Figure 5. Vitamin C visual stability as a function of water content in emulsions at 50°C after 1 month; a) glycerin-in-silicone emulsion, b) (glycerin + water)-in-silicone emulsion and c) w/s emulsion

After the samples were stored for one month at 50°C, the glycerin-in-silicone anhydrous emulsion with vitamin C was found to perform best visually (see Figure 5), which was confirmed by HPLC data (see Table 5).