Felbinac Patch Adhesive Base Without L-Menthol

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Solution Overview

Problem

Existing felbinac-containing patches face issues with low bioavailability, skin irritation, and instability due to L-menthol degradation and adhesion problems, while lacking effective percutaneous absorption and stability.

Innovation Solution

A felbinac-containing external patch with an adhesive base comprising styrene-isoprene-styrene block copolymer, alicyclic saturated hydrocarbon resin, softener, and diethyl sebacate, where felbinac has an average particle diameter of 5-100 µm and a ratio of felbinac to diethyl sebacate is 1:0.1 to 1:15, without L-menthol, enhancing drug release and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If L-menthol is added as a solvent to enhance felbinac solubility and percutaneous absorption, then drug release properties are improved, but felbinac stability deteriorates due to ester degradation

Engineering Contradiction:
Improvedrug release propertiesVSAvoidfelbinac stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent removes L-menthol from the patch formulation entirely, extracting the problematic substance that causes felbinac degradation while maintaining alternative solubilizing agents that do not react with the drug

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces diethyl sebacate as an intermediary substance to replace L-menthol's solubilizing function, providing a non-reactive medium that enhances felbinac solubility and percutaneous absorption without causing ester degradation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If L-menthol is used to improve percutaneous absorption, then drug absorption is enhanced, but skin irritation increases due to sublimation odor and reactivity

Engineering Contradiction:
Improvepercutaneous absorptionVSAvoidskin irritation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent eliminates L-menthol from the formulation, removing the source of sublimation odor and skin irritation while preserving the essential function of enhancing percutaneous absorption through alternative agents

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces L-menthol with diethyl sebacate, a more stable substance that does not sublime or irritate skin, providing a long-term stable formulation without the temporary but harmful effects of L-menthol

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Productivity

If crotamiton is added as a percutaneous absorption enhancer, then felbinac absorption is improved, but adhesion decreases over time due to bleeding onto the adhesive layer surface

Engineering Contradiction:
Improvepercutaneous absorption propertiesVSAvoidadhesion durability
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The patent removes crotamiton from the adhesive layer formulation, eliminating the substance that migrates to the surface and compromises adhesion while exploring alternative absorption enhancers or delivery mechanisms

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces diethyl sebacate as an intermediary that provides percutaneous absorption enhancement without the adverse migration and bleeding effects of crotamiton, maintaining both absorption efficacy and adhesion integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

4Adaptability or versatility

If gel preparation or liquid preparation is used for felbinac administration, then drug flexibility is improved, but quantitative administration becomes difficult and bioavailability is low

Engineering Contradiction:
Improvepreparation flexibilityVSAvoidquantitative administration accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent employs a flexible adhesive patch film that can be applied to various body surfaces while providing controlled, quantitative drug delivery through the adhesive matrix, combining the flexibility advantage with precise dosing capability

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent transforms the drug delivery system from liquid/gel form to a solid adhesive matrix with controlled drug distribution, changing the physical state parameters to enable both flexibility and quantitative precision

Inventive Principle:
Principle #35Parameter changes

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 drug release properties, low skin irritation, and improved stability, making it effective for treating conditions like osteoarthritis and pain management without the drawbacks of previous formulations.

Implementation Method 1

addition of a percutaneous absorption enhancer such as crotamiton, fatty acids, fatty acid esters, monoterpenes, polyhydric alcohols, and pyrrolidones has been investigated

Methodology Applied
Scientific EffectPercutaneous absorption enhancement: Solvation

Implementation Method 2

L-menthol reacts with felbinac to produce an L-menthol ester as a degradation product

Methodology Applied
Scientific EffectEsterification reaction: Chemical Bonding

Implementation Method 3

Irritating odor produced by sublimation of L-menthol is offensive to many people

Methodology Applied
Scientific EffectSublimation: Sublimation

Implementation Method 4

crotamiton tends to bleed out onto the surface of the adhesive layer

Methodology Applied
Scientific EffectBleeding out: Diffusion

Data Source

PatentEP2636405B1Felbinac-containing external patch
Publication Date: 2018.03.14 TEIKOKU SEIYAKU CO LTD

AI summary

Provided is a felbinac-containing external patch which can exhibit high drug release properties, low skin irritation, and high drug stability, wherein felbinac having an average particle diameter of 5 µm or more and less than 100 µm is dispersed and mixed in an adhesive base including a styrene-isoprene-styrene block copolymer, an alicyclic saturated hydrocarbon resin, a softener, and diethyl sebacate, and does not contain L-menthol. Specifically, in the felbinac-containing external patch, 0.1 to 10% by weight of felbinac having an average particle diameter of 5 µm or more and less than 100 µm is dispersed and mixed in an adhesive base including 10 to 30% by weight of a styrene-isoprene-styrene block copolymer, 10 to 50% by weight of an alicyclic saturated hydrocarbon resin, 10 to 75% by weight of a softener, and 0.1 to 10% by weight of diethyl sebacate.