Azelaic acid (AzA), or nonanedioic acid, is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the formula HOOC(CH₂)₇ COOH. This saturated

dicarboxylic acid In organic chemistry, a dicarboxylic acid is an organic compound containing two carboxyl groups (). The general molecular formula for dicarboxylic acids can be written as , where R can be aliphatic or aromatic.Boy Cornils, Peter Lappe "Dicarbox ...

exists as a white powder. It is found in

wheat Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...

rye Rye (''Secale cereale'') is a grass grown extensively as a grain, a cover crop and a forage crop. It is grown principally in an area from Eastern and Northern Europe into Russia. It is much more tolerant of cold weather and poor soil than o ...

, and

barley Barley (), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains; it was domesticated in the Fertile Crescent around 9000 BC, giving it nonshattering spikele ...

. It is a precursor to diverse industrial products including polymers and plasticizers, as well as being a component of several hair and skin conditioners. AzA inhibits

tyrosinase Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. The enzyme is mainly involved in two distinct reactions of melanin synthesis otherwise known as the Raper–Mason pathway. Firstly, the hydroxy ...

Production

Azelaic acid is industrially produced by the

ozonolysis In organic chemistry, ozonolysis is an organic reaction where the Saturated and unsaturated compounds, unsaturated bonds are Bond cleavage, cleaved with ozone (). Multiple carbon–carbon bond are replaced by carbonyl () groups, such as aldehydes ...

oleic acid Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish due to the presence of impurities. In chemical terms, oleic acid is cl ...

. The side product is nonanoic acid. It is produced naturally by '' Malassezia furfur'' (also known as ''Pityrosporum ovale''), a

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

that lives on normal

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

. The bacterial degradation of nonanoic acid gives azelaic acid.

Biological function

Plants biology

In plants, azelaic acid serves as a "distress flare" involved in defense responses after infection. It serves as a signal that induces the accumulation of

salicylic acid Salicylic acid is an organic compound with the formula HOC6H4COOH. A colorless (or white), bitter-tasting solid, it is a precursor to and a active metabolite, metabolite of acetylsalicylic acid (aspirin). It is a plant hormone, and has been lis ...

, an important component of a plant's defensive response.

Human biology

The mechanism of action in humans is thought to be through the inhibition of hyperactive protease activity that converts

cathelicidin Cathelicidin antimicrobial peptide (CAMP) is an antimicrobial peptide encoded in the human by the ''CAMP'' gene. The active form is LL-37. In humans, ''CAMP'' encodes the peptide precursor CAP-18 (18 kDa), which is processed by proteinase 3-me ...

into the antimicrobial skin peptide LL-37.

Applications

Polymers and related materials

Esters of this dicarboxylic acid find applications in lubrication and plasticizers. In lubricant industries, it is used as a thickening agent in lithium complex grease. With hexamethylenediamine, azelaic acid forms

Nylon Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups. Nylons are generally brownish in color and can possess a soft texture, with some varieti ...

-6,9, which finds specialized uses as a plastic.

Medical

In 2022, it was the 298th most commonly prescribed medication in the United States, with more than 300,000 prescriptions. Azelaic acid is used to treat mild to moderate acne, both comedonal acne and inflammatory acne. It belongs to a class of chemicals called

s. It works by killing acne bacteria that infect skin pores. It also decreases the production of

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

, which is a natural substance that promotes the growth of acne bacteria. Azelaic acid is also used as a topical gel treatment for

rosacea Rosacea is a long-term skin condition that typically affects the face. It results in redness, pimples, swelling, and small and superficial dilated blood vessels. Often, the nose, cheeks, forehead, and chin are most involved. A red, en ...

, due to its ability to reduce inflammation. It clears the bumps and swelling caused by rosacea. In topical pharmaceutical preparations and scientific research AzA is typically used in concentrations between 15% and 20% but some research demonstrates that in certain vehicle formulations, the pharmaceutical effects of 10% Azelaic acid have the potential to be fully comparable to that of some 20% creams.

Acne treatment

Azelaic acid is effective for mild to moderate acne when applied topically at a 15%-20% concentration. In patients with moderate

acne Acne ( ), also known as ''acne vulgaris'', is a long-term Cutaneous condition, skin condition that occurs when Keratinocyte, dead skin cells and Sebum, oil from the skin clog hair follicles. Typical features of the condition include comedo, ...

