Formulation Guides
Vitamin C Stability: How to Formulate Without Oxidation
Dr. Sarah ChenFebruary 14, 20247 min read
L-Ascorbic Acid (LAA) is the most biologically active form of Vitamin C but also the most challenging to work with. Oxidation turns it from white to yellow to orange — rendering it inactive and potentially irritating.
Key Stability Factors
pH — Effective at pH 2.5–3.5. Above pH 4, efficacy drops significantly. Oxygen exposure — Use airless pumps or nitrogen-flushed packaging. Temperature — Store below 25°C during manufacture and retail.
Antioxidant Synergists
Combine LAA with Vitamin E (Tocopherol) at 0.5–1% and Ferulic Acid at 0.5% to dramatically extend stability. This trio creates a synergistic antioxidant network studied extensively in dermatology literature.