The main feature of urea is that it is able to prevent water loss through the skin. But it also has another useful property, 

PELLETED UREA

INCI: Urea

CAS Number: 57-13-6

Nº(EINECS): 200-315-5

Function: Antistatic / humectant / foot conditioner

Synonyms: Carbamide. Amide carbonyl. carbonyl diamide

Urea is a component of many creams that has slowly been gaining more notoriety and variety. It is a natural, water-soluble product.

The main feature of urea is that it is able to prevent water loss through the skin. But it also has another useful property, it is capable of affecting skin cells so as to promote their scaling.

All these properties make the urea product increasingly used in cosmetic moisturizers, besides in treating skin diseases such as hyperkeratosis (thickening of the outer layer of the skin), dermatitis, psoriasis, eczema, etc.

The main difference in these uses, the concentration of urea.

A cosmetic moisturizer, urea will concentrations less than 5%.
For medical uses the skin creams have