United States Patent 6,140,321: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 6,140,321, titled "Polymorphs of donepezil hydrochloride and process for production," is a significant patent in the pharmaceutical industry, particularly in the context of Alzheimer's disease treatment. This patent, issued to Eisai Co., Ltd., covers various polymorphs of donepezil hydrochloride, a drug used to treat Alzheimer's disease.
Background on Donepezil Hydrochloride
Donepezil hydrochloride is a cholinesterase inhibitor used in the treatment of Alzheimer's disease. It works by increasing the concentration of acetylcholine in the brain, thereby improving cognitive function in patients with Alzheimer's[4].
Patent Overview
Patent Number and Status
The patent number is US 6,140,321, and it has expired due to fee-related issues[4].
Publication and Priority Dates
The patent was published on October 31, 2000, with a priority date of June 30, 1995[4].
Scope of the Patent
Polymorphs of Donepezil Hydrochloride
The patent describes four polymorphs of donepezil hydrochloride, each with distinct physical and chemical properties. These polymorphs are crucial for the stability, bioavailability, and efficacy of the drug[4].
Process for Production
The patent also details a process for producing these polymorphs, which involves specific conditions and methods to ensure the formation of the desired polymorphic forms. This process is essential for maintaining the quality and consistency of the drug[4].
Claims of the Patent
Independent Claims
The patent includes several independent claims that define the scope of the invention. These claims cover the different polymorphs of donepezil hydrochloride and the methods for their production. For example, Claim 1 might specify a particular polymorph of donepezil hydrochloride, while Claim 2 could describe the process for producing that polymorph[4].
Dependent Claims
Dependent claims further narrow down the scope by specifying additional features or conditions. These claims often build upon the independent claims, providing more detailed descriptions of the invention[4].
Patent Landscape
Hatch-Waxman Act and Orange Book Listing
The patent is listed in the FDA's Orange Book, which is a critical component of the Hatch-Waxman Act. This act regulates the approval process for new drugs and generic equivalents. The listing of this patent in the Orange Book means that any generic manufacturer seeking to market a generic version of donepezil hydrochloride must address this patent through one of the four certifications required by the Hatch-Waxman Act (Paragraph I, II, III, or IV certifications)[1][2].
Paragraph IV Certification
A generic manufacturer must file a Paragraph IV certification if it believes the patent is invalid or will not be infringed by the manufacture, use, or sale of the generic drug. This certification triggers a potential infringement suit by the patent holder and can lead to a 30-month stay on FDA approval of the generic drug application (ANDA)[1][2].
Impact on Generic Drug Approval
Infringement Suits and 30-Month Stay
The filing of a Paragraph IV certification can lead to an infringement suit by Eisai Co., Ltd., the patent holder. If such a suit is filed within 45 days of the notice, the FDA approval of the ANDA is subject to a 30-month stay. This stay can significantly delay the entry of generic versions of donepezil hydrochloride into the market[1][2].
Patent Expiration and Generic Entry
Since the patent has expired due to fee-related issues, generic manufacturers can now seek FDA approval without the need for a Paragraph IV certification. This expiration allows for the potential entry of generic versions of donepezil hydrochloride into the market, which can increase competition and reduce drug prices[4].
Industry and Market Implications
Competition and Pricing
The expiration of the patent and the potential entry of generic versions can lead to increased competition in the market. This competition often results in lower drug prices, making the medication more accessible to patients[4].
Innovation and R&D
The patent landscape in the pharmaceutical industry, including patents like US 6,140,321, influences innovation and research and development (R&D) activities. The protection offered by patents can incentivize companies to invest in R&D, but the expiration of patents can also spur further innovation as generic manufacturers enter the market[3].
Conclusion
The United States Patent 6,140,321 is a significant patent in the pharmaceutical industry, particularly for the treatment of Alzheimer's disease. Understanding its scope, claims, and the broader patent landscape is crucial for both innovator companies and generic manufacturers. The expiration of this patent has opened the door for generic competition, which can benefit patients by increasing access to affordable medications.
Key Takeaways
- Patent Scope: The patent covers four polymorphs of donepezil hydrochloride and the process for their production.
- Claims: Independent and dependent claims define the specific polymorphs and production methods.
- Hatch-Waxman Act: The patent is listed in the Orange Book, requiring generic manufacturers to address it through Paragraph I, II, III, or IV certifications.
- Generic Entry: The patent's expiration allows for the entry of generic versions, increasing market competition and potentially reducing drug prices.
- Industry Impact: The patent landscape influences innovation, R&D, and market dynamics in the pharmaceutical industry.
FAQs
What is the significance of the United States Patent 6,140,321?
The patent is significant because it covers the polymorphs of donepezil hydrochloride, a drug used to treat Alzheimer's disease, and the process for their production.
Why is the Hatch-Waxman Act important in this context?
The Hatch-Waxman Act regulates the approval process for new drugs and generic equivalents, requiring generic manufacturers to address listed patents through specific certifications, which can impact the timing of generic drug entry into the market.
What happens when a generic manufacturer files a Paragraph IV certification?
Filing a Paragraph IV certification can trigger an infringement suit by the patent holder and lead to a 30-month stay on FDA approval of the generic drug application.
How does the expiration of the patent affect the market?
The expiration of the patent allows generic manufacturers to seek FDA approval without a Paragraph IV certification, potentially leading to increased competition and lower drug prices.
What is the impact of patent expiration on innovation and R&D?
Patent expiration can spur further innovation as generic manufacturers enter the market, but it also means that the protection offered by the patent is no longer available to incentivize R&D investments by the innovator company.
