Transdermal Patch with Dual PEG Fractions for Drug Stability
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Solution Overview
Problem
Transdermal patches containing non-steroidal anti-inflammatory drugs face issues with crystallization and sublimation of the drug over time, leading to reduced absorbability, and conventional methods to suppress crystallization, such as increasing polyethylene glycol, result in an overly cohesive adhesive layer that interferes with patch processing.
Innovation Solution
A patch composition including a transdermal preparation with a specific ratio of low molecular weight polyethylene glycol (PEG 400) and high molecular weight polyethylene glycol, along with a styrene-isoprene-styrene block copolymer and polyisobutylene, which suppresses crystallization and sublimation while maintaining adhesive layer flowability and skin permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the amount of polyethylene glycol is increased to suppress crystallization of the non-steroidal anti-inflammatory drug, then the drug crystallization is suppressed, but the adhesive layer becomes overly cohesive and interferes with patch processing
Solution Approach 1:
The polyethylene glycol component is segmented into two distinct molecular weight fractions: low molecular weight PEG (0.3-5% by weight, preferably 0.5-2%) and high molecular weight PEG (1-10% by weight, preferably 2-7.5%). This segmentation allows each fraction to perform its specific function - low molecular weight PEG suppresses drug crystallization while high molecular weight PEG maintains adhesive layer processability, resolving the contradiction between drug stability and manufacturing ease.
Solution Approach 2:
The invention changes the molecular weight parameter of the polyethylene glycol from a single fraction to a dual fraction system with specific weight ratios. By controlling the molecular weight distribution and content ratios of different PEG fractions, the system achieves optimal balance between suppressing drug crystallization and maintaining adhesive layer flowability for patch processing.
2Productivity
If a nonaqueous adhesive composition is used to dissolve poorly water-soluble non-steroidal anti-inflammatory drugs, then the drug can be dissolved in the adhesive composition, but the drug may crystallize and sublime over time, reducing transdermal absorbability
Solution Approach 1:
The low molecular weight polyethylene glycol is incorporated into the nonaqueous adhesive composition beforehand to create a crystallization-suppressing environment. This preliminary action prevents drug crystallization during storage, ensuring the drug remains in dissolved state and maintains transdermal absorbability throughout the product shelf life.
Solution Approach 2:
The adhesive composition is formulated as a composite system combining nonaqueous base materials with polyethylene glycol (both low and high molecular weight fractions). This composite material structure allows the system to simultaneously achieve drug dissolution, prevent crystallization, and maintain transdermal permeability, resolving the contradiction between initial drug dissolution and long-term absorbability.
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 effectively prevents crystallization and sublimation of non-steroidal anti-inflammatory drugs, maintains storage stability, and ensures complete removal without leaving residue, with excellent skin permeability and improved industrial adaptability.
Implementation Method 1
a polyethylene glycol component composed of 0.3 to 5% by weight of a low molecular weight polyethylene glycol and 1 to 10% by weight of a high molecular weight polyethylene glycol that can suppress crystallization or sublimation of the non-steroidal anti-inflammatory drug
Data Source
AI summary
The present invention is directed to a patch containing a non-steroidal anti-inflammatory drug including an adhesive layer composed of a transdermal preparation on a support, the transdermal preparation including a) 10 to 40% by weight of a nonaqueous base material based on the total weight of the transdermal preparation, b) 1 to 10% by weight of a non-steroidal anti-inflammatory drug based on the total weight of the transdermal preparation, and c) a polyethylene glycol component composed of 0.3 to 5% by weight of a low molecular weight polyethylene glycol based on the total weight of the transdermal preparation, and 1 to 10% by weight of a high molecular weight polyethylene glycol based on the total weight of the transdermal preparation.