Anticipating cosmetic emulsion stability using a novel multi-analytical approach

Area of Science:

• Cosmetic Science
• Materials Science
• Physical Chemistry

Background:

• Physicochemical stability is critical for cosmetic emulsion commercialization and consumer satisfaction.
• Traditional methods for assessing emulsion stability are time-consuming.

Purpose of the Study:

• To develop an innovative protocol combining rheology, turbidimetry, and granulometry for efficient prediction of cosmetic emulsion stability.
• To compare the efficacy of this combined protocol against standard testing methods.

Main Methods:

• Selected industrial and commercial cosmetic emulsions with minimal formulation differences.
• Employed granulometry, turbidimetry, and rheology to assess physical and structural properties.
• Utilized advanced statistical analysis with experimental design methods for data interpretation.

Main Results:

• Granulometry, turbidimetry, and rheology effectively differentiated stable from unstable emulsions.
• Unstable emulsions showed increased particle size and viscosity changes, unlike stable ones.
• The combined protocol detected instability in 8 days, significantly faster than the 30-day standard ISO methods, with a Turbiscan Stability Index (TSI) threshold of 3.

Conclusions:

• Integrating granulometry, turbidimetry, and rheology offers a rapid, reliable, and sensitive method for predicting cosmetic emulsion stability.
• This approach accelerates formulation development, enhances quality control, and reduces time-to-market.
• Further research will explore the protocol's application to diverse emulsion types.