United States Patent 10,703,763: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 10,703,763, titled "Production of medicinal preparations containing rifaximin for oral and topical use," is a significant patent in the pharmaceutical industry, particularly for the drug rifaximin. This patent, issued on March 4, 2019, is part of a broader patent landscape that protects various aspects of rifaximin production, use, and distribution.
Background of the Invention
Rifaximin is an antibiotic used primarily to treat diarrhea-associated irritable bowel syndrome (IBS-D) and other gastrointestinal conditions. The patent 10,703,763 focuses on the production methods of rifaximin for both oral and topical applications, ensuring standardized and controlled manufacturing processes to achieve homogeneous and sound results in terms of polymorphism of the production batches[4].
Claims of the Patent
The patent includes 9 claims that delineate the specific methods and compositions related to the production of rifaximin. Here are some key aspects of these claims:
- Claim 1: This claim describes a method for producing a medicinal preparation containing rifaximin, involving specific steps such as crystallization and purification to ensure the desired polymorphic form.
- Claims 2-5: These claims detail various aspects of the production process, including the use of specific solvents, temperature conditions, and purification techniques.
- Claims 6-9: These claims cover the compositions resulting from the production methods, including the physical and chemical characteristics of the rifaximin preparations[4].
Patent Classification
The patent is classified under several categories, including:
- CPC C07D 491/22: This classification pertains to heterocyclic compounds containing nitrogen as a ring member.
- A61K 9/0053: This classification is related to pharmaceutical preparations for oral administration.
- A61K 31/437: This classification pertains to pharmaceutical preparations for topical use[4].
References and Prior Art
The patent cites numerous prior art documents, including several U.S. patents and international patent applications. These references highlight the evolution of rifaximin production and use, and they are crucial for understanding the novelty and non-obviousness of the current patent. For example, U.S. Patents 8,183,196, 8,193,196, and 8,518,949 are referenced, indicating a continuum of research and development in the field[4].
Patent Landscape and Litigation
The patent 10,703,763 is part of a complex patent landscape surrounding rifaximin. Several other patents, such as the '196, '949, '904, '968, and '763 patents, are listed in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations (the “Orange Book”) for Xifaxan®, a brand name for rifaximin. These patents are subject to various legal challenges and litigations.
For instance, Salix Pharmaceuticals, Inc., and other related entities have filed complaints against generic manufacturers like Zydus Pharmaceuticals, alleging patent infringement. These cases involve disputes over the validity and enforceability of the patent claims, including those related to the '763 patent[2][5].
Impact on Generic Manufacturers
Generic manufacturers seeking to produce rifaximin must navigate this intricate patent landscape. The ANDA (Abbreviated New Drug Application) process for generic drugs involves certifying that the generic product does not infringe the listed patents or that the patents are invalid or unenforceable. The '763 patent, along with other related patents, poses significant hurdles for generic entry, as seen in the litigation between Salix Pharmaceuticals and Zydus Pharmaceuticals[1][2].
Regulatory Requirements
The production methods described in the '763 patent must comply with stringent regulatory requirements. The European Medicines Agency (EMA) and the FDA mandate that manufacturing methods for active pharmaceutical ingredients (APIs) be standardized and controlled to ensure homogeneous and sound results. This includes specifications for chemistry, manufacturing, and controls (CMC) to guarantee the quality and safety of the drug products[4].
Industry Implications
The '763 patent and its associated claims have significant implications for the pharmaceutical industry. The broad scope of these patents can make it challenging for innovators to develop and market new drugs without infringing existing patents. This is particularly true in the context of genus claims, where the Federal Circuit's rigid application of Section 112(a) of the U.S. patent laws has made it difficult to obtain meaningful patent protection for drugs and biologics[3].
Challenges in Patent Protection
The pharmaceutical and biotechnology industries face unique challenges in patent protection. The need to balance broad claims that capture the full scope of an invention against the risk of claims being too narrow and easily designed around is a critical issue. The '763 patent exemplifies this challenge, as it seeks to protect specific production methods while ensuring that these methods are not so narrow that they can be easily circumvented by competitors[3].
Conclusion
The United States Patent 10,703,763 is a crucial component of the patent landscape surrounding rifaximin. Its claims and production methods are meticulously detailed to ensure compliance with regulatory standards and to protect the intellectual property of the inventors. However, this patent also highlights the complexities and challenges inherent in patent protection within the pharmaceutical industry.
Key Takeaways
- Production Methods: The patent details specific production methods for rifaximin, ensuring standardized and controlled processes.
- Claims: The patent includes 9 claims that cover various aspects of rifaximin production and composition.
- Patent Classification: The patent is classified under several categories related to heterocyclic compounds and pharmaceutical preparations.
- Litigation: The patent is part of ongoing litigations involving generic manufacturers and brand-name pharmaceutical companies.
- Regulatory Compliance: The production methods must comply with stringent regulatory requirements to ensure drug quality and safety.
- Industry Implications: The patent has significant implications for the pharmaceutical industry, particularly in the context of genus claims and patent protection.
Frequently Asked Questions (FAQs)
Q: What is the main focus of the United States Patent 10,703,763?
A: The main focus is on the production methods of rifaximin for oral and topical use, ensuring standardized and controlled manufacturing processes.
Q: How many claims does the patent include?
A: The patent includes 9 claims that detail various aspects of rifaximin production and composition.
Q: What are the implications of this patent for generic manufacturers?
A: Generic manufacturers must navigate the complex patent landscape and certify that their products do not infringe the listed patents or that the patents are invalid or unenforceable.
Q: What regulatory requirements must the production methods comply with?
A: The production methods must comply with stringent regulatory requirements to ensure homogeneous and sound results in terms of polymorphism of the production batches.
Q: How does this patent fit into the broader patent landscape for rifaximin?
A: The patent is part of a complex landscape that includes several other patents listed in the FDA’s Orange Book for Xifaxan®, and it is subject to various legal challenges and litigations.
Sources Cited
- FDA Letter: Rifaximin Tablets - accessdata.fda.gov
- Complaint Document: Case 1:24-cv-09512 Document 1 Filed 09/27/24 - insight.rpxcorp.com
- Eviscerating Patent Scope: DigitalCommons@NYLS - digitalcommons.nyls.edu
- United States Patent 10,703,763: Production of medicinal preparations containing rifaximin - patentimages.storage.googleapis.com
- Salix Pharmaceuticals v. Norwich Pharmaceuticals: United States Court of Appeals for the Federal Circuit - cafc.uscourts.gov
