The multiple uses of azelaic acid in dermatology: mechanism of action, preparations, and potential therapeutic applications.

Azelaic acid (AZA) is a naturally occurring saturated dicarboxylic acid whose topical application has found multiple uses in dermatology. Its anti-inflammatory, antioxidant and antimicrobial properties against Propionibacterium acne are currently used in the treatment of various types of acne such as rosacea and acne vulgaris. AZA is an inhibitor of tyrosinase, mitochondrial respiratory chain enzymes and DNA synthesis, and is a scavenger of harmful free radicals and inhibits the production of reactive oxygen species by neutrophils. Interestingly, AZA also has anti-proliferative and cytotoxic effects on various cancer cells. To date, its inhibitory effect on melanocytes has been mainly used, making it widely used in the treatment of hyperpigmentation disorders such as melasma and post-inflammatory hyperpigmentation. Commercially available topical formulations with cosmetic and drug status contain 5% to 20% AZA in the form of gels and creams. The use of liposomal technology allows greater control over the pharmacokinetics and pharmacodynamics of the formulations. When applied topically, AZA is well tolerated, and side effects are limited to generally mild and transient local skin irritation. Importantly, liposomal technology has enabled the drug to penetrate all layers of the skin while maintaining a very high accumulation of the active ingredient. This solution could be revolutionary for the treatment of skin cancer, where until now the main obstacle was poor absorption through the skin, making the treatment require multiple applications to maintain long-term activity levels. In this review, we will present the mechanism of action and pharmacokinetics of AZA. We will summarize its use in the treatment of dermatoses and its potential in skin cancer therapy. We will provide an overview of the preparations available on the market, taking into consideration technologies used.