Understanding the Scope and Claims of United States Patent 8,722,084
Introduction
The United States Patent 8,722,084, titled "Controlled Release Preparation," is a significant innovation in the field of pharmaceuticals, particularly in the development of controlled release formulations. This patent, assigned to Takeda Pharmaceutical Company Limited, addresses the need for drug formulations that release active ingredients over an extended period, ensuring optimal therapeutic effects.
Background and Objectives
The patent aims to provide a controlled release preparation that maintains the release of the active ingredient in the gastrointestinal tract for an extended duration. This is crucial for drugs that are sensitive to acidic or basic environments and need to be released in specific pH conditions to be effective[1][4].
Key Components of the Invention
Controlled Release Mechanism
The invention involves a capsule, tablet, granule, or fine granule that contains an active ingredient and a gel-forming polymer. The release of the active ingredient is controlled through various mechanisms:
- Release-Controlled Coating-Layer: The core particle containing the active ingredient is coated with a release-controlled layer. This layer can be pH-dependently soluble or diffusion-controlled, ensuring the drug is released in the appropriate part of the gastrointestinal tract[1][4].
pH-Dependent Solubility
The release-controlled coating-layer often contains a pH-dependently soluble polymer. This means the coating dissolves at specific pH levels, allowing the drug to be released only when it reaches the desired part of the gastrointestinal tract. For example, the inner coating layer might dissolve in the pH range of 6.0-7.0, while the outermost layer dissolves at a pH of 7.0 or above[1].
Dual Coating Layers
The patent also describes formulations with two or more kinds of release-controlled coating-layers. The outermost layer is typically soluble at a higher pH than the inner layer, ensuring a staggered release of the active ingredient. This dual-layer approach allows for a more precise control over the release profile[1].
Technical Details
Gel-Forming Polymer
The capsule or tablet includes a gel-forming polymer that helps in maintaining the controlled release. This polymer swells in the presence of water, creating a gel matrix that slows down the release of the active ingredient[1].
Particle Size and Composition
The granules or fine granules are designed to have a specific particle size, typically around 600 μm or more, to ensure they stay in the gastrointestinal tract long enough to release the drug effectively. The composition includes a high concentration of the acid-unstable chemical blended with a basic inorganic salt[5].
Patent Claims and Scope
Claim Structure
The patent includes several claims that define the scope of the invention. These claims cover various aspects, such as:
- The composition of the capsule, tablet, granule, or fine granule.
- The type and structure of the release-controlled coating-layers.
- The use of pH-dependently soluble polymers and diffusion-controlled layers.
- The specific pH ranges for the dissolution of the coating layers[1][4].
Scope of Protection
The patent provides broad protection for the controlled release preparation, including different forms of the drug formulation and the methods of manufacturing them. This ensures that any similar formulations that use the described mechanisms would infringe on this patent[1].
Patent Landscape and Exclusivities
Related Patents
The patent is part of a larger family of patents related to controlled release formulations. Other patents, such as US 7,790,755 and US 8,105,626, also owned by Takeda Pharmaceuticals, cover related aspects like the composition of granules containing acid-unstable chemicals and methods of treating gastrointestinal disorders[5].
Expiration Dates and Generic Launch
The patent US 8,722,084 has expired, but other related patents and exclusivities granted by the FDA can delay the generic launch of similar drugs. For example, the generic launch of Dexilant, a drug protected by similar patents, is estimated to be in 2032 due to ongoing patent protections and exclusivities[2][5].
Practical Applications
Therapeutic Benefits
The controlled release preparation described in the patent is particularly beneficial for treating gastrointestinal conditions such as erosive esophagitis and heartburn. By ensuring the drug is released in the appropriate part of the gastrointestinal tract, it enhances the therapeutic efficacy and reduces side effects[2].
Manufacturing and Development
The patent provides detailed guidance on the manufacturing process, including the use of specific polymers and coating layers. This helps pharmaceutical companies in developing similar controlled release formulations, ensuring compliance with the patent claims and scope[1].
Key Takeaways
- Controlled Release Mechanism: The patent describes a controlled release mechanism using pH-dependently soluble polymers and diffusion-controlled layers.
- Dual Coating Layers: The use of two or more coating layers allows for precise control over the release profile.
- Gel-Forming Polymer: The inclusion of a gel-forming polymer helps in maintaining the controlled release.
- Patent Claims and Scope: The patent provides broad protection for the composition, structure, and manufacturing methods of the controlled release preparation.
- Patent Landscape and Exclusivities: The patent is part of a larger family of patents, and related exclusivities can delay the generic launch of similar drugs.
FAQs
What is the main objective of the United States Patent 8,722,084?
The main objective is to provide a controlled release preparation that ensures the release of the active ingredient over an extended period in the gastrointestinal tract.
How does the pH-dependent solubility work in this patent?
The coating layers dissolve at specific pH levels, allowing the drug to be released only when it reaches the desired part of the gastrointestinal tract.
What is the role of the gel-forming polymer in this invention?
The gel-forming polymer helps in maintaining the controlled release by swelling in the presence of water and creating a gel matrix that slows down the release of the active ingredient.
Are there other related patents to US 8,722,084?
Yes, there are other related patents, such as US 7,790,755 and US 8,105,626, that cover similar aspects of controlled release formulations.
When is the generic launch of similar drugs expected?
The generic launch of similar drugs, such as Dexilant, is estimated to be in 2032 due to ongoing patent protections and exclusivities.
Sources
- United States Patent and Trademark Office, "US 8,722,084 B2 - Controlled release preparation," May 13, 2014.
- Pharsight, "Dexilant patent expiration," Accessed December 20, 2024.
- SLWIP, "Patent Analytics," Accessed December 20, 2024.
- Google Patents, "US8722084B2 - Controlled release preparation," Accessed December 20, 2024.
- Drugs.com, "Generic Dexilant Availability," November 6, 2024.
