Development of water in oil nanoemulsion lipsticks

Abstract

In this study, the anhydrous lipstick base was designed to incorporate with water. The additional water was formulated and prepared into the nanoscale water in oil (w/o) emulsions before mixed with the lipstick base to form w/o nanoemulsion lipsticks. The formulation parameters that are likely to affect the physicochemical properties of lipsticks were evaluated. These parameters included type of emulsifiers as well as dose of water and emulsifiers. The studied nanoemulsions composed of water, isopropyl myristate, mineral oil and PEG-30 dipolyhydroxystearate was prepared in the high speed homogenizer following with the high pressure homogenizer at 500 bars for 3 cycles. The final w/o nanoemulsions with different doses of water and emulsifiers were separately incorporated into the lipstick base. The conventional w/o emulsions with the same formulas that were prepared by the high speed homogenizer at 1000 rpm for 10 min were compared in parallel. The mean particle size, size distribution, stability and physicochemical properties in terms of hardness and spreading ability were operated. Results revealed the water content significantly affected to the hardness of w/o nanoemulsion lipsticks whereas the emulsifier did not. Additionally, the particle size of the preparations also affected to the hardness of lipsticks.