Polyelectrolyte Complex for Controlled Release of Charged Actives
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current controlled release systems for hydrophilic and electrostatically charged active ingredients face challenges in effective incorporation and sustained release due to rapid solubility and swelling issues, leading to unsatisfactory release profiles.
Innovation Solution
A degradable polymer matrix is used in conjunction with an acid-sensitive polyelectrolyte complex, where the active principle is complexed with a polyelectrolyte partner of opposite charge, and the matrix generates acidic degradation products to catalyze the release of the complex, ensuring a controlled and prolonged release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydrophilic active ingredients are directly incorporated into a polymer matrix, then the incorporation is difficult and release is too rapid, but using a hydrophobic matrix improves incorporation difficulty
Solution Approach 1:
The patent introduces a polyelectrolyte complex as an intermediary between the hydrophilic active ingredient and the hydrophobic polymer matrix. The complex has amphiphilic character with both hydrophilic (active ingredient) and hydrophobic (polyelectrolyte) components, enabling effective incorporation into the matrix while controlling release. This mediator resolves the contradiction by providing both good incorporation and sustained release.
Solution Approach 2:
The invention creates a composite system consisting of three components: the active ingredient, the polyelectrolyte complexing agent, and the degradable polymer matrix. This composite structure combines the advantages of hydrophilic and hydrophobic materials, allowing the hydrophilic active ingredient to be effectively incorporated and released in a controlled manner through the composite's dual character.
2Ease of manufacture
If the active principle is directly incorporated into the matrix, then release is rapid due to high solubility, but complexation with polyelectrolyte masks hydrophilicity and promotes incorporation
Solution Approach 1:
The patent changes the physicochemical parameters of the active ingredient by forming a complex with a polyelectrolyte. This complexation alters the solubility, hydrophilicity, and molecular size of the active ingredient, enabling effective incorporation into the hydrophobic matrix. The parameter changes resolve the contradiction by improving incorporation while the degradable matrix ensures controlled release.
3Reliability
If a stable polyelectrolyte complex is used, then the active principle is protected, but the complex cannot be destabilized and released effectively
Solution Approach 1:
The patent employs a dynamic system where the polyelectrolyte complex's stability is temporarily maintained during incorporation and storage, then dynamically changed during release. The complex is stable under physiological conditions to protect the active ingredient, but becomes unstable and releases the active ingredient when exposed to acidic conditions from matrix degradation. This dynamic behavior resolves the contradiction between protection and release efficiency.
Solution Approach 2:
The release mechanism follows a periodic pattern: the complex remains stable during a protection phase, then undergoes destabilization and release when triggered by acidic conditions from matrix degradation. This periodic stability-destabilization cycle allows the system to first protect the active ingredient and then efficiently release it when needed.
4Productivity
If the matrix degrades rapidly, then the active principle is released quickly, but rapid degradation does not provide controlled release profile
Solution Approach 1:
The patent ensures continuous controlled release through the sequential degradation of the degradable polymer matrix. As the matrix continuously degrades over time, it continuously generates acidic conditions that progressively destabilize the polyelectrolyte complex and release the active ingredient. This continuous action resolves the contradiction by maintaining both adequate release speed and a suitable prolonged release profile.
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
This approach effectively masks hydrophilicity, promotes incorporation, and achieves a delayed release of the active principle, modulating its delivery based on the degradation rate of the polyelectrolyte and matrix, resulting in a stable and prolonged release profile without chemical modification of the bioactive compound.
Implementation Method 1
degradable by hydrolytic degradation with generation of acidic compounds
Implementation Method 2
generating acids which catalyze the degradation of the complexing polyelectrolyte
Implementation Method 3
the active principle is engaged, with a polyelectrolyte partner of opposite charge, in a solid polyelectrolyte complex
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to a system for controlled release of an active principle, comprising at least (a) a degradable polymer matrix which produces acid compounds and (b) at least one acid-sensitive complex of an active principle having at least one electrostatic charge and a complexing polyelectrolyte partner of opposite charge which complexes with the active principle. The invention further relates to a method for preparation of such a system. The release of the active principle (7P) is prolonged over 18 days (ternary system PMLA/7P/PLAGA) in comparison to binary systems (7P/PLAGA) and (PMLA/7P).