Tetrahexyldecyl Ascorbate (VC-IP) - Stable Vitamin C Derivative
Tetrahexyldecyl Ascorbate (VC-IP) - Properties, Applications, and Safety
Tetrahexyldecyl ascorbate (CAS 183476-82-6), also known as ascorbyl tetraisopalmitate or VC-IP, is a highly stable, oil-soluble derivative of L-ascorbic acid (vitamin C). It is a tetraester formed by the esterification of ascorbic acid with four molecules of isopalmitic acid (2-hexyldecanoic acid). This modification significantly enhances the compound's stability, lipophilicity, and skin penetration compared to conventional water-soluble vitamin C forms.
Chemical and Physical Properties
VC-IP has the molecular formula C₇₀H₁₂₈O₁₀ and a molecular weight of approximately 1129.8 g/mol. The compound appears as a clear to pale yellow, slightly viscous oil with a faint characteristic odor. It is highly soluble in oils, organic solvents, and triglycerides, but is practically insoluble in water. The density is in the range of 0.928–0.941 g/mL at 20°C. The boiling point is predicted to be approximately 947.4°C. VC-IP is stable at elevated temperatures and, unlike L-ascorbic acid, does not readily oxidize upon exposure to light and air.
Mechanism of Action
As a lipophilic vitamin C derivative, VC-IP penetrates the skin more effectively than water-soluble ascorbic acid due to its high affinity for the lipid-rich stratum corneum. Upon absorption, the ester bonds are hydrolyzed by skin enzymes, releasing free L-ascorbic acid. The liberated vitamin C exerts its biological effects: it is a potent antioxidant that scavenges reactive oxygen species and inhibits matrix metalloproteinases (MMPs). It also stimulates collagen synthesis, suppresses melanin production by inhibiting tyrosinase, and supports skin barrier repair. Additionally, VC-IP exhibits SOD‑like (superoxide dismutase) activity.
Applications
Anti‑Aging Skincare: VC‑IP is used in serums, creams, and lotions to stimulate collagen synthesis, reduce fine lines and wrinkles, and improve skin firmness and elasticity.
Skin Brightening and Pigmentation Control: It is a key ingredient in formulations targeting hyperpigmentation, melasma, age spots, and post‑inflammatory hyperpigmentation. It inhibits melanin synthesis, providing a more even and radiant skin tone.
Photoprotection: VC‑IP is often combined with UV filters to enhance photoprotection and prevent UV‑induced damage. It also works synergistically with vitamin E (tocopherol).
Formulation Compatibility: Due to its oil solubility, VC‑IP is easily incorporated into anhydrous, oil‑based, and emulsion systems, including sunscreens, foundations, lip products, and serums. It is stable at acidic pH (below 5).
Safety and Toxicology
The Cosmetic Ingredient Review (CIR) Expert Panel has evaluated ascorbyl tetraisopalmitate and related esters and concluded that they are safe for use in cosmetics under current practices. VC‑IP is considered non‑irritating and non‑sensitizing, even at high concentrations. Patch tests using 30% VC‑IP have yielded completely negative results. Maximum reported use concentrations are up to 2.5% in rinse‑off products and up to 3% in leave‑on products. It is suitable for all skin types, including sensitive skin. The EWG safety rating for VC‑IP is 1 (low concern), and the ingredient is approved for use in cosmetics in the US, EU, and Japan.
Storage and Handling
VC‑IP should be stored in a cool, dry place, protected from light and moisture. The compound is stable at room temperature for extended periods but may be stored at –20°C for long‑term preservation. Containers should be tightly sealed to prevent contamination and oxidation. Use appropriate personal protective equipment (gloves, safety goggles) when handling large quantities.