Surface-Modified Hydrogel Microparticles for Controlled Release

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Solution Overview

Problem

Hydrogels and hydrogel microparticles face challenges in controlling the release of active ingredients due to limited resistance to premature release when exposed to aqueous and alcohol systems, and they are difficult to handle due to moisture sensitivity and tackiness.

Innovation Solution

Surface-modified hydrogels and microparticles are developed with hydrophobic coatings formed by treating hydrogels or microparticles with free-radical polymerizable compounds and organoborane initiators, creating a barrier that modulates the transport of water and water-compatible compounds, thereby controlling the release of active ingredients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hydrogels are used to encapsulate and deliver active ingredients, then encapsulation and delivery capability is improved, but resistance to premature release deteriorates when exposed to aqueous and alcohol systems

Engineering Contradiction:

Improveencapsulation and delivery capabilityVSAvoidresistance to premature release

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

A hydrophobic coating layer is applied to the surface of the hydrogel microparticles, forming a protective shell that is permeable to oxygen but resistant to water and alcohol. This shell maintains the encapsulation capability while preventing premature release of active ingredients when exposed to aqueous and alcohol systems.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The invention creates a composite structure combining hydrogel core material with a hydrophobic coating layer. The hydrogel provides encapsulation and delivery functionality, while the hydrophobic coating provides barrier properties against water and alcohol, achieving both reliable delivery and resistance to premature release.

Inventive Principle:

Principle #40Composite materials

2Reliability

If hydrogels are used for active ingredient delivery, then delivery effectiveness is improved, but handling characteristics deteriorate due to moisture sensitivity and tackiness

Engineering Contradiction:

Improvedelivery effectivenessVSAvoidhandling characteristics

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The hydrophobic coating forms a protective shell that reduces surface tackiness and moisture sensitivity of the hydrogel microparticles, making them easier to handle during processing and application while maintaining their delivery effectiveness.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The surface properties of the hydrogel microparticles are modified by changing the chemical composition of the outer layer from hydrophilic to hydrophobic, which alters parameters such as surface energy, tackiness, and moisture absorption, thereby improving handling characteristics without affecting core delivery functionality.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If a hydrophobic coating is applied to control water transport, then control over active ingredient release is improved, but device complexity increases

Engineering Contradiction:

Improvecontrol over active ingredient releaseVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A single-layer hydrophobic coating is applied to the hydrogel surface, providing controlled water and alcohol transport properties. This simple shell structure enables reliable control over active ingredient release without requiring complex multi-layer or multi-component structures.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The release control is achieved by modifying the surface chemical properties through hydrophobic coating, which naturally creates selective permeability to different molecules based on their polarity. This parameter change approach provides control functionality without adding structural complexity.

Inventive Principle:

Principle #35Parameter changes

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 surface-modified hydrogels and microparticles effectively resist solvent washing and control the release of active ingredients, improving handling characteristics and maintaining the hydrophilic properties necessary for optimal loading and delivery.

Implementation Method 1

treating the hydrogel or microparticle with a free-radical polymerizable compound and an organoborane initiator, thereby forming a coating on the surface of the hydrogel or microparticle

Methodology Applied

Scientific EffectFree radical polymerization: Photopolymerisation

Implementation Method 2

surface coatings that resist solvent washing and act as barriers (temporary or permanent) for the migration of water and/or water-compatible compounds

Methodology Applied

Scientific EffectPermeation barrier: Permeation

Data Source

PatentUS9574109B2Surface-modified hydrogels and hydrogel microparticles

Publication Date: 2017.02.21 DOW SILICONES CORP

AI summary

Provided in various embodiments are surface-modified hydrogels and hydrogel microparticles, methods for their preparation, and uses thereof for delivery of personal care and healthcare active ingredients, and agricultural active ingredients. In some embodiments, such hydrogels and hydrogel microparticles comprise surface coatings that are resistant to solvent washing and can act as barriers for the migration of water and/or water-compatible alcohols and actives soluble therein.