Implantable Macromolecular Drug Reservoir With EVA Diffusion Membrane
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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 large molecular weight and chain entanglements, leading to reduced diffusion coefficients and inconsistent release rates.
Innovation Solution
An implantable device with a core polymer matrix containing a hydrophobic polymer and dispersed macromolecular drug compound, combined with a membrane layer of water-soluble particles with controlled particle size and ethylene vinyl acetate copolymer, allowing for sustained and controlled release of the drug.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If drug molecules are solubilized into a matrix polymer for delivery, then the device structure is simplified and manufacturing is easier, but macromolecular drug compounds have reduced diffusion coefficient due to their large molecular weight and chain entanglements, leading to poor release performance
Solution Approach 1:
The device is divided into two distinct layers: a core layer containing the macromolecular drug compound in a hydrophobic polymer matrix, and a membrane layer containing hydrophilic polymer particles with solubilized drug. This segmentation allows each layer to perform its specialized function - the core provides structural integrity while the membrane enables controlled release through dissolution and diffusion pathways
Solution Approach 2:
Different regions of the device have different properties optimized for their specific functions. The core layer uses hydrophobic polymer with high drug loading capacity, while the membrane layer uses hydrophilic polymer particles that dissolve to create release channels. Each layer's material composition and structure are locally optimized to address the specific requirements of drug retention and release
2Stability of the object's composition
If the drug compound has large molecular weight and chain entanglements, then the drug stability is improved, but the diffusion coefficient is reduced, preventing sustained release over time
Solution Approach 1:
The membrane layer acts as an intermediary between the drug reservoir in the core and the external environment. The hydrophilic polymer particles in the membrane dissolve to create a gel-like matrix that facilitates drug diffusion, effectively mediating the transport of macromolecular drugs that would otherwise be trapped by their own chain entanglements in the core layer
Solution Approach 2:
The device combines hydrophobic polymer materials in the core with hydrophilic polymer particle materials in the membrane. This composite structure leverages the complementary properties of hydrophobic and hydrophilic materials - the hydrophobic core stabilizes and concentrates the macromolecular drug, while the hydrophilic membrane enables water penetration and drug release through dissolution and diffusion
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 release of macromolecular drug compounds over extended periods, typically 5 to 150 days, with controlled release rates, ensuring therapeutic effectiveness.
Implementation Method 1
the membrane layer comprises a plurality of water-soluble particles distributed within a membrane polymer matrix
Implementation Method 2
drug elution is highly dependent upon the diffusion coefficient of the drug molecule
Implementation Method 3
the ethylene vinyl acetate copolymer has a vinyl acetate monomer content of from about 25 wt. % to about 50 wt. %, a melt flow index of from about 10 to about 80 grams per 10 minutes as determined in accordance with ASTM D1238-20 at a temperature of 190° C. and a load of 2.16 kilograms, and/or a melting temperature of from about 60° C. to about 120° C.
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 plurality of water-soluble particles distributed within a membrane polymer matrix containing an ethylene vinyl acetate copolymer, wherein the water-soluble particles have a D50 particle size of about 150 micrometers or less and contain a non-polymeric, hydroxy-functional compound.