Crosslinked Polysaccharide Microcapsules for Friction-Triggered Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microencapsulated delivery systems for controlled release of active ingredients face challenges such as non-biodegradability, safety concerns due to use of non-GRAS reactive monomers, premature release in humid environments, and difficulty in achieving anhydrous, free-flowing, biodegradable microcapsules that release actives in response to friction and enzymes.
Innovation Solution
Development of controlled release particles comprising 10-70 wt.% hydrophobic active ingredient, 21-72 wt.% polysaccharide, 3.80-12 wt.% crosslinking agent, 1.00-6 wt.% catalyst, and 0.10-5 wt.% silica flow aid, encapsulated in a crosslinked polysaccharide matrix, which are anhydrous and designed to release the active in response to friction and enzymes, with optional inclusion of epoxidized oil and amine-functionality containing materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If crosslinked polymers are used to provide a barrier membrane, then the lifetime of the polymer is increased, but the biodegradability is reduced
Solution Approach 1:
The patent uses transient crosslinking where the crosslink density dynamically changes over time. Initially, crosslinks provide structural integrity and barrier function, but as environmental triggers (water, enzymes, pH) are encountered, the crosslinks break down, allowing biodegradation. This temporal parameter change resolves the contradiction between long lifetime and biodegradability.
Solution Approach 2:
The polymer network transitions from a static crosslinked structure to a dynamic one that can reconfigure and degrade. The crosslinking is designed to be reversible or cleavable under specific conditions, making the polymer lifetime adaptive rather than fixed, thus enabling both durability when needed and biodegradation when environmental conditions change.
2Object-affected harmful factors
If polysaccharide-based microcapsules are used for encapsulation, then biodegradability is improved, but premature release of active occurs in humid environments
Solution Approach 1:
The patent creates composite microcapsules combining polysaccharides with hydrophobic materials (oils, waxes, or synthetic polymers). The polysaccharide provides biodegradability while the hydrophobic component forms a water-resistant barrier that prevents premature release in humid environments. This composite structure resolves the contradiction between biodegradability and retention reliability.
3Ease of operation
If core/shell microcapsules are used for friction-triggered release, then release upon shear application is achieved, but environmental biodegradability is reduced
Solution Approach 1:
The shell material uses reversible crosslinking or weak bonds that maintain structural integrity during storage and handling but break down under friction stress. After friction-triggered release, the degraded materials remain biodegradable in the environment. The key is that the bonds break at different stress thresholds: intact during normal conditions, fractured during friction events.
4Strength
If larger particle size is used, then fracture strength is reduced for better consumer activity response, but fracture during spray drying increases
Solution Approach 1:
The patent performs crosslinking after spray drying rather than before. This preliminary action sequence allows large particles to be formed first without fracture during drying, then crosslinked in a separate step to provide the necessary mechanical strength and controlled release properties. This resolves the contradiction by decoupling particle formation from strength development.
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 solution provides environmentally biodegradable, anhydrous microcapsules that effectively retain hydrophobic actives upon water exposure and release them in response to friction and enzymes, offering improved stability and controlled release profiles, reducing volatile loss and enabling use in various applications including food, pharmaceuticals, and personal care products.
Implementation Method 1
hydrophobic active ingredient is encapsulated in a crosslinked polysaccharide matrix effective to retain the hydrophobic active ingredient upon exposure to water
Implementation Method 2
effective to release the hydrophobic active ingredient in response to friction and enzymes
Implementation Method 3
effective to release the hydrophobic active ingredient in response to friction and enzymes
Implementation Method 4
0.10-5 wt.% of a silica flow aid
Data Source
Figure 1A~1C
Figure 2A~3
Figure 4~5
AI summary
Disclosed are: (a) controlled release matrix particles containing 10-70 wt.% of a hydrophobic active ingredient, 21-72 wt.% of a polysaccharide, 3.80-12 wt.% of a crosslinking agent, 1.00-6 wt.% of a catalyst and 0.10-5 wt.% of a silica flow aid; (b) controlled release core/shell particles containing 10-70 wt.% of a hydrophobic active ingredient, 1.0-3.2 wt.% of an epoxidized oil, 21-64 wt.% of a polysaccharide, 7.6-23% of an amine-functionality containing material, and 0.10-5 wt.% of a silica flow aid; and (c) hybrid particles wherein the core/shell particles are contained in a matrix. Also disclosed are methods for making the particles and compositions containing the particles.