Vitamin C (GO-VC) The New Kid On The Block

Ascorbic acid is used widely in cosmetics because of its various skin physiological effects, however it notoriously unstable and generates ROS in the skin.  After being applied to the skin surface, Ascorbic Acid partly becomes ascorbic acid radicals, which have ROS characteristics and are likely to give unwelcome adverse effects to the skin. For overcoming these disadvantages, ascorbic acid derivatives have been developed, and water-soluble ascorbyl phosphate esters (AP), including sodium ascorbyl phosphate (APS) and magnesium ascorbyl phosphate (APM), fat-soluble AsA derivatives, including ascorbyl tetraisopalmitate (VCIP), and amphiphilic AsA derivatives, including trisodium ascorbyl isopalmitate phosphate and potassium tocopheryl ascorbyl phosphate (EPC), are available on the market. These Ascorbic Acid derivatives have been reported to be highly stable.

Recently, a new Ascorbic Acid derivative, 2-glyceryl 3-octyl ascorbate (GO-VC) has been developed. The derivative has a unique structure where glyceryl and octyl groups are introduced to hydroxyl groups at the C-2 and C-3 positions of Ascorbic Acid, respectively and become a nonionic and amphiphilic Ascorbic Acid derivative, which was previously unavailable anywhere in the world.

The derivatives that have been developed previously whilst stable can often give the feeling of skin dryness.  Because of this instability scientists have been researching to find derivatives of Vitamin C that don't have these drawbacks.

The modification of Ascorbic Acid with functional groups gives the derivatives characteristics such as water or fat solubility.  These new derivatives show all the benefits of Ascorbic Acid plus new benefits such as hydration as well.

The addition of a glyceryl group at C-2 gives GO-VC a humectant effect.  The addition of the octyl group at C-3provides anti-bacterial properties to the compound.  As a solution, 2-glyceryl 3-octyl ascorbate (GO-VC) has been developed and found to have not only a higher stability but also inhibits Propionibacterium acnes.  Something that Ascorbic Acid does not have.  This new vitamin c has been found to be effective for acne vulgaris,  pigmentation and wrinkles.  The benefit of GO-VC is that it is suited to all skin types.   GO-VC is the next-generation of Vitamin C derivatives.

Sensory Benefit

GO-VC was tested for 7 evaluation criteria with a 1% cream.  It was compared to ascorbyl glycoside (AA2G), a water-soluble derivative, and APPS (Tri sodium ascorbyl phosphate), an amphiphilic derivative.  The seven evaluation areas were: favourable, high skincompatible feeling, no frictional feeling, comfortable moisturising feeling, no stickiness, skin softness, and skin smoothness.

As a result, 2-glyceryl 3-octyl ascorbate obtained high scores in the seven evaluation areas, and was scored higher than AA2G and APPS.   GO-VC gives a comfortable moisturising feeling without the feeling of stickiness.

Proliferation inhibitory effect on P. acnes

The octyl group in the Vitamin C is antibacterial.  Tests have shown that GO-VC is effective against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Propionobacterium acnes and Candida.  Ascorbic Acid has no effect on proliferaton of p.acnes.

A clinical study was conducted by Dr Ayako Mori, Clinic Mori, Minato ward, Tokyo, Japan. Thirteen female volunteers, aged from 12 to 71 (average: 39.8 years old), were asked to apply a gel sample containing 0.1% 2-glyceryl 3-octyl ascorbate to their whole faces at morning and night after washing their faces for 1-5 months. During or after the gel treatment, the volunteers’ faces were analysed by a facial imaging and an analysing system (VISIA) (Canfield Scientific, Fairfield, NJ, US). A patient with metal allergic pigmentation in the forearm was asked to apply 0.1% 2-glyceryl 3-octyl ascorbate gel to the site at night, and at one month after the start of treatment, the forearms were photographed by a digital SLR camera.

As a result, without noticeable adverse effects, the damaged skin with acne vulgaris, the skin pigmentation, and the wrinkles were found to be improved by the gel sample containing 0.1% 2-glyceryl 3-octyl ascorbate. In the case of metal allergic pigmentation at the forearm, a 3-month hydroquinone treatment was found to be ineffective, and 0.1% 2-glyceryl 3-octyl ascorbate gel was applied to the site and found to show a remarkable improvement, indicating that 2-glyceryl 3-octyl ascorbate had a high skin brightening ability.

[caption id="attachment_2272" align="aligncenter" width="488"] Acne before and after. 2 months[/caption]

[caption id="attachment_2275" align="aligncenter" width="744"] Metal Allergy 1 month of GO-VC[/caption]

GO-VC proliferation of fibroblasts

The fibroblast proliferating ability of GO-VC was investigated.  Concentrations of 10, 30, 100, and 300 ìmol/L, GO-VC was found to enhance the proliferation of fibroblasts.  GO-VC has a fibroblast proliferating ability and can show an anti-wrinkle effect by enhancing the productions of collagen and elastin in the skin.

The melanogenesis-suppressing ability of GO-VC

GO-VC was compared to hydroquinone and arbutin for effect on reduction of pigmentation.  GO-VC was found to suppress the melanin production dose-dependently, and the suppressing effect appeared at a lower concentration than that of arbutin, which is a famous skin whitening agent. Although the melanogenesis suppressing ability of GO-VC was unable to exceed that of hydroquinone, GO-VC was speculated to have a melanogenesis suppressing potential similar to that of hydroquinone, because GO-VC was able to show its melanogenesis suppressing ability at a lower concentration of 30 ìmol/L.

Toxicity

The human skin-sensitivity test [repeat insult patch test (RIPT)], ocular irritation test [bovine corneal opacity and permeability (BCOP) assay], genetic toxicity (Ames test), and clinical human-skin patch test of GO-VC have been performed, confirming the safety of GO-VC. GO-VC is a highly interesting derivative, which can overcome all disadvantages of L-Ascorbic Acid.

Conclusion
GO-VC is a highly stable amphiphilic AsA derivative made by introducing glycerin and octanol molecules. GO-VC has a melanogenesis suppressing effect, a fibroblast proliferation enhancing effect, a type-I collagen production enhancing effect, and also an antimicrobial effect to P. acnes on the skin.  GO-VC gives the skin a comfortable moisturising feeling, allowing GO-VC to be applied to the skin regardless of skin characteristics and without enhancing skin dryness. Being confirmed to have a skin improving effect on acne vulgaris, reddish skin, pigmentation, and wrinkles, GO-VC is believed to be a next-generation AsA derivative, which overcomes the weak points of conventional AsA derivatives.

References
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