Transdermal Patch Layer Segmentation for Active Ingredient Utilization

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Solution Overview

Problem

Transdermal therapeutic systems face low active ingredient utilization rates and dosage accuracy issues due to high layer thickness requirements and high solubility of active ingredients in polymers, making them economically inefficient and potentially non-compliant with regulatory standards.

Innovation Solution

A transdermal therapeutic system design featuring a polyisobutylene-based backing layer, a thin acrylate copolymer skin-contact layer with reduced active ingredient content, and a detachable protective layer, where the backing layer has a coating weight of at least 80 g/m2 and the skin-contact layer is less than 50 g/m2, optimizing active ingredient utilization and dosage accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If large layer thicknesses are used in adhesive and reservoir layers, then adhesiveness and producibility are improved, but active ingredient utilization rate deteriorates

Engineering Contradiction:
Improveadhesiveness and producibilityVSAvoidactive ingredient utilization rate
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The transdermal system is divided into functionally distinct layers: a reservoir layer (backing layer) with high active ingredient content for storage, and a thin adhesive layer for skin contact and controlled release. This segmentation allows each layer to be optimized independently - the reservoir can be thick for adequate supply while the adhesive layer remains thin to minimize active ingredient loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the system have different compositions and thicknesses tailored to their specific functions. The reservoir layer uses polymers with high saturation solubility for active ingredient storage, while the thin adhesive layer uses polymers with lower saturation solubility to minimize active ingredient dissolution and loss during application.

Inventive Principle:
Principle #3Local quality

2Productivity

If high saturation solubility of active ingredient in polymer is achieved, then transdermal delivery capability is improved, but active ingredient loss increases

Engineering Contradiction:
Improvetransdermal delivery capabilityVSAvoidactive ingredient loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The system separates the high solubility function to the reservoir layer where active ingredient loss is acceptable, while the adhesive layer uses lower solubility polymers to minimize loss during skin contact and delivery.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different polymer materials are selected for different layers based on their solubility characteristics. The reservoir layer polymer is chosen for high saturation solubility to enable adequate active ingredient supply, while the adhesive layer polymer is chosen for lower saturation solubility to minimize active ingredient dissolution and loss.

Inventive Principle:
Principle #3Local quality

3Loss of substance

If thin adhesive layer is used, then active ingredient utilization is improved, but adhesiveness deteriorates

Engineering Contradiction:
Improveactive ingredient utilizationVSAvoidadhesiveness
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The adhesive layer is designed with specific polymer composition and controlled thickness to provide adequate adhesion while minimizing active ingredient loss. The polymer selection and layer design ensure that the thin layer maintains sufficient bonding strength for transdermal application.

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 system achieves improved active ingredient utilization and dosage accuracy, reducing economic and regulatory challenges by minimizing active ingredient dissipation and adhering to stricter pharmaceutical standards.

Implementation Method 1

the property of most adhesive compositions of dissolving a large proportion of active ingredient before the high thermodynamic activity (close to the saturation solubility) necessary for transdermal use is reached

Methodology Applied
Scientific EffectSolubility: Solvation

Implementation Method 2

the so-called system utilization rate is relatively low

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentUS9717698B2Transdermal therapeutic system with high rate of utilization of active substance and dosing accuracy
Publication Date: 2017.08.01 LTS LOHMANN THERAPIE SYST AG

AI summary

A transdermal therapeutic system for administering at least one active pharmaceutical ingredient, including a polymer-based layer which is remote from the skin with a rate of application of at least 80 g/m2, and an adhesive skin-contact layer which is adjacent to the polymer-based layer remote from the skin and is based on acrylate copolymers with a rate of application of not more than 50 g/m2. The at least one active pharmaceutical ingredient is present in both the polymer-based layer remote from the skin and the skin-contact layer.