Azeco Cosmeceuticals

Solubility

7. Question: When Azepur99® is dissolved in glycols or glycerin, what rheology modifier should be used to make a fully transparent gel of this solution? Answer: Glycerin is very viscous so, even if the product is soluble in a good quantity, it is very difficult to achieve an homogeneous product. It is always recommended to mix glycerin with different glycols such as propylen glycol or 1,3-Butylen glycol. 8. Question: Except Hydroxypropylcellulose (HPC), and Sodium Polyacryloyldimethyl Taurate, can other rheology modifier be used? Answer: The rheology modifier to be used must be soluble and/or dispersible in the chosen solvent. Both of them you have indicated work in water phases. In these media also xanthan gum works well. 9. Question: What can be done to make the Azelaic accid penetrate even deeper into the skin? Answer: The penetrating action is important for the main action of Azelaic acid (antiacne, whitening, etc.). In any case to better penetrate into the skin it must be well solubilized, for example in glycols that can act as a vehicle. 10. Question: We have developed an emulsion with 10% Azelaic acid, to increase the solubility of Azelaic acid, we need to increase pH of the aqueous phase before emulsification and before adding the Azelaic acid. Should the pH raised to 7 or more? To have good stability and to avoid the crystallization of Azelaic acid, what should be the optimum pH of the emulsion? Answer: The increase of the water phase pH can help only in o/w emulsions. It is not required for w/o emulsions. This information is also reported in the Essential Guide. In case of a o/w emulsion, as the final pH of a skincare emulsion it is better to stay below 6, the solu bility of Azelaic acid up to 10% must been increased by using the right ingredients glycols, polyglycols, glycerin, glyceryl derivatives or ethoxylated sorbitane derivatives.

For more information, please download the Cosmos Listed INCI names that improve the solibity of Azelaic acid via the website: azeco-cosmeceuticals.com/downloads/cosmos-listed-inci-names-improve-solubility-Azelaicacid/.

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