United States Patent 6,488,962: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 6,488,962, titled "Tablet Shapes To Enhance Gastric Retention of Swellable Controlled-Release Oral Dosage Forms," is a crucial patent held by Depomed, Inc., a specialty pharmaceutical company. This patent is part of a broader portfolio related to controlled-release oral drug delivery systems. Here, we will delve into the scope, claims, and the patent landscape surrounding this invention.
Background
The '962 Patent was issued to Depomed as the assignee of the inventors on December 3, 2002, from a patent application filed on June 20, 2000. This patent is significant for its innovative approach to enhancing gastric retention of oral dosage forms, particularly relevant for drugs like gabapentin, used in treating conditions such as postherpetic neuralgia[4].
Scope of the Patent
The '962 Patent focuses on a controlled-release oral drug dosage form designed to release a drug within the stomach and upper gastrointestinal tract. The key innovation lies in the shape and composition of the dosage form, which is engineered to swell in the presence of gastric fluid, thereby enhancing gastric retention.
Key Features
- Non-Circular Shape: The dosage form is a solid monolithic matrix with a non-circular shape, specifically an oval or parallelogram when projected onto a plane[4].
- Swelling Characteristics: The matrix swells in an unrestricted manner along both orthogonal axes upon imbibition of water. The longer axis has a maximum length of 3.0 cm when unswollen, and the shorter axis achieves a minimum length of 1.2 cm within one hour of immersion in water[4].
- Gastric Retention: The swelling mechanism promotes gastric retention of the dosage form in the stomach, especially in a fed mode, ensuring a controlled release of the drug over several hours[4].
Claims of the Patent
The '962 Patent includes several claims that define the scope of the invention.
Independent Claim 1
Independent Claim 1 is the foundational claim that describes the controlled-release oral drug dosage form. It specifies:
- A solid monolithic matrix with the drug contained therein.
- The matrix is non-circular in shape with first and second orthogonal axes of unequal length.
- The matrix swells in an unrestricted manner along both axes upon imbibition of water.
- The longer axis has a maximum length of 3.0 cm when unswollen, and the shorter axis achieves a minimum length of 1.2 cm within one hour of immersion in water[4].
Dependent Claims
Claims 5, 8, and 10 are dependent on Claim 1 and add additional limitations to further define the invention. These claims may include specific dimensions, material compositions, or other characteristics that enhance the functionality of the dosage form[4].
Patent Landscape
The '962 Patent is part of a larger patent portfolio related to controlled-release drug delivery systems.
Related Patents
Other patents held by Depomed, such as U.S. Patent Nos. 6,340,475, 6,635,280, 7,736,667, and 7,780,987, also pertain to similar drug-delivery technologies. These patents collectively cover various aspects of controlled-release systems, including different materials, coating techniques, and release profiles[1][2].
Litigation and Enforcement
Depomed has actively enforced the '962 Patent and other related patents against generic manufacturers. For instance, in the case of Depomed, Inc. v. Actavis Elizabeth LLC, the court found that Actavis’ generic product infringed the '962 Patent, among others, and that the patents were valid and not obvious[2].
Claim Construction and Interpretation
Claim construction is a critical aspect of patent law, as it determines the scope of protection afforded by the patent.
"Polymeric Matrix" and Similar Terms
While the '962 Patent does not specifically use the term "polymeric matrix," similar patents in the portfolio do. The construction of such terms is crucial for understanding the scope of the invention. For example, in Depomed, Inc. v. Sun Pharma Global FZE, the court had to construe terms like "polymeric matrix" to determine the validity and infringement of related patents[1].
Impact on Pharmaceutical Industry
The '962 Patent and similar patents have significant implications for the pharmaceutical industry.
Controlled Release Technologies
These patents protect innovative technologies that enhance the efficacy and patient compliance of oral drug delivery systems. By ensuring controlled release over an extended period, these technologies can improve the therapeutic outcomes for various diseases[4].
Generic Competition
The enforcement of these patents against generic manufacturers can delay the entry of generic versions into the market, allowing the patent holder to maintain market exclusivity for a longer period. This can have economic implications for both the patent holder and the generic manufacturers[2].
Future Directions and Opportunities
The patent landscape around controlled-release drug delivery systems is dynamic and evolving.
Patent Analytics
Using patent analytics tools, companies like Depomed can track their patent claims and identify gaps or opportunities in their intellectual property portfolio. This helps in strategic decision-making regarding patent maintenance, licensing, and enforcement[3].
Design Opportunities
Interactive claim charts and scope concepts can help engineers, scientists, and management to determine new design options and ensure that future products do not infringe existing patents. This approach also highlights potential future directions and the value of maintaining certain patents[3].
Key Takeaways
- The '962 Patent is a key component of Depomed's portfolio related to controlled-release oral drug delivery systems.
- The patent's scope includes specific shapes and swelling characteristics of the dosage form to enhance gastric retention.
- The claims are carefully constructed to define the invention and distinguish it from prior art.
- The patent has been enforced in various litigation cases, protecting Depomed's market exclusivity.
- The broader patent landscape includes related patents that collectively protect various aspects of controlled-release technologies.
FAQs
Q: What is the main innovation protected by the '962 Patent?
A: The main innovation is the design of a controlled-release oral drug dosage form that swells in the presence of gastric fluid, enhancing gastric retention.
Q: Which drug is specifically mentioned in relation to the '962 Patent?
A: Gabapentin, used in treating conditions such as postherpetic neuralgia.
Q: How does the shape of the dosage form contribute to its functionality?
A: The non-circular shape, specifically an oval or parallelogram, allows the dosage form to swell in an unrestricted manner, promoting gastric retention.
Q: What is the significance of claim construction in patent law?
A: Claim construction determines the scope of protection afforded by the patent, which is crucial for infringement analysis and enforcement.
Q: How does Depomed use patent analytics to manage its intellectual property?
A: Depomed uses patent analytics to track claims, identify gaps or opportunities, and make strategic decisions regarding patent maintenance and enforcement.
Sources
- Depomed, Inc. v. Sun Pharma Global Fze, Case No. C 06-00100, 2006 U.S. Dist. LEXIS 100311 (N.D. Cal. December 20, 2006).
- Depomed, Inc. v. Actavis Elizabeth LLC, No. 12-1358-JAP, 2014 U.S. Dist. LEXIS 118096 (D.N.J. Aug. 18, 2014).
- Patent Analytics, Schwegman Lundberg & Woessner, P.A.
- United States Patent 6,488,962, "Tablet Shapes To Enhance Gastric Retention of Swellable Controlled-Release Oral Dosage Forms."
