Undecylenic Acid

Products

Undecylenic acid is commercially available in many countries as an ointment (Undex, combination preparation). Solutions and creams are also available in some countries. Undecylenic acid has been used medicinally for many decades. Undex ointment has been approved in many countries since 1951.

Structure and properties

Undecylenic acid (C11H20O2, Mr = 184.3 g/mol) exists as a white to very pale yellow crystalline mass or as a colorless to pale yellow liquid and is practically insoluble in water. It is a monounsaturated C11 fatty acid (undec-10-enoic acid). It is also found in pharmaceuticals in the form of the zinc salt zinc undecylenate, and other salts such as calcium undecylate are used. Esters are also referred to as undecylenates. Undecylenic acid can be prepared from ricinoleic acid from castor oil.

Effects

Undecylenic acid (ATC D01AE04) has antifungal (fungistatic to fungicidal) properties against dermatophytes. Zinc undecylenate is additionally astringent.

Indications

For the treatment of fungal skin infections, especially athlete’s foot.

Dosage

According to the professional information. The ointment is applied locally two to three times a day and rubbed in gently.

Contraindications

  • Hypersensitivity

For complete precautions, see the drug label.

Interactions

No information on drug-drug interactions is available.

Adverse effects

Possible adverse effects include local skin reactions.