United States Patent 5,656,296: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 5,656,296, titled "Dual control sustained release drug delivery systems and methods for preparing same," is a significant innovation in the field of pharmaceuticals. This patent, filed on August 12, 1997, and assigned to Warner-Lambert Company, introduces a novel approach to sustained drug release, enhancing the efficacy and convenience of medication administration.
Scope of the Patent
Overview
The patent describes a dual control sustained release drug delivery system designed to prolong the release of medicaments over an extended period, typically up to 12 hours or more. This system consists of a core and a porous coating layer, each playing a crucial role in the controlled release mechanism[1].
Core Composition
The core of the drug delivery system contains a medicament and an edible material with a melting point between 25°C and 100°C. This edible material can be a fatty acid, natural wax, synthetic wax, or a mixture thereof. The medicaments can be water-soluble or water-insoluble drugs, including their acid addition or metallic salts such as hydrochloride, hydrobromide, and sodium, potassium, calcium, or magnesium salts[1].
Porous Coating Layer
The porous coating layer is a critical component that regulates the drug release. This layer is composed of a specific combination of polymeric materials, which can include water-soluble cellulosic polymers like hydroxypropyl cellulose and water-insoluble acrylic polymers such as Eudragit E30D. The porous nature of this layer allows for controlled diffusion of the medicament[1].
Claims of the Patent
Key Claims
- The patent claims a dual control mechanism achieved by the combination of the core and the porous coating layer, ensuring a sustained release of the medicament.
- It specifies the use of fatty acids or waxy materials in the core and particular polymeric materials in the coating layer.
- The claims also cover the methods for preparing these drug delivery systems and the various pharmaceutically acceptable carriers and confectionery bulking agents that can be used[1].
Dependent Claims
- Dependent claims further detail the specific types of medicaments, edible materials, and polymeric materials that can be used.
- These claims also outline the various formulations and methods of preparation, including the use of different solvents and manufacturing processes[1].
Patent Landscape
Prior Art
The patent builds upon earlier innovations in sustained release drug delivery systems. For example, U.S. Pat. No. 4,789,549 describes a sustained release composition with a medicament in a water-soluble polymer matrix coated with a semi-permeable membrane. Another relevant patent, U.S. Pat. No. 4,816,264, issued to Phillips et al., involves a core with a cellulosic gelling polymer coated with a semi-permeable membrane layer[1].
Related Patents
- U.S. Pat. No. 4,851,233, also assigned to Warner-Lambert Company, discusses compressed tablet binders with sustained release properties, which are related to the dual control mechanism described in the current patent[1].
- Other patents, such as U.S. Pat. No. 5,656,296, contribute to the broader landscape of sustained release drug delivery systems, each offering unique improvements and variations.
Impact on Pharmaceutical Industry
Enhanced Efficacy
The dual control sustained release drug delivery system significantly enhances the efficacy of medication by ensuring a consistent and prolonged release of the medicament. This reduces the need for frequent dosing, improving patient compliance and therapeutic outcomes[1].
Versatility
The system can be used with a wide variety of drugs and can be formulated in different carriers and bulking agents, making it versatile for various pharmaceutical applications.
Patient Convenience
By providing a once-daily or extended-release formulation, this system enhances patient convenience, which is a critical factor in adherence to medication regimens.
Methods for Preparation
Manufacturing Process
The patent details methods for preparing the dual control sustained release drug delivery systems. This includes mixing the medicament with the edible material, forming the core, and applying the porous coating layer using specific solvents and manufacturing techniques[1].
Quality Control
Ensuring the quality of the final product is crucial. The patent suggests various quality control measures to ensure the consistency and efficacy of the drug delivery system.
Legal Status and Expiration
Current Status
The patent has expired due to fee-related issues. This means that the technology described in the patent is now in the public domain and can be freely used and improved upon by other entities[1].
Future Developments
Continued Innovation
The expiration of the patent opens up opportunities for further innovation and improvement in sustained release drug delivery systems. Researchers and pharmaceutical companies can build upon this technology to develop even more efficient and effective drug delivery mechanisms.
Regulatory Considerations
Any new developments or improvements must comply with current regulatory standards. This includes ensuring that the new formulations meet safety, efficacy, and quality standards set by regulatory bodies.
Key Takeaways
- Dual Control Mechanism: The patent introduces a dual control mechanism using a core with a medicament and an edible material, and a porous coating layer.
- Prolonged Release: The system ensures a sustained release of the medicament for up to 12 hours or more.
- Versatility: It can be used with various drugs and formulated in different carriers.
- Patient Convenience: Enhances patient compliance by reducing the need for frequent dosing.
- Expired Patent: The technology is now in the public domain, allowing for further innovation.
FAQs
What is the main innovation of United States Patent 5,656,296?
The main innovation is the dual control sustained release drug delivery system, which ensures a prolonged release of medicaments using a core with a medicament and an edible material, and a porous coating layer.
What types of medicaments can be used in this system?
The system can use both water-soluble and water-insoluble drugs, including their acid addition or metallic salts.
How does the porous coating layer regulate drug release?
The porous coating layer, composed of specific polymeric materials, allows for controlled diffusion of the medicament, ensuring a sustained release.
What is the significance of the edible material in the core?
The edible material, such as fatty acids or waxes, has a melting point between 25°C and 100°C and plays a crucial role in the dual control mechanism.
Why has the patent expired?
The patent has expired due to fee-related issues, making the technology described in the patent available for public use.
How does this patent impact patient compliance?
By providing a once-daily or extended-release formulation, the system enhances patient convenience and compliance by reducing the need for frequent dosing.
Sources
- US5656296A - Dual control sustained release drug delivery systems and methods for preparing same - Google Patents
- Filed: March 10, 2016 UNITED STATES PATENT AND ... - ExParte Inc
- Patent Claims Research Dataset - USPTO
- Search for patents - USPTO
- Pramipexole once-daily dosage form - Patent US-2005175691-A1 - PubChem
