Products
Urea is available as a pure substance in pharmacies. It is contained in numerous skin and body care products, for example in creams, ointments and lotions. It is also known as carbamide, urea or urea.
Structure and properties
Urea (CH4N2O, Mr = 60.06 g/mol) exists as a white, crystalline, slightly hygroscopic and odorless powder or as transparent crystals and is very soluble in water. It is a natural substance that is excreted with urine. The urea in commerce is produced synthetically, for example, from ammonia and carbon dioxide under pressure:
- 2 NH3 (ammonia) + CO2 (carbon dioxide) H2N-COO–NH4+ (ammonium carbamate) CH4N2O (urea) + H2O (water)
Effects
Urea (ATC D02AE01) has skin conditioning, hydrating, keratolytic (higher concentrations from about 10%), antipruritic and antibacterial properties. It promotes the binding of water in the skin and the desquamation of the callus.
Fields of application
For skin care, for example, in dry and scaly skin, hyperkeratosis, ichthyosis, psoriasis, other skin diseases and eczema. For the dissolution of the nails in the case of a nail fungus, see under urea ointment 40%.
Dosage
According to the package insert. The products with a medium concentration (e.g. 10%) are usually applied once or twice a day.
Contraindications
- Hypersensitivity.
- Contact with the mucous membrane and eyes.
- Open, damaged and acutely inflamed skin.
- Large area application in case of renal insufficiency.
Full precautions can be found in the drug label.
Interactions
Urea promotes the absorption of other agents into the skin, for example glucocorticoids. Other keratolytics may potentiate the effects.
Adverse effects
Possible adverse effects include local skin reactions such as irritation.
