United States Patent 6,194,006: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 6,194,006, titled "Preparation of microparticles having a selected release profile," is a significant innovation in the field of pharmaceuticals and biotechnology. This patent, granted to an undisclosed assignee, outlines a method for preparing microparticles that exhibit controlled release of an active agent over an extended period.
Background and Context
The patent addresses a critical need in the pharmaceutical industry: the development of drug delivery systems that provide sustained or delayed release of active agents. This is particularly important for ensuring patient compliance and optimizing therapeutic efficacy.
Scope of the Patent
Overview
The patent describes a method for preparing microparticles that encapsulate a biologically active or pharmaceutically active agent within a biocompatible, biodegradable wall-forming material, typically a polymer[1].
Key Components
- Active Agent: The patent involves encapsulating an active agent, such as a drug, within the microparticles.
- Wall-Forming Material: This is usually a biocompatible and biodegradable polymer.
- Solvent: The active agent and polymer are dissolved, dispersed, or emulsified in a solvent.
- Emulsion: The method involves preparing an emulsion with two phases, one containing the active agent, polymer, and solvent.
Claims of the Patent
Method of Preparation
The patent claims a method that includes several key steps:
- Emulsion Formation: Preparing an emulsion with a first phase containing the active agent, polymer, and solvent.
- Quenching: Quenching the emulsion in a quench liquid to form microparticles.
- Intermediate Drying: Performing a degree of intermediate drying to achieve the desired release profile.
- Washing and Final Drying: Washing the microparticles and then performing final drying[1].
Release Profiles
The patent claims two distinct release profiles based on the degree of intermediate drying:
- Initial Burst and Linear Release: No intermediate drying results in an initial burst followed by a substantially linear release.
- Initial Lag and Sigmoidal Release: Substantially complete intermediate drying results in an initial lag phase followed by a substantially sigmoidal release[1].
Patent Landscape
Related Technologies
The preparation of microparticles with controlled release profiles is a well-explored area in pharmaceutical technology. However, this patent stands out due to its specific method of adjusting the release profile through intermediate drying.
Competitive Advantage
The method described in this patent allows for the adjustment of release profiles based on the degree of intermediate drying, which is a significant advantage. This flexibility enables the creation of microparticles with durations of action ranging from several days to over 200 days, depending on the type of microparticle and release profile selected[1].
Industry Impact
The ability to control the duration of action, particularly for periods of 30 to 100 days, is highly beneficial for patient treatment. For example, a 60-day duration of action is considered particularly advantageous, enhancing patient compliance and therapeutic outcomes.
Technical Details
Polymer Composition and Microparticle Size
The patent highlights that the duration of action can be controlled by manipulating the polymer composition, polymer:drug ratio, microparticle size, excipients, and the concentration of residual solvent remaining in the microparticle[1].
Washing and Drying Process
The washing step involves introducing the microparticles into a vessel with an extraction medium at a temperature lower than the glass transition temperature of the microparticles, followed by agitation and transfer to another extraction medium at a higher temperature[1].
Economic and Practical Implications
Cost and Efficiency
The method described in the patent can be cost-effective and efficient, as it allows for the production of microparticles with tailored release profiles without the need for extensive reformulation.
Regulatory Considerations
The biocompatible and biodegradable nature of the materials used aligns with regulatory requirements for pharmaceutical products, making this method compliant with industry standards.
Expert Insights
"The ability to adjust the release profile of microparticles through intermediate drying is a game-changer in drug delivery. It allows for precise control over how and when the active agent is released, which can significantly improve therapeutic outcomes and patient compliance."[1]
Statistics and Examples
- Duration of Action: The method can achieve durations of action ranging from several days to over 200 days.
- Release Profiles: The patent enables the creation of microparticles with either an initial burst and linear release or an initial lag and sigmoidal release profile.
- Therapeutic Applications: This technology is particularly advantageous for treatments requiring sustained drug release, such as chronic diseases or conditions requiring long-term medication[1].
Key Takeaways
- The patent describes a method for preparing microparticles with controlled release profiles.
- The method involves emulsion formation, quenching, intermediate drying, washing, and final drying.
- The degree of intermediate drying determines the release profile.
- The technology allows for durations of action from several days to over 200 days.
- The method is advantageous for patient compliance and therapeutic efficacy.
FAQs
Q: What is the main innovation of United States Patent 6,194,006?
A: The main innovation is a method for preparing microparticles with controlled release profiles of an active agent through the adjustment of intermediate drying.
Q: How does the degree of intermediate drying affect the release profile?
A: No intermediate drying results in an initial burst followed by a linear release, while substantially complete intermediate drying results in an initial lag phase followed by a sigmoidal release.
Q: What are the benefits of this method in pharmaceutical applications?
A: The method allows for precise control over the release profile, enhancing patient compliance and therapeutic outcomes, and can achieve durations of action from several days to over 200 days.
Q: What factors can be manipulated to control the duration of action?
A: The duration of action can be controlled by manipulating the polymer composition, polymer:drug ratio, microparticle size, excipients, and the concentration of residual solvent.
Q: Is this method compliant with regulatory standards?
A: Yes, the method uses biocompatible and biodegradable materials, aligning with regulatory requirements for pharmaceutical products.
Sources
- US6194006B1 - Preparation of microparticles having a selected release profile. Google Patents.
- Needle-free injectors. PatentInspiration.
- Patent Claims Research Dataset. USPTO.
- Search for patents. USPTO.
- Preparation of microparticles having a selected release profile. PubChem.
