Selenium Disulfide Cosmetic Composition Rheology and Stability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Selenium disulfide-based anti-dandruff compositions face issues with color stability and distribution on the hair and scalp, leading to poor effectiveness and stability in shampoo formulations.

Innovation Solution

Formulating selenium disulfide with a specific rheological profile (relaxation time of 1 to 18 ms) and combining it with two-fatty chain ethers and fatty alcohols, which enhances distribution, stability, and color stability, while allowing for easy adjustment of viscosity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If selenium disulfide is used in anti-dandruff compositions, then anti-dandruff activity is improved, but color stability deteriorates (gradually turns brown over time)

Engineering Contradiction:

Improveanti-dandruff activityVSAvoidcolor stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses a surfactant as an intermediary substance that interacts with selenium disulfide to prevent its oxidation and color change. The surfactant forms a protective association with the selenium disulfide particles, acting as a mediator that maintains color stability while preserving anti-dandruff activity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite formulation by combining selenium disulfide with specific surfactants and optional two-fatty chain ethers. This composite approach allows the surfactant to stabilize the selenium disulfide, preventing the brown color change while maintaining the therapeutic benefits.

Inventive Principle:

Principle #40Composite materials

2Reliability

If selenium disulfide is used in shampoo formulations, then anti-dandruff treatment is provided, but distribution on hair and scalp deteriorates (difficulty in spreading)

Engineering Contradiction:

Improveanti-dandruff treatment effectivenessVSAvoiddistribution on hair and scalp

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The surfactant serves as a distribution intermediary, facilitating the even spread of selenium disulfide across the hair and scalp surface. Its amphiphilic nature allows it to bridge the hydrophobic selenium disulfide particles and the aqueous shampoo base, improving wetting and distribution properties.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the rheological parameters of the shampoo formulation by incorporating specific surfactants and controlling relaxation time (1 to 18 ms). This parameter change improves the flow and spreading characteristics of the product, enabling better distribution on hair and scalp.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If zinc salts are added to improve color stability, then color stability is improved, but viscosity adjustment and conditioning agent deposition deteriorate

Engineering Contradiction:

Improvecolor stabilityVSAvoidviscosity adjustment

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The invention extracts or removes zinc salts from the formulation and replaces them with surfactants that provide color stability without the detrimental effects on viscosity and conditioning agent deposition. This substitution eliminates the manufacturing difficulties associated with zinc salt-containing formulations.

Inventive Principle:

Principle #2Taking out (Extraction)

4Reliability

If selenium disulfide is used in compositions, then anti-dandruff activity is improved, but stability in shampoo formulations deteriorates

Engineering Contradiction:

Improveanti-dandruff activityVSAvoidstability in shampoo formulations

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The surfactant acts as a stabilizing intermediary that protects selenium disulfide from degradation in the shampoo formulation. It forms a protective complex that prevents aggregation and maintains uniform distribution, thereby improving formulation stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent develops a composite shampoo formulation where selenium disulfide is integrated with surfactants and optional two-fatty chain ethers. This composite structure enhances the overall stability of the formulation, preventing separation and degradation during storage and use.

Inventive Principle:

Principle #40Composite 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 solution results in improved distribution and effectiveness of the anti-dandruff treatment, providing abundant and airy foam, rapid rinsing, and enhanced cosmetic properties like softness and smoothing, while maintaining color stability over time.

Implementation Method 1

formulating selenium disulfide, in compositions having a particular rheological profile characterized by a relaxation time of 1 to 18 ms., measured at 25°C

Methodology Applied

Scientific EffectRheological modification:

Implementation Method 2

abundant and airy foam, rapid development of the foam

Methodology Applied

Scientific EffectFoam formation: Foam

Implementation Method 3

selenium disulfide has been particularly recommended because of its powerful cytostatic activity

Methodology Applied

Scientific EffectCytostatic activity:

Data Source

PatentEP1707180B1Cosmetic or dermatological compositions comprising selendioxide, a surfactant and an ether with at least two specific fatty chains and processes for cosmetic treatment

Publication Date: 2016.05.04 LOREAL SA

AI summary

The present invention relates to a cosmetic or dermatological composition comprising, in an aqueous medium, a cleansing base and selenium disulfide, and having a rheological profile defined by a relaxation time of 1 to 18 ms, measured at 25 °C. It also relates to a cosmetic or dermatological composition comprising, in an aqueous medium, selenium disulfide, a cleansing base and at least one two-chain fatty ether.