Self-Dissolving Polymer Matrix for Controlled Drug Release
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Solution Overview
Problem
Existing crosslinked hydrogels used as active ingredient carriers are not suitable for self-dissolution in the body, particularly in areas with limited enzyme presence, such as the surface of the eye, and do not dissolve quickly enough to avoid long-term presence and potential side effects, as they primarily swell rather than dissolve in aqueous environments.
Innovation Solution
A polymer matrix composed of a ternary system including a gel-forming polymer, a cross-linking agent, and a dissolving agent, where the dissolving agent is activated by an external stimulus, such as pH change, to break the cross-linking bonds and facilitate the hydrogel's dissolution, allowing for controlled release and self-dissolution within a few hours.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If cross-linked hydrogels are used as active ingredient carriers, then delayed release of active substance is achieved, but the hydrogels do not dissolve quickly and remain at the application site requiring removal
Solution Approach 1:
The patent incorporates a dissolving agent (such as EDTA or other chelating agents) into the cross-linked hydrogel matrix during fabrication. This dissolving agent remains dormant during cross-linking but becomes activated later to break down the cross-links. The preliminary incorporation of this agent allows the hydrogel to be designed with built-in self-dissolution capability, resolving the contradiction between maintaining structural integrity for delayed release and enabling subsequent rapid dissolution without surgical removal.
Solution Approach 2:
The patent utilizes changes in environmental parameters (pH, temperature, presence of specific ions) to trigger the activation of the dissolving agent. For example, the dissolving agent may be activated by pH changes in the body environment or by specific ions present at the application site. This parameter-based activation allows the hydrogel to transition from a stable, cross-linked state to a dissolving state, achieving both delayed release and self-dissolution without removal.
2Strength
If covalently cross-linked gels are used to limit swelling, then release occurs over several hours, but the gels can only be eroded to a limited extent and remain at the application site
Solution Approach 1:
The patent introduces a dissolving agent as an intermediary substance that mediates between the cross-linked gel structure and the body environment. This agent (such as a chelating agent like EDTA) specifically targets and breaks the cross-links by binding to the metal ions involved in cross-linking, allowing the gel to dissolve completely rather than just erode. This intermediary mechanism enables the gel to maintain its strength during the release period and then fully dissolve without remaining at the application site.
Solution Approach 2:
The patent designs the hydrogel system to be self-dissolving through the incorporation of a dissolving agent that activates under physiological conditions. The gel essentially serves itself by containing within its structure the means to break down its own cross-links, eliminating the need for surgical removal or persistent presence at the application site. This self-service approach resolves the contradiction between maintaining gel integrity and achieving complete dissolution.
3Volume of moving object
If hydrogels are not cross-linked, then they swell considerably in aqueous environment, but active substance is released within a very short time
Solution Approach 1:
The patent applies preliminary cross-linking to the hydrogel network before application, creating a stable structure that prevents excessive swelling and controls the release rate. The cross-links are established in advance to provide the necessary structural framework, while the incorporated dissolving agent remains dormant during this phase. This preliminary cross-linking action ensures both volume control and extended release duration.
Solution Approach 2:
The patent creates a composite hydrogel system combining the gel-forming polymer, cross-linking agents, and dissolving agents into a unified material with optimized properties. This composite structure integrates the swelling control function of cross-links with the extended release function, while the dissolving agent component provides the self-dissolution capability. The composite nature allows simultaneous achievement of volume control and prolonged release duration.
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 polymer matrix effectively self-dissolves within hours at the application site, independent of enzyme presence, enabling controlled release of active substances and avoiding the need for removal, making it suitable for applications where rapid dissolution is required, like the eye surface.
Implementation Method 1
The individual polymer chains can be cross-linked with the aid of polyvalent cations, the cations forming ionic bonds with the guluronic acid of different polymer chains
Implementation Method 2
The dissolving agent, which is a complexing agent, is able to break the bonds between the binding sites and the cross-linking agent
Implementation Method 3
the dissolving agent is activated by an external stimulus, such as pH change, to break the cross-linking bonds
Data Source
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AI summary
The object of the present invention includes cross-linked polymer matrices used as active ingredient supports and able to be applied locally or parenterally in human or animal bodies. The present invention relates in particular to self-releasing cross-linked polymer matrices.