L-ascorbic acid, is a cofactor for collagen synthesis and is naturally found in vegetables, fruits, and tea. Topical vitamin C must be in the form of L-ascorbic acid to be beneficial to the skin. Topical application of vitamin C performs 3 main function in skin metabolism. 1) Vitamin C plays an substantial role in the formation of collagen, which is the main structural protein in the skin. 2) Vitamin C is a strong antioxidant. Antioxidants block some of the damage caused by free radicals, substances that damage DNA. As an antioxidant, vitamin C suppresses the improvement of skin cancer caused by UV exposure. 3) As a melanin inhibitor, helps to lighten the skin. Melanin determines skin color. The production of melanin is stimulated by your exposure to sunlight and ultraviolet (UV) rays in especially. Vitamin C is a tyrosinase inhibitor, it decreases melanin production and encourages cellular renewal through exfoliation.
L-Ascorbic Acid and Skin Care
L-ascorbic acid (a form of vitamin C) is an antioxidant found in skin care products that helps increase the production of collagen. Some researches demonstrate that, when applied to the skin, L-ascorbic acid stimulates collagen synthesis, provides sun protection and protects the skin by reducing free radicals. Also, L-ascorbic acid is known to be the primary replenisher of vitamin E, the of most important inhibitor of lipid peroxidation in cell membranes. A study reported by the American Society for Dermatologic Surgery showed that L-ascorbic acid, which is accurate vitamin C, is the chemical derivative of ascorbic acid that is chemically reactive and bioavailable. In this study, researchers, showed that free L-ascorbic acid is the only molecular structure proven to penetrate into the skin and neutralize free radicals.
In 1992, Dr. Sheldon Pinnell reported the results of a study that showed the vitamin-C form of L-ascorbic acid decreased sun damage. L-ascorbic acid, develops the appearance of skin by lessens fine lines and wrinkles and reduces the effects of sunburns. Once it is in the skin, L-ascorbic acid, which is vitamin C’s active form; stimulates collagen synthesis, provides photoprotection, stays in the skin or up to 72 hours, and avoids ultraviolet (UV) rays immunosuppression. Researchers in a study improved a stable aqueous solution of 15% L-ascorbic acid and 1% vitamin E. The combination of 15% L-ascorbic acid and 1% vitamin E provided significant prevention against erythema and sunburn cell formation; either L-ascorbic acid or 1% vitamin E alone was protective but the combination was better. In a clinical study, participants were treated with 10% solution of L-ascorbic acid or vehicle controls before UV-B irradiation. Regions treated with topical L-ascorbic acid demonstrated a noteworthy decrease of the minimal erythema dose.
Typical concentrations of topical products range from 5% to 25%. Most products on contain L-Ascorbic acid in aqueous solution and they have inefficient stability. Spite of the positive effects of L-ascorbic acid; when exposed to air, it oxidizes and becomes inactive and produces free radicals. L-ascorbic acid, aqueous formula is prone to oxidation. Therefore, for the treatment of photoaged skin, a new formula that contains 23.8% L-ascorbic acid and a chemical penetration enhancer was improved.