United States Patent 4,652,441: A Detailed Analysis
Introduction
United States Patent 4,652,441, titled "Prolonged release microcapsule and its production," was granted on November 1, 1984, and expired on November 1, 2004. This patent is significant in the field of pharmaceuticals, particularly in the development of drug delivery systems.
Background and Context
The patent was part of a broader portfolio of patents related to pharmaceutical formulations and drug delivery technologies. It is essential to understand the context in which this patent was filed and the impact it had on the industry.
Inventors and Assignees
The patent was assigned to Takeda Pharmaceutical Company Limited, a major player in the pharmaceutical industry. The inventors and assignees played a crucial role in the development and commercialization of the technology described in the patent.
Claims and Scope
Summary of Claims
The patent describes a method for producing prolonged release microcapsules with an average diameter of about 2 to 200 μm, designed for injection. Here are the key claims:
- Claim 1: A method for producing a prolonged release microcapsule comprising preparing a water-in-oil emulsion, adding a polymer substance to the oil layer, and then solidifying the polymer to form microcapsules[4].
- Claim 2: The microcapsule as claimed in claim 1, wherein the polymer substance in the oil layer is a copolymer of lactic acid and glycolic acid[5].
- Claim 3: The method as claimed in claim 1, where the microcapsules are washed and dried to remove any residual solvent.
Detailed Description
The patent provides a detailed description of the production process, including the preparation of the water-in-oil emulsion, the addition of the polymer substance, and the solidification process. The microcapsules are designed to release the active ingredient over a prolonged period, which is crucial for maintaining therapeutic levels of the drug in the body.
Patent Landscape
Related Patents
The patent is part of a larger family of patents related to drug delivery systems and pharmaceutical formulations. Other patents in this family include U.S. Patent Nos. 4,677,191, 4,728,721, 4,849,228, and 4,917,893, which were also involved in litigation related to false patent marking[1][2].
Industry Impact
The technology described in this patent has had a significant impact on the pharmaceutical industry, particularly in the development of sustained-release formulations. This technology allows for more efficient and effective drug delivery, which can improve patient compliance and therapeutic outcomes.
Litigation and Legal Issues
False Patent Marking
The patent was involved in a lawsuit related to false patent marking. Promote Innovation LLC alleged that Abbott Laboratories Inc. and Takeda Pharmaceutical Company Limited falsely marked products with expired patent numbers, including U.S. Patent No. 4,652,441. This false marking was claimed to have deterred innovation and stifled competition in the marketplace[1].
Infringement Claims
In another case, Takeda Pharmaceutical Company Limited sued OWL Pharmaceuticals, L.L.C., and Oakwood Laboratories, L.L.C., for infringement of several patents, including U.S. Patent No. 4,652,441. The lawsuit sought to prevent the defendants from commercializing products that allegedly infringed on Takeda's patents[2].
Technological Significance
Drug Delivery Systems
The technology described in this patent is crucial for the development of drug delivery systems that provide sustained release of active ingredients. This is particularly important for drugs that require long-term administration to maintain therapeutic levels.
Pharmaceutical Formulations
The patent's focus on microcapsules and their production process has contributed significantly to the field of pharmaceutical formulations. It has enabled the development of more sophisticated drug delivery systems that can be tailored to specific therapeutic needs.
Statistical Overview
Patent Applications and Grants
The patent landscape in the pharmaceutical domain shows a trend where the number of granted patents is significantly lower than the number of patent applications. For example, in the rare disease and Alzheimer’s disease patent corpora, only about half of the patent applications were granted patents[3].
Industry Trends and Future Directions
Increasing Interest in Novel Treatments
There is an increasing interest in novel treatments for various diseases, which is reflected in the rising number of patent applications in the pharmaceutical domain. The 2011 Patent Reform Act in the United States, which shifted from a "first-to-invent" to a "first-to-file" system, has also influenced the prosecution of patent applications[3].
High Costs and Complexity
The research and development process in pharmaceuticals is highly costly and complex. This complexity, along with the time-consuming process of reviewing patent documents, contributes to the lower ratio of granted patents to applications[3].
Key Players
Organizations and Individuals
In the field of Alzheimer’s disease, for example, organizations are leading the patenting activity, with 10,017 organizations, 1,778 individuals, and 1,386 acquired organizations contributing to the patent landscape over the past 20 years[3].
Conclusion and Impact on Competition
The false marking of products with expired patents, such as U.S. Patent No. 4,652,441, can deter innovation and stifle competition. It creates a misleading impression of technological superiority and can discourage potential competitors from entering the market[1].
Key Takeaways
- Patent Scope: U.S. Patent 4,652,441 describes a method for producing prolonged release microcapsules.
- Industry Impact: The patent has significantly contributed to the development of sustained-release formulations in the pharmaceutical industry.
- Litigation: The patent was involved in lawsuits related to false patent marking and infringement claims.
- Technological Significance: The patent is crucial for drug delivery systems and pharmaceutical formulations.
- Industry Trends: There is an increasing interest in novel treatments, and the patent landscape is influenced by legal reforms and high R&D costs.
FAQs
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What is the main subject of U.S. Patent 4,652,441?
- The main subject is a method for producing prolonged release microcapsules for injection.
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Who was the assignee of U.S. Patent 4,652,441?
- The assignee was Takeda Pharmaceutical Company Limited.
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What was the legal status of U.S. Patent 4,652,441 as of 2004?
- The patent expired on November 1, 2004.
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Why was U.S. Patent 4,652,441 involved in litigation?
- It was involved in lawsuits related to false patent marking and infringement claims.
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How has U.S. Patent 4,652,441 impacted the pharmaceutical industry?
- It has significantly contributed to the development of sustained-release formulations and drug delivery systems.
Cited Sources
- UNITED STATES DISTRICT COURT FOR THE EASTERN DISTRICT OF TEXAS MARSHALL DIVISION PROMOTE INNOVATION LLC, Plaintiff, v. ABBOTT LABORATORIES INC., TAKEDA PHARMACEUTICAL COMPANY LIMITED, Defendants.
- IN THE UNITED STATES DISTRICT COURT FOR THE NORTHERN DISTRICT OF OHIO EASTERN DIVISION TAKEDA PHARMACEUTICAL COMPANY LIMITED, Plaintiff, v. OWL PHARMACEUTICALS, L.L.C., OAKWOOD LABORATORIES, L.L.C., Defendants.
- A novel approach to understand patents from the drug discovery perspective.
- US4652441A - Prolonged release microcapsule and its production.
- United States Patent (19) - googleapis.com.
