Ropinirole Adhesive Patch Stability
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Solution Overview
Problem
Transdermal absorption preparations using acid addition salts of ropinirole have lower permeability and stability issues due to incomplete conversion and potential skin irritation from metal salts, limiting the effectiveness of ropinirole patches for Parkinson's disease treatment.
Innovation Solution
A transdermal absorption patch using an acrylic-based adhesive with a hydroxyl group or pyrrolidone group, without cross-linking agents, and containing free ropinirole, which enhances drug permeability and stability by ensuring complete dissolution and avoiding metal salt precipitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acid addition salt of ropinirole is used in transdermal preparation, then stability and handleability are improved, but transdermal absorbability deteriorates
Solution Approach 1:
The patent changes the chemical form parameter of ropinirole from acid addition salt to free form, and modifies the adhesive base composition by selecting specific polymers without carboxyl groups. This parameter change enables the free drug form to be maintained in the preparation, significantly improving transdermal absorbability while maintaining acceptable stability through the carefully selected adhesive base.
2Productivity
If dehydrochlorinating agent is used to convert acid addition salt to free ropinirole, then transdermal absorbability is improved, but drug amount in adhesive base is limited and conversion is incomplete
Solution Approach 1:
Instead of converting the acid addition salt to free drug form using dehydrochlorinating agents, the patent inverts the approach by directly using free ropinirole from the beginning and selecting an adhesive base that is compatible with the free drug form. This eliminates the need for conversion and ensures complete drug availability for transdermal absorption.
3Productivity
If dehydrochlorinating agent is used for conversion, then free ropinirole is generated, but metal salt precipitates causing skin irritation
Solution Approach 1:
The patent extracts and eliminates the dehydrochlorinating agent and its associated metal salts from the preparation system. By directly using free ropinirole and selecting an adhesive base that does not require metal-based dehydrochlorinating agents, the harmful metal salt precipitation and associated skin irritation are completely avoided.
4Ease of manufacture
If acrylic-based adhesive with carboxyl group is used, then adhesive performance is improved, but free ropinirole stability deteriorates due to interaction
Solution Approach 1:
The patent changes the chemical composition parameter of the adhesive base by selecting acrylic-based polymers that lack carboxyl groups. This parameter change prevents harmful interactions with free ropinirole, maintaining drug stability while preserving adequate adhesive performance through the selected polymer structure and 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 patch achieves high transdermal absorbability and excellent drug stability, effectively delivering ropinirole for Parkinson's disease treatment with improved safety and efficacy.
Implementation Method 1
free ropinirole is added to a specific acrylic-based adhesive in consideration of the chemical characteristics of ropinirole, favorable drug permeability and high drug stability can be obtained
Data Source
AI summary
Provided is an adhesive patch containing ropinirole serving as a therapeutic drug for Parkinson's disease, with the ropinirole used being free ropinirole (ropinirole in free form) added to an adhesive base, wherein the patch exhibits favorable drug permeability and excellent drug stability. Also provided is a transdermal absorption patch using, as an adhesive base, an acrylic-based adhesive having no specific carboxyl group and having a hydroxyl group or a pyrrolidone group, with the patch including free ropinirole added to the adhesive base. Further provided is a ropinirole-containing transdermal absorption patch including a transdermal absorption promoting agent.