Topical vitamin C (ascorbic acid) and some of its derivatives are vital tools for keeping skin healthy, but what are the best sources and what should formulators know when working with this essential, but tricky ingredient? Pauline Hili, founder of Nourish London, explains
Everyone has heard of vitamin C. But do we know why it’s so important for skin health, what the best sources are and what the most effective ways of incorporating vitamin C into a topical product may be?
Dr Pauline Hili is the founder of high-performance skin care brand Nourish London, a Fellow of the Royal Society of Chemistry and one of the UK’s top organic skin care experts.
In this article, she provides the lowdown on the benefits of vitamin C and how these can be amplified in finished products.
Pauline Hili, PhD,
As a high-performance skin care formulator, people often ask me what I think is one of the best ingredients for skin health. Without a doubt vitamin C (ascorbic acid) always features among the top three.
Ascorbic acid and some of its derivatives are important tools in our formulation strategy to keep the skin staying and looking healthy.
General health-wise, a deficiency of vitamin C often manifests itself in a number of skin conditions such as:
1. Rough bumpy skin
2. Dry, damaged skin
3. Slow healing wound
4. Cracked fingernails
This vitamin is essential for the production of collagen and acts as an antioxidant in the skin, protecting it from free radical damage. It protects our cells and helps to maintain healthy skin, blood vessels, bones and capillaries.
Interestingly, most mammals have the ability to produce their own vitamin C. For example, an averaged sized goat produces about 13,000mg of vitamin C in a day. Humans have, however (along with some species of bats and guinea pigs) lost the ability to do so. This is due to a mutation in the gluconolactone oxidase gene, which results in the inability to synthesise the enzyme responsible for its production.
Dietary and topical vitamin C have beneficial effects on skin cells. Inside our bodies, vitamin C generally reaches the dermis and epidermis transported by our bloodstream. Special transport proteins are found in all layers of the skin. It is found in higher quantities in the epidermis than the dermis and believed to play a role in protecting the skin from UV light and external pollutants.
The Australian Kakadu plum (Terminalia ferdinandiana) provides one of the richest dietary sources of vitamin C and contains 100 times more vitamin C than oranges. This superfood contains up to 5.3g of this vitamin per 100g and one plum can provide over 1,000% of the required daily intake.
Recent research has shown that applying vitamin C to the skin topically in the correct formulation is up to 20-30 times more effective for the skin than when taken orally. There are a number of reasons why using it can be beneficial in formulations.
When formulating for topical delivery of vitamin C it is important to understand the parameters with which to get best results. Firstly, vitamin C is sensitive to light and air, and is inherently unstable. If formulated incorrectly it will turn brown and formulation spoilage will occur very quickly.
Secondly, it is important to remember that for successful transportation into the skin ascorbic acid needs to be at low pH, ideally less than 4. At this pH, the charge on the molecule is neutralised and it can be transported more easily across the stratum corneum.
Thirdly, it is really helpful to look at other ingredients within your formulation that enhance or even amplify the effects of vitamin C. Both vitamin E and ferulic acid (found in argan oil) have synergistic effects on the benefits your skin obtains from this key vitamin. Using natural ingredients with high levels of vitamin C in the formulation can also increase its effectiveness on the skin.
Esterified forms of vitamin C such as ascorbyl palmitate and magnesium ascorbyl palmitate offer more stable forms for formulation. These are however not water soluble and can notoriously be difficult to solubilise, but with careful experimentation can yield wonderful end formula results.
At Nourish London we are big fans of vitamin C and have prominently featured it in our Protect Range and our Argan Skin Rescue, specifically targeted for dry skin. Our vitamin C-rich formulations within the Protect Range have just launched in Holland & Barrett.
Arriving at formulations with demonstrated clinical results is always an exciting step in the formulation process. Vitamin C and its derivatives are undoubtedly some of the key ingredients to help deliver exceptional clinical results.