비타민 C 안정성 향상을 위한 비수계 제형 설계

Abstract

Vitamin C is widely used in cosmetics for its ability to protect the skin from reactive oxygen species, promote collagen synthesis, and achieve skin whitening effects. However, its susceptibility to oxidation poses challenges in achieving stable product formulations. To address this issue, non-aqueous formulations were employed in this study. Formulations with polyol-to-oil ratios of (7:3, 5:5, and 3:7) were designed, with aqueous formulations serving as a control group. Subsequently, samples were analyzed for pH, appearance, and changes in vitamin C content under various temperature and pH conditions for one month. Temperature conditions included accelerated storage at 40°C and cycling between 0°C, 25°C, and 50°C for 24 hours each. pH conditions were categorized as acidic (pH < 3.5), and slightly acidic (pH 5.0∼6.0). Changes in vitamin C content were measured using HPLC. Overall, non-aqueous formulations demonstrated superior stability compared to aqueous formulations under all conditions. Considering both color and content changes, the formulation with a polyol-to-oil ratio of 5:5 (P:O=5:5) exhibited the most effective protection of vitamin C and interfacial chemical stability, even under elevated temperature and pH conditions. This study is significant for its formation of a chemically stable Oil in Polyol (O/P) phase, which stabilizes high concentrations of pure vitamin C in cosmetic formulations. Based on these findings, future research on improving sensory properties and safety evaluation of non-aqueous formulations, as well as studies on the absorption of vitamin C in the body, are anticipated to further advance vitamin C cosmetics. In addition, if lipophilic vitamins are incorporated into the O/P phase used in this study, the protective effect of P:O=3:7 with high oil content and superior formulation stability is expected to be excellent.