Benefits of next-generation ascorbic acid derivative

Although many AsA derivatives have been developed for overcoming the weak point, some AsA derivatives give an uncomfortable skin-stretching feeling and enhance the skin dryness, and still no perfect solution is found. As a solution, 2-glyceryl 3-octyl ascorbate (GO-VC) has been developed and found to have not only a higher stability but also a Propionibacterium acnes proliferation-inhibitory effect, which is never found in AsA. GO-VC is also confirmed to have a higher improving effect for acne vulgaris and improving effects for pigmentation and wrinkles. Giving the skin a comfortable moisturising feeling without an uncomfortable frictional and stickiness feeling, GO-VC is believed to be a next-generation AsA derivative satisfying all people regardless of their skin characteristics.

Ascorbic acid (AsA) (vitamin C), which is famous for having a high antioxidant effect, is known to be an important water-soluble vitamin for the skin, because AsA can enhance collagen production and suppress the production of melanin, which could induce the appearance of skin spots. Many commercial skin care products contain AsA, and in medical institutions, AsAintravenous drip treatment is provided as a cosmetic-medical treatment in many cases, indicating that AsA is an essential component for anti-ageing treatments. AsA, however, is known to be vulnerable to ultraviolet (UV) light irradiation, heat, acid, and base attacks, and can be destroyed easily as its weak points. UV irradiation and other possible radical reactions could convert AsA itself into AsA radical, a reactive oxygen species (ROS), which gives various adverse effects to the skin, as another weak point.

In order to overcome AsA’s weak points, many AsA derivatives have been developed to date. Because AsA derivatives are modified with various functional groups having unique characters such as water- or fat-soluble ability, the stabilities of the derivatives are improved. Expecting the unique characters of the modified functional groups, the derivatives can show not only the genuine AsA effects but also new possible effects due to the modified groups. At present, the developments of water- and fat-soluble AsA derivatives, and amphiphilic derivatives having both waterand fat-soluble functions are also in progress. Although conventional watersoluble ascorbyl phosphate esters (AP) can show a high acne-skin improving effect,1–3 the derivative gives uncomfortable sensory textures including stretched and dryness feelings, which are known to be originated from AsA. For improving these weak points, GO-VC (2-glyceryl 3-octyl ascorbate) has been developed (Fig. 1). Being introduced with glycerin and octanol to hydroxyl groups at the C-2 and C-3 positions of AsA, respectively, GO-VC can show high stability in aqueous solutions. Since glycerin is famous as a humectant, GO-VC can give a comfortable moisturising feeling to the skin rather than an accelerated dryness feeling. Because octanol is expected to show an antimicrobial effect, GO-VC has a possibility to express an antimicrobial effect on Propionibacterium acnes on the skin. Therefore, this study investigated the sensory texture of GO-VC and its antimicrobial effect on P. acnes, and performed the clinical study of GO-VC for treating the acne, reddish skin, pigmentation, and wrinkles.