United States Patent 6,106,864: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 6,106,864, titled "Pharmaceutical formulations containing darifenacin," is a significant patent in the pharmaceutical industry, particularly in the development and formulation of medications for gastrointestinal tract administration. This patent, granted to Pfizer Inc., focuses on optimizing the delivery and bioavailability of darifenacin, a medication used to treat overactive bladder.
Background and Inventors
The patent was filed on January 29, 1999, and granted on August 22, 2000. The inventors listed are Andrew A. B. Dolan, David S. Fradet, and others from Pfizer Inc.[4].
Scope of the Patent
Medication and Purpose
The patent revolves around pharmaceutical formulations of darifenacin, which is a muscarinic receptor antagonist used primarily to treat overactive bladder. The formulations are designed to minimize unwanted side effects and enhance the bioavailability of the drug when administered via the gastrointestinal tract[4].
Formulation Types
The patent describes various formulations, including particulate forms such as powders, granulates, microbeadlets, microspheres, and pellets. These formulations can be produced through processes like spray drying, spray freeze drying, and solvent evaporation[4].
Claims of the Patent
Key Claims
- The patent includes claims for pharmaceutical dosage forms adapted for administration to the gastrointestinal tract, comprising darifenacin and a pharmaceutically acceptable excipient.
- Specific claims cover the use of darifenacin in various physical forms, such as particulate forms, agglomerates, and solid products obtained through different manufacturing processes.
- Claims also include the use of organic macromolecular compounds and polysaccharides as excipients or coating materials[4].
Claim Coverage
The claims are categorized under several classifications, including:
- A61K9/14: Particulate form, e.g., powders, processes for size reducing of pure drugs or the resulting products.
- A61K9/16: Agglomerates; Granulates; Microbeadlets; Microspheres; Pellets.
- A61K9/50: Microcapsules having a gas, liquid, or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer[4].
Patent Landscape
Related Patents and Technologies
The patent landscape surrounding US 6,106,864 includes a range of related patents and technologies focused on pharmaceutical formulations and delivery systems. For example:
- Patents related to other muscarinic receptor antagonists and their formulations.
- Patents on various excipients and coating materials used in pharmaceutical formulations.
- Technologies involving different manufacturing processes for pharmaceuticals, such as spray drying and solvent evaporation[4].
Claim Coverage Matrix
To understand the full scope of the patent and its claims, a Claim Coverage Matrix can be useful. This matrix categorizes patents by claims and scope concepts, helping to identify which patents and claims are actively protecting the intellectual property and where gaps or opportunities exist. This approach is particularly useful for companies with a large portfolio of patents, as it streamlines the analysis of complex claim structures[3].
Claim Charts and Scope Concepts
Using tools like ClaimScape® software, companies can generate interactive claim charts that help technical experts determine whether a particular scope concept is applicable to a target product or method. These charts can highlight areas where there are gaps in current coverage and indicate future design opportunities. The scope concepts are categorized into high, medium, or low value based on their current and potential future importance to the company[3].
Litigation and Enforcement
Infringement and Legal Actions
The patent has been involved in legal actions, with companies like Warner Chilcott seeking injunctive relief to prevent infringement prior to the patent's expiration. Such legal actions underscore the importance of this patent in protecting intellectual property related to darifenacin formulations[5].
Expiration and Impact
Patent Expiration
The patent has expired, which means that the formulations and methods described are now in the public domain. This expiration can lead to increased competition and innovation in the development of similar pharmaceutical formulations.
Post-Expiration Landscape
After the patent's expiration, other companies can freely use the described formulations and manufacturing processes. This can lead to a broader availability of generic versions of darifenacin and potentially lower costs for patients. However, it also means that Pfizer Inc. no longer holds exclusive rights to these formulations, which could impact their market share and revenue from darifenacin products[4].
Key Takeaways
- Formulation Innovations: The patent introduced innovative formulations of darifenacin that enhanced bioavailability and minimized side effects.
- Claim Structure: The patent includes detailed claims covering various physical forms and manufacturing processes.
- Patent Landscape: The patent is part of a broader landscape involving related technologies and formulations.
- Legal and Litigation: The patent was involved in legal actions to protect intellectual property.
- Expiration Impact: The expiration of the patent has opened up the market for generic versions and increased competition.
FAQs
What is the primary focus of United States Patent 6,106,864?
The primary focus of this patent is on pharmaceutical formulations containing darifenacin, designed to improve bioavailability and reduce side effects when administered via the gastrointestinal tract.
Who are the inventors listed on the patent?
The inventors listed on the patent include Andrew A. B. Dolan, David S. Fradet, and others from Pfizer Inc.
What types of formulations are described in the patent?
The patent describes various formulations, including particulate forms, agglomerates, microbeadlets, microspheres, and pellets, produced through processes like spray drying and solvent evaporation.
How does the Claim Coverage Matrix help in patent analysis?
The Claim Coverage Matrix helps by categorizing patents by claims and scope concepts, making it easier to identify which patents and claims are actively protecting intellectual property and where gaps or opportunities exist.
What is the current status of the patent?
The patent has expired, meaning the described formulations and methods are now in the public domain.
How has the expiration of the patent impacted the market?
The expiration has led to increased competition and the potential for generic versions of darifenacin, which could lower costs for patients but also impact Pfizer Inc.'s market share and revenue.
