Nanofiber Skin Composition for Poorly Water-Soluble Actives

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Solution Overview

Problem

Existing methods for applying poorly water-soluble components to the skin are inefficient and do not maintain the amorphous state of these components, which affects their applicability and solubility.

Innovation Solution

A skin external composition comprising a polymer soluble in water and alcohol or ketone, combined with a poorly water-soluble component, is immobilized in a nanofiber deposit or crushed product, allowing the component to be dispersed in an aqueous medium in a liquid-liquid dispersion form, maintaining an amorphous state and enhancing solubility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If poorly water-soluble components are applied directly to the skin, then the component concentration can be high, but the solubility and applicability are poor

Engineering Contradiction:
Improvecomponent concentrationVSAvoidsolubility
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

A water-soluble polymer is used as an intermediary substance to solubilize the poorly water-soluble component. The polymer forms a complex with the active ingredient, enabling it to be dispersed in aqueous media while maintaining high concentration. This mediator approach resolves the contradiction by providing a bridge between the hydrophobic active ingredient and the hydrophilic application medium.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The solubility parameters of the poorly water-soluble component are modified through complexation with the water-soluble polymer. By changing the chemical environment and molecular interactions, the component achieves enhanced solubility in aqueous media while maintaining its high concentration, thus resolving the contradiction between concentration and solubility.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If nanofibers are used to support oil components, then the applicability to skin is improved, but the component may not maintain its amorphous state

Engineering Contradiction:
Improveapplicability to skinVSAvoidamorphous state maintenance
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

A composite material system is formed by combining the water-soluble polymer with the poorly water-soluble component in specific ratios. This composite structure provides both the skin applicability of nanofibers and the stability to maintain the amorphous state of the active ingredient, resolving the contradiction between ease of application and compositional stability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The local environment within the nanofiber structure is optimized to maintain the amorphous state of the poorly water-soluble component. By controlling the local composition, molecular interactions, and physical state within the fiber matrix, the system achieves both good skin applicability and stable amorphous state maintenance simultaneously.

Inventive Principle:
Principle #3Local quality

3Reliability

If the component is dissolved in aqueous medium, then solubility is improved, but the concentration may be reduced due to saturation limits

Engineering Contradiction:
ImprovesolubilityVSAvoidcomponent concentration
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The water-soluble polymer acts as a mediator that increases the apparent solubility of the poorly water-soluble component in aqueous media. By forming soluble complexes, the system can achieve higher component concentrations than would be possible through simple dissolution, resolving the contradiction between solubility improvement and concentration maintenance.

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 composition efficiently applies a higher concentration of poorly water-soluble agents to the skin, maintaining their amorphous state for improved solubility and applicability, facilitating direct skin contact and supersaturated states.

Implementation Method 1

The component (b) is contained in an amorphous state in the fiber, and a particle size of the component (b) contained in the fiber is 0.1 nm or larger and 10 nm or smaller

Methodology Applied
Scientific EffectAmorphous state maintenance:

Implementation Method 2

a method for applying a liquid composition to the skin, comprising the step of dissolving the assembly of fiber in an aqueous medium to obtain the liquid composition

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 3

dispersed in a liquid comprising the component (C) as the main component. The liquid skin external composition is preferably a liquid skin external composition in a liquid-liquid dispersion form

Methodology Applied
Scientific EffectLiquid-liquid dispersion: Dispersion (of waves)

Implementation Method 4

EP 2 589 693 A1 concerns a nanofiber made of a water-soluble polymer, having a cavity, and containing an oily component in the cavity

Methodology Applied
Scientific EffectElectrospinning: Electrohydrodynamics

Data Source

PatentEP4104862B1Skin composition for external use
Publication Date: 2025.11.26 KAO CORP
  • EP4104862B1 patent drawingFigure 1~2
  • EP4104862B1 patent drawingFigure 3~4
  • EP4104862B1 patent drawing

AI summary

Provided is a liquid skin external composition which allows a poorly water-soluble component to be applied to a skin in a liquid state. An assembly of fiber for use in production of a liquid skin external composition, the assembly of fiber comprising (a) a polymer soluble in water and an alcohol or a ketone in a content of 50 mass% or more and 98 mass% or less with respect to the whole assembly of fiber and (b) a poorly water-soluble component in a content of 2 mass% or more and 40 mass% or less with respect to the whole assembly of fiber.