Colloidal Transdermal Formulation Reduces Skin Irritation

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Solution Overview

Problem

Current transdermal absorptive formulations using phosphatidyl choline and propylene glycol often result in cutaneous irritation and have a prolonged transdermal absorption lag time, limiting their effectiveness for rapid and sustained medicament delivery.

Innovation Solution

A colloidal liquid formulation where a medicament is colloidally dispersed in propylene glycol or a propylene glycol-containing solvent with phosphatidyl choline and optionally an alkanolamine, such as triethanolamine, to achieve enhanced transdermal permeability and reduced skin irritation, with a particle diameter of 50-500 nm and phosphatidyl choline content between 0.1-5 w/w%, allowing for immediate and prolonged skin permeation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If phosphatidyl choline is used to form micelles for transdermal delivery, then transdermal permeability is improved, but cutaneous irritation occurs

Engineering Contradiction:

Improvetransdermal permeabilityVSAvoidcutaneous irritation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical state of phosphatidyl choline from micellar solution to colloidal dispersion, and optimizes particle size parameters (50-500 nm) to reduce skin irritation while maintaining transdermal permeability. This parameter transformation resolves the contradiction between effectiveness and safety.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite colloidal system combining phosphatidyl choline with specific medicaments in propylene glycol solvent, forming a novel dosage form that simultaneously achieves high transdermal permeability and reduced cutaneous irritation through the synergistic interaction of components.

Inventive Principle:

Principle #40Composite materials

2Reliability

If conventional transdermal formulations are used, then medicament delivery is achieved, but transdermal absorption lag time is prolonged

Engineering Contradiction:

Improvemedicament deliveryVSAvoidtransdermal absorption lag time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent transforms the dissolution state of medicament from molecularly dissolved to colloidally dispersed, creating particles of 50-500 nm that exhibit enhanced transdermal absorption kinetics. This state transformation eliminates the lag time while maintaining sustained delivery capability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent pre-forms colloidal particles of medicament-phosphatidyl choline complexes before application, which are already in an optimal size range for rapid skin penetration. This preliminary preparation eliminates the time required for in-situ micelle formation or dissolution during skin absorption.

Inventive Principle:

Principle #10Preliminary action

3Stability of the object's composition

If medicament is completely dissolved in solvent, then concentration gradient is established, but transdermal permeability is insufficient for rapid absorption

Engineering Contradiction:

Improveconcentration gradientVSAvoidtransdermal permeability

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent changes the dispersion state from molecular dissolution to colloidal suspension, creating particles with specific size parameters (50-500 nm) that provide both stability for concentration gradient maintenance and enhanced permeability for rapid absorption through skin barriers.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The colloidal particles create a porous-like distribution pattern in the formulation, allowing enhanced penetration through skin layers while maintaining the concentration gradient necessary for sustained drug delivery.

Inventive Principle:

Principle #31Porous materials

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 formulation significantly improves transdermal permeability, reduces skin irritation, and enables rapid and sustained medicament absorption, making it suitable for both acute and chronic administration by achieving high blood concentrations similar to oral administration with minimized lag time.

Implementation Method 1

a medicament or a salt thereof is colloidally dispersed in propylene glycol or a propylene glycol-containing solvent in the presence of phosphatidyl choline

Methodology Applied

Scientific EffectColloidal dispersion: Colloid

Implementation Method 2

the formulation in which a medicament and phosphatidyl choline are colloidally dispersed in Propylene glycol or a propylene glycol-containing solvent as particles having 50-500 nm diameter exhibits extremely excellent transdermal permeability

Methodology Applied

Scientific EffectPermeation: Permeation

Implementation Method 3

adding an alkanolamine... achieving a shortened transdermal absorption lag time and high plasma concentration of the medicament

Methodology Applied

Scientific EffectAbsorption promotion: Absorption (physical)

Data Source

PatentUS11660344B2Transdermal colloidal solution agent

Publication Date: 2023.05.30 MEDRX CO LTD

AI summary

Disclosed is a transdermal absorptive liquid preparation in which a medicament or a salt thereof is colloidally dispersed in propylene glycol or a propylene glycol-containing solvent, whose transdermal permeability of the medicament is excellent, problem of skin irritation is reduced. This transdermal absorptive liquid formulation has a mode of particle diameter at around 100 nm, and an average particle size of 50 to 500 nm. This transdermal absorptive liquid formulation makes marked improvement in the transdermal permeability by further containing an absorption promoter such as triethanolamine.