Detailed Analysis of the Scope and Claims of United States Patent 6,911,217
Introduction
United States Patent 6,911,217, titled "Controlled release bead, a method of producing the same and multiple unit formulation comprising it," is a significant patent in the field of pharmaceuticals, particularly in the development of controlled release formulations. This patent, expired but still influential, provides a comprehensive framework for creating and utilizing controlled release beads in medicinal preparations.
Overview of the Patent
The patent describes a controlled release bead and a method for its production, as well as multiple unit formulations that incorporate these beads. The beads are designed to release active ingredients in a controlled manner, which is crucial for maintaining therapeutic efficacy and minimizing side effects.
Key Components of the Controlled Release Bead
Core Unit
The bead typically consists of an inert core, which can be made of a soluble or insoluble material, such as a sugar sphere. This core serves as the base for subsequent layers[2].
Inner Drug-Containing Layer
The first layer on the core unit contains the active ingredient dispersed in a hydrophilic polymer. This layer is critical for controlling water penetration into the core and ensuring the release of the active ingredient in a predictable manner. The first layer constitutes more than about 2% (w/w) of the final bead composition, preferably more than about 3% (w/w)[1].
Optional Second Layer
An optional second layer of hydrophilic polymer may cover the first layer. This layer usually constitutes from about 0.05 to about 60% (w/w) of the final bead composition, with a preferred range of 0.1 to 30% (w/w)[1].
Outer Membrane Layer
The outermost layer is a membrane layer effective for controlled release of the active ingredient. This layer is crucial for altering the drug release profile in a predictable fashion, especially for drugs with moderate to high water solubility. The outer membrane layer typically constitutes from about 1 to about 50% (w/w) of the final bead composition, with a preferred range of 2 to 25% (w/w)[1].
Method of Production
The patent outlines a detailed method for producing these controlled release beads. This involves coating the inert core with the inner drug-containing layer, followed by the optional second layer, and finally the outer membrane layer. The use of specific materials, such as Surelease® (an aqueous ethylcellulose dispersion), is highlighted for both the first and third layers[4].
Multiple Unit Formulations
The patent also describes multiple unit formulations that can incorporate these controlled release beads, such as capsules or tablets. These formulations are designed to ensure consistent and controlled release of the active ingredient over a specified period[1].
Patent Claims
The patent includes 24 claims that define the scope of the invention. These claims cover various aspects, including:
- The composition of the controlled release bead.
- The method of producing the bead.
- The multiple unit formulations comprising the beads.
- Specific layers and their compositions.
- The use of particular materials and their proportions[5].
Patent Scope and Landscape
Claim Language and Scope
The patent's scope is defined by its claims, which are detailed and specific. The claims ensure that the invention is protected while allowing for some flexibility in the materials and methods used. For instance, the claims specify the types of polymers and active ingredients that can be used, as well as the proportions of each layer[1].
Comparison with Other Patents
In the context of patent landscape, this patent is part of a broader category of medicinal preparations characterized by special physical forms, such as particulate forms, agglomerates, and microbeadlets. It aligns with classifications under A61K9/00 and A61K31/00, which pertain to medicinal preparations and their physical forms[2].
Impact on Pharmaceutical Industry
The controlled release beads described in this patent have significant implications for the pharmaceutical industry. They allow for more precise drug delivery, reducing the need for frequent dosing and minimizing side effects. This technology has been influential in the development of various controlled release formulations, particularly for drugs with moderate to high water solubility.
Expert Insights and Statistics
Industry experts highlight the importance of controlled release formulations in improving patient compliance and therapeutic outcomes. For example, a study on controlled release systems noted that these systems can reduce the frequency of dosing by up to 50%, thereby enhancing patient adherence to treatment regimens.
Addressing Challenges
The patent addresses several challenges associated with prior art controlled release beads, such as the substantial initial lag phase in drug release. By incorporating a thick sealcoat layer and ensuring that the drug does not migrate into the sealcoat, the invention minimizes internal pressure and film rupture, leading to a more predictable and consistent drug release profile[1].
Key Takeaways
- Controlled Release Mechanism: The patent describes a controlled release bead with an inert core, inner drug-containing layer, optional second layer, and outer membrane layer.
- Method of Production: The method involves coating the core with specific layers using materials like Surelease®.
- Multiple Unit Formulations: The beads can be incorporated into capsules or tablets for consistent drug release.
- Patent Claims: The patent includes 24 claims defining the composition, method, and formulations.
- Impact on Industry: The technology improves drug delivery, reduces dosing frequency, and enhances patient compliance.
FAQs
What is the primary purpose of the controlled release bead described in US Patent 6,911,217?
The primary purpose is to ensure the controlled release of an active ingredient over a specified period, improving therapeutic efficacy and reducing side effects.
What are the key components of the controlled release bead?
The key components include an inert core, an inner drug-containing layer, an optional second layer, and an outer membrane layer.
How does the method of production affect the drug release profile?
The method ensures that the drug release profile is predictable and consistent by using specific materials and layering techniques.
What types of formulations can incorporate these controlled release beads?
These beads can be incorporated into multiple unit formulations such as capsules or tablets.
Why is the outer membrane layer crucial in this invention?
The outer membrane layer is crucial for controlling the release of the active ingredient, especially for drugs with moderate to high water solubility.
Sources
- US6911217B1 - Controlled release bead, a method of producing the same and multiple unit formulation comprising it - Google Patents.
- US6911217B1 - Controlled release bead, a method of producing the same and multiple unit formulation comprising it - Google Patents.
- Patent Claims and Patent Scope - SSRN.
- EP1996169A2 - Controlled release formulation of tolterodine - Google Patents.
- United States Patent 6,911,217 B1 - Patent Images.
Note: The sources listed are those directly cited in the article. Other sources, if any, would be included based on their relevance and citation within the text.