United States Patent 5,798,338: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,798,338, titled "Solid dosage forms that contain clathrates of 17α-ethinyl estradiol," is a significant patent in the pharmaceutical field, particularly in the area of hormone therapy. This patent, granted to various assignees over its lifecycle, involves the development and formulation of solid dosage forms containing specific clathrates of 17α-ethinyl estradiol, a synthetic estrogen commonly used in contraceptive and hormone replacement therapies.
Background and Context
The patent was filed and granted in the late 1990s, a period of significant advancement in pharmaceutical formulations. The development of new dosage forms was crucial for improving the efficacy, stability, and patient compliance of drugs.
Scope of the Patent
Claims Overview
The patent includes multiple claims that define the scope of the invention. Here are some key aspects:
- Claim 1: This claim typically defines the broadest scope of the invention, often describing the composition of the solid dosage form and the presence of clathrates of 17α-ethinyl estradiol.
- Dependent Claims: These claims narrow down the scope by specifying particular aspects such as the type of clathrate, the formulation components, and the method of preparation[2].
Clathrates of 17α-ethinyl Estradiol
The patent focuses on the use of clathrates, which are inclusion compounds where the guest molecule (in this case, 17α-ethinyl estradiol) is trapped within a lattice structure of the host molecule. This formulation enhances the stability and bioavailability of the active ingredient[2].
Claims Analysis
Independent Claims
Independent claims are crucial as they define the standalone inventions. For example:
- Claim 1 might state: "A solid dosage form comprising a clathrate of 17α-ethinyl estradiol and a pharmaceutically acceptable carrier."
- This claim sets the foundation for what constitutes the invention, allowing for various interpretations and applications within the scope of the claim.
Dependent Claims
Dependent claims build upon the independent claims, adding specific details that further define the invention. For instance:
- Claim 2 might state: "The solid dosage form of claim 1, wherein the clathrate is formed with a cyclodextrin."
- These claims help in narrowing down the scope and provide additional protection for specific embodiments of the invention.
Patent Landscape
Related Patents and Continuations
The patent landscape around US 5,798,338 includes other related patents and continuations that may have been filed to extend the scope or term of the original patent. For example, if there are continuation-in-part patents or divisional patents, these would be part of the same patent family and would share a common priority date[1].
Competitor Patents
Other companies or inventors may have filed similar patents in the same field, which could potentially infringe on or be infringed by US 5,798,338. Conducting a thorough search using tools like the USPTO's Patent Public Search or international databases such as the European Patent Office's esp@cenet can help identify these patents[4].
Assignments and Ownership
Assignment History
The patent has likely undergone several assignments and changes in ownership since its grant. The USPTO's Patent Assignment Search database can be used to track these changes, which are crucial for understanding the current ownership and any potential licensing agreements[4].
Impact on Market
Changes in ownership can significantly impact the market, especially if the patent is licensed to multiple parties or if it is part of a larger portfolio used for strategic advantage. For instance, a pharmaceutical company acquiring this patent could use it to strengthen its market position in hormone therapy products.
Examination and Reexamination
Examination Process
The original examination process would have involved a thorough review of the patent application to ensure that the invention was novel, non-obvious, and useful. The examiner would have considered prior art and the claims would have been adjusted accordingly.
Reexamination Proceedings
If the patent underwent reexamination, this would have involved a re-evaluation of the patent's validity based on new prior art or other grounds. This process can result in the patent being upheld, modified, or even invalidated, as seen in cases like the Cellect LLC appeal where obviousness-type double patenting (ODP) was a key issue[1].
International Protection
Global Dossier and International Filings
To protect the invention globally, the patent holders might have filed corresponding applications in other countries through the Patent Cooperation Treaty (PCT) or directly in national patent offices. Tools like the Global Dossier can help track these international filings and their status[4].
Harmonization and Citation Data
International harmonization efforts, such as the Common Citation Document (CCD) application, help in consolidating prior art citations across different patent offices. This facilitates a more unified approach to patent searching and examination globally[4].
Economic and Strategic Impact
Market Domination
Holding a patent like US 5,798,338 can provide significant market advantages, including exclusive rights to manufacture and sell the specified solid dosage forms. This can lead to market domination in the hormone therapy sector.
Licensing and Revenue
The patent can also be licensed to other companies, generating revenue through royalties. This is particularly beneficial if the patent covers a widely used formulation.
Challenges and Controversies
Litigation and Disputes
Patents in the pharmaceutical sector are often subject to litigation and disputes over infringement, validity, or scope. For example, disputes over obviousness-type double patenting (ODP) can arise, as seen in the Cellect LLC case[1].
Regulatory Compliance
Compliance with regulatory requirements, such as those set by the FDA, is crucial. The patent must align with the approved drug formulations and manufacturing processes.
Key Takeaways
- Scope and Claims: The patent covers solid dosage forms containing clathrates of 17α-ethinyl estradiol, with specific claims defining the composition and formulation.
- Patent Landscape: The patent is part of a broader landscape that includes related patents, competitor patents, and international filings.
- Assignments and Ownership: Changes in ownership can impact market strategy and licensing agreements.
- Examination and Reexamination: The patent's validity can be challenged through reexamination proceedings.
- International Protection: Global filings and harmonization efforts are essential for comprehensive protection.
- Economic and Strategic Impact: The patent can provide market advantages and revenue through licensing.
FAQs
What is the main subject of United States Patent 5,798,338?
The main subject of this patent is the development of solid dosage forms that contain clathrates of 17α-ethinyl estradiol, a synthetic estrogen used in hormone therapy.
How does the clathrate formulation enhance the drug?
The clathrate formulation enhances the stability and bioavailability of 17α-ethinyl estradiol, making the drug more effective and easier to administer.
What is the significance of dependent claims in this patent?
Dependent claims narrow down the scope of the invention by specifying particular aspects such as the type of clathrate and the method of preparation, providing additional protection for specific embodiments.
How can changes in ownership affect the market?
Changes in ownership can impact market strategy, licensing agreements, and the overall competitive landscape in the pharmaceutical sector.
What tools can be used to track international filings of this patent?
Tools like the Global Dossier and international patent databases such as the European Patent Office's esp@cenet can be used to track international filings and their status.
