Polymeric Core-Sheath Drug Delivery for Independent Dual Release
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Solution Overview
Problem
Existing drug delivery systems face challenges in maintaining a controlled and sustained release of multiple active ingredients, particularly in polymer systems, with issues such as dose dumping, variability in release rates, complex manufacturing processes, and difficulty in achieving a specified delivery ratio of drugs, which are compounded by the unique behavior of each drug combination.
Innovation Solution
A drug delivery system comprising a core with a first polymeric material and a sheath with a high concentration of a second polymeric material, where the sheath contains a second active ingredient dispersed at least 10 wt%, allowing for independent and simultaneous release of two active ingredients, achieving a substantially zero-order release profile over an extended period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reservoir system with a non-medicated membrane is used, then zero-order release is achieved while the reservoir is saturated, but dose dumping occurs when the reservoir is depleted or membrane defects are present
Solution Approach 1:
The invention extracts the harmful non-medicated membrane from the system and replaces it with a medicated matrix where the drug is uniformly distributed throughout the polymer material. This eliminates the reservoir-membrane interface that causes dose dumping while maintaining controlled release through the bulk polymer matrix.
Solution Approach 2:
The invention uses a composite polymeric matrix material that combines drug loading and release control functions in a single homogeneous phase. The polymer matrix serves both as a drug carrier and a rate-controlling medium, eliminating the need for a separate non-medicated membrane layer that could develop defects.
2Ease of manufacture
If a monolithic system with uniform drug loading is used, then manufacturing is simplified, but release rate decreases over time due to increased diffusion distance
Solution Approach 1:
The invention changes the geometric parameters of the delivery system by using a thin-film matrix configuration rather than a thick reservoir structure. This reduces the average diffusion distance for drug molecules while maintaining uniform loading, thereby sustaining release rates over the device lifetime without complicating manufacturing.
3Adaptability or versatility
If a blend of drugs is placed in a single delivery device, then simultaneous delivery is achieved, but the delivery rate ratio cannot be controlled as desired due to different permeation rates
Solution Approach 1:
The invention applies local quality by creating regions with different drug concentrations within the matrix. By controlling the spatial distribution and concentration of each drug component in specific zones of the polymeric matrix, the system achieves independent control over the release rate ratio of multiple drugs despite their different inherent permeation rates.
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 system provides stable, zero-order release of active ingredients, reducing variability and manufacturing complexity, while ensuring a controlled and simultaneous delivery of two drugs without dose dumping, suitable for subcutaneous, vaginal, or uterine implantation.
Implementation Method 1
controlled and sustained release of active ingredients preferably by diffusion through the surface of the device
Data Source
Figure 1
Figure 2(a)~4(c)
Figure 5A~5B
AI summary
The present invention relates to a drug delivery system (1) comprising a core (2) made of a first polymeric material (3) and comprising a first active ingredient (4),, and a sheath (5) made of a second polymeric material (6) and comprising a second active ingredient (7) dispersed and/or incorporated in the second polymeric material in a concentration of above 10 wt% based on the weight of the sheath (5), and below the percolation threshold of said second active ingredient in the sheath (5). Using the drug delivery system according to the present the inventors have found that it is possible to attain independent and optimal release of two active ingredients without the need for complex assembly of parts and without the need to use sophisticated multi-layer extrusion technology.