Ascorbic Acid (Vitamin C – L-Ascorbic Acid)
Introduction
Ascorbic Acid (CAS No. 50-81-7; Molecular Formula: ; Molecular Weight: 176.12 g/mol) is the biologically active form of Vitamin C, a water-soluble organic compound classified as a lactone with strong reducing and antioxidant properties. Naturally occurring in fruits and vegetables such as citrus, berries, and leafy greens, it is essential for human health, functioning as a cofactor in enzymatic hydroxylation reactions and as a key molecule in redox balance.
In industrial production, Ascorbic Acid is predominantly manufactured through the Reichstein process or a two-step fermentation of glucose or sorbitol using microbial oxidation and chemical synthesis steps. These processes yield ≥99% purity material that complies with international pharmacopeial standards (USP, BP, EP, FCC), making it suitable for use in pharmaceutical, nutraceutical, and cosmetic-grade applications.
Physicochemically, Ascorbic Acid presents as a white to pale yellow crystalline powder, with a melting point of 190–192 °C (decomposition) and high water solubility (~330 g/L at 20 °C). It has two dissociation constants (pKa₁≈4.10, pKa₂≈11.8) that influence its stability and reactivity in formulations. The compound is sensitive to heat, light, and oxygen, requiring protective packaging and stabilizing systems for extended shelf life.
Technical Profile
|
Parameter |
Typical Value |
Significance |
|
Purity |
≥99% |
High potency for diverse applications |
|
Appearance |
White to pale yellow crystalline powder |
Quality control indicator |
|
Melting Point |
190–192 °C (decomp.) |
Processing temperature limit |
|
Water Solubility |
~330 g/L @ 20 °C |
Excellent for aqueous systems |
|
pKa Values |
4.10 / 11.8 |
pH-sensitive stability |
|
Redox Potential |
+0.08 V |
Strong reducing capacity |
|
Global Production |
~70% in China |
Stable industrial supply chain |
Benefits
✓ Potent Antioxidant & Anti-Aging
Neutralizes free radicals, promotes collagen production, and protects against photo-aging.creams, and aqueous systems.
✓ Brightening & Tone Enhancement
Reduces pigmentation and brightens skin by interfering with melanin formation.creams, and aqueous systems.
✓ Skin Health & Repair
Supports structural integrity of skin and accelerates regeneration (e.g., post-sun damage).creams, and aqueous systems.
✓ Formulation Versatility
High solubility and broad pH compatibility facilitate inclusion in serums, creams, and aqueous systems.
Application
Anti-Aging Serums: High-concentration (10–20%) serums targeting fine lines, firmness, and brightness
Antioxidant Boosters: Daily creams or essences delivering photoprotection and oxidative defense
Brightening Systems: Multi-actives combining Vitamin C with niacinamide, exfoliants, or peptides
Supplemental Use: Included in dietary supplements for nutritional and skin health support
Product Processing
