Development and stability evaluation of liquid crystal-based formulations containing glycolic plant extracts and nano-actives

Abstract

Emulsions are of great use in cosmetic formulations due to their stability. The aim of this work was to develop and assess organoleptic, physicochemical, and microscopic properties of four auto-emulsifiable oil-in-water formulations. Such formulations were developed containing 4.0% cetearyl alcohol, dicetyl phosphate, and ceteth-10 phosphate (Formulation A), nano-actives obtained from safflower, coconut, and clove oils (Formulation B); a mixture of glycolic extracts from Centella asiatica leaves, Aesculus hippocastanum seeds, and Hamamelis virginiana leaves (Formulation C); association between the nano-actives and glycolic extracts described above (Formulation D). The formulations were trialed for 90 days under the normal stability test. The developed formulations were considered all stable and homogeneous, with liquid crystals possibly being formed. Organoleptic parameters and pH of Formulations A and B remained unchanged, but the color of Formulations C and D changed due to the natural color of the glycolic extracts used. It can be concluded that the formation of liquid crystals increased the stability of the formulations, and future tests should be carried out in order to assess the rheological properties and hydration potential of the developed formulations.