, twice daily application over 3 months of 20% AzA significantly reduced the number of comedones, papules, and pustules; at this strength, it’s considered to be as effective as benzoyl peroxide 5%, tretinoin 0.05%, erythromycin 2%, and oral tetracycline at 500 mg-1000 mg. In a comparative review of effects of topical AzA,

Salicylic acid Salicylic acid is an organic compound with the formula HOC6H4COOH. A colorless (or white), bitter-tasting solid, it is a precursor to and a active metabolite, metabolite of acetylsalicylic acid (aspirin). It is a plant hormone, and has been lis ...

Nicotinamide Nicotinamide (International nonproprietary name, INN, British Approved Name, BAN ) or niacinamide (United States Adopted Name, USAN ) is a form of vitamin B3, vitamin B3 found in food and used as a dietary supplement and medication. As a suppl ...

, Sulfur, Zinc, and

alpha-hydroxy acid Alpha hydroxy carboxylic acids, or α-hydroxy carboxylic acids (AHAs), are a group of carboxylic acids featuring a hydroxy group located ''one'' carbon atom away from the acid group. This structural aspect distinguishes them from beta hydroxy aci ...

, AzA had more high-quality evidence of effectiveness than the rest. Results can be expected after 4 weeks of twice-daily treatment. The effectiveness of long-term use is unclear, but it’s been recommended that AzA be used for at least 6 months continuously for maintenance.

Whitening agent

Azelaic acid is used for the treatment of skin pigmentation, including

melasma Melasma (also known as chloasma faciei,James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . or the mask of pregnancy when present in pregnant women) is a tan or dar ...

and postinflammatory

hyperpigmentation Hyperpigmentation, also known as the dark spots or circles on the skin, is the darkening of an area of Human skin, skin or nail (anatomy), nails caused by increased melanin. Causes Hyperpigmentation can be caused by sun damage, inflammation, or ...

, particularly in those with darker skin types. It has been recommended as an alternative to

hydroquinone Hydroquinone, also known as benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, a derivative of benzene, having the chemical formula C6H4(OH)2. It has two hydroxyl groups bonded to a benzene ring in a ''para' ...

. As a

inhibitor, azelaic acid reduces synthesis of

melanin Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are ...

. According to one report in 1988, azelaic acid in combination with

zinc sulfate Zinc sulfate is an inorganic compound with the formula ZnSO4. It forms hydrates ZnSO4·''n''H2O, where ''n'' can range from 0 to 7. All are colorless solids. The most common form includes water of crystallization as the heptahydrate, with the che ...

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

was found to be a potent (90% inhibition) 5α-reductase inhibitor, similar to the hair loss drugs

finasteride Finasteride, sold under the brand names Proscar and Propecia among others, is a medication used to treat pattern hair loss and benign prostatic hyperplasia (BPH) in men. It can also be used to treat hirsutism, excessive hair growth in women. It ...

and

dutasteride Dutasteride, sold under the brand name Avodart among others, is a medication primarily used to treat the symptoms of a benign prostatic hyperplasia (BPH), an enlarged prostate not associated with cancer. A few months may be required before bene ...

. In vitro research during mid-1980s evaluating azelaic acid's depigmenting (whitening) capability concluded it is effective (cytotoxic to

melanocyte Melanocytes are melanin-producing neural-crest, neural crest-derived cell (biology), cells located in the bottom layer (the stratum basale) of the skin's epidermis (skin), epidermis, the middle layer of the eye (the uvea), the inner ear, vagina ...

s) at only high concentrations. A 1996 review claimed 20% AzA is as potent as 4%

after a period of application of three months without the latter's adverse effects and even more effective if applied along with

tretinoin Tretinoin, also known as all-''trans'' retinoic acid (ATRA), is a medication used for the treatment of acne and acute promyelocytic leukemia. For acne, it is applied to the skin as a cream, gel or ointment. For acute promyelocytic leukemia, ...

for the same period of time.

Brand names

Brand names for azelaic acid include Dermaz 99, Crema Pella Perfetta (micronized azelaic acid, kojic dipalmitate, and liquorice extract), Azepur99, Azetec99, Azaclear (azelaic acid and niacinamide), AzClear Action, Azelex, White Action cream, Finacea, Finevin, Melazepam, Skinoren, Ezanic, Azelac, Azelan, Azaderm, (Acnegen, Eziderm, Acnicam, Azelexin in Pakistan)

References

External links

* * {{Navbox linear saturated dicarboxylic acids 5α-Reductase inhibitors Dicarboxylic acids Anti-acne preparations Skin whitening