PCA Cleansing Composition for Skin pH and Barrier Protection

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Solution Overview

Problem

Existing cleansing products disrupt the skin's acid mantle, leading to weakened skin barrier and compromised ability to defend against bacteria, while failing to effectively remove bacteria and maintain skin pH.

Innovation Solution

A cleansing composition containing 0.025% to 0.035% pyrrolidone carboxylic acid (PCA), 5% to 5.5% sodium lauryl sulfate, and 2% to 2.5% cocamidopropyl betaine, with a pH of 4 to 5, effectively removes bacteria and balances skin pH to maintain the acid mantle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional cleansing products are used to remove bacteria from skin, then bacterial removal is achieved, but skin's acid mantle is disrupted and skin barrier is weakened

Engineering Contradiction:
Improvebacterial removalVSAvoidskin barrier function
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention changes the pH parameter of the cleansing composition to be within the physiological pH range of skin (pH 4-7), matching the natural acid mantle. This parameter adjustment allows the product to effectively remove bacteria while maintaining skin barrier function, resolving the contradiction between bacterial removal and skin protection

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces pyrrolidone carboxylic acid (PCA) as a key ingredient that acts as an intermediary substance. PCA helps maintain the acid mantle while enabling effective cleansing, serving as a mediator between the cleansing action and skin protection, thus resolving the contradiction between removing harmful bacteria and preserving skin barrier reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If cleansing products wash away natural moisturizing factors, then cleaning effect is achieved, but skin's acid mantle is disrupted and moisture retention is compromised

Engineering Contradiction:
Improvecleaning effectVSAvoidnatural moisturizing factors
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

By adjusting the pH parameter to match skin's physiological range, the invention enables effective cleaning without stripping away natural moisturizing factors. The optimized pH ensures that proteins and lipids in the skin barrier remain intact while still allowing removal of dirt and bacteria

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the potential harm of pH imbalance into a benefit by formulating the product with physiological pH. This transforms what would normally be a harmful disruption of the acid mantle into a protective effect, maintaining moisture retention while achieving thorough cleaning

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 effectively removes bacteria, maintains skin pH, and enhances the skin's ability to defend against bacteria by balancing the acid mantle, with minimal disruption to the skin's natural barrier.

Implementation Method 1

PCA is a key NMF that is naturally produced in the skin. It was found that PCA can maintain skin's acidic pH due to its natural buffering capacity, while also being gentle to the skin.

Methodology Applied
Scientific EffectBuffering capacity:

Implementation Method 2

A cleansing composition comprising: (a) 0.025% to 0.035% of pyrrolidone carboxylic acid; (b) 5% to 5.5% of sodium lauryl sulfate; (c) 2% to 2.5% of cocamidopropyl betaine

Methodology Applied
Scientific EffectSurfactant action: Surfactant

Data Source

PatentEP4362903B1Cleansing composition with pyrrolidone carboxylic acid
Publication Date: 2026.03.11 PROCTER & GAMBLE CO
  • EP4362903B1 patent drawingFigure 1
  • EP4362903B1 patent drawingFigure 2A~2B
  • EP4362903B1 patent drawingFigure 3

AI summary

A cleansing composition comprising: a. 0.005% to 0.1% pyrrolidone carboxylic acid; and b. a surfactant composition comprising: i. 2% to 7% sodium lauryl sulfate, and ii. 0.5% to 5% of a co-surfactant selected from zwitterionic surfactant, amphoteric surfactant, nonionic surfactant, and combinations thereof, wherein the composition has a pH of 3 to 6. Use of the cleansing composition to provide a skin benefit selected from helping skin maintain its natural barrier against bacteria, washing away 99% of bacteria, balancing skin pH, retaining skin moisture, and combinations thereof. A method of washing hands to provide a skin benefit, comprising: a. providing a container that contains the cleansing composition wherein the container is configured to dispense the composition; b. dispensing the cleansing composition onto a user's hands; c. lathering the composition by rubbing the hands together; d. spreading the lathered hand wash composition across the surface of the hands; and e. rinsing the composition off of the hands, wherein the cleansing composition provides a benefit selected from helping skin maintain its natural barrier against bacteria, washing away 99% of bacteria, balancing skin pH, retaining skin moisture, and combinations thereof.