Development of loose face powder containing water-entrapped silica particles

Abstract

The objective of this study was to develop loose face powder containing water-entrapped silica particles. Water-entrapped silica particle was fabricated via simple mixing process operated with high shearing and pouring water all at once. The obtained product was core shell like structure and self-assembly form. The inner core was water droplet while the shell was the loose networking of hydrophobic silica (Aerosil® R812S). The weight ratio between R812S and deionized water of 3:97 was determined as the suitable quantity on the formation of water-entrapped silica particle. It provided an acceptable free flowing and dry powder including high percentage of water entrapment efficiency (more than 95%) even after storage in the accelerated condition up to 3 months. Water-entrapped silica particle produced was then incorporated in basic formulation of loose face powder. Due to the physical instability of water-entrapped silica particle, gentle mixing pattern was chosen. Basic loose face powder was initially produced by high shear mixer and then blended with the water-entrapped silica particle in tumble mixer. The mixing time during tumble was critically concerned. Five minutes of such mixing would be an optimal mixing time since the core shell structure of particle still retained. The loose face powder containing 40% of water-entrapped silica particles showed the acceptable property in accordance with the specified criteria. It provided desirable burst cooling sense with moisturizing effect. Nevertheless, oil absorption property of the above formulation had lower capacity than its positive control formulation. In conclusion, the developed formulation comprised of the first component of water-entrapped silica particles (the mixture of R812S and DI water) and the second component of the basic loose face powder. They were blend together in gentle mixer with optimum mixing time.