United States Patent 5,134,122: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 5,134,122, titled "Method for preparing a pharmaceutical composition in the form of microparticles," is a significant patent in the pharmaceutical industry. This patent, issued on August 25, 1992, describes a method for preparing pharmaceutical compositions in the form of microparticles, which has implications for drug delivery and formulation. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background of the Patent
The patent was granted to inventors who developed a method for preparing pharmaceutical compositions in the form of microparticles. This method involves encapsulating active substances within a copolymer matrix, resulting in microparticles that can be used for various pharmaceutical applications, including injectable formulations[4].
Scope of the Patent
Overview of the Invention
The patent covers a method for preparing microparticles that contain an active substance, such as a drug, encapsulated within a copolymer. The process involves mixing the active substance with a copolymer and other components, followed by a series of steps to form the microparticles. The resulting microparticles are designed to have specific characteristics, such as a particular grain size, which is crucial for their pharmaceutical application[4].
Technical Details
The method described in the patent includes several key steps:
- Preparation of the Mixture: The active substance is mixed with a copolymer and other excipients.
- Formation of Microparticles: The mixture is then processed to form microparticles, which can involve techniques such as emulsion or spray drying.
- Characterization: The microparticles are characterized based on their size, shape, and other physical properties[4].
Claims of the Patent
Independent Claims
The patent includes several independent claims that define the scope of the invention. These claims are critical as they specify what is protected under the patent. For example:
- Claim 1 describes the method for preparing the microparticles, including the steps of mixing the active substance with a copolymer and forming the microparticles.
- Claim 2 describes the composition of the microparticles, including the active substance and the copolymer[4].
Dependent Claims
Dependent claims further narrow down the scope of the independent claims by adding additional limitations. These claims often specify particular aspects of the method or composition, such as the type of copolymer used or the size range of the microparticles.
Patent Landscape
Related Patents
The patent landscape in the field of pharmaceutical microparticles is extensive. Other patents may cover similar methods or compositions, but with different specifics. For instance, patents may vary in the type of active substance, the copolymer used, or the method of microparticle formation.
Litigation and Enforcement
Patents in the pharmaceutical industry are often subject to litigation, particularly when generic versions of drugs are developed. The process of listing patents in the Orange Book, as required by FDA regulations, is crucial for innovator companies to protect their intellectual property. Failure to list relevant patents can lead to legal disputes, as seen in cases where generic companies challenge the validity or infringement of listed patents[5].
Patent Quality and Scope Metrics
Claim Clarity and Scope
The clarity and scope of patent claims are critical for determining the validity and enforceability of a patent. Metrics such as independent claim length and independent claim count can be used to measure patent scope. Clear and concise claims are essential to avoid ambiguity and ensure that the patent is fully supported by the description[3].
Functional Claiming
Functional claiming, where claims are defined by the function they perform rather than the structure, can be problematic. This type of claiming has been criticized for being overly broad and unclear, particularly in software and biotechnology patents. The USPTO and courts have been addressing these issues to ensure that patents are granted with clear and specific claims[3].
Expiration and Current Status
The patent US 5,134,122 has expired, as it was issued in 1992 and the typical term for a U.S. patent is 20 years from the filing date. The expiration of this patent means that the method and compositions described are now in the public domain and can be freely used without infringing on the original patent[4].
Impact on Pharmaceutical Industry
Drug Delivery and Formulation
The method described in this patent has contributed significantly to the field of drug delivery and formulation. Microparticles are used in various pharmaceutical applications, including injectable formulations, to improve the stability, bioavailability, and targeted delivery of drugs.
Innovation and Competition
The expiration of this patent has opened up opportunities for other companies to develop similar or improved methods for preparing pharmaceutical microparticles. This competition can drive innovation and lead to better drug delivery systems.
Key Takeaways
- Method and Composition: The patent describes a method for preparing pharmaceutical compositions in the form of microparticles, which involves encapsulating an active substance within a copolymer matrix.
- Claims and Scope: The patent includes independent and dependent claims that define the scope of the invention, with a focus on the method and composition of the microparticles.
- Patent Landscape: The patent is part of a broader landscape in pharmaceuticals, with related patents and ongoing litigation and enforcement issues.
- Expiration: The patent has expired, making the method and compositions public domain.
- Impact: The method has contributed to drug delivery and formulation, and its expiration has opened up opportunities for innovation and competition.
FAQs
What is the main invention described in US Patent 5,134,122?
The main invention is a method for preparing pharmaceutical compositions in the form of microparticles, involving the encapsulation of an active substance within a copolymer matrix.
What are the key steps in the method described in the patent?
The key steps include preparing a mixture of the active substance and copolymer, forming the microparticles, and characterizing the resulting microparticles based on their physical properties.
What is the significance of the patent's expiration?
The expiration of the patent means that the method and compositions described are now in the public domain and can be freely used without infringing on the original patent.
How does this patent impact the pharmaceutical industry?
The patent has contributed to advancements in drug delivery and formulation, particularly in the use of microparticles for injectable formulations. Its expiration has opened up opportunities for innovation and competition in developing similar or improved methods.
Are there any related patents or ongoing litigation in this field?
Yes, there are related patents and ongoing litigation in the field of pharmaceutical microparticles. Companies often engage in legal disputes over patent validity and infringement, especially when generic versions of drugs are developed.
Sources
- US5134122A - Method for preparing a pharmaceutical composition in the form of microparticles - Google Patents
- The Claims - USPTO
- Patent Claims and Patent Scope - Hoover Institution
- US5134122A - Method for preparing a pharmaceutical composition in the form of microparticles - Google Patents
- In the United States District Court - District of Delaware
