Detailed Analysis of the Scope and Claims of United States Patent 8,105,626
Introduction
United States Patent 8,105,626, assigned to Takeda Pharmaceutical Company Limited, is a significant patent in the pharmaceutical industry, particularly for the formulation and manufacture of acid-unstable medications. This patent is crucial for understanding the protection and innovation surrounding drugs like Dexilant®, a branded medication used to treat gastrointestinal disorders.
Patent Overview
Issuance and Expiration
The patent was issued on January 31, 2012, and is set to expire on September 27, 2026[2][4].
Inventors and Assignees
The inventors listed are Shimizu Toshihiro and Nakano Yoshinori, with Takeda Pharmaceutical Company Limited as the assignee[2][4].
Scope of the Patent
Purpose and Description
The patent aims to provide preparations such as capsules containing an acid-unstable medicament, specifically benzimidazole compounds with antiulcer effects. These preparations are designed to maintain the stability of the medicament by using a specific formulation process[2][4].
Key Components
-
Granules: The patent describes granules that contain an acid-unstable medicament in high concentration. These granules have a principal ingredient layer, an intermediate coating layer, and an enteric coating layer. The intermediate coating layer prevents direct contact between the principal ingredient layer and the enteric coating layer, thereby stabilizing the acid-unstable medicament[4][5].
-
Formulation: The granules are prepared by blending the acid-unstable chemical with a basic inorganic salt to achieve granules with an average particle size of about 600 μm or more. The formulation ensures that the acid-unstable medicament is contained in a high concentration, typically 12% by weight or more based on the total granules[2][4].
Claims of the Patent
Claim Construction
The claims of the patent are specific to the method of preparing and the structure of the granules. Key claims include:
- The use of a principal ingredient layer containing the acid-unstable medicament.
- The inclusion of an intermediate coating layer to stabilize the medicament.
- The application of an enteric coating layer to protect the medicament from acidic environments.
- The specific particle size and concentration of the granules[4][5].
Interpretation of Claim Terms
In patent litigation, the interpretation of claim terms is crucial. The court considers the context in which the term is used within the entire patent, including the specification and the prosecution history. For example, if the specification provides a special definition for a claim term that differs from its ordinary meaning, the inventor's lexicography governs[1].
Patent Landscape
Related Patents
The patent landscape surrounding Dexilant® includes several other patents, such as:
- U.S. Patent No. 7,790,755: Expiring on August 2, 2026.
- U.S. Patent No. 8,173,158: Expiring on March 17, 2030. This patent relates to methods of treating gastrointestinal disorders independent of food intake[2].
Litigation and Settlements
The patent has been involved in litigation under the Hatch-Waxman Act, where generic pharmaceutical companies have filed Abbreviated New Drug Applications (ANDAs) for generic versions of Dexilant®. Takeda Pharmaceutical Co. has asserted infringement claims against several defendants, including Par Pharmaceutical, Inc. and Handa Pharmaceuticals, LLC. Some of these cases have been settled, while others are ongoing[1].
Impact on Generic Availability
FDA Approval and Commercial Availability
Although a generic version of Dexilant® has been approved by the FDA, commercial availability is not guaranteed until the relevant patents expire. The expiration of U.S. Patent No. 8,105,626 in 2026 will likely pave the way for more generic versions to enter the market[2].
Patent Scope and Quality
Metrics for Measuring Patent Scope
Research on patent scope suggests that metrics such as independent claim length and independent claim count can be used to measure the breadth of a patent. Narrower claims are often associated with a higher probability of grant and a shorter examination process. The examination process tends to narrow the scope of patent claims, ensuring clarity and validity[3].
Key Takeaways
- Patent Expiration: U.S. Patent No. 8,105,626 expires on September 27, 2026.
- Formulation: The patent describes a specific formulation process for acid-unstable medicaments, including granules with multiple coating layers.
- Litigation: The patent has been involved in significant litigation under the Hatch-Waxman Act.
- Generic Availability: The expiration of this patent will likely facilitate the commercial availability of generic versions of Dexilant®.
- Patent Scope: The patent's scope is defined by its specific claims and the context provided by the specification and prosecution history.
FAQs
What is the main purpose of U.S. Patent No. 8,105,626?
The main purpose of U.S. Patent No. 8,105,626 is to provide a method for preparing capsules containing acid-unstable medicaments, such as benzimidazole compounds, in a stable and effective form.
Who are the inventors and assignees of this patent?
The inventors are Shimizu Toshihiro and Nakano Yoshinori, and the assignee is Takeda Pharmaceutical Company Limited.
What are the key components of the granules described in the patent?
The granules have a principal ingredient layer, an intermediate coating layer, and an enteric coating layer, with the acid-unstable medicament contained in high concentration and an average particle size of about 600 μm or more.
How does the patent landscape affect the availability of generic versions of Dexilant®?
The expiration of U.S. Patent No. 8,105,626 and other related patents will facilitate the commercial availability of generic versions of Dexilant®.
What metrics are used to measure the scope of a patent?
Metrics such as independent claim length and independent claim count are used to measure the scope of a patent, with narrower claims often associated with higher grant probabilities and shorter examination processes.
Sources
- Par Pharmaceutical, Inc. v. Takeda Pharmaceutical Co. - Casetext
- Generic Dexilant Availability - Drugs.com
- Patent Claims and Patent Scope - SSRN
- US8105626B2 - Granules containing acid-unstable chemical in large amount - Google Patents
- US-8105626-B2 - Unified Patents Portal
