Azelaic Acid: A Versatile Chemical Compound in Modern Applications

Introduction

Azelaic acid, an organic compound with the formula HOOC(CH2)7COOH, has garnered significant attention in the chemical and pharmaceutical industries. Known for its multifaceted properties and wide range of applications, azelaic acid is a dicarboxylic acid naturally occurring in grains such as wheat, rye, and barley. This compound's importance has been highlighted due to its therapeutic properties and utility in various industrial processes.

Figure 1 Characteristics of Azelaic acid

Properties

Azelaic acid is a saturated dicarboxylic acid, which means it contains two carboxyl functional groups (–COOH) attached to a linear carbon chain with no double bonds. It appears as a white crystalline powder and is soluble in alcohol and slightly soluble in water. Its molecular weight is 188.22 g/mol, and it has a melting point of approximately 106-109°C. The chemical stability and non-reactivity under normal conditions make azelaic acid a versatile compound in various applications.

The acid's primary chemical properties include its ability to inhibit tyrosinase, an enzyme involved in the production of melanin, which is crucial for its role in dermatological treatments. Additionally, azelaic acid exhibits antibacterial properties, particularly against Propionibacterium acnes, a bacterium responsible for acne. Its anti-inflammatory properties further enhance its therapeutic potential, making it a valuable compound in treating skin conditions such as rosacea.

Main Components

Azelaic acid is composed of a nine-carbon chain terminated by two carboxyl groups. This simple structure allows for a range of derivatives and formulations. While the pure form of azelaic acid is commonly used, it can also be formulated with various excipients to enhance its solubility, stability, and delivery in pharmaceutical products.

The purity of azelaic acid is crucial for its effectiveness, especially in medical applications. Pharmaceutical-grade azelaic acid is typically produced through oxidative cleavage of oleic acid, a method that ensures high purity and consistency. This process involves the use of oxidizing agents such as ozone or potassium permanganate, followed by purification steps to remove any by-products.

Uses

Azelaic acid's diverse range of applications spans several industries, from pharmaceuticals and cosmetics to industrial manufacturing. Its most notable uses include:

Dermatological Treatments: Azelaic acid is widely used in topical creams and gels for treating acne and rosacea. Its ability to reduce the growth of bacteria on the skin, decrease keratin production, and reduce inflammation makes it an effective treatment for these conditions. It is often included in concentrations ranging from 15% to 20% in over-the-counter and prescription products.

Pigmentation Disorders: Due to its inhibitory effect on tyrosinase, azelaic acid is also used to treat hyperpigmentation disorders such as melasma. It helps to lighten dark patches of skin by reducing melanin production.

Cosmetics: Beyond medical treatments, azelaic acid is an ingredient in various cosmetic products aimed at improving skin texture and tone. Its exfoliating properties help to unclog pores and promote cell turnover, leading to clearer and smoother skin.

Industrial Applications: In the industrial sector, azelaic acid is used as a precursor for the synthesis of polymers and plasticizers. It serves as a building block for producing biodegradable polyesters and other specialty chemicals.

Storage Methods

Proper storage of azelaic acid is essential to maintain its stability and effectiveness. The compound should be stored in a cool, dry place, away from direct sunlight and moisture. Containers should be tightly sealed to prevent contamination and degradation. For large-scale industrial storage, azelaic acid is typically kept in stainless steel or glass-lined containers to avoid any reaction with the storage material.

In pharmaceutical and cosmetic formulations, azelaic acid should be stored in airtight containers, preferably made of materials that do not react with the acid, such as high-density polyethylene (HDPE) or glass. Temperature control is also crucial; azelaic acid should be stored at temperatures between 15°C and 25°C to prevent melting and decomposition.

For laboratory use, azelaic acid should be handled with care, using appropriate personal protective equipment (PPE) to avoid inhalation or skin contact, as it can irritate. Safety data sheets (SDS) provided by manufacturers offer detailed guidelines on the safe handling and storage of azelaic acid.

References

[1]Nazzaro-Porro, Marcella. "Azelaic acid."Journal of the American Academy of Dermatology17.6 (1987): 1033-1041.

[2]Sieber, M. A., and J. K. E. Hegel. "Azelaic acid: properties and mode of action."Skin pharmacology and physiology27.Suppl. 1 (2013): 9-17.