Non-Aqueous Microcapsules for Moisture-Sensitive Active Agents
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sol-gel encapsulation methods struggle with controlling reaction rates, leading to loss of morphological and structural control over final oxide materials, and are limited in encapsulating moisture-sensitive and hydrophilic compounds, restricting their use in commercial applications.
Innovation Solution
A non-aqueous sol-gel process is employed using oil-in-oil emulsions and interfacial polymerization to form metal oxide or polyurea shells, enabling encapsulation of both hydrophilic and hydrophobic active agents, including moisture-sensitive compounds, in high loading and non-aqueous formulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If aqueous sol-gel process is used for microencapsulation, then encapsulation can be performed at room temperature with silica providing protection and biodegradability, but moisture-sensitive and hydrophilic active agents cannot be encapsulated due to the need to use water in the process
Solution Approach 1:
The patent changes the fundamental parameter of the sol-gel process from aqueous to non-aqueous conditions. By using organic solvents instead of water, the process enables encapsulation of moisture-sensitive and hydrophilic compounds while maintaining the beneficial features of room temperature processing and silica shell formation. This parameter change resolves the contradiction by eliminating water as the limiting factor.
Solution Approach 2:
The patent introduces an organic solvent as an intermediary medium that facilitates the sol-gel process without requiring water. This intermediary allows the formation of silica shells around hydrophilic and moisture-sensitive compounds by providing an alternative reaction medium that is compatible with these sensitive materials while still enabling the necessary condensation reactions.
2Reliability
If aqueous sol-gel process is used, then inorganic shell formation is achieved, but control over reaction rates is lost resulting in loss of morphological and structural control
Solution Approach 1:
By changing from aqueous to non-aqueous conditions, the patent modifies the reaction rate parameters of the sol-gel process. The non-aqueous environment provides different reaction kinetics that enable better control over shell formation, allowing precise control of morphology and structure while maintaining reliable inorganic shell formation.
3Adaptability or versatility
If aqueous sol-gel process is used, then encapsulation of hydrophilic materials is possible, but long term storage stability of formed microcapsules is restricted
Solution Approach 1:
The patent changes the sol-gel process parameters from aqueous to non-aqueous conditions, which fundamentally improves the long term storage stability of the formed microcapsules. The non-aqueous environment prevents hydrolysis and other water-related degradation reactions, thereby enhancing the stability of both the shell and encapsulated hydrophilic materials during storage.
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 process allows for the encapsulation of hydrophilic and hydrophobic active agents, including moisture-sensitive compounds, in high loading, while forming non-aqueous formulations not possible with traditional sol-gel methods, providing enhanced control over microcapsule properties and stability.
Implementation Method 1
the transformation of the sol-gel precursor into a highly crosslinked solid. Hydrolysis leads to a sol, a dispersion of colloidal particles in a liquid, and further condensation results in a gel
Implementation Method 2
performing an interfacial polymerization using metal oxide precursors in order to form the metal oxide shell of the microcapsule
Implementation Method 3
forming an oil-in-oil emulsion using polar and non-polar phases
Data Source
AI summary
The present invention provides microcapsules encapsulating hydrophilic or hydrophobic active agents in an inorganic shell, processes for their preparation and compositions comprising them.