Diclofenac Adhesive Patch with Oily Solubilizer System
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Solution Overview
Problem
Existing transdermal absorption preparations of diclofenac hydroxyethylpyrrolidine face issues with insufficient drug absorption and low adhesiveness to the skin, along with stability concerns.
Innovation Solution
An oily external patch is developed, comprising an adhesive layer with styrene-isoprene-styrene block copolymer, tackifier resin, softening agents, and solubilizers like N-methyl-2-pyrrolidone, propylene glycol, and dimethyl sulfoxide, optimized with diclofenac hydroxyethylpyrrolidine, to enhance absorption and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If an aqueous base material is used for transdermal absorption preparation, then water solubility and compatibility are improved, but transdermal absorption and adhesiveness deteriorate
Solution Approach 1:
The invention changes the base material parameter from aqueous to oily, specifically using isopropyl myristate as the oil phase to improve transdermal absorption while maintaining drug solubility through optimized concentration ratios
Solution Approach 2:
The invention creates a composite adhesive system combining synthetic resin (acrylic polymer), natural resin (rosin), and oily base material (isopropyl myristate) to achieve synergistic effects for both solubility and transdermal absorption
2Quantity of substance
If an aqueous base material is used for transdermal absorption preparation, then water solubility and compatibility are improved, but adhesiveness to skin deteriorates
Solution Approach 1:
The invention changes the base material from aqueous to oily (isopropyl myristate), and adjusts the adhesive composition ratio to achieve optimal adhesiveness while maintaining drug solubility
Solution Approach 2:
The invention uses a composite adhesive system with synthetic resin (30-70 parts), natural resin (10-40 parts), and oily base material (50-150 parts) to achieve both solubility and adhesiveness
3Ease of manufacture
If conventional cataplasm formulation is used, then manufacturing simplicity is maintained, but drug stability deteriorates
Solution Approach 1:
The invention changes the pH parameter of the adhesive layer to 4-6 through buffer addition, which stabilizes diclofenac hydroxyethylpyrrolidine against degradation while maintaining ease of manufacture
Solution Approach 2:
The invention introduces a buffer substance (sodium hydroxide or hydrochloric acid) as an intermediary to control pH and prevent drug degradation, while keeping the formulation process simple
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 excellent transdermal absorption, low skin irritation, and improved stability of diclofenac hydroxyethylpyrrolidine, outperforming conventional cataplasms in absorption and stability tests.
Implementation Method 1
0.5-20% by weight of one or more solubilizers selected from N-methyl-2-pyrrolidone, propylene glycol and dimethyl sulfoxide
Implementation Method 2
excellent transdermal absorption of diclofenac hydroxyethylpyrrolidine
Data Source
Figure 1
AI summary
An external patch containing diclofenac hydroxyethylpyrrolidine prepared by laminating an adhesive layer on a backing, wherein said adhesive layer is characterized by comprising 5-50% by weight of styrene·isoprene·styrene block copolymer, 20-50% by weight of a tackifier resin, 5-70% by weight of a softening agent, and 0.5-20% by weight of one or more solubilizers selected from N-methyl-2-pyrrolidone, propylene glycol and dimethyl sulfoxide as essential ingredients, and 0.5-20% by weight of diclofenac hydroxyethylpyrrolidine as an active ingredient. The patch has excellent transdermal absorption, less skin-irritation and excellent stability of the drug.