Profile of 3‑O‑Ethyl Ascorbic Acid
INCI Name: 3‑O‑Ethyl Ascorbic Acid CAS No.: 86404‑04‑8 Molecular Formula: C₈H₁₂O₆ Molecular Weight: 204.18 Appearance: White to off‑white crystalline powder, odorless or with faint characteristic odor.
3‑O‑ethyl ascorbic acid is obtained via ethylation modification at the 3‑hydroxyl group of the vitamin‑C molecule. This structural modification protects the 3‑hydroxyl group from ionization, greatly mitigating oxidative degradation and yellowing issues of native L‑ascorbic acid, while retaining the core biological activity of vitamin C. It exhibits amphiphilic properties: soluble in water and partially soluble in oils. Such amphiphilic character facilitates penetration through the stratum corneum. After entering skin tissue, it is metabolized by enzymes into active vitamin C to exert its biological effects.
Key Physicochemical Properties
Excellent stability: Resistant to oxygen, heat and light; less prone to yellowing in finished formulations compared with native L‑ascorbic acid. Stable pH range: 3.0‑6.0; optimal pH: 4.0‑5.5, which is close to physiological skin pH and reduces irritation risks.
Good solubility: Freely soluble in water and partially soluble in oils. Compatible with both aqueous and emulsion systems, suitable for transparent toners, serums, creams and lotions.
Enhanced skin penetration: Its amphiphilic structure promotes stratum‑corneum penetration and delivers higher bioavailability than many other vitamin‑C derivatives. It is relatively mild and can be incorporated into sensitive‑skin formulations at appropriate dosages.
Mechanism of Action
Skin brightening and melanin‑inhibiting effect: Inhibits tyrosinase activity to block melanin biosynthesis. It can also reduce pre‑formed melanin into colorless substances, improving dull complexion, post‑inflammatory hyperpigmentation and uneven skin tone for brightening benefits.
Antioxidation and anti‑photoaging: Scavenges free radicals induced by ultraviolet radiation and environmental stress, alleviates oxidative damage, defends against photoaging and repairs skin irritation caused by external aggressors.
Collagen‑biosynthesis promotion: After being converted into active vitamin C in skin, it participates in collagen synthesis, helping to diminish fine lines and improve skin firmness.
Quick comparison note: Native vitamin C delivers potent efficacy yet requires low‑pH conditions and tends to oxidize and turn yellow. 3‑O‑ethyl ascorbic acid features superior stability, skin‑friendly pH compatibility and mildness, making it more suitable for leave‑on daily‑use skincare products. Vitamin‑C derivatives are not pharmaceutical agents. Seek medical advice for severe skin conditions.
Application Fields
Thanks to its amphiphilic nature and high stability, 3‑O‑ethyl ascorbic acid is compatible with diverse dosage forms including aqueous solutions, gels, serums and creams. It is mainly applied in leave‑on skincare products and can also be added to certain hair‑and‑body‑care products.
Serums & skin priming essences: The most common application. High‑activity brightening & antioxidant serums targeting dullness and post‑acne marks; a popular active ingredient in performance‑driven skincare.
Lotions, creams & brightening moisturizers: Daily antioxidant and brightening moisturizers for morning‑and‑night usage, combining moisturization with skin‑tone conditioning.
Toners & gels: Transparent aqueous or gel‑type formulas, ideal for oily and combination skin.
Masks: Sheet masks and rinse‑off masks, added for auxiliary antioxidant effects and dullness improvement.
Hair‑&‑body‑care products: Hair‑treatment essences, shampoos and body washes. Incorporated at low dosage for auxiliary antioxidant and skin‑brightening effects.
Synergistic combined formulations: Frequently compounded with niacinamide, arbutin, tranexamic acid and plant extracts for synergistic brightening and antioxidation. It can also be combined with humectants such as sodium hyaluronate to lower potential irritation and optimize sensory feel.
⚠️ Disclaimer: This article is for cosmetic‑raw‑material science popularization only. Cosmetic raw materials are not medicines. Please consult a dermatologist for skin disorders.
Recommended Dosage & Formulation Best Practices
The values below serve as general industry references. Final addition levels shall be determined according to product positioning, efficacy claims, regulatory requirements and stability lab trials.
表格
Product Type | Recommended Dosage (mass fraction) | Remarks |
|---|---|---|
Leave‑on brightening & antioxidant serum | 1.0%‑3.0% | Commercial products mostly adopt 1‑2%; up to 3.0% for high‑efficacy formulas. Excessively high loading is not advised. |
Leave‑on lotions & creams | 0.5%‑2.0% | 0.5‑1.0% for daily maintenance; 1‑2% for performance‑oriented products. |
Toners & gels | 0.5%‑2.0% | Monitor pH value for transparent systems. |
Masks (sheet / rinse‑off) | 0.5%‑2.0% | Adjust dosage appropriately for short skin‑contact duration. |
Hair‑&‑body‑care products (shampoo / body wash) | 0.1%‑0.5% | For auxiliary antioxidation; not designed for strong skin‑brightening performance. |
Critical Formulation Notes
Feeding temperature: Add below 40 °C. Elevated temperature impairs long‑term stability. It dissolves rapidly when directly introduced into aqueous phase.
pH control: Maintain system pH at 4.0‑5.5; avoid strongly acidic or strongly alkaline environments. Sodium citrate buffer system is suggested to enhance long‑term stability.
Compatibility: Shows good compatibility with niacinamide, arbutin, sodium hyaluronate and most botanical extracts. Avoid co‑formulation with high‑concentration strong oxidizing agents.
Packaging & storage: Store raw material hermetically in cool and dark conditions. Light‑proof packaging is preferred for finished goods to retard activity loss.
Pre‑production trials: Conduct accelerated stability tests including high‑low‑temperature cycling before mass manufacturing to check for discoloration, precipitation and active‑ingredient retention.
Summary
The major merit of 3‑O‑ethyl ascorbic acid lies in overcoming native vitamin C’s instability and yellowing tendency. It balances skin penetration and mildness, features skin‑friendly formulation‑pH tolerance and fits a wide range of cosmetic dosage forms, establishing itself as a mature vitamin‑C derivative for brightening‑antioxidant skincare.
During formulation development, set proper addition levels based on product positioning, control feeding temperature and system pH, deploy buffer systems and suitable packaging. In this way, its antioxidant and skin‑tone‑evening functions can be stably achieved.
References
[1] Fotis Iliopoulos,et al.3-O-ethyl-l-ascorbic acid: Characterisation and investigation of single solvent systems for delivery to the skin[J].Int J Pharm X,2019,1:100025. https://pmc.ncbi.nlm.nih.gov/articles/PMC6733298/
[2] Liao W C,et al.Antioxidant Ability and Stability Studies of 3-O-Ethyl Ascorbic Acid, a Cosmetic Tyrosinase Inhibitor[J].Journal of Cosmetic Science,2018,69(4):233-243. https://pubmed.ncbi.nlm.nih.gov/30222331/