United States Patent 4,757,128: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,757,128, titled "High Molecular Weight Polyanhydride and Preparation Thereof," was issued on July 12, 1988, to inventors A. J. Domb and R. S. Langer. This patent is significant in the field of organic synthesis, particularly for biomedical applications. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background and Invention Overview
The patent describes a method for synthesizing high molecular weight polyanhydrides, which are crucial for various biomedical applications due to their biodegradable and biocompatible properties. The invention focuses on improving the synthesis process to produce polymers with desired physical and chemical characteristics[4].
Scope of the Patent
Objectives of the Invention
The primary objectives of this patent include:
- Developing a method to synthesize high molecular weight polyanhydrides.
- Creating less hydrophobic polyanhydride polymers suitable for biomedical applications.
- Optimizing the reaction conditions to achieve the desired polymer properties[4].
Technical Details
The patent outlines a detailed synthesis process involving melt polycondensation of highly pure isolated prepolymers. The method modifies earlier techniques described by Hill and Carothers, emphasizing the importance of optimizing temperature, time, and the removal of condensation products[4].
Claims of the Patent
Independent Claims
The patent includes several independent claims that define the scope of the invention:
- Claim 1 describes the high molecular weight polyanhydride polymer itself, specifying its composition and properties.
- Claim 2 outlines the method of preparing the polyanhydride, including the steps of synthesizing prepolymers and conducting melt polycondensation[4].
Dependent Claims
Dependent claims further specify the details of the invention, such as:
- The use of specific catalysts like calcium oxide, calcium carbonate, and diethyl zinc.
- The characterization of the polymers using techniques like infrared spectroscopy, thermal analysis, and gel permeation chromatography (GPC)[4].
Patent Landscape
Related Patents and Applications
The patent landscape around US 4,757,128 includes other patents and applications related to polyanhydride synthesis and biomedical applications. For instance, the European Patent Office (EPO) and other international patent offices have similar patents that might be relevant for global protection and prior art searches[1].
Global Dossier and International Patent Offices
Using tools like the Global Dossier, one can access the file histories of related applications from participating IP Offices, including the IP5 Offices (USPTO, EPO, JPO, KIPO, and CNIPA). This helps in understanding the global patent family and any office actions or citations related to similar inventions[1].
Prior Art and Citations
The patent cites prior art from Hill and Carothers, indicating the evolution of the synthesis method. It also highlights the importance of citing relevant prior art to establish the novelty and non-obviousness of the invention. Tools like the Common Citation Document (CCD) can help consolidate citation data from multiple offices, facilitating a comprehensive prior art search[1][3].
Impact on Biomedical Applications
Biodegradable and Biocompatible Polymers
The high molecular weight polyanhydrides synthesized using this method are particularly useful in biomedical applications such as drug delivery systems, tissue engineering, and surgical implants. The biodegradable nature of these polymers ensures they can be safely metabolized by the body, reducing the risk of long-term complications[4].
Research and Development
This patent has contributed significantly to the field of biological engineering, as evidenced by its inclusion in academic courses and research papers. For example, the patent is referenced in lectures on biological engineering design, highlighting its importance in educational and research contexts[5].
Metrics for Patent Scope
Independent Claim Length and Count
Research on patent scope metrics suggests that the length and count of independent claims can be indicative of the patent's breadth and complexity. In the case of US 4,757,128, the independent claims are detailed and specific, suggesting a well-defined scope. Studies have shown that narrower claims at publication are associated with a higher probability of grant and a shorter examination process[3].
Search and Analysis Tools
USPTO Resources
For conducting a thorough search and analysis of patents like US 4,757,128, the USPTO offers several resources:
- The Patent Public Search tool provides modern interfaces for enhanced access to prior art.
- The Public Search Facility and Patent and Trademark Resource Centers (PTRCs) offer additional support and training in patent search techniques[1].
International Databases
Searching international patent databases such as those provided by the EPO, JPO, WIPO, and other offices is crucial for understanding the global patent landscape. These databases often include machine translations and full-text searches, facilitating a comprehensive search[1].
Key Takeaways
- Synthesis Method: The patent describes a detailed method for synthesizing high molecular weight polyanhydrides through melt polycondensation.
- Biomedical Applications: The polymers are biodegradable and biocompatible, making them suitable for various biomedical applications.
- Patent Scope: The independent claims are specific and detailed, indicating a well-defined scope.
- Global Landscape: The patent is part of a broader global landscape that includes similar patents and applications from other IP offices.
- Search and Analysis: Utilizing tools like the USPTO's Patent Public Search and international databases is essential for a thorough search and analysis.
FAQs
Q: What is the main objective of US Patent 4,757,128?
A: The main objective is to develop a method for synthesizing high molecular weight polyanhydrides suitable for biomedical applications.
Q: How does the patent improve upon previous synthesis methods?
A: The patent modifies earlier techniques by optimizing reaction conditions, using highly pure isolated prepolymers, and specifying the removal of condensation products.
Q: What are the key applications of the polyanhydrides described in the patent?
A: The polyanhydrides are primarily used in biomedical applications such as drug delivery systems, tissue engineering, and surgical implants.
Q: How can one conduct a comprehensive search for related patents?
A: Using tools like the USPTO's Patent Public Search, Global Dossier, and international patent databases such as those from the EPO, JPO, and WIPO.
Q: What metrics can be used to measure the scope of a patent like US 4,757,128?
A: Metrics such as independent claim length and count can be used to measure the scope and complexity of the patent.
Sources
- USPTO: Search for patents - USPTO. Retrieved from https://www.uspto.gov/patents/search
- Canadian Patents Database: Patent 2466039 Summary - Canadian Patents Database. Retrieved from https://brevets-patents.ic.gc.ca/opic-cipo/cpd/eng/patent/2466039/summary.html?wbdisable=true
- SSRN: Patent Claims and Patent Scope - Search eLibrary :: SSRN. Retrieved from https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2844964
- Google Patents: High molecular weight polyanhydride and preparation thereof. Retrieved from https://patents.google.com/patent/US4757128A/en
- MIT OpenCourseWare: Lectures and Readings | Biological Engineering Design | Biological ... Retrieved from https://ocw.aprende.org/courses/biological-engineering/20-380j-biological-engineering-design-spring-2010/other/
