Frequently Asked Questions
1. Does azelaic acid occur naturally in foods?
Yes, Azelaic acid occurs in cereals.
2. How is Azelaic acid created?
Azelaic acid is manufactured by epoxidation of vegetable oleic acid, followed by oxidation of the epoxide. It then must be purified and micro-milled to become the cosmetic grade of azelaic acid.
3. What are the most common applications for azelaic acid?
Azelaic acid has proven in studies to be effective for the treatments of acne, rosacea, stimulating hair growth, skin lightening, treating “liver” spots.
4. What concentration Azelaic acid would I need for acne treatment?
If you are creating a pharmaceutical for use in treating acne the U.S. Food & Drug Administration (FDA) has approved a 20% concentration of Azelaic acid. For treatment of rosacea the FDA specifies a 15% concentration – both these must be used by people with a doctor’s prescription. For use in cosmetic products you must use a less than 15% concentration which then is not regulated by FDA regulations.
5. Does azelaic acid only act upon Acne vulgaris or also on other forms of acne?
No, Azelaic acid also works superior on Acne ectopia (hidradenitis suppurativa). Realize if you are creating a pharmaceutical product it should contain 20% concentration to be in line with FDA regulations, for cosmetic products you can use any concentration up to 14% and studies have shown it will still be 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?
You would need 5-14% Azelaic acid for a cosmetic product and 15% for a pharmaceutical product to conform with FDA regulations. Again, with a cosmetic product, the higher the concentration the better the product will perform.
7. What concentration of azelaic acid would I need for hair (re)growth treatment?
Tests have shown results using from 10% – 14% has produced the best results. There is no FDA guideline for using the product other than you must use a less than 15% concentration.
8. What concentration of azelaic acid would I need for skin lightening and liver (sic) spots?
Tests have shown results using from 3% – 10% has produced the best results. There is no FDA guideline for using the product other than you must use a less than 15% concentration.
9. Is Azelaic acid soluble in water and can its solubility be improved?
Azelaic acid exhibits poor solubility in water, but using 1,2-glycols or glycerin as the solvent will greatly improve the solubility of Azelaic acid.
10. When dissolved in 1,2-glycols or glycerin, how can I make a gel of this solution ?
This Azelaic acid solution can be thickened to a fully transparent gel with the following:
- Hydroxypropylcellulose (HPC)
- Carbomers (anhydrous systems only).
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. 2- methyl-1,3-propanediol is recommended.
12. Is azelaic acid mentioned in the USP?
13. What is the toxicological profile of Azelaic acid?
The toxicological profile of Azelaic acid is excellent:
- LD50-value (oral/rat) is >5000 mg/kg body weight;
- In pure form mild skin & eye irritancy, that disappears upon dilution;
- No CMR properties.
14. What purity level must azelaic acid constitute for pharmaceutical uses?
Pharmaceutical acid must be greater than 99% pure.
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.
16. Is aazelaic 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 items up to a concentration of 14%. Anything over that concentration is considered a drug and subject to FDA controls and uses. According to EU Commission Regulation 1223/209 of April 26, 2015 azelaic acid can be used without restriction. In several Asian countries azelaic acid is mentioned in Annex II, but it is highly likely that it will be shifted to Annex III shortly.
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.
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 inhibits 5-a-reductase, an a-blocker, and delays the formation of dihydrotestosterone from testosterone.
20. Can cytotoxicity induced by Azelaic acid be suppressed?
Yes! That is best done using betaine (trimethylglycine).