Characterisation of liquid marbles in commercial cosmetic products

Liquid marbles are droplets of up to 98% fluid, coated with a hydrophobic powder. Commercially produced products have been found to last over two years while laboratory made marbles survive for days at most. The aim of this paper is to investigate the characteristics of twelve commercial products based on liquid marble technology to gain insight into their prolonged stability. The particle size distribution moisture content, visual appearance and general stability of the commercial liquid marble products were examined. Based on the analysis of commercial formulations, a simple formulation based on the top most common components (silica, water and VP/VA copolymer) was used to create liquid marbles and investigate the role of the formulation ingredients on liquid marble stability. The inclusion of 2% and 5% VP/VA as film former extended the survival time of the liquid marbles but this was still well short of the commercial formulations. Further work is required to replicate the properties of commercial liquid marbles and extend the survival time of these structured solid-liquid particles.