Azelaic acid (AzA) is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

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. In general, dicarboxylic acids show ...

exists as a white powder. It is found in

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...

rye Rye (''Secale cereale'') is a grass grown extensively as a grain, a cover crop and a forage crop. It is a member of the wheat tribe (Triticeae) and is closely related to both wheat (''Triticum'') and barley (genus ''Hordeum''). Rye grain is u ...

, and

barley Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley pr ...

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

Production

Azelaic acid is industrially produced by the ozonolysis of

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. In chemical terms, oleic acid is classified as a monounsaturated omega ...

. The side product is

nonanoic acid Pelargonic acid, also called nonanoic acid, is an organic compound with structural formula CH3(CH2)7CO2H. It is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, ...

. It is produced naturally by ''

Malassezia furfur ''Malassezia furfur'' (formerly known as ''Pityrosporum ovale'' in its hyphal form) is a species of yeast (a type of fungus) that is naturally found on the skin surfaces of humans and some other mammals. It is associated with a variety of dermat ...

'' (also known as ''Pityrosporum ovale''), a

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

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 cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...

. The bacterial degradation of

gives azelaic acid.

Biological function

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 HOC6H4CO2H. A colorless, bitter-tasting solid, it is a precursor to and a metabolite of aspirin (acetylsalicylic acid). It is a plant hormone, and has been listed by the EPA Toxic Substance ...

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

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 generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic. Nylon is a silk-like thermoplastic, generally made from petro ...

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

Medical

Azelaic acid is used to treat mild to moderate acne, both comedonal acne and inflammatory acne. It belongs to a class of medication 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''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...

, 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, enlarge ...

, due to its ability to reduce inflammation. It clears the bumps and swelling caused by rosacea. The mechanism of action is thought to be through the inhibition of hyperactive protease activity that converts cathelicidin into the antimicrobial skin peptide LL-37. 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 has 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, black ...

, 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 500mg-1000mg. In a comparative review of effects of topical AzA,

Salicylic acid Salicylic acid is an organic compound with the formula HOC6H4CO2H. A colorless, bitter-tasting solid, it is a precursor to and a metabolite of aspirin (acetylsalicylic acid). It is a plant hormone, and has been listed by the EPA Toxic Substance ...

Nicotinamide Niacinamide or Nicotinamide (NAM) is a form of vitamin B3 found in food and used as a dietary supplement and medication. As a supplement, it is used by mouth to prevent and treat pellagra (niacin deficiency). While nicotinic acid (niacin) may ...

, Sulfur, Zinc, and

alpha-hydroxy acid α-Hydroxy acids, or alpha hydroxy acids (AHAs), are a class of chemical compounds that consist of a carboxylic acid with a hydroxyl group substituent on the adjacent (alpha) carbon. Prominent examples are glycolic acid, lactic acid, mandelic acid ...

, 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 has been used for treatment of skin pigmentation, including melasma and postinflammatory

hyperpigmentation Hyperpigmentation is the darkening of an area of skin or nails caused by increased melanin. Causes Hyperpigmentation can be caused by sun damage, inflammation, or other skin injuries, including those related to acne vulgaris.James, William; Ber ...

, 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 tyrosinase inhibitor, azelaic acid reduces synthesis of

melanin Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...

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

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

was found to be a potent (90% inhibition)

5α-reductase inhibitor 5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of ...

, similar to the hair loss drugs

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

and dutasteride. 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-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart. ...

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 leukemia, it is taken by mouth f ...

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, Azaderm, (Acnegen, Eziderm, Acnicam, Azelexin in Pakistan)

References

External links

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