Emulsion Antiperspirant Composition with Calcium Salt Stabilization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing emulsion antiperspirant (AP) compositions often face challenges in maintaining high activity, achieving good rheological stability, and minimizing irritation potential.

Innovation Solution

The development of emulsion AP compositions that incorporate an aluminium-zirconium penta-chlorohydrex-glycine complex in combination with a water-soluble calcium salt, which are activated through a specific heating process to enhance antiperspirancy performance, stability, and reduce irritation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If activated AP salts are prepared by prolonged heating of basic aluminium chloride solutions followed by spray-drying, then enhanced antiperspirant activity is achieved, but the composition must be formulated into essentially anhydrous forms to maintain high activity

Engineering Contradiction:
Improveantiperspirant activityVSAvoidformulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the formulation parameters by incorporating water-soluble calcium salts and amino acids/hydroxy acids that stabilize the activated AP salt in aqueous environments. This allows the composition to maintain high antiperspirant activity while being formulated as aqueous emulsions rather than anhydrous forms, thus resolving the contradiction between maintaining activity and simplifying formulation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces water-soluble calcium salts and amino acids/hydroxy acids as intermediary substances that mediate between the activated AP salt and the aqueous environment. These intermediaries prevent the loss of enhanced activity that would otherwise occur in aqueous formulations, enabling the AP salt to maintain its high activity while being used in water-based emulsion compositions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If water-in-oil emulsion gels comprising aluminium-zirconium AP salts activated using calcium ions are used, then good rheological stability is achieved, but irritation potential increases

Engineering Contradiction:
Improverheological stabilityVSAvoidirritation potential
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces amino acids or hydroxy acids as intermediary substances that mediate between the calcium-activated AP salt and the skin. These intermediaries reduce the irritation potential by buffering the interaction, while the calcium ions maintain the rheological stability of the water-in-oil emulsion gel. This resolves the contradiction between stability and irritation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If anhydrous suspension formulations comprising particulate AP salts are used, then enhanced activity is maintained, but manufacturing complexity increases

Engineering Contradiction:
Improveantiperspirant activityVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the physical state parameters by formulating the composition as an aqueous emulsion rather than an anhydrous suspension. By incorporating water-soluble calcium salts and amino acids/hydroxy acids, the activated AP salt can be effectively delivered in an aqueous environment, simplifying the manufacturing process while maintaining enhanced antiperspirant activity.

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 proposed solution delivers superior antiperspirancy performance, excellent storage stability, particularly in terms of rheological stability, and low irritancy due to the high pH of the composition.

Implementation Method 1

activated through a specific heating process to enhance antiperspirancy performance

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

emulsion AP compositions comprising an aqueous phase, an oil phase and an emulsifier

Methodology Applied
Scientific EffectEmulsion: Emulsion

Data Source

PatentEP4366679B1Emulsion antiperspirant compositions
Publication Date: 2025.04.16 UNILEVER IP HLDG BV

AI summary

An emulsion antiperspirant composition comprising an aqueous phase, an oil phase and an emulsifier, wherein the aqueous phase comprises an aluminium-zirconium tri-, tetra-,or penta-chlorohydrex-glycine complex and a water-soluble calcium salt.