Tin Phosphate Complex Antiperspirant Stability

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Solution Overview

Problem

There is a need for alternative antiperspirant actives that are effective and stable, as tin (II) fluoride tends to oxidize and form insoluble precipitates, and existing aluminum and zirconium compounds have limitations.

Innovation Solution

The formation of an aqueous soluble tin phosphate complex using tin (II) fluoride and a pyrophosphate salt, such as tetrapotassium pyrophosphate or tetrasodium pyrophosphate, which forms a stable complex that acts as an occlusive active to inhibit sweat when contacted with proteins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If tin (II) fluoride is used as an antiperspirant active, then alternative to aluminum/zirconium compounds is provided, but it oxidizes to form insoluble precipitates reducing stability

Engineering Contradiction:
Improvealternative active ingredientVSAvoidstability of tin (II) fluoride
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

A chelating agent (intermediary substance) is introduced to bind with tin (II) fluoride and prevent its oxidation. The chelating agent acts as a protective mediator that maintains tin (II) fluoride in a stable, soluble state, allowing it to function as an effective antiperspirant active without forming insoluble precipitates.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The chemical environment parameters are modified by adding chelating agents that alter the oxidation state stability and solubility characteristics of tin (II) fluoride. This parameter change prevents the unwanted oxidation reaction while maintaining the antiperspirant efficacy.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If tin (II) fluoride forms insoluble compounds with phosphates, then precipitation occurs, but aqueous soluble tin phosphate complex is needed for effectiveness

Engineering Contradiction:
Improveeffectiveness of antiperspirantVSAvoidsolubility of tin phosphate
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The pH and chemical composition parameters of the formulation are adjusted to create conditions where tin phosphate remains soluble. By controlling these parameters and incorporating specific chelating agents, the formulation maintains aqueous solubility while preserving the antiperspirant activity of the tin phosphate complex.

Inventive Principle:
Principle #35Parameter changes

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 tin phosphate complex effectively reduces sweat by forming a precipitate that physically blocks sweat glands, providing a stable and effective antiperspirant solution.

Implementation Method 1

tin (II) fluoride forms an aqueous soluble tin phosphate complex upon mixture with a pyrophosphate salt

Methodology Applied
Scientific EffectComplexation: Chemical Bonding

Implementation Method 2

when the complex is contacted with proteins to simulate sweat, the aqueous soluble tin phosphate complex forms a white precipitate

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Data Source

PatentEP3380064B1Personal care compositions
Publication Date: 2020.05.06 COLGATE PALMOLIVE CO
  • EP3380064B1 patent drawingFigure 1
  • EP3380064B1 patent drawingFigure 2
  • EP3380064B1 patent drawingFigure 3A~3C

AI summary

Described herein, are aqueous soluble tin phosphate complexes formed from a mixture comprising tin (II) fluoride and a pyrophosphate salt. Also described are external personal care compositions comprising the complexes, and uses thereof.