Ascorbyl Palmitate has recently garnered a lot of interest in the skincare sector, to the point where it can be found in very small quantities in a number of different cosmetic products. But what is it and why is it used so extensively? Let's explore in this article the advantages and disadvantages it offers if you're considering using it.
What is "Ascorbyl Palmitate" and what is its utility?
Published on July 16, 2024, by Stéphanie, PhD, Doctorate in Life and Health Sciences — 10 min of reading
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"Ascorbyl Palmitate": What is its purpose?
The vitamin C is available in various active forms, including ascorbyl palmitate (INCI: Ascorbyl Palmitate). This is a synthetic fatty acid ester with lipophilic properties, formed from ascorbic acid and palmitic acid, a saturated fatty acid.
Ascorbyl palmitate has been specifically developed to overcome the stability and permeability issues of vitamin C, while preserving its benefits. Indeed, although it is one of the most powerful antioxidants, vitamin C quickly oxidises when exposed to light, thus no longer producing the expected results and causing undesirable effects.
Ascorbyl palmitate is often used to help stabilise more sensitive skincare ingredients, such as pure Vitamin C.
It is also known to be effective at a neutral pH, unlike pure vitamin C which requires a pH lower than 3.5 to enhance its stability and facilitate its penetration, thus making ascorbyl palmitate easier to formulate and less irritating.
| Chemical and Physical Characteristics | Values |
|---|---|
| Chemical Formula | C22H38O7 |
| Synonym | Ascorbic acid-6-palmitate, vitamin C palmitate, ascorbate 6-palmitate |
| Appearance | White and light yellow powder |
| Molar Mass | 414.5 g/mol |
| Dosage | Often used between 0.05 and 1% |
| Solubility | Soluble in alcohol and vegetable oils; Slightly soluble in water |
According to a comparative study, this improved fat-soluble variant of ordinary vitamin C appears to maintain a "similar" stability to ascorbic acid. Research has even shown that other forms have better long-term stability, thus not remaining unaffected by degradation due to continuous exposure to heat and aerobic conditions. Indeed, its chemical modification (addition of a lipid component) is located on carbon 6, thus offering less protection to ascorbic acid against hydrolysis.
| Forms of Vitamin C | Remaining content of vitamin C or its derivatives after 60 days of storage at room temperature | Remaining content of Vitamin C or its derivatives after 60 days of storage at 42°C |
|---|---|---|
| Pure Vitamin C (INCI: Ascorbic Acid) | 37% | 0% |
| Ascorbyl Palmitate (INCI: Ascorbyl Palmitate) | 77% | 47% |
| Magnesium Ascorbyl Phosphate (INCI: Magnesium Ascorbyl Phosphate) | 95% | 83% |
Analyse de la stabilité de l'acide ascorbique, du palmitate d'ascorbyle et du phosphate d'ascorbyle de magnésium.
Des solutions aqueuses contenant 1% d'acide ascorbique, de phosphate d'ascorbyl de magnésium ou de palmitate d'ascorbyl ont été stockées à la fois à température ambiante et à 42°C dans l'obscurité pendant 60 jours (test de vieillissement accéléré). Source : BETTERO A. & al. Stability of vitamin C derivatives in solution and topical formulations. Journal of Pharmaceutical and Biomedical Analysis (1997).
However, studies have shown that ascorbyl palmitate appears to easily penetrate the stratum corneum due to its lipid nature, unlike the hydrophilic ascorbic acid. However, although it has better skin penetration, it would remain on the surface of the cells and therefore does not easily convert into L-ascorbic acid, the biologically active form.
Structure of Ascorbyl Palmitate.
Source: PubChem.
"Ascorbyl Palmitate": How can it assist in a formulation?
Present in over a thousand cosmetic formulations (lip balms, after-sun lotions, shampoos, facial serums, etc.), ascorbyl palmitate is believed to have numerous beneficial functions for the skin.
Antioxidant agent: it helps to protect the skin from oxidative damage caused by free radicals, which are generated by solar radiation, smoking, diet, environmental pollution, etc. It reduces cellular levels of free radicals in a dose-dependent manner through a process of transfer and/or electron donation. However, its antioxidant activity has only been demonstrated in in vitro models, but not in vivo.
However, a study has shown that the use of ascorbic acid-6-palmitate (10 to 100 μM) during the day would promote the generation of oxidised lipid molecules (lipid peroxidation) induced by UV rays, which would damage cells. This study suggests that, despite its antioxidant properties, ascorbyl palmitate could potentially enhance skin damage through this mechanism following UVB irradiation. However, this is an in vitro study, which means it was conducted on cultures of human keratinocytes and not on actual people.
Furthermore, another study has revealed that this amphiphilic antioxidant binds to the surface of human erythrocytes, where it helps to protect the cellular membrane from damage caused by peroxidative agents originating from the outside, thereby strengthening the cell's defences against external oxidative stress. As a result, additional studies in vivo are necessary to provide further insight.
Given that sunscreens are only partially effective at blocking the free radicals produced by UV exposure, the addition of antioxidants, such as ascorbyl palmitate, could help to enhance the efficacy of sun protection.
Anti-erythema function: An initial study was conducted in which individuals who had suffered sunburn and were treated with topical ascorbyl palmitate (5%) demonstrated a 50% reduction in redness earlier compared to areas that had not received it. In a second experiment, the forearms of 5 subjects were left unprotected (controls) or received a local application of 3% ascorbyl palmitate prior to UVB exposure. Compared to untreated skin, the absence of erythema or a decrease in erythema was observed after pre-treatment with ascorbyl palmitate. These data demonstrate its photoprotective nature, probably
attributed to its anti-inflammatory and antioxidant properties.
Compared to other forms of Vitamin C, Ascorbyl Palmitate is believed to have moisturising properties due to its palmitate component.
Melanin production inhibitor (anti-melanogenesis): a single-centre study examining the synergistic effect of ascorbyl palmitate and sodium ascorbyl phosphate reported a significant decrease in melanin content after 12 weeks of application. It is hypothesised that they interact with copper ions at the active sites of tyrosinase, the main enzyme responsible for the conversion of tyrosine into melanin, thus inhibiting its action. By reducing melanin production, these vitamin C derivatives could potentially help to lighten brown spots. However, although it has been demonstrated that ascorbyl palmitate can potentially inhibit melanin production, studies remain limited and may not be as effective as other active ingredients.
A clinical study on 11 adult women has shown that the combined use of ascorbyl palmitate and sodium ascorbyl phosphate could potentially reduce the skin's sebum content, due to their ability to inhibit 5-α-reductase.
Can Ascorbyl Palmitate be safely used on human skin?
Widely approved by regulatory bodies such as the FDA, ascorbyl palmitate is among the substances recognised as safe and non-irritating for most skin types in commonly used concentrations. Although data agrees that it has a lower irritant potential, some individuals may experience adverse reactions.
In rare instances, it may cause skin irritation, erythema and/or skin dryness, particularly in individuals with sensitive skin or those suffering from a skin condition. As a result, it is advised to exercise a degree of caution before using this active ingredient. It is therefore recommended to perform a patch test on a small area of the body before using widely products containing ascorbyl palmitate.
Ascorbyl palmitate is synthesised through the esterification of ascorbic acid, derived from the fermentation of corn, with palmitic acid extracted from palm oil. It is present in our shimmering dry body oil.
Sources
Fiche fournisseur.
BETTERO A. & al. Stability of vitamin C derivatives in solution and topical formulations. Journal of Pharmaceutical and Biomedical Analysis (1997).
MAY J. M. & al. Ascorbate 6-palmitate protects human erythrocytes from oxidative damage. Free Radical Biology and Medicine (1999).
PEUS D. & al. Vitamin C derivative ascorbyl palmitate promotes ultraviolet-B-induced lipid peroxidation and cytotoxicity in keratinocytes. Journal of Investigative Dermatology (2002).
PECAR S. & al. Skin protection against ultraviolet induced free radicals with ascorbyl palmitate in microemulsions. European Journal of Pharmaceutics and Biopharmaceutics (2003).
MOYANO M. A. & al. Stability of vitamin C derivatives in topical formulations containing lipoic acid, vitamins A and E. International Journal of Cosmetic Science (2008).
STAMFORD N. P. J. Stability, transdermal penetration, and cutaneous effects of ascorbic acid and its derivatives. Journal of Cosmetic Dermatology (2012).
NAWAZ Z. & al. Synergistic effects of ascorbyl palmitate and sodium ascorbyl phosphate loaded in multiple emulsions on facial skin melanin and erythema content. Biomedical Research (2016).
ALI A. & al. Assessment of combined ascorbyl palmitate (AP) and sodium ascorbyl phosphate (SAP) on facial skin sebum control in female healthy volunteers. Drug Research (2017).
HELDRETH B. & al. Safety assessment of ethers and esters of ascorbic acid as used in cosmetics. International Journal of Toxicology (2022).
