Azeco Cosmeceuticals

Azelaic acid and other ingredients

57. Question: Are there skincare ingredients that should not be combined with Azelaic acid? For example Retinol? Answer: In consideration of the chemical nature of retinol, it is compatible with Azelaic acid. It is unknown if there is affectivily interaction. In any case, being two high performant ingredient it is always reccomended to use them separately. 58. Question: We currently using Vitamin A and Vitamin C in a skin whitening application. Both can cause skin irritation. Is there a comparative table available where the different adverse effects are showed for Vitamin A and Vitamin C compared to Azelaic acid. Is Azelaic acid less irritating than the named vitamins?

Answer: Comparative table among Azelaic acid and Vitamin C and Vitamin A.

Legend: (++ Very strong effects) (+ Noticable effects) (+/- Hardly noticable) (- Not noticable)

Vitamin C is a naturally occurring drug with multiple desirable effects. With an excellent safety profile, it finds increasing use in pho toageing, hyperpigmentation, tissue inflammation and promotion of tissue healing. It can also be used for the treatment of hyperpig mentation. Its main drowback is that it is unstable and it is also difficult to deliver it into the dermis in the optimum dosage. So it is more difficult to vehiculate Vitamin C than Azelaic acid. Vitamin C stability in finished products is also not so good. It is easily oxidated by the oxygen in the air. So Vitamin C is a good antioxidant. Vitamin C interacts with copper ions at the tyrosinase‑active site and inhibits action of the enzyme tyrosinase, thereby decreasing the melanin formation. Vitamin C also acts on the perifollicular pigment [5,7,8]. However, Vitamin C is an unstable compound. It is therefore often combined with other depigmenting agents such as soy and liquorice for better depigmenting effect. So probably to have a sufficient and stable depigmenting product, Vitamin C could be used in combination with Azelaic acid.

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