United States Patent 4,382,938: A Detailed Analysis
Overview of the Patent
United States Patent 4,382,938, titled "Zolpidem Tartrate and Processes for Its Preparation," was granted to Sanofi, a French multinational pharmaceutical company. This patent is significant in the pharmaceutical industry, particularly for the drug Ambien, which is a widely used medication for the short-term treatment of insomnia.
Patent Claims and Scope
Drug Substance and Product Patents
The patent claims cover the compound zolpidem tartrate, its salts, and processes for its preparation. Specifically, it includes claims for the drug substance itself and the drug product formulations that contain zolpidem tartrate[4].
Method of Use Patents
In addition to the compound and formulation claims, the patent may also include method of use claims. These claims would cover specific methods of using zolpidem tartrate for treating insomnia or other sleep disorders[1].
Exclusivity and Market Protection
The patent was listed in the FDA's Orange Book, which compiles patent information for approved drug products. This listing is crucial for determining the exclusivity period and potential generic competition. The Orange Book entry includes the patent number, expiration date, and the type of patent (drug substance, drug product, or method of use)[1].
Patent Expiration and Term Extension
Original Expiration Date
The patent was originally set to expire based on its filing and issue dates. However, regulatory reviews and approvals can impact the patent term.
Patent Term Extension
Under 35 U.S.C. 156(e)(1), patents that claim products or methods subject to FDA regulatory review can be extended for up to five years. This extension is intended to compensate for the time spent in regulatory review. For U.S. Patent 4,382,938, any such extension would have been calculated based on the FDA approval date of Ambien, which was approved in 1992[2].
Competitive Landscape and Market Insights
Market Dominance
Ambien, the drug product protected by this patent, was a top-selling medication in its class. The patent protection allowed Sanofi to maintain market exclusivity for a significant period, preventing generic competition and ensuring high revenue from the drug[1].
Generic Competition
The launch of generic versions of zolpidem tartrate was delayed until the patent expired. The first generic versions were approved after the patent's expiration, marking the end of Sanofi's exclusivity period. This transition is critical for understanding the market dynamics and the impact of patent protection on pharmaceutical pricing and accessibility[1].
Patent Analysis and Strategic Insights
Prior Art Search
Conducting a prior art search for U.S. Patent 4,382,938 would involve identifying earlier patents and publications related to zolpidem tartrate or similar compounds. This search is essential for assessing the novelty and non-obviousness of the invention claimed in the patent[3].
Citation Analysis
Analyzing citations to and from this patent can provide insights into its influence on subsequent innovations in the field. High citation counts often indicate a patent's significance and impact on the technological landscape[3].
Patent Family Analysis
Examining the patent family of U.S. Patent 4,382,938 involves looking at related patents filed in other countries. This analysis helps in understanding the global protection strategy and the geographical scope of the patent[3].
Technology Trends
The patent's focus on zolpidem tartrate and its formulations reflects trends in the development of sleep disorder treatments. Analyzing this patent in the context of broader innovation trends can help identify areas of rapid development and emerging technologies in the pharmaceutical sector[3].
Regulatory and Legal Aspects
FDA Approval and Orange Book Listing
The patent information for zolpidem tartrate was submitted to the FDA as part of the New Drug Application (NDA) process. The FDA's Orange Book lists this patent, along with its expiration date, to inform generic drug manufacturers about potential patent barriers to market entry[1][4].
Patent Certifications
Generic drug applicants must address the patents listed in the Orange Book through various certifications (Paragraph I, II, III, or IV). For U.S. Patent 4,382,938, generic applicants would need to certify that the patent had expired or would not be infringed by their product[4].
Impact on Market Access and Pricing
Exclusivity Period
The patent protection period for Ambien ensured that Sanofi had a monopoly on the market for zolpidem tartrate, allowing the company to set prices without generic competition. The end of this exclusivity period led to the entry of generic versions, which typically reduces drug prices and increases market access[1].
Generic Entry
The launch of generic zolpidem tartrate marked a significant shift in the market, making the drug more affordable for consumers. This transition aligns with broader policy goals, such as the Executive Order on Promoting Competition in the American Economy, which aims to promote generic drug competition to lower prices and improve access to prescription drugs[1].
Key Takeaways
- Patent Scope and Claims: U.S. Patent 4,382,938 covers zolpidem tartrate, its salts, and processes for its preparation, including method of use claims.
- Patent Expiration and Extension: The patent's term could be extended due to FDA regulatory reviews, but it has since expired.
- Competitive Landscape: The patent protected Ambien's market exclusivity, delaying generic competition until its expiration.
- Regulatory and Legal Aspects: The patent was listed in the FDA's Orange Book, and generic applicants must address it through certifications.
- Market Impact: The end of patent protection led to generic entry, reducing prices and increasing market access.
FAQs
What is the main subject of U.S. Patent 4,382,938?
U.S. Patent 4,382,938 covers zolpidem tartrate, its salts, and processes for its preparation, particularly for the drug Ambien.
How does the FDA's Orange Book relate to this patent?
The FDA's Orange Book lists U.S. Patent 4,382,938, including its expiration date, to inform generic drug manufacturers about potential patent barriers to market entry.
What happens when a patent like U.S. Patent 4,382,938 expires?
When a patent like U.S. Patent 4,382,938 expires, generic versions of the drug can enter the market, typically reducing prices and increasing consumer access.
Can the term of a patent like U.S. Patent 4,382,938 be extended?
Yes, under 35 U.S.C. 156(e)(1), patents subject to FDA regulatory review can be extended for up to five years to compensate for the time spent in review.
How does patent analysis help in understanding the competitive landscape?
Patent analysis helps in identifying competitors, understanding their intellectual property strategies, and assessing the strengths and weaknesses of their patent portfolios, which is crucial for making informed business decisions.
Sources
- USPTO-FDA Report on Drug Patent and Exclusivity: USPTO, December 7, 2018.
- Extension Under 35 U.S.C. 156(e)(1): United States Patent and Trademark Office, July 29, 2003.
- Patent Analysis: Evalueserve.
- FDA Review of Intermezzo (Zolpidem Tartrate): FDA, November 23, 2011.
