Definition
Azelaic acid is a chemical substance which belongs to the group of so-called carboxylic acids. Other synonymous terms for azelaic acid are nonadic acid or 1,7-heptadicarboxylic acid. The latter is a precise description of the chemical composition of azelaic acid.
Salts of azelaic acid are called azelates. Azelaic acid is a white, crystalline solid. The chemical substance is mainly used as a pharmaceutical agent in the treatment of acne and rosacea.
The drug is only available on prescription, so creams and ointments containing azelaic acid are not freely available. In the conventional preparation, 20% creams and 15% gels are available. The application is therefore topical.
Azelaic acid is industrially produced by oxidation from castor oil and potassium permanganate. This produces the whitish, solid powder which is processed into creams and ointments. However, there is no internal application in form of tablets or capsules.
In topical application the active agent is hardly absorbed through the skin into the blood system so that there are practically no side effects which would affect the whole body. The half-life of the drug is about 12 hours. This is the time after which the concentration of a drug has dropped to half. It is therefore a very long-acting substance.
Indications
There are two important indications for treatment with creams and ointments containing azelaic acid. The first important indication to be mentioned is mild to moderate acne. The second indication for treatment with azelaic acid is rosacea.
Both diseases are skin diseases which can be quite similar in their appearance. However, the underlying causes are very different. While acne is a collective term for diseases of the sebaceous glands and hair follicles, rosacea is a complex skin disease whose cause has not yet been fully clarified.
An involvement of the vessels, the nervous and immune system as well as a bacterial component are discussed. Externally, acne usually affects the skin through blackheads and papules as well as pustules on the face and other parts of the body. Rosacea, on the other hand, manifests itself through reddening of the midface and proliferations of the nose (bulbous nose), which particularly affect men.
In both diseases, azelaic acid is only approved for external use. In “off-label-use” (outside the approved use) azelaic acid is also used to prevent acne after successful acne treatment. The therapy is usually carried out over weeks and months and can also be used for longer, provided it does not cause any side effects and is well tolerated.
Effect
Azelaic acid has several mechanisms of action that are beneficial in the treatment of rosacea and acne. In its composition it is similar to fatty acids and helps to normalize the cornification disorder of the skin. This is an important pathological component of acne.
The cornification disorders, also called hyperkeratoses, are caused by excessive growth of the so-called keratinocytes, which are skin cells. This growth is inhibited by azelaic acid. Hyperkeratosis leads to the development of disturbing blackheads and blocked pores.
The azelaic acid promotes the detachment of skin scales and thus helps to reduce blackheads and to aerate the pores. Furthermore azelaic acid has anti-inflammatory effects by reducing the concentration of free fatty acids. These cause redness of the skin.
This mechanism helps, among other things, against the redness of rosacea. Another very important effect of azelaic acid is an antimicrobial effect. The so-called propionibacterium acnes is inhibited by azelaic acid.
This is significantly involved in the development of acne disease. A very small amount of azelaic acid is absorbed through the skin into the body’s bloodstream. There the azelaic acid also reduces the number of free fatty acids and thus has an anti-inflammatory effect. However, the effect is very small as azelaic acid actually acts purely topically, i.e. at the place of application.
