Transdermal Patch Adhesive Layer Tolterodine Acetate

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Solution Overview

Problem

Conventional transdermal patches for administering tolterodine have insufficient adhesion force, leading to short-term skin attachment and reduced therapeutic efficacy due to rapid metabolism and absorption of tolterodine.

Innovation Solution

Incorporating tolterodine acetate or its salts into the adhesive layer of the patch, along with a (meth)acrylate copolymer containing vinyl acetate, to enhance adhesion force and allow for deacetylation to tolterodine post-transdermal absorption, maintaining therapeutic levels for a longer period.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If conventional transdermal patches are used for transdermal administration of tolterodine, then the active ingredient can be delivered through the skin, but the adhesion force is insufficient leading to short-term skin attachment

Engineering Contradiction:
Improveskin attachment durationVSAvoidadhesion force
Core Design Contradiction:
Duration of action of stationary objectVSForce

Solution Approach 1:

The adhesive layer is formulated as a composite containing multiple components: tolterodine (or its salts), (meth)acrylate copolymer with vinyl acetate, and tolterodine acetate (or its salts). This composite structure combines the therapeutic active ingredient with adhesive polymers and metabolic precursors to achieve both therapeutic effect and enhanced adhesion duration.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the chemical composition parameters of the adhesive layer by incorporating tolterodine acetate and specifying precise content ranges (tolterodine acetate: 0.01-50% by mass, tolterodine: 3-60% by mass, (meth)acrylate copolymer: 5-95% by mass). These parameter changes optimize both adhesion force and duration of skin attachment.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If tolterodine is administered through conventional patches, then the active ingredient is delivered, but rapid metabolism and absorption reduce therapeutic efficacy

Engineering Contradiction:
Improvetherapeutic efficacyVSAvoidtherapeutic level maintenance time
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The adhesive layer is pre-formulated with tolterodine acetate, which serves as a precursor that will be deacetylated to tolterodine after transdermal absorption. This preliminary inclusion of the acetate form allows the body to convert it to the active ingredient post-absorption, extending the duration of therapeutic effect.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Tolterodine acetate acts as an intermediary substance in the adhesive layer. It is incorporated in advance and then converted to tolterodine through deacetylation after transdermal absorption, serving as a reservoir that maintains therapeutic levels for a longer period.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If tolterodine is included in the adhesive layer, then transdermal delivery is achieved, but adhesion force remains insufficient without additional components

Engineering Contradiction:
Improvetolterodine delivery amountVSAvoidadhesion force
Core Design Contradiction:
Quantity of substanceVSForce

Solution Approach 1:

The adhesive layer combines tolterodine with (meth)acrylate copolymer containing vinyl acetate and tolterodine acetate. This composite formulation ensures that the active ingredient is delivered in sufficient quantities while the polymer matrix provides the necessary adhesion force for prolonged skin attachment.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention creates different functional zones within the adhesive layer: tolterodine provides the therapeutic active ingredient, (meth)acrylate copolymer provides the adhesive matrix, and tolterodine acetate provides the extended-release precursor. Each component has its local quality optimized for its specific function while working together as a unified system.

Inventive Principle:
Principle #3Local quality

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 a strong and persistent adhesion to the skin, maintaining effective blood concentrations of tolterodine, thereby improving the therapeutic effect and adhesion force compared to conventional patches.

Implementation Method 1

or is caused to be formed over time in the adhesive agent layer... derived from the at least one selected from the group consisting of tolterodine and salts thereof

Methodology Applied
Scientific EffectDeacetylation: Hydrolysis

Data Source

PatentEP2601944B1Transdermal patch and method for augmenting adhesive strength thereof
Publication Date: 2021.02.17 HISAMITSU PHARM CO INC

AI summary

A patch comprising a support and an adhesive agent layer, wherein the adhesive agent layer comprises at least one selected from the group consisting of tolterodine acetate and salts thereof.