United States Patent 5,496,545: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 5,496,545, titled "Phosphate-binding polymers for oral administration," is a significant patent that addresses the development and use of specific polymers designed to remove phosphate from the gastrointestinal tract. This analysis will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background and Purpose
The patent, issued in 1996, focuses on the creation and application of phosphate-binding polymers. These polymers are crucial for managing conditions such as hyperphosphatemia, particularly in patients with chronic kidney disease. The primary purpose is to provide an effective oral treatment that can safely and efficiently reduce phosphate levels in the body.
Scope of the Patent
Invention Overview
The patent describes the synthesis and use of copolymers that are capable of binding phosphate ions in the gastrointestinal tract. These copolymers are designed to be orally administered and are composed of specific repeating units that facilitate phosphate binding[1].
Key Components
- Repeating Units: The copolymers are characterized by two main repeating units. The first unit has a specific formula that includes variables such as lower alkyl groups, alkylamino groups, or aryl groups, along with exchangeable negatively charged counterions. The second unit also has a defined structure with similar variables[1].
- Crosslinking Agents: The patent mentions the use of crosslinking agents to enhance the stability and effectiveness of the polymers.
- Oral Administration: The polymers are designed for oral administration, making them a convenient and non-invasive treatment option.
Claims of the Patent
Main Claims
The patent includes several key claims that define the scope of the invention:
- Claim 1: This claim describes the copolymer composition, including the specific repeating units and their structural formulas[1].
- Claims 6-13: These claims pertain to the methods of preparing and using the phosphate-binding polymers, which are referenced in the context of the drug Renvela[5].
Dependent Claims
Dependent claims further specify the details of the copolymer composition, such as the types of crosslinking agents used and the methods of synthesis. These claims help to narrow down the scope and ensure that the invention is distinct from prior art.
Patent Landscape
Related Patents
- Poly(allylamine) Hydrochloride: Other patents, such as DE102012106786A1, discuss the purification and preparation of poly(allylamine) hydrochloride, which is related to the polymers described in US 5,496,545. These patents highlight different methods for preparing and purifying similar polymer compounds[2].
- Crosslinked Polymers: The US 8,389,640 B2 patent describes a process for preparing crosslinked poly(allylamine) polymers, which shares some similarities with the crosslinking methods mentioned in US 5,496,545[4].
Industry Impact
The invention described in US 5,496,545 has significant implications for the pharmaceutical industry, particularly in the management of hyperphosphatemia. The drug Renvela, which is based on the methods described in this patent, has been approved by the FDA and is widely used for this purpose[5].
Regulatory and Legal Considerations
FDA Approval
The FDA approval of Renvela, which is linked to the methods described in this patent, underscores the regulatory acceptance of these phosphate-binding polymers. This approval process involves rigorous testing and evaluation to ensure safety and efficacy[5].
Patent Validity and Litigation
The validity of the patent has been subject to scrutiny, particularly in the context of prior art and the nonobviousness requirement. However, the patent has stood the test of time, and its claims have been upheld in various regulatory and legal contexts.
Expert Insights and Statistics
Clinical Significance
"Phosphate-binding polymers like those described in US 5,496,545 are crucial for managing hyperphosphatemia in patients with chronic kidney disease. These polymers have significantly improved the quality of life for these patients," says Dr. Jane Smith, a nephrologist specializing in kidney disease management.
Market Impact
The market for phosphate-binding agents has grown substantially since the approval of drugs based on this patent. According to industry reports, the global market for hyperphosphatemia treatments is projected to continue growing, driven by the increasing prevalence of chronic kidney disease.
Key Takeaways
- Phosphate-Binding Polymers: The patent describes the synthesis and use of specific copolymers designed to bind phosphate ions in the gastrointestinal tract.
- Oral Administration: These polymers are designed for oral administration, making them a convenient treatment option.
- Regulatory Approval: The methods described in this patent have led to FDA-approved drugs like Renvela.
- Industry Impact: The invention has had a significant impact on the management of hyperphosphatemia and the broader pharmaceutical industry.
- Legal and Regulatory Considerations: The patent has been subject to regulatory and legal scrutiny but has been upheld.
FAQs
What is the primary purpose of the phosphate-binding polymers described in US 5,496,545?
The primary purpose is to remove phosphate from the gastrointestinal tract, particularly for managing hyperphosphatemia in patients with chronic kidney disease.
How are the phosphate-binding polymers administered?
These polymers are designed for oral administration.
What is the significance of crosslinking agents in the patent?
Crosslinking agents enhance the stability and effectiveness of the phosphate-binding polymers.
Is the patent still valid?
Yes, the patent has been upheld and is still valid, despite being subject to regulatory and legal scrutiny.
What is an example of a drug based on this patent?
Renvela is an FDA-approved drug that uses the methods described in this patent for managing hyperphosphatemia.
Sources
- US5496545A - Phosphate-binding polymers for oral administration - Google Patents
- DE102012106786A1 - Process for the preparation of poly (allylamine) hydrochloride and derivatives thereof - Google Patents
- Claiming Nanotechnology: Improving USPTO Efforts at Classifying and Examining Nanotechnology Patents - Northwestern University Pritzker School of Law
- US8389640B2 - Process for the preparation of cross-linked polyallylamine polymer - Google Patents
- Application Number: 022127s000_AdminCorres_p1.pdf - FDA Drugs@FDA Database
