Adhesive Patch Drug Solubility and Skin Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional adhesive patches face challenges in achieving both high percutaneous absorbability of drugs and adhesiveness to the skin, with the use of carboxylic acids leading to insufficient cohesive force and low adhesiveness.
Innovation Solution
An adhesive patch incorporating a backing with an adhesive layer containing a drug, levulinic acid, and an acrylic adhesive with a vinyl-based monomer having a solubility parameter of 9 (cal/cm3)1/2 or more, which improves the drug's solubility and adhesiveness by maintaining the drug in a dissolved state and reducing excessive leakage of levulinic acid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If carboxylic acid is used to improve percutaneous absorbability of the drug, then the drug can be kept in a dissolved state, but the cohesive force of the adhesive layer becomes insufficient and adhesiveness to the skin decreases
Solution Approach 1:
The patent changes the chemical parameters of the adhesive system by replacing carboxylic acid with levulinic acid and adjusting the adhesive polymer composition to achieve both drug dissolution and adequate cohesive force. This parameter change resolves the contradiction by finding a chemical composition that satisfies both requirements simultaneously.
Solution Approach 2:
The patent uses a composite adhesive layer containing levulinic acid in combination with specific adhesive polymers (polyacrylic acid, carboxymethyl cellulose, or hydroxypropyl cellulose) at controlled ratios. This composite material approach allows the system to achieve both drug solubility and sufficient cohesive force that neither component could achieve alone.
2Quantity of substance
If the drug is kept in a dissolved state to improve percutaneous absorbability, then drug transfer to skin surface is enhanced, but the drug easily crystallizes in the adhesive layer causing instability
Solution Approach 1:
Levulinic acid acts as an intermediary substance that maintains the drug in a dissolved state within the adhesive layer. It mediates between the drug and the adhesive polymer matrix, preventing crystallization while enabling percutaneous absorption. The levulinic acid is controlled to prevent excessive migration to the skin surface.
Solution Approach 2:
The patent controls the content ratio of levulinic acid to drug within specific ranges (0.1-10 mass ratio, preferably 0.5-5) and sets the adhesive layer composition parameters to maintain drug solubility while preventing excessive levulinic acid migration. These parameter controls ensure stable drug dissolution state throughout the product shelf life.
3Quantity of substance
If levulinic acid is used to improve percutaneous absorbability, then drug solubility is enhanced, but excessive leakage of levulinic acid reduces adhesiveness to the skin
Solution Approach 1:
The patent precisely controls the levulinic acid content ratio relative to the drug (0.1-10 mass ratio) and the overall adhesive layer composition to balance drug solubility enhancement with prevention of excessive levulinic acid migration. This parameter optimization ensures adequate adhesiveness while maintaining drug solubility.
Solution Approach 2:
The patent creates a composite adhesive system where levulinic acid is combined with specific adhesive polymers in controlled proportions. This composite structure allows the system to achieve both high drug solubility and sufficient adhesiveness by distributing the functional roles among different components.
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 adhesive patch achieves excellent percutaneous absorbability and adhesiveness, allowing for effective drug delivery with reduced side effects and improved skin compatibility, while maintaining stability and adhesiveness over time.
Implementation Method 1
the adhesive layer including a drug, levulinic acid, and an acrylic adhesive
Implementation Method 2
an acrylic adhesive including an acrylic polymer (A) containing a vinyl-based monomer (I) moiety having a solubility parameter of 9 (cal/cm3)1/2 or more
Implementation Method 3
transfer the drug in this dissolved state to the skin surface
Data Source
AI summary
An object is to provide an adhesive patch that is excellent in both percutaneous absorbability of a drug and adhesiveness to the skin. An adhesive patch of the present invention includes a backing and an adhesive layer integrally laminated on one side of the backing, the adhesive layer including a drug, levulinic acid, and an acrylic adhesive including an acrylic polymer (A) containing a vinyl-based monomer (I) moiety having a solubility parameter of 9 (cal/cm3)1/2 or more. According to the present invention, it is possible to provide an adhesive patch that is excellent in both percutaneous absorbability of a drug and adhesiveness to the skin.