United States Patent 6,299,900: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 6,299,900, titled "Dermal Penetration Enhancers and Drug Delivery Systems Involving Same," is a significant patent in the field of pharmaceuticals, particularly in the area of transdermal drug delivery. This patent, assigned to Acrux DDS Pty Ltd., has been a focal point in several legal and technological discussions.
Background and Invention Overview
The patent, filed on February 19, 1997, and granted on October 9, 2001, describes a transdermal drug delivery system that includes at least one physiologically active agent or prodrug and at least one dermal penetration enhancer. This system is designed to improve the delivery of drugs through the skin, enhancing the efficacy and convenience of treatment[4].
Claims of the Patent
The patent includes multiple claims that define the scope of the invention. Here are some key claims:
- Claim 1: A transdermal drug delivery system comprising at least one physiologically active agent or prodrug thereof and at least one dermal penetration enhancer.
- Claim 2: The system of claim 1, wherein the dermal penetration enhancer is selected from a group of compounds including fatty acids, fatty acid esters, and terpenes.
- Claim 3: The system of claim 1, wherein the physiologically active agent is a steroid or a non-steroidal anti-inflammatory drug (NSAID)[4].
Scope of the Patent
The scope of the patent is broad, covering various aspects of transdermal drug delivery systems. It includes:
- Dermal Penetration Enhancers: The patent specifies various types of dermal penetration enhancers that can be used to facilitate the delivery of drugs through the skin.
- Physiologically Active Agents: The patent covers a wide range of active agents, including steroids and NSAIDs, which can be delivered using the system.
- Drug Delivery Systems: The patent describes the composition and method of preparing the transdermal drug delivery system, including the use of patches, gels, and other formulations[4].
Patent Landscape and Related Patents
The patent 6,299,900 is part of a larger family of patents related to transdermal drug delivery systems. Here are some related patents and their significance:
- Continuation and Divisional Patents: This patent is a continuation of earlier applications, including PCT/AU97/00091 and US09/910,780, and is related to other patents such as 6,818,226 and 6,923,983[1][5].
- Later Patents: Subsequent patents like 8,071,075 and 8,435,944 build upon the technology described in the '900 patent, further refining and expanding the scope of transdermal drug delivery systems[2][5].
Litigation and Infringement Claims
The '900 patent has been involved in several litigation cases, particularly in the context of generic pharmaceuticals:
- Eli Lilly and Company vs. Perrigo Company: This case involves allegations of patent infringement related to the commercial manufacture and sale of generic versions of Eli Lilly's Axiron® (testosterone) product. The defendants argued that the '900 patent claims are invalid, unenforceable, or would not be infringed by their generic product[5].
- Actavis Laboratories: Similar infringement claims were made against Actavis Laboratories, where the plaintiffs alleged that Actavis's submission of an Abbreviated New Drug Application (ANDA) to the FDA constituted an act of infringement under 35 U.S.C. § 271(e)(2)[2].
Impact on Pharmaceutical Industry
The '900 patent has significant implications for the pharmaceutical industry:
- Innovation: The patent has driven innovation in transdermal drug delivery, encouraging the development of more effective and convenient drug delivery systems.
- Litigation Costs: The involvement of this patent in various litigation cases highlights the complexities and costs associated with patent disputes in the pharmaceutical sector[3][5].
Patent Scope Metrics
The scope of the '900 patent can be analyzed using metrics such as independent claim length and count. Research suggests that narrower claims, like those in this patent, are associated with a higher probability of grant and a shorter examination process[3].
Expiry and Legal Status
The '900 patent has expired, which means that the technology described is now in the public domain. However, the legal battles surrounding this patent have set important precedents for future patent disputes[4].
Key Takeaways
- Transdermal Drug Delivery: The '900 patent is a cornerstone in the development of transdermal drug delivery systems.
- Broad Scope: The patent covers a wide range of dermal penetration enhancers and physiologically active agents.
- Litigation: The patent has been central in several high-profile litigation cases involving generic pharmaceutical companies.
- Innovation: Despite its expiry, the patent continues to influence innovation in drug delivery systems.
- Patent Landscape: It is part of a complex patent landscape with multiple related patents and continuations.
FAQs
Q: What is the main invention described in the '900 patent?
A: The main invention is a transdermal drug delivery system that includes at least one physiologically active agent or prodrug and at least one dermal penetration enhancer.
Q: Which companies have been involved in litigation related to the '900 patent?
A: Companies such as Eli Lilly and Company, Acrux DDS Pty Ltd., Perrigo Company, and Actavis Laboratories have been involved in litigation related to this patent.
Q: What are the implications of the '900 patent for the pharmaceutical industry?
A: The patent has driven innovation in transdermal drug delivery and has been a focal point in discussions about patent scope and litigation costs.
Q: Is the '900 patent still in force?
A: No, the '900 patent has expired, and the technology described is now in the public domain.
Q: How can the scope of the '900 patent be measured?
A: The scope can be measured using metrics such as independent claim length and count, which indicate that narrower claims are associated with a higher probability of grant and a shorter examination process.
Cited Sources
- US8071075B2 - Dermal penetration enhancers and drug delivery systems involving the same.
- Insight.rpxcorp.com - Litigation Documents.
- SSRN - Patent Claims and Patent Scope.
- Google Patents - US6299900B1 - Dermal penetration enhancers and drug delivery systems involving same.
- Insight.rpxcorp.com - UNITED STATES DISTRICT COURT SOUTHERN DISTRICT OF INDIANA INDIANAPOLIS DIVISION.
