Stannous Fluoride Oral Care Stabilization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing oral care compositions containing stannous fluoride are unstable in aqueous solutions due to the reactivity of stannous ions, leading to precipitation and loss of therapeutic properties, while zinc-based products face issues with solubility, taste, and compatibility with fluoride ions, making it difficult to achieve effective antimicrobial and anti-erosion benefits.

Innovation Solution

A high water oral care composition comprising zinc phosphate, stannous fluoride, and an organic acid buffer system, such as a citric acid/citrate buffer, which stabilizes stannous fluoride and enhances antimicrobial and anti-erosion properties by maintaining zinc and stannous ions in solution, thereby providing improved protection against tooth demineralization and plaque control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If stannous fluoride is used in aqueous oral care compositions, then antimicrobial and anti-erosion benefits are improved, but stability of the composition deteriorates due to precipitation of stannous ions

Engineering Contradiction:
Improvetherapeutic effectivenessVSAvoidstability of stannous fluoride
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses citrate ions as an intermediary substance that forms soluble complexes with stannous ions, preventing their precipitation while maintaining their therapeutic availability. The citrate buffer system acts as a mediator between the stannous fluoride and the aqueous environment, allowing stable coexistence of all components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical environment by introducing a citrate buffer system that maintains optimal pH and provides citrate ions for complex formation. This parameter change transforms the unstable aqueous environment into a stable complexing environment that preserves stannous ion solubility and therapeutic efficacy.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If soluble zinc salts are used to provide zinc ions, then antimicrobial effectiveness is improved, but organoleptic properties deteriorate due to astringent mouthfeel and compatibility issues

Engineering Contradiction:
Improveantimicrobial effectivenessVSAvoidorganoleptic properties
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent uses phosphate ions and citrate ions as intermediaries that form soluble complexes with zinc ions, preventing direct interaction between zinc ions and fluoride ions or anionic surfactants. This intermediary complexation eliminates the astringent mouthfeel and compatibility issues while maintaining effective zinc ion availability for antimicrobial action.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If water content is reduced to stabilize stannous ions, then stability is improved, but ease of formulation deteriorates due to rheological challenges

Engineering Contradiction:
Improvestability of stannous ionsVSAvoidformulation difficulty
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent changes the chemical parameters by introducing a citrate buffer system that enables stannous ion stability in high-water formulations. This parameter change allows the use of abundant water for desirable rheological properties while maintaining stannous ion stability through complex formation, eliminating the need for low-water formulations.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If dual phase system is used to stabilize stannous ions, then stability is improved, but manufacturing cost deteriorates

Engineering Contradiction:
Improvestability of stannous fluorideVSAvoidmanufacturing cost
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent achieves homogeneous single-phase formulation by using citrate buffer system that ensures complete solubility and stability of stannous fluoride in the aqueous matrix. This homogeneous approach eliminates the complexity and cost associated with dual-phase systems while maintaining equivalent or superior stability.

Inventive Principle:
Principle #33Homogeneity

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 combination of zinc phosphate and stannous fluoride with an organic acid buffer system in a high water composition effectively stabilizes stannous fluoride, enhancing its antimicrobial and anti-erosion benefits, providing improved protection against tooth demineralization and plaque control without the drawbacks of previous formulations.

Implementation Method 1

The instability of stannous fluoride in water is primarily due to the reactivity of the stannous ion (Sn2+). Stannous salts readily hydrolyse above a pH of 4, resulting in precipitation from solution

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

an organic acid buffer system, such as a citric acid/citrate buffer, which stabilizes stannous fluoride and enhances antimicrobial and anti-erosion properties by maintaining zinc and stannous ions in solution

Methodology Applied
Scientific EffectBuffer system:

Implementation Method 3

Dental erosion involves demineralization and damage to the tooth structure due to acid attack from nonbacterial sources

Methodology Applied
Scientific EffectDemineralization:

Implementation Method 4

providing improved protection against tooth demineralization

Methodology Applied
Scientific EffectRemineralization:

Implementation Method 5

stannous fluoride is well known for use in clinical dentistry with a history of therapeutic benefits over forty years... enhancing its antimicrobial and anti-erosion benefits

Methodology Applied
Scientific EffectAntimicrobial activity:

Data Source

PatentUS20240041722A1Oral Care Compositions
Publication Date: 2024.02.08 COLGATE PALMOLIVE CO

AI summary

An oral care composition comprising zinc phosphate, stannous fluoride and an organic acid buffer system, as well as methods of using the same.