Crosslinked Pressure-Sensitive Adhesive for Donepezil Transdermal Patches
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Solution Overview
Problem
Percutaneously absorbable preparations using donepezil or donepezil hydrochloride for long-term administration face challenges with cohesive failure of the pressure-sensitive adhesive layer, leading to adhesive transfer and skin irritancy issues during peeling.
Innovation Solution
Incorporating a metal chloride into a crosslinked pressure-sensitive adhesive layer, along with a liquid plasticizer, to enhance cohesiveness and reduce skin irritancy, thereby preventing adhesive transfer and improving skin feel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a percutaneously absorbable preparation is used for long-term administration, then the treatment duration is extended, but the preparation causes cohesive failure of the pressure-sensitive adhesive layer leading to adhesive transfer and skin irritancy
Solution Approach 1:
The patent changes the chemical parameters of the pressure-sensitive adhesive layer by incorporating specific additives and modifying the crosslinking structure. This involves adjusting the composition ratios of adhesive components, adding co-solvents or plasticizers, and optimizing the crosslinking density to prevent cohesive failure during long-term wear while maintaining skin adhesion.
Solution Approach 2:
The patent creates a composite pressure-sensitive adhesive layer by combining multiple materials with complementary properties. This includes mixing different adhesive polymers, incorporating crosslinking agents, adding plasticizers or co-solvents, and integrating these components in specific ratios to achieve both long-term stability and skin compatibility.
2Strength
If the pressure-sensitive adhesive layer is crosslinked to improve cohesiveness, then the adhesive strength increases, but cohesive failure occurs during peeling
Solution Approach 1:
The patent optimizes the crosslinking parameters by controlling the crosslinking agent concentration, crosslinking temperature, and curing time. This balances the crosslinking density to provide sufficient strength while preventing excessive rigidity that would cause cohesive failure during peeling.
Solution Approach 2:
The patent introduces intermediary substances such as plasticizers, co-solvents, or modifying agents into the crosslinked adhesive system. These intermediaries act as buffers that reduce internal stress during peeling, prevent brittle failure, and maintain flexibility while preserving the crosslinked structure's strength.
3Object-affected harmful factors
If the pressure-sensitive adhesive layer is made softer to reduce skin irritancy, then the skin feel improves, but the cohesiveness of the adhesive layer decreases
Solution Approach 1:
The patent adjusts the physical parameters of the adhesive layer by modifying the glass transition temperature, viscosity, or flexibility through additive incorporation. This allows the adhesive to remain soft and skin-friendly while maintaining adequate cohesive strength through compensatory crosslinking or polymer selection.
Solution Approach 2:
The patent formulates a composite adhesive system combining soft polymers with crosslinking agents and reinforcing additives. This creates a multi-phase material that provides both softness for skin comfort and structural integrity for cohesive strength, with each component contributing specific properties.
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 stabilizes the pressure-sensitive adhesive layer's cohesiveness, reduces skin irritancy, and prevents adhesive transfer during peeling, resulting in a more effective and comfortable long-term administration method.
Implementation Method 1
a percutaneously absorbable preparation comprising 2-[(1-benzyl-4-piperidinyl)methyl]-5,6-dimethoxyindan-1-on and/or its hydrochloride and a metal chloride in a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is crosslinked
Implementation Method 2
a method of including a liquid component in the pressure-sensitive adhesive layer to produce a gel, thereby giving a softer feeling to the pressure-sensitive adhesive layer
Data Source
AI summary
[Object] The present invention provides a percutaneously absorbable preparation for percutaneous absorption of donepezil or its hydrochloride which is stable and resistant to loss of cohesiveness of the pressure-sensitive adhesive layer while attached and resistant to adhesive transfer due to cohesive failure during removal by peeling. [Solution] The percutaneously absorbable preparation comprises 2-[(1-benzyl-4-piperidinyl)methyl]-5,6-dimethoxyindan-1-on and/or its hydrochloride and a metal chloride in a pressure-sensitive adhesive layer which has been crosslinked.