Transdermal Patch Adhesive with Fatty Acid Ester

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Solution Overview

Problem

Transdermal patches for DMAE or its pharmacologically acceptable salt face issues with preservation stability, transdermal absorbency, and manufacturing costs, as well as skin stimulation and adhesive transfer due to degradation and complex production processes.

Innovation Solution

A transdermal patch with a plaster layer containing 2-amino-1-(2', 5'-dimethoxyphenyl) ethanol or its pharmacologically acceptable salt, using an acrylic adhesive copolymerized with alkyl methacrylate and alkyl acrylate, and a fatty acid ester to enhance solvency and diffusibility, improving preservation stability and transdermal absorbency while simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a transdermal patch contains DMAE or its salt with conventional adhesives and additives, then transdermal absorbency is improved, but preservation stability becomes insufficient and skin stimulation occurs due to degradation products

Engineering Contradiction:
Improvetransdermal absorbencyVSAvoidpreservation stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the adhesive system by selecting specific acrylic adhesives with controlled polymer chain structures and incorporating fatty acid esters with specific chain lengths. These parameter changes optimize both the solubility of DMAE (improving absorbency) and the chemical stability of the system (preventing degradation), thereby resolving the contradiction between productivity and reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite adhesive system combining acrylic polymer adhesive with fatty acid esters. This composite material provides synergistic effects: the acrylic adhesive ensures proper adhesion and controlled release, while the fatty acid esters enhance solubility and act as stabilizers. The composite formulation achieves both high transdermal absorbency and excellent preservation stability without skin irritation from degradation products.

Inventive Principle:
Principle #40Composite materials

2Strength

If a transdermal patch uses a noncrosslinked adhesive layer laminated with a crosslinked adhesive layer, then adhesive strength is improved, but manufacturing complexity increases and cost rises

Engineering Contradiction:
Improveadhesive strengthVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent extracts the crosslinking function from a separate adhesive layer and incorporates it into the plaster layer composition itself. By using fatty acid esters that can form ester bonds with hydroxyl groups in the acrylic adhesive, the system achieves crosslinked network formation within the single plaster layer, eliminating the need for a separate crosslinked adhesive layer and simplifying the manufacturing process.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges multiple functions into a single plaster layer: adhesion, drug delivery, and crosslinking. The acrylic adhesive provides base adhesion, the fatty acid esters provide both solubility enhancement and crosslinking capability, and the DMAE is delivered transdermally. This consolidation of functions into one layer reduces manufacturing steps and eliminates the complexity of laminating multiple adhesive layers.

Inventive Principle:
Principle #5Merging (Combining)

3Quantity of substance

If the DMAE content in the transdermal patch is increased, then therapeutic effect is improved, but degradation reactions increase and preservation stability decreases

Engineering Contradiction:
ImproveDMAE contentVSAvoidpreservation stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent introduces fatty acid esters as intermediary substances that mediate between DMAE and the acrylic adhesive. These intermediaries enhance the solubility of DMAE in the adhesive matrix, allowing higher DMAE content to be incorporated without phase separation. The fatty acid esters also create a more stable chemical environment that reduces degradation reactions, thus enabling high DMAE content while maintaining preservation stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 improved preservation stability, enhanced transdermal absorbency, and reduced skin stimulation, ensuring a stable and effective delivery of DMAE, with a more straightforward and cost-effective production method.

Implementation Method 1

using an acrylic adhesive copolymerized with alkyl methacrylate and alkyl acrylate, and a fatty acid ester to enhance solvency and diffusibility

Methodology Applied
Scientific EffectSolvation: Solvation

Implementation Method 2

using an acrylic adhesive copolymerized with alkyl methacrylate and alkyl acrylate, and a fatty acid ester to enhance solvency and diffusibility

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP2062575B1Adhesive preparation comprising desglymidodrine
Publication Date: 2012.02.15 SEKISUI CHEMICAL CO LTD
  • EP2062575B1 patent drawingFigure 1
  • EP2062575B1 patent drawingFigure 2
  • EP2062575B1 patent drawingFigure 3

AI summary

The present invention provides a transdermal patch having excellent preservation stability and transdermal absorbency of DMAEs. The patch has a support and a plaster layer integrally laminated on one surface of the support, and the plaster layer includes: DMAEs; an acrylic adhesive prepared by copolymerizing monomers respectively containing 30 to 99% by weight of alkyl methacrylate having an alkyl group with a carbon number of 6 to 22 and 1 to 70% by weight of alkyl acrylate having an alkyl group with a carbon number of 2 to 20; and fatty acid ester prepared by dehydro-condensing saturated fatty acid having an alkyl group with a carbon number of 10 to 20 and saturated aliphatic monohydric alcohol having an alkyl group with a carbon number of 2 to 20, wherein solubility of the DMAEs is 0.05 to 5 g at 25°C with respect to the fatty acid ester.