Dependance of viscoelastic properties of two emulsion formulations on preparation process

Abstract

Rheological properties determine cosmetic formulation behavior during production and application. Oil-in-water emulsions (pH 6.86-7.10) used decyl-oleate as internal phase with either K-stearate (A-formulations) or polyglyceryl-stearate and -behenate (N-formulations) as emulsifiers. Formulations were prepared by adding water to oil phase or vice versa. Oscillatory measurements showed all samples behaved as viscoelastic solids at low stresses. Crossover of storage and loss moduli for AA happened at nine times higher stress compared to the other formulations. AA formulation provided superior feel properties needed cosmetically, with nonionic emulsifier demonstrating greater processing independence than anionic alternatives.