The proportions of the various components in the emulsions are (wt):
• 30% of oily phase
• 12% of emulsifiants
• 3% glycerol
• 55% aqueous phase (water)
We developed a mixture design with constraint [14], Table 1, to predict the dependence of observed responses on the cosmetic matrix compositions. The proportions of emulsifiers (tween 80 and soya lecithin) vary in relation to the proportions of oils (miglyol, rapeseed and salmon) used for the mixture design.