Implantable Drug Reservoir Membrane for Macromolecule Release Control
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Solution Overview
Problem
Existing implantable delivery devices struggle to controllably deliver biologic macromolecule drug compounds over a sustained period due to their larger molecular weight and chain entanglements, leading to reduced diffusion coefficients and inconsistent release profiles.
Innovation Solution
An implantable device with a core and membrane layer structure, where the core contains a hydrophobic polymer matrix with dispersed macromolecular drug compounds and the membrane layer comprises a combination of hydrophobic and hydrophilic polymers, allowing for controlled release of the drug over an extended period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If macromolecular drug compounds are delivered using traditional implantable devices with solubilized drug molecules in a matrix polymer, then the device structure is simple, but the diffusion coefficient is reduced due to larger molecular weight and chain entanglements, leading to poor sustained release performance
Solution Approach 1:
The implantable device is segmented into multiple functional layers: a core layer containing the macromolecular drug compound dispersed in a hydrophobic polymer matrix, and one or more membrane layers comprising hydrophobic polymer combined with hydrophilic compound. This segmentation allows each layer to perform its specific function - the core provides drug reservoir and the membrane layers control diffusion, thereby improving sustained release performance while maintaining manageable structural complexity
Solution Approach 2:
The device uses composite materials throughout: the core employs hydrophobic polymer matrix to disperse and retain macromolecular drug compounds, while the membrane layers use composite formulation of hydrophobic polymer and hydrophilic compound. This composite material approach optimizes both drug retention and controlled release, resolving the contradiction between simple structure and reliable sustained release
2Reliability
If the molecular weight of drug molecules is increased to achieve macromolecular therapeutic effects, then therapeutic benefits are enhanced, but the diffusion coefficient decreases due to larger molecular weight and chain entanglements
Solution Approach 1:
The invention changes the physical and chemical parameters of the delivery system by using hydrophobic polymer matrices and hydrophilic compounds in specific weight ratios (hydrophobic polymer to hydrophilic compound from about 0.25 to about 200). This parameter optimization allows macromolecular drug compounds with high molecular weight to achieve both therapeutic effect and sufficient diffusion rate through careful control of polymer properties and composition
Solution Approach 2:
Hydrophilic compounds act as intermediaries in the membrane layers, facilitating the diffusion of macromolecular drug compounds through the hydrophobic polymer matrix. The hydrophilic compound creates pathways or modifies the matrix properties to enable macromolecules to diffuse at therapeutically effective rates while maintaining their high molecular weight for therapeutic benefit
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves sustained and controlled release of macromolecular drug compounds for therapeutic effects, maintaining a consistent release profile over several days to months, with cumulative release ratios ranging from 20% to 85% after 15-30 days.
Implementation Method 1
the polymer matrix containing a hydrophobic polymer... wherein the membrane polymer matrix contains a hydrophobic polymer in combination with a hydrophilic compound
Implementation Method 2
drug elution is highly dependent upon the diffusion coefficient of the drug molecule... macromolecular drug compounds tend to have a lower diffusion coefficient due to their larger molecular weight
Data Source
AI summary
An implantable device for delivery of a macromolecular drug compound is provided. The device comprises a core having an outer surface and a membrane layer positioned adjacent to the outer surface of the core. The core comprises a core polymer matrix within which is dispersed a drug compound having a molecular weight of about 0.5 kDa or more, the polymer matrix containing a hydrophobic polymer. Further, the membrane layer comprises a membrane polymer matrix within which the macromolecular drug compound is optionally dispersed. The membrane polymer matrix contains a hydrophobic polymer in combination with a hydrophilic compound, and the weight ratio of the hydrophobic polymer to the hydrophilic compound within the membrane polymer matrix ranges from about 0.25 to about 200.