Topical Vitamin C: Mechanisms, Stability, and Advanced Delivery Technologies

Unlocking the Power of Topical Vitamin C: Mechanisms, Stability, and Advanced Delivery Technologies

Vitamin C (ascorbic acid) has long been recognised as a powerhouse ingredient in dermatological formulations due to its potent antioxidant properties, its role in collagen biosynthesis, and its ability to brighten skin tone. However, its instability—particularly in comparison to its more stable derivatives—poses significant challenges for formulators. This article explores the biochemical properties of Vitamin C, its stability challenges, and how innovative delivery systems, such as CosminC by Cosmodec, enhance the bioavailability and performance of ascorbic acid in topical applications.

The Benefits of Vitamin C in Skincare

Vitamin C is renowned for a variety of skincare benefits for both the appearance and feel of skin throughout its lifecycle.

Antioxidant Protection

As a potent antioxidant, ascorbic acid neutralises reactive oxygen species (ROS) such as superoxide and hydroxyl radicals, which are generated by UV exposure and pollution. This action prevents oxidative damage to skin cells, lipids, and proteins, reducing premature ageing and protecting against environmental stress (Pinnell et al., 2001; Brignone et al., 2019).

Collagen Production

Vitamin C plays a critical role in collagen biosynthesis by serving as a cofactor for prolyl and lysyl hydroxylase, enzymes responsible for stabilising collagen's triple helix structure. This helps maintain skin firmness, reduce wrinkles, and support the extracellular matrix (Telang, 2013; Segall & Moyano, 2008).

Brightening the Skin

By inhibiting tyrosinase, the enzyme responsible for melanin production, Vitamin C can reduce hyperpigmentation and improve skin tone uniformity (Pullar, Carr & Vissers, 2017).

Photo-protection

Studies show that topical Vitamin C protects the skin from UV-induced damage by neutralising free radicals and improving the skin's defence mechanisms (Farris, 2005). This protection extends to preventing collagen degradation and photoaging.

Stability Challenges of Pure Vitamin C in Formulations

While the benefits of pure ascorbic acid are well-established, its chemical instability in skincare products is a significant barrier. Ascorbic acid degrades rapidly when exposed to environmental factors such as air, light, and heat due to its low pKa (~4.2), resulting in the formation of dehydroascorbic acid—a much less potent form (Pinnell et al., 2001). This degradation not only reduces the ingredient's efficacy but can also cause discolouration of the product, which is a common concern for consumers (Brignone et al., 2019).

Vitamin C Derivatives: A Compromise Between Stability and Bioavailability

To address these challenges, several Vitamin C derivatives have been developed, offering greater stability in formulations. However, these derivatives often exhibit reduced bioavailability, meaning they need to be converted back into active ascorbic acid within the skin.

Magnesium Ascorbyl Phosphate (MAP) is a water-soluble derivative that is highly stable but must be enzymatically converted to ascorbic acid after penetrating the skin. While MAP offers enhanced stability, its reduced bioavailability limits its capacity for collagen synthesis (Telang, 2013).

Ascorbyl Palmitate is another such example. This is a fat-soluble derivative that can penetrate the skin’s lipid layers more effectively than water-soluble forms but also requires conversion to active ascorbic acid within the skin. This conversion reduces its immediate efficacy (Pullar, Carr & Vissers, 2017).

Though these derivatives improve stability, their lower bioavailability compared to pure ascorbic acid means they often deliver less immediate results.

CosminC: A Revolutionary Solution to Stabilising Vitamin C

Cosmodec's CosminC represents a breakthrough in the stabilisation of pure ascorbic acid for topical use. Leveraging Smart Bio-Shell technology, CosminC encapsulates ascorbic acid within a protective polymer shell. This innovative encapsulation not only preserves the stability of ascorbic acid but also ensures its high bioavailability upon application, addressing both the stability and efficacy concerns associated with Vitamin C formulations (Cosmodec, 2024).

High Bioavailability 

Unlike derivatives, which require conversion to active ascorbic acid, CosminC delivers 100% bioavailable ascorbic acid directly to the skin. This high bioavailability ensures faster and more effective antioxidant protection, collagen production, and reduction in pigmentation (Lawrence Industries, 2024).

Improved Stability

The unique Smart Bio-Shell encapsulation protects Vitamin C from oxidative degradation by shielding it from air, light, and moisture. This offers improved stability and can be shown by stability tests which show that CosminC retains more than 95% of its ascorbic acid content after six months, even at elevated temperatures (Cosmodec, 2024).

Figure 1: The performance results from a HPLC stability test of CosminC at 50 ˚C for 6 months. It shows that over 95 % of the Vitamin C remains even after 25 weeks.

Enhanced Penetration

The positive zeta potential of the bio-shell enhances adhesion to the skin surface which has a negative zeta potential. This improves penetration and allows for deeper delivery into the epidermis (Brignone et al., 2019).

No Discolouration

Unlike traditional Vitamin C formulations that oxidise and turn brown, CosminC remains stable, ensuring consistent efficacy and aesthetic appeal (Lawrence Industries, 2024).

Figure 2: A comparison of the discolouration of 3 % pure Vitamin C and 43 % CosminC (=3 % Vitamin C) over 4 weeks when heated in an oven at 50 ˚C. The CosminC shows excellent stability against both heat and air.

Clinical Efficacy of Stabilised Vitamin C

Numerous clinical studies have demonstrated the superior performance of pure ascorbic acid compared to its derivatives, particularly in terms of bioavailability. In a 12-week study, participants who applied a serum containing 10% pure ascorbic acid experienced significant improvements in skin firmness, reduced fine lines, and a brighter complexion, compared to those using derivatives (Farris, 2005). By maintaining the stability of pure Vitamin C, CosminC offers consistent, high-level efficacy over time.

Conclusion: Maximising Both Bioavailability and Stability

Vitamin C is essential for effective skincare, but balancing its bioavailability and stability has long been a challenge for formulators. CosminC by Cosmodec offers a groundbreaking solution by stabilising pure ascorbic acid while preserving its high bioavailability. This innovation allows for the development of advanced skincare products that deliver both immediate and long-term benefits. For R&D chemists and formulators, technologies like CosminC open the door to creating more stable, effective, and consumer-friendly Vitamin C products.

If you would like more information on how to formulate with CosminC, contact us here to get in touch with our technical experts. 

References:

Brignone, S., Hergert, L., Allemandi, D., & Palma, S. (2019). Ascorbic Acid in Skin Health. Cosmetics, 6(4), 58.

Maia Campos, P.M.B.G., Gonçalves, G.M.S., and Gaspar, L.R., 2008. In vitro antioxidant activity and in vivo efficacy of topical formulations containing vitamin C and its derivatives studied by non-invasive methods. Skin Research and Technology, 14(3), pp.376-380. Available at: https://doi.org/10.1111/j.1600-0846.2008.00288.x.

Cosmodec. (2024). CMD CosminC504: Stabilised Ascorbic Acid Complex. Available at: https://www.cosmetic-labs.com.

Farris, P.K. (2005). "Topical vitamin C: A useful agent for treating photoaging and other dermatologic conditions." Dermatol. Surg., 31(7 Pt 2), 814-818.

Lawrence Industries. (2024). CMD CosminC504: Stabilised Ascorbic Acid Complex. Available at: https://www.l-i.co.uk.

Pinnell, S.R., et al. (2001). "Topical L-ascorbic acid: Percutaneous absorption studies." Dermatol. Surg., 27(2), 137-142.

Pullar, J., Carr, A., & Vissers, M. (2017). "The roles of vitamin C in skin health." Nutrients, 9(8), 866.

Telang, P. (2013). "Vitamin C in dermatology." Indian Dermatol. Online J., 4(2), 143-146.

Segall, A. & Moyano, M. (2008). "Stability of vitamin C derivatives in topical formulations containing lipoic acid, vitamins A and E." Int. J. Cosmet. Sci., 30(6), 453–458.