Formulation of Dry Emulsion for Topical Applications

Abstract

Dry emulsions were investigated for their possible use in cosmetic and pharmaceutical fields and an extract of Vitis vinifera leaves was obtained and characterized in terms of quality and quantitative levels, which can be introduced in a selected dry emulsion formulation. Several pre-dry emulsions were prepared, six of which were chosen as a consequence of their satisfying physico-chemical and over-time stability characteristics. They were successively freeze-dried and reconstituted after optimising the reconstitution modalities and characterized by optical microscopy, granulometric and thermal analysis, FTIR analysis, rheology, and texture studies. The best formulation was chosen to introduce Vitis vinifera dry extract prepared by percolation: a fair increase in anthocians stability was noted over time in dry emulsions as compared with classic emulsions.

Keywords:

• Dry emulsions
• freeze-drying
• Vitis vinifera

Notes

∗L2: process pressure.

∗L3: greatest pressure allowed.

The depressurisation of the system starts after 2 hours.

L2 = 100% corresponds to a pressure of 0.1 mbar, which is achieved in 1 hour; then the primary drying period starts, corresponding to an increase of temperature.

At the end of the process, the manual stop of the instrument allows the restoring of the initial pressure in the system.

τ₀ yield value stress.

η₀ apparent viscosity.

G′ elastic module.

G′′ viscous module.

∗Freeze-dried and reconstituted with 100% water.

Part of the special issue, Surface and Colloid Chemistry Without Borders: An International Festschrift for Professor Per Stenius on the Occasion of His 70th Birthday.