Necessity and practicality
Our body can’t synthesize vitamin C which is one of the most crucial components. Vitamin C is a water-soluble antioxidant and co-factor of 8 ferment reactions.
What Vitamin C does to our skin:
- Works as an oxidant
- Decreases skin maturing speed
- Decreases inflammation caused by UV light
- Brightens the skin and lightens pigmentation
- Heals acne prone skin
- Decreases gingivitis in the mouth
One of the factors, starting the rapid skin aging is an oxidation process. The oxidation process is caused by the increased concentration of active forms of oxygen happening because of the repeated UV-radiation and decreasing of antioxidant protection of the skin. We must note that while Vitamin C is not synthesized by our body, it’s a key element of the antioxidant system.
Main signs of skin aging:
- Wrinkles appearance
- Decreased elasticity
- Change in skin tone evenness and pigmentation
- The appearance of small blood vessels on the skin
- General skin dehydration
Boyera conducted research and proved that local Vitamin C application helps to maintain the level of collagen and normalizes skin elasticity and strengthens collagen fibers. Another research has shown that vitamin C can stimulate collagen synthesis.
In research with the local application of vitamin C (3-10%) for 12 weeks, there was observed a decrease in new wrinkles appearance, the quantity of broken protein of connective tissue, visual skin roughness, and the increased collagen production.
Another research has shown that people with an increased level of vitamin C intake (internally) didn’t show any skin condition change.
Local application and concentration
We mentioned before that Vitamin C is one of the antioxidant system components. It’s important to note that it doesn’t work alone. For the effective work of Vitamin C, the following ingredients are required: fat soluble and non-fermented antioxidants with low molecular weight: Vitamin E, Coenzyme Q10, beta-carotene, Glutathione, Urea, Ferulic acid. Unfortunately, Vitamin C doesn’t work when alone.
Antioxidant system of skin is not evenly distributed: the outside layer of skin has more of it than the dermal layer. Various atmosphere pollutants such as ozone, smog, and tobacco smoke help to decrease the amount of vitamin C in the skin. You might have heard the saying: one cigarette a day is one more wrinkle. Asian researchers say that going outside without antipollution skincare products is even more dangerous than smoking.
You might be wondering by now how much of vitamin C do you need and how deeply it should be applied to get the maximum benefits. The question "where" is easier.
Horny layer and epidermis are the main zones where Vitamin C should be applied to. As we discussed before, the dermal layer has only a little vitamin C making external applications useless. This should be rather solved by taking vitamin supplements internally and having a good diet.
Now let’s talk about the dose and concentration. Antioxidants are tricky. Use too much and antioxidant will become a prooxidant, starting the oxidation process. That’s why 100% of ascorbic acid is never used in skincare. And though they conducted experiments with 30% concentration, the maximum efficiency was reached at 20%.
Another important note, the efficiency of Vitamin C absorption through the skin depends on the pH level of the product. Products with a pH level below 4, help to transport vitamin C in the most efficient way. This is not the best acidity for skincare products, that’s why scientists learned to synthesize forms of vitamin C that are stable and properly absorbed even at a higher pH level.
Stability and safety
Vitamin C stability is the biggest headache of the skincare industry. The activity of L-ascorbic acid is high, but its life cycle is very short. Scientists learned how to synthesize more stable forms of vitamin C. However, Vitamin C is still sensitive to light, heat, and pH of the final product. Research shows that the stability and safety of vitamin C can be increased significantly by combining several different antioxidants in one product. For example, the addition of Ferulic acid to vitamins C and E increases the stability of the formula twice and doesn’t create toxic reactions.
We must also mention the bad combinations. In vitro research has shown that Vitamin C reacts with ions of iron and copper and produces free radicals – prooxidant effect. This means that you must be careful combining vitamin C and copper containing peptides. Otherwise, instead of prolonging the youth of your skin, you’d speed up the aging.
What about innovations?
Nowadays 39 variations of Vitamin C are allowed in the EU market. Let’s have a look at the most interesting forms.
Ascorbyl Glucoside (trade name AA2G, manufactured by Hayashibara Japan). Water-soluble, stable at pH 5.0 – 8.0. In Japan, Ascorbyl-glycozid is considered to be the @golden standard@ of whitening forms of vitamin C. According to research 2% Ascorbyl-glycozid cream showed significant skin whitening in 90 days (up to 4 times) and wrinkle depth decrease by 39%.
Ascorbyl Lactoside (trade name EVERWHITE VCL-E, manufactured by Sino Lion, China). The stable and water-soluble form of vitamin C. Compared to kojic acid and arbutin, Ascorbyl Lactoside is safer but equally effective.
3-0-Ethyl Ascorbic Acid (trade name ET-VC, manufactured by Corum, Taiwan). Water-soluble form stable at pH 4.0-5.5. It contains the highest concentration of vitamin C (> 86%) and respectively shows the highest level of absorption through the skin.
Tetrahexyldecyl Ascorbate (trade name BV-OSC, manufactured by Barnet USA). Oil-soluble stable form. It’s very similar to the epidermis and absorbs easier than other forms. It’s a strong whitening product and significant effect is visible after 16 weeks.
Sodium Ascorbyl Phosphate (trade name Stay-C 50, manufactured by DSM Nutritional Products USA). Water-soluble form stable at 5.0-7.0. Research shows that in 12 weeks 5% Sodium Ascorbyl Phosphate lotion showed clinically more effective results than 5% benzoyl peroxide. This component has a strong antimicrobial effect. Apart from acne treatment, this component is also whitening.
Glyceryl Octyl Ascorbate (trade name Amitose GOA Taiwan). Oil-soluble form, exciding stability of all other forms. Added glycerine contributes to moisturizing and antibacterial properties. This component is effective at preventing acne and treating the already existing spots.
- Korean Kiwi Beauty