Undecylenic

Undecylenic acid is an 11-carbon monounsaturated fatty acid, commonly referred to as undecylenic acid. Its systematic name is undec-10-enoic acid. It is produced commercially from ricinoleic acid, a major component of castor oil, through industrial processing that converts ricinoleic acid into undecylenic acid and related products.

In clinical and consumer contexts, undecylenic acid is best known as a topical antifungal agent. It is used in over-the-counter preparations such as creams, powders, and solutions to treat fungal infections of the skin, including athlete’s foot, ringworm, and related dermatophytosis. The activity is primarily against dermatophytes, and undecylenic acid is generally described as fungistatic rather than fungicidal.

Chemical and physical properties of undecylenic acid include its status as a colorless to pale yellow liquid with a characteristic odor. It is soluble in many organic solvents but only sparingly soluble in water. In commerce it is also supplied in salt forms, such as undecylenate salts, which can be used in different formulations or as intermediates in chemical synthesis.

Safety and regulation: undecylenic acid is approved for topical use in many countries and is widely used in OTC dermatological products. Adverse effects are typically mild but can include skin irritation or allergic contact dermatitis in sensitive individuals. It should not be ingested and products should be used as directed, with care taken to avoid application to broken skin or eyes.

Name recognition and uses: beyond topical antifungal applications, undecylenic acid can serve as a chemical building block and intermediate in polymer chemistry and related manufacturing processes.