Adjustable Occlusion Plaster with Composite Adhesive
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Solution Overview
Problem
Transdermal and topical systems face challenges in achieving occlusive conditions with textile backing layers, which are not extensible, and adhesives like polyisobutylene or block polymers have poor adhesion to moist skin, leading to detachment issues.
Innovation Solution
A transdermal or topical plaster with a textile backing layer and a matrix layer containing polyacrylate or silicone adhesives with dispersed water vapor-impermeable polymers like polyisobutylene or styrene-isoprene-styrene block copolymers, allowing for adjustable occlusion and improved adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If textile materials are used for backing layers to provide stretch and wearing comfort, then extensibility and wearing comfort are improved, but water vapor permeability increases and occlusive conditions are lost
Solution Approach 1:
The patent uses a composite adhesive system combining polyacrylate adhesive (for extensibility and comfort) with polyisobutylene or block polymers (for occlusion). This composite approach allows the plaster to simultaneously achieve stretchability from the textile backing and occlusive properties from the impermeable polymer components in the adhesive layer.
2Object-affected harmful factors
If adhesives like polyisobutylene or block polymers are used to achieve occlusion, then water vapor impermeability is improved, but adhesion to moist skin deteriorates
Solution Approach 1:
The patent creates a composite adhesive where polyacrylate provides good adhesion to moist skin while polyisobutylene or block polymers provide occlusive properties. The synergistic combination allows both functions to coexist without compromising either adhesion or water vapor impermeability.
Solution Approach 2:
The adhesive system exhibits local quality differentiation where different polymer components perform different functions: polyacrylate at the skin interface provides adhesion, while polyisobutylene/block polymers in the bulk provide occlusion. This spatial functional differentiation resolves the contradiction between adhesion and impermeability.
3Object-affected harmful factors
If non-stretchy materials are used for occlusive layers, then water vapor impermeability is improved, but wearing comfort and adaptability deteriorate
Solution Approach 1:
The patent employs composite materials where the textile backing provides stretch and comfort while the adhesive layer containing polyisobutylene or block polymers provides occlusion. This multi-layer composite structure allows the plaster to conform to body contours while maintaining water vapor impermeability.
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 effective occlusion and adhesion to moist skin, reducing water vapor permeability and enhancing the absorption of active ingredients, as demonstrated by the permeation studies with diclofenac sodium salt, with optimal results at specific polyisobutylene content and matrix thickness.
Implementation Method 1
one with the base polymer is not or only very slightly miscible second polymer with a low water vapor permeability
Implementation Method 2
a transdermal or topical plaster with a textile backing layer and a matrix layer containing polyacrylate or silicone adhesives
Implementation Method 3
the occlusion effect can be varied within wide limits due to the amount of water vapor impermeable polymer and the thickness of the matrix
Data Source
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AI summary
The invention relates to a transdermal or topical plasters that contain active ingredient, comprising a non-occlusive back layer, a matrix composed of one or more polymer layers having at least one pharmaceutical active ingredient in one or more of the layers, wherein the structure-forming base polymers of the layer(s) are non-occlusive or only slightly occlusive and a second polymer that has a low water-vapor permeability and that is immiscible or only very slightly miscible with the base polymer is dispersed in at least one of the polymer layers.