FAQs for products containing Vit C
▶ Why do Vit C. products turn yellow after a while or when experience high temperature?
Vitamin C is an excellent antioxidant which is susceptible to moisture, light and high temperature. Exposure to one of these conditions results in oxidation of vitamin C that will also change the colour to dark yellow or brown.
It is possible that products which contain vitamin C as a main ingredient in higher percentage may turn light yellow. However, this excludes products is dark yellow which indicates oxidization which reduces efficiency of the product.
Vitamin C is a challenging ingredient to stabile even when if it passes stability tests. It is recommended that you do not continue using if the product turns dark yellow or brown as this suggests that the product is inefficient.
▶ Why do products that contain vitamin C sometimes seen as separate layers?
Products which vitamin C as a main ingredients are varied in texture, depending on derivatives of vitamin C. Vitamin C oxidizes very easily in hydrous solution therefore the chemical structure is developed to enhance stabilization. This also effect absorption or application. L-Ascorbic acid is a popular solution in skincare products due to efficiency.
The stability of vitamin C in topical solution is a concern. Vitamin C is soluble in hydrous, but it needs anhydrous solution to make it stabile. Chemical techniques, chemical and physical properties are used to stabile vitamin C as an antioxidant.
If you find that your skincare which contains vitamin C is seen as two separate layers, clear liquid and white cream, it is considered normal. This doesn’t affect chemical structure or reduce the efficiency of the product by any means. The clear liquid is anhydrous solution.
To continue using the product, simply shake the container to mix the two layers together. If clear liquid is dispense from the container, it could be the existing liquid in the pump. Keep pumping until the white cream is dispensed.
▶ Why do some people experience stinging sensation or itch when using product which contain vitamin C as a main ingredient?
Vitamin is of low PH balance and is a weak acid. Raising PH balance will reduce the efficiency and lower absorption. To maintain the efficiency, Vitamin C PH balance remains the same. People who has sensitive or dry skin may experience tingling or itchy sensation. Hydrating skin will alleviate this problem and enhance the absorption. Using in small amount together with moisturizer will relieve the above sensations.