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Sodium Ascorbyl Phosphate

Also known as: Sodium Ascorbyl Phosphate, SAP, Ascorbate-2-phosphate sodium salt

Overview

Sodium Ascorbyl Phosphate (SAP) is a stable, water-soluble derivative of vitamin C (ascorbic acid) widely used in topical skin care formulations. Unlike ascorbic acid, SAP exhibits greater stability and resistance to oxidation, making it suitable for cosmetic and dermatological applications. It is valued for its antioxidant, anti-aging, and skin-brightening properties. SAP converts to active vitamin C within the skin, providing localized benefits. It is incorporated into various products, including creams, serums, and lotions, to reduce wrinkles, improve skin texture, and protect against environmental damage. Research includes clinical studies and physicochemical analyses, demonstrating its efficacy and stability.

Benefits

Sodium Ascorbyl Phosphate (SAP) offers several evidence-based benefits for the skin. A randomized controlled trial (RCT) demonstrated that a 5% SAP emulgel significantly reduced wrinkles, showing comparable or superior results to 5% ascorbic acid, along with better physicochemical stability. SAP functions as a potent antioxidant, shielding the skin from oxidative damage induced by UV radiation and environmental stressors. Additionally, SAP contributes to skin brightening and revitalization by inhibiting melanin synthesis and promoting collagen production. These benefits have been observed in healthy adult volunteers exhibiting signs of skin aging, with improvements noted over weeks of consistent topical application.

How it works

Sodium Ascorbyl Phosphate (SAP) functions by converting enzymatically within the skin to ascorbic acid, the active form of vitamin C. This conversion allows ascorbic acid to exert its antioxidant effects by scavenging reactive oxygen species (ROS), thereby reducing oxidative stress. SAP primarily interacts with the skin's extracellular matrix, stimulating collagen synthesis and inhibiting enzymes like matrix metalloproteinases that degrade collagen. Its molecular targets include ROS, collagen-producing fibroblasts, and melanocytes, influencing pigmentation. SAP's water-soluble nature facilitates skin penetration, and its stability ensures effective delivery of active vitamin C locally.

Side effects

Sodium Ascorbyl Phosphate (SAP) is generally considered safe for topical use, with a low incidence of adverse effects. Common side effects are minimal, with some users experiencing mild skin irritation or redness. Uncommon side effects, occurring in 1-5% of users, include rare reports of allergic reactions. No significant adverse events have been reported in controlled studies. Due to its topical application, SAP has no known systemic drug interactions. Contraindications include hypersensitivity to vitamin C derivatives or any of the formulation's excipients. While safe for use in adults, there is limited data on its use in children or pregnant women, warranting caution in these populations.

Dosage

For topical applications, a 5% concentration of Sodium Ascorbyl Phosphate (SAP) is commonly used and supported by clinical data for anti-aging effects. While higher concentrations have not been extensively studied, safety data suggest that concentrations up to 12% magnesium ascorbyl phosphate are used in cosmetics without adverse effects. Daily topical application is typical, with benefits accruing over several weeks. Emulgel or cream formulations are recommended to enhance stability and skin penetration. SAP's stability at neutral to slightly acidic pH enhances absorption. No specific cofactors are required, although antioxidants like vitamin E may synergize with its effects.

FAQs

Is SAP better than ascorbic acid?

SAP is more stable and less irritating than ascorbic acid, making it preferable for sensitive skin while providing comparable antioxidant benefits.

How long until results appear?

Visible skin improvements typically appear after several weeks of consistent use.

Is it safe for sensitive skin?

Generally yes, SAP is less irritating than ascorbic acid, making it a suitable option for sensitive skin types.

Can it be used with other skin treatments?

Usually yes, but caution should be exercised when using strong exfoliants or retinoids to avoid potential irritation.

Research Sources

https://onlinelibrary.wiley.com/doi/10.1111/jocd.13471 – A 2020 randomized controlled trial compared a 5% SAP emulgel to a 5% ascorbic acid formulation. The study found that the SAP emulgel demonstrated superior physicochemical stability and significant anti-wrinkle efficacy compared to the ascorbic acid formulation in human volunteers, suggesting it is a more stable and effective option for topical applications.
https://www.cir-safety.org/sites/default/files/Ascorbic%20Acid.pdf – This safety assessment reviews the use of ascorbic acid and its derivatives, including SAP, in cosmetics. It concludes that SAP and related derivatives are safe for cosmetic use, highlighting their antioxidant activity and supporting their use in various skin care products. The assessment compiles data from multiple studies to establish the safety profile of these compounds.
https://www.mdpi.com/1420-3049/30/3/748 – This systematic review examines the effects of vitamin C derivatives, including SAP, on skin health. It highlights that these derivatives improve skin health through antioxidant and collagen-promoting effects. While the review covers vitamin C derivatives broadly, it supports the inclusion of SAP in formulations aimed at improving skin health and reducing signs of aging.
https://pubs.acs.org/doi/10.1021/acsomega.0c04318 – This study investigates the antioxidant properties of SAP and its ability to protect the skin from oxidative stress. The research confirms SAP's antioxidant activity, demonstrating its potential to shield the skin from damage caused by UV radiation and environmental stressors. The findings support the use of SAP as an active ingredient in skin care products designed to combat oxidative damage.
https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-Ascorbyl-Phosphate – This entry from PubChem provides chemical identifiers and properties of Sodium Ascorbyl Phosphate. It offers key information about the compound's structure and classification. It serves as a reference for understanding the chemical nature of SAP.