Lactic Acid Skin Care Composition with PHA Buffering Salt

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing low-pH skin care compositions face challenges in reducing skin irritation and improving skin barrier function, particularly when used at low pH, under UV radiation, with polar emollients, hydroxycinnamic acid, co-solvents, or mica.

Innovation Solution

A low-pH, aqueous skin care composition comprising lactic acid, a polyhydroxy acid (PHA), a buffering salt of the PHA, and water, with a specific weight ratio among these ingredients, which reduces skin irritation and improves skin barrier function while maintaining skin care efficacy and composition stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lactic acid buffering system is used at low pH, then skin care efficacy is improved, but skin irritation increases

Engineering Contradiction:

Improveskin care efficacyVSAvoidskin irritation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces PHA and its buffering salt as intermediary substances between lactic acid and the skin. These intermediaries buffer the low pH environment, reducing direct irritation from lactic acid while maintaining the pH-dependent skin care efficacy. The buffering system acts as a mediator that decouples the harsh low pH condition from the beneficial skin care effects.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the buffering parameters by switching from traditional lactic acid/lactate buffering to a PHA/PHA buffering salt system. This parameter change allows maintaining low pH (2.5-4.5) for efficacy while the PHA buffering system provides gentler skin interaction, thus reducing irritation while preserving skin care benefits.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If lactic acid buffering system is used under UV radiation, then skin care efficacy is maintained, but skin irritation increases

Engineering Contradiction:

Improveskin care efficacyVSAvoidskin irritation under UV radiation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

PHA and its buffering salt serve as protective intermediaries that buffer UV-induced stress on the skin. The buffering system mitigates the combined effect of low pH and UV radiation, reducing irritation while allowing the low pH environment to maintain skin care efficacy even under UV exposure conditions.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If gluconic acid is used as buffering system, then skin irritation is reduced, but composition stability decreases

Engineering Contradiction:

Improveskin irritationVSAvoidcomposition stability

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent creates a composite buffering system combining PHA and its buffering salt, leveraging the complementary properties of each component. This composite approach achieves the gentle skin profile of gluconic acid while improving composition stability through the specific buffering capacity and chemical properties of the PHA/PHA buffering salt system.

Inventive Principle:

Principle #40Composite materials

4Reliability

If lactic acid buffering system is used with mica, then skin care efficacy is improved, but composition stability decreases

Engineering Contradiction:

Improveskin care efficacyVSAvoidphoto stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

PHA buffering salt acts as an intermediary that stabilizes the interaction between lactic acid and mica particles. This buffering intermediary prevents direct adverse reactions between lactic acid and mica, maintaining photo stability while allowing the low pH environment to provide skin care efficacy enhancement.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20250186317A1Skin care composition comprising lactic acid, polyhydroxy acid, and its buffering salt

Publication Date: 2025.06.12 PROCTER & GAMBLE CO

AI summary

A low-pH, aqueous skin care composition that contains lactic acid, a polyhydroxy acid (PHA), a buffering salt of the polyhydroxy acid (PHA), and water. The pH of the composition is from about 2.5 to 4.5. The composition provides reduced skin irritation and/or improving skin barrier function, while providing skin care efficacy/improving skin condition and/or providing stability of the composition.