Azeco Cosmeceuticals

Question: I found that you are supplying Azelaic acid and I’m doing my masters project for pigmentation and using Azelaic Acid. However, I cannot find what was the highest % of Azelaic Acid we can use in cosmetics in EU. I found, that one website suggests to use up to 10% for pigmentation and in USA max 14% are allowed in cosmetics. Answer: The mechanisms of skin pigmentation, hyperpigmentation and depigmentation are poorly understood. Several mechanisms have been proposed but none of those give a closed answer, for example inhibition of tyrosinase and related melanogenic enzymes. I have attached an interesting paper for you reviewing the various proposed mechanisms and the products enabling skin lightening. The paper comes with an impressive citation list. Ebanks paper describes several products related to hydroquinone. Hydroquinone is not allowed in personal care & cosmetic pro- ducts because of the toxicity profile of hydroquinone. Azelaic acid is also in the list, and probably it is the best skin lightening ingre - dient, with a superb toxicological profile. Azelaic acid has in vitro been demonstrated to be superior to all other skin lightening pro - ducts, but in vivo the results are frequently disappointing. The problem is that azelaic acid is at ambient temperature poorly soluble in the usual cosmetic “solvents”: water, lower alcohols, mineral hydrocarbons, silicone oil, cosmetic esters, vegetable oils, etc. There is a second problem: how to get the product where it is needed: in the living dermis. Both themes can be approached by using the so-called “super solvents”. A good example is dimethyl sulfoxide (DMSO): this is not allowed in personal care & cosmetic products, but may be used in medical devices (provided the cytotoxicity of the final product is OK) or in pharmaceutical products. Other good solvents for azelaic acid are alkylated polyethylene glycols and alkylated polypropylene glycols, as their ethers. Than you will be able to properly dissolve azelaic acid in concentrations up to 20%. To control the effective concentration of azelaic acid there where it needs to give its performance you will need transdermal trans- port. One of the techniques to do so is using organogels, that also are the basis for transdermal patches such as pain relief patches, smoking cessation patches, contraceptive patches, etc. These are based on phosphatidylcholine. You will find more information and leads in two papers that I have attached for you. In systems where (1) azelaic acid is properly dissolved and (2) wherein transdermal has been made possible you will be able to make effective skin lightening products, using a concentration azelaic acid of 5-8%. Note that in the EU azelaic acid is not restricted in con- centration for skin lightening products. There are no real temperature limitations I also cannot find what is the max temperature I can heat AA to. I thought maybe you would have any suggestions/information.

I trust this information satisfies your needs.

Mussenberg 1 • 6049 GZ Roermond • The Netherlands

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