Azeco Cosmeceuticals

The picture shows that the concentration of the three species is pH dependant. At very low pH (e.g. pH=1,5 most fumaric acid is pre- sent as the free acid. At very high pH the disodium salt is dominant. At pH=3 we have almost equal quantities of the free acid and the monosodium salt, and at pH=5 we have almost equal amounts of the monosodium salt and disodium salt, and only a small quantity of the free acid. So, the pH determines how much of each species is present. That is valid for fumaric acid, but also for azelaic acid.. Does this affect the functionality of azelaic acid ? No ! In the tallow gland where azelaic acid must do the job all species act equally. However, at eleva- ted pH the solubility of azelaic acid increase.

I trust this clarifies the situation and is an answer to the question.

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