United States Patent 7,985,418: A Detailed Analysis of Scope and Claims
Overview of the Patent
United States Patent 7,985,418, titled "Aliphatic amine polymer salts for tableting," is a patent that focuses on the development and use of specific polymer salts in pharmaceutical formulations, particularly in the form of tablets. This patent is crucial in the field of medicinal preparations and is associated with several key aspects of pharmaceutical science.
Patent Background
The patent was granted on July 26, 2011, and is part of a broader category of patents related to medicinal preparations characterized by special physical forms, such as pills, tablets, and discs[1].
Scope of the Patent
Physical Form and Composition
The patent pertains to tablets, compositions, and methods involving carbonate salts of aliphatic amine polymers. These polymers are preferred for their water-insoluble, non-absorbable, and optionally cross-linked properties. The scope includes various types of aliphatic amine polymers, such as polyethyleneimine, polyallylamine, polyvinylamine, and polydiallylamine polymers[1].
Protonation Levels
The patent specifies that 10% to 70% of the amines in these polymers can be protonated, with a preferred range of approximately 40%. This level of protonation is significant for the functionality and stability of the polymer salts[1].
Cross-Linking
The polymers are rendered water-insoluble through cross-linking with multifunctional cross-linking agents. These agents react with the amino groups of the monomers, enhancing the structural integrity and stability of the polymer salts[1].
Claims of the Patent
Independent Claims
The patent includes several independent claims that define the scope of the invention. These claims cover:
- The composition of the tablets, including the aliphatic amine polymer salts and their specific characteristics.
- The method of preparing these tablets, including the process of cross-linking the polymers.
- The use of these tablets in medicinal preparations, particularly for controlling phosphate levels in the blood, as seen in drugs like Renagel®[1].
Dependent Claims
Dependent claims further specify the details of the independent claims, such as the types of polymers, the degree of protonation, and the cross-linking agents used. These claims provide a detailed framework for the implementation of the invention[1].
Patent Landscape
Related Patents
The patent is part of a larger landscape of patents related to medicinal preparations and pharmaceutical formulations. Other patents, such as US6177478-B1, also deal with methods for reducing oxalate levels using non-absorbable amines, indicating a broader interest in using polymer salts for various therapeutic applications[5].
Classification
The patent is classified under several categories in the International Patent Classification (IPC) system, including A61K9/20 for pills, tablets, discs, and rods, and A61K31/13 for medicinal preparations containing organic active ingredients like amines[1].
Industrial Applications
Pharmaceutical Use
The primary application of this patent is in the pharmaceutical industry, particularly in the development of drugs that control phosphate levels in the blood. Drugs like Sevelamer (Renagel®) use these polymer salts to bind dietary phosphate in the gut, preventing its absorption and reducing serum parathyroid hormone levels[4].
Manufacturing Process
The patent provides detailed methods for manufacturing these tablets, including the preparation of the polymer salts and their formulation into tablets. This is crucial for ensuring the consistency and efficacy of the final product[1].
Expert Insights
Patent Quality and Scope
The scope and claims of this patent are significant in the context of patent quality debates. Research has shown that narrower claims, such as those found in this patent, are associated with a higher probability of grant and a shorter examination process. This suggests that the patent office tends to favor more specific and well-defined claims[3].
Statistical Significance
Clinical Trials and Approval
The drugs developed using these polymer salts, such as Sevelamer, have undergone extensive clinical trials. For example, Sevelamer has been through multiple phases of clinical trials, including Phase 0, 1, 2, 3, and 4, indicating a rigorous testing process before approval[4].
Economic Impact
The economic impact of such patents is substantial. The revenue generated from these drugs, as well as the licensing and litigation costs associated with them, highlight the importance of clear and specific patent claims[3].
Key Takeaways
- Specific Polymer Salts: The patent focuses on aliphatic amine polymer salts, which are water-insoluble and non-absorbable.
- Cross-Linking: The polymers are cross-linked to enhance stability.
- Pharmaceutical Use: The primary application is in controlling phosphate levels in the blood.
- Manufacturing Process: Detailed methods are provided for preparing and formulating these tablets.
- Patent Quality: Narrower claims are associated with a higher probability of grant and shorter examination process.
FAQs
What is the main purpose of the United States Patent 7,985,418?
The main purpose of this patent is to describe the development and use of aliphatic amine polymer salts in pharmaceutical formulations, particularly for controlling phosphate levels in the blood.
Which types of polymers are preferred in this patent?
The preferred polymers are aliphatic amine polymers, such as polyethyleneimine, polyallylamine, polyvinylamine, and polydiallylamine.
How are the polymers rendered water-insoluble?
The polymers are rendered water-insoluble through cross-linking with multifunctional cross-linking agents that react with the amino groups of the monomers.
What is the clinical significance of the drugs developed using these polymer salts?
Drugs like Sevelamer, developed using these polymer salts, are used to control phosphate levels in the blood by binding dietary phosphate in the gut, thereby reducing serum parathyroid hormone levels.
How does the patent landscape influence the scope of this patent?
The patent landscape, including related patents and classifications, indicates a broader interest in using polymer salts for therapeutic applications, which influences the specificity and clarity of the claims in this patent.
What are the economic implications of this patent?
The patent has significant economic implications, including revenue from drug sales and the costs associated with licensing and litigation, which are influenced by the clarity and specificity of the patent claims.
