Azeco Cosmeceuticals

Formulations

11. Question: How to create a base formulation and add per skin type a different active ingredient? Answer Such a base formulation can be generated by dissolution of Azelaic acid in propanediol (Zemea, ex.Dupont), chemically identified as 1,3-propanediol. The solution of Azelaic acid in propanediol does not require preservation and may be thickened using 3-4% hydroxy propylcellulose (HPC; Ashland). To the obtained gel other active ingredients can be added, provided the additive is miscible with the Azelaic acid/propanediol gel. That is the case for hydrophilic extracts, but also oil-in-water emulsions. The solubility of Azelaic acid in propanediol is relatively high. We frequently use solutions of 10-15%. We do not know what the maximum solubility of Azelaic acid in propanediol would be. That would need to be researched. Note that gelation of propanediol with HPC is a tedious process. 12. Question: In the formulation we experienced some colouring due to oxidation. Could you recommend addition of an anti-oxidant in the formulation? Answer: It is difficult to suggest an antioxidant without having information on the product composition and some tests done to understand wich is the cause of the discoloration. 13. Question: Which combination can you recommend for Azelaic acid together with other ingredients to reinforce the whitening action: niacinamide? Answer: As a whitening booster they can use for example glycolic acid (about 3%), as a low price ingredient, or niacinamide at 3-4%. Also a low amount of allantoin (0,5 %) can help.

Mussenberg 1 • 6049 GZ Herten • The Netherlands

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