Frequently Asked Questions

1. Does azelaic acid occur naturally in foods?

Yes, Azelaic acid is a naturally occurring straight-chained saturated dicarboxylic acid present in rye, wheat, and barley.

2. How is Azelaic acid created?

It is obtained  by  oxidative  cleavage  of  the  double  bond  of  oleic chain of the triglyceride of Sunflower oil. After several purification steps it is micro-milled to become Azepur99®, the highest pure azelaic acid for personal care products. 

3. What are the most common applications for azelaic acid?

Several studies are available in the art able to prove Azelaic acid is  effective for the treatments of impure skin, acne, rosacea, stimulating hair growth, skin lightening, treating “liver” spots. Azelaic acid is also approved worldwide as Active Pharmaceutical Ingredient (API) for the treatment of acne and rosacea.

4. What concentration Azelaic acid would I need for acne treatment?

If you are working to develop a pharmaceutical product for use in treating acne, the U.S. Food & Drug Administration (FDA) has approved 20% by weight of Azelaic acid based creams. For treatment of rosacea 15% by weight of Azelaic based pharma approved products are available on the market.  To buy these products a a doctor’s prescription is required. For cosmetic use in general a quantity below15% by weight is recommended. 

5. Does azelaic acid only act upon Acne vulgaris or also on other forms of acne?

No, for example, Azelaic acid is also very effective on Acne Ectopia (hidradenitis suppurativa). Realize if you are creating a pharmaceutical product it should contain 20% concentration to be in line with the other approved FDA products, for cosmetic products in general a concentration up to 14% is recommended and several studies are available to demonstrate that also at such a concentration Azelaic acid is effective against various types of acne breakouts. Obviously the effectiveness will depend upon the concentration of azelaic acid in the product. 

6. What concentration of Azelaic acid would I need for rosacea treatment?

Considering the pharma approved products (drugs) are based on a 15% by weight content of Azelaic content, surely cosmetic products  containing from 5 to 15% by weight of azelaic acid will be effective to treat skin affected by rosacea.. Again,  the higher the concentration the better the product will perform. 

7. What concentration of azelaic acid would I need for hair (re)growth treatment?

Many studies are available in the art demonstrating Azelaic acid from 3 to 10% is able to stimulate hair (re)growth. Very good results are obtained using a combination of Azelaic acid with zinc sulphate and vitamin B6.

8. What concentration of azelaic acid would I need for skin lightening and liver (sic) spots?

Data are available in the art  showing positive results using from 3% to 10% by weight of azelaic acid. 

9. Is Azelaic acid soluble in water and can its solubility be improved?

Azelaic acid exhibits poor solubility in water, but the pre-solubilisation in an organic phase mainly based onglycols, glycerin, poloxamer, surfactants such as alkyl glucosides can greatly improve its solubility in the final cosmetic product. In this way it is also possible to obtain oil free serums with high concentration of azelaic acid (10-20% by weight).

10. When dissolved in 1,2-glycols or glycerin, how can I make a gel of this solution ?

This Azelaic acid based solution can be thickened to a fully transparent gel with several rheology modifiers, such as

• Hydroxypropylcellulose (HPC)
• Carbomers (anhydrous systems only). 
• Sodium Polyacryloyldimethyl Taurate

11. Are salts of azelaic acid soluble in water?

The alkali salts of Azelaic acid are reasonably soluble in water, but a co-solvent such as e.g. propylen glycol is recommended. 

12. Is azelaic acid mentioned in the USP?

Yes azelaic acid is listed in the main pharmacopoeiae. A dedicated monograph is also available in the Indian Pharmacopoeia.

13. What is the toxicological profile of Azelaic acid?

In pure form it is a mild skin & eye irritant. According to the specific classification limits present in its REACH registration dossier, products containing up to 15% by weight of Azelaic acid are not irritant. No CMR properties. 

14. What purity level must azelaic acid constitute for pharmaceutical uses?

Pharmaceutical Azelaic acid should have a purity greater than 99% by weight. 

15. What are the impurities present in azelaic acid ?

The pharmaceutical grade has a typical purity of 99.7- 99.9%, which is today the highest available purity on the market. The remaining substances are dicarboxyl acids such as pelargonic acid, suberic acid and related products. The pharmaceutical grade has a typical purity of 99.7- 99.9%, which is today the highest available purity on the market. The remaining substances are dicarboxyl acids such as pelargonic acid, suberic acid and related products. 

16. Is azelaic acid allowed to be used in personal care & cosmetic products?

The U.S. Food & Drug Administration (FDA) does not control the ingredients used in cosmetics other than prohibiting certain ingredients. Azelaic acid is not prohibited and may be used in cosmetics or personal care also at high concentration. s. According to the EU Commission Regulation 1223/2009 azelaic acid can be used without restriction. In some Asian countries whitening creams in general (also the ones based on Azelaic acid) are not coonsidered cosmetic products but “quasi drug” products, so they require a pre-market notification.

17. Can azelaic acid be used as a broad spectrum preservative?

No, but azelaic acid works specifically on particular organisms such as Propionibacterium acnes and Staphylococcus epidermides, so it can be used as a specific skin antibacteria agent

18. Does azelaic acid affect the commensal skin flora?

No, its activity is limited to opportunistic organisms such as P.acnes & S.epidermides. 

19. What is the mechanism of azelaic acid on hair (re)growth?

Azelaic acid is a very potent 5-α-reductase inhibitor, the enzyme that converts testosterone into 5α-dihydrotestosterone, a major cause for alopecia areata and hair loss.

20. How to improve the solubility of azelaic acid?

Azelaic acid is poorly soluble in water, as described earlier by Brand-Garnys & Brand. The monosodium & disodium slats are slightly better soluble but as a result the pH of these solutions is alkaline, frequently a disadvantage. Mather & Stahl (WO 1996.039119) described several combinations of solvent, frequently glycols that enable to properly dissolve azelaic acid.

Example 1.
40 parts ethoxydiglycol
3 parts diisopropyl adipate 1-10% azelaic acid
Mix & stir until a clear solution has been obtained.

Example 2.
40 parts dipropylene glycol 1-10% azelaic acid
Mix & stir while heating to 60°C until a clear solution has been obtained.
Dipropylene glycol and ethoxydiglycol are excellent solvent systems for azelaic acid. It is recommended to further dilute the solutions
of example 1 and example 2 with other glycols, more particularly propanediol (1,3-dihydroxypropane), pentylene glycol (1,2- dihy
droxypentane), glycerol, ethoxylated glycerol (glycereth-12, 18,20 & 26) and similar polyols.
The solutions enable to dissolve up to 25% azelaic acid, and may function as the basis of serum preparations for use in personal care
& cosmetic preparations as well as medical device, as well as a starting product for e.g. emulsion & gel preparations.

21. How to dissolve azelaic acid?

The limited solubility of azelaic acid in aqueous conditions requires some creativity. There are several methods to incorporate azelaic acid in a final formulation using a premix. The most straight forward approach is to dissolve azelaic acid in ethanol or isopropanol. For many preparations these alcohols are not the most preferred substances. In that case a suitable diol will do the job. We have tested
propanediol (Zemea®; Dupont), as well as 1,3-butylene glycol and pentylene glycol. Pentylene offers the advantage that it also gives a massive microbiological protection. Pentylene glycol is available from petrochemical origin (Symrise, Minasolve), but also from vegetable origin, obtained by hydroge
nation of furfuraldehyde (from wood processing; Minacare Pentiol Green/Minasolve). Also glycerin and glycerin/water mixtures are suitable solvent systems; the maximum concentration water in this solvent mixture are not properly defined and not reported in the literature. A second, but far more expensive option is to dissolve azelaic acid is a mixture of phosphatidylcholine & isopropyl palmitate. In this case a premix is made of azelaic acid in an aqueous glycerin solution. This procedure is only recommended when dissolution in glycols of glycerin/water mixtures fails.

22. CIC Code Code of Conduct

CIC code is available