promoting innovation by providing a clear understanding of what is protected.
Sources
- Federal Register / Vol. 62, No. 54 / Thursday, March 20, 1997 / Notices
- Patent 2937222 Summary - Canadian Patents Database
- Patent Claims and Patent Scope - Search eLibrary :: SSRN
- Search for patents - USPTO
- US4260769A - 5,5-Diphenylhydantoins - Google Patents
