3-O-Ethyl Ascorbic Acid (CAS 86404-04-8; INCI: 3-O-Ethyl Ascorbic Acid) is a cosmetic vitamin C derivative used in brightening serums, essences and antioxidant emulsions. Unlike L-ascorbic acid, the ethyl ether is designed to be more stable in formulation, but the finished serum still depends on the solvent route, target pH, packaging and the quality of the batch COA.
Why formulators choose the ethyl ether
L-ascorbic acid is effective but can be difficult to stabilize in water-based products. 3-O-Ethyl Ascorbic Acid is used as a more formulation-friendly derivative for leave-on skincare. It is typically supplied as a white to off-white powder and can be incorporated into water/glycol systems, depending on the grade and the supplier’s TDS.
Solvent route
For a brightening serum, the powder is usually dispersed in the water phase or a water/glycol blend. A common practical approach is to pre-disperse the powder in a small amount of water or a glycol such as propanediol or glycerin, then add it to the main phase at the appropriate stage. Avoid adding it to a hot, strongly alkaline phase; confirm the exact temperature and pH window in the current TDS before scaling up.
If the formula contains high levels of electrolytes, chelating agents or reactive metals, run a small stability trial first. Color drift and pH drift are the usual early indicators that the system needs adjustment.
pH and stability
There is no single pH that fits every formula. The target pH should be set from the supplier’s TDS and confirmed in the finished base. In practice, formulators evaluate the candidate pH range with a real accelerated stability trial, checking appearance, pH and assay over time. Do not copy a pH number from a marketing page into a production formula without batch-specific data.
COA checklist for a brightening serum
- Batch number and manufacture/expiry dates
- Appearance and identification
- Assay / content by HPLC
- pH of the specified test solution
- Loss on drying / moisture
- Heavy metals and microbial limits
- Packaging and storage conditions
Ask for a COA that matches the actual batch you will receive, not only a representative certificate. For a serum trial, request a small sample and the current TDS at the same time.
Request a sample or current COA
BIOF supplies cosmetic-grade 3-O-Ethyl Ascorbic Acid powder. Send your target application, use level, quantity and destination through the contact form, and the team will confirm the current batch COA/TDS and sample availability.
View 3-O-Ethyl Ascorbic Acid product page · COA & TDS library
Post time: Nov-12-2026
