United States Patent 5,626,874: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,626,874, titled "Multilayer Tablet," is a significant patent in the field of pharmaceuticals, particularly in the development of oral sustained-release and immediate-release formulations. This patent, granted to a pioneering entity in the pharmaceutical industry, outlines a novel approach to designing multilayer tablets that enhance drug delivery and patient compliance.
Background and Context
The patent was filed in response to the need for more effective and controlled drug delivery systems. Traditional tablets often had limitations such as rapid release of the active ingredient, which could lead to side effects or reduced efficacy. The multilayer tablet design addressed these issues by providing a sustained release of the active ingredient over a prolonged period.
Patent Scope and Claims
Overview of the Patent
The patent describes a multilayer tablet consisting of two outer layers and an inner layer. The outer layers contain gellable or erodible polymers, while the inner layer contains the active ingredient. This design allows for a controlled release of the drug, ensuring that the therapeutic levels are maintained over a longer period[1].
Key Claims
- Outer Layers: The patent claims the use of gellable or erodible polymers in the outer layers. These polymers can be hydroxypropyl methyl cellulose, poly(ethylene oxide), or other similar materials that facilitate the controlled release of the active ingredient[1].
- Inner Layer: The inner layer contains the active pharmaceutical ingredient (API) which is released as the outer layers erode or gel.
- Sustained-Release Formulation: The patent emphasizes the sustained-release nature of the tablet, ensuring that the API is released over an extended period, improving patient compliance and therapeutic efficacy.
Claim Structure
The claims are structured to cover various aspects of the multilayer tablet:
- Composition Claims: These claims detail the materials used in each layer, including the specific polymers and the active ingredient.
- Method Claims: These claims describe the process of manufacturing the multilayer tablet, including the steps involved in forming each layer.
- Use Claims: These claims specify the therapeutic uses of the multilayer tablet, such as treating various medical conditions through sustained drug release.
Technical Details
Materials Used
The patent specifies the use of various polymers for the outer layers, including:
- Hydroxypropyl Methyl Cellulose (HPMC): A common polymer used in pharmaceutical formulations for its gelling properties.
- Poly(ethylene oxide) (PEO): Another polymer that can be used for its erodible properties[1].
Manufacturing Process
The manufacturing process involves several steps:
- Formulation of the Inner Layer: This involves mixing the active ingredient with appropriate excipients.
- Formulation of the Outer Layers: This involves preparing the gellable or erodible polymers.
- Layering: The inner layer is sandwiched between the two outer layers to form the final tablet.
Patent Landscape
Related Patents
The patent landscape in this area is rich with innovations related to drug delivery systems. For example:
- US20100040681A1: This patent describes an oral sustained-release triple layer tablet, which is a more recent development in the field and builds upon the principles outlined in the '874 patent[1].
- Other Patents: There are numerous other patents that focus on different aspects of multilayer tablets, such as varying the composition of the layers or the manufacturing process.
Litigation and Validity
Patents in the pharmaceutical industry are often subject to litigation, particularly regarding issues of obviousness and written description. For instance, the case of Allergan USA, Inc. v. MSN Laboratories Private Ltd. highlights the complexities involved in patent validity and the importance of clear and specific claim language[2].
Impact on the Pharmaceutical Industry
Improved Drug Delivery
The multilayer tablet design has significantly improved drug delivery systems by providing a controlled and sustained release of the active ingredient. This has enhanced patient compliance and therapeutic efficacy.
Innovation and Competition
The '874 patent has spurred further innovation in the field, with numerous subsequent patents building upon its principles. This has led to a competitive landscape where pharmaceutical companies continually seek to improve drug delivery systems.
Metrics for Patent Scope
Independent Claim Length and Count
Research on patent scope suggests that metrics such as independent claim length and count can be used to measure the breadth and clarity of patents. Narrower claims, as seen in the '874 patent, are often associated with a higher probability of grant and a shorter examination process[3].
Searching and Analyzing Patents
Tools and Resources
For professionals interested in analyzing patents like the '874 patent, several tools and resources are available:
- USPTO Patent Public Search: Allows for full-text searching of patent grants and applications from the United States and other countries[4].
- PATENTSCOPE Database: Provides access to international Patent Cooperation Treaty (PCT) applications and patent documents from participating national and regional patent offices[4].
Conclusion
United States Patent 5,626,874 represents a significant advancement in pharmaceutical technology, particularly in the design of multilayer tablets for sustained drug release. The patent's scope and claims are well-defined, covering the composition, manufacturing process, and therapeutic uses of the multilayer tablet.
Key Takeaways
- Multilayer Design: The patent introduces a novel multilayer tablet design with gellable or erodible outer layers and an inner layer containing the active ingredient.
- Controlled Release: The design ensures a controlled and sustained release of the active ingredient, enhancing patient compliance and therapeutic efficacy.
- Impact on Industry: The patent has driven innovation in drug delivery systems and remains a cornerstone in the development of sustained-release formulations.
- Patent Landscape: The patent is part of a rich landscape of innovations in pharmaceutical technology, with ongoing developments and litigation shaping the field.
FAQs
Q: What is the main innovation of United States Patent 5,626,874?
A: The main innovation is the design of a multilayer tablet with gellable or erodible outer layers and an inner layer containing the active ingredient, ensuring a controlled and sustained release of the drug.
Q: What materials are commonly used in the outer layers of the multilayer tablet?
A: The outer layers commonly use polymers such as hydroxypropyl methyl cellulose (HPMC) and poly(ethylene oxide) (PEO).
Q: How does the multilayer tablet improve drug delivery?
A: The multilayer tablet improves drug delivery by providing a sustained release of the active ingredient, which enhances patient compliance and therapeutic efficacy.
Q: What tools are available for searching and analyzing patents like the '874 patent?
A: Tools such as the USPTO Patent Public Search and the PATENTSCOPE database are available for searching and analyzing patents.
Q: Why is the '874 patent significant in the pharmaceutical industry?
A: The '874 patent is significant because it introduced a novel design for sustained-release formulations, driving innovation and improving drug delivery systems.
Sources
- US20100040681A1 - Oral Sustained-Release Triple Layer Tablet - Google Patents
- Allergan USA, Inc. v. MSN Laboratories Private Ltd. - United States Court of Appeals for the Federal Circuit
- Patent Claims and Patent Scope - SSRN
- Research and Course Guides: Patent Searching, Advanced - Clemson University Libraries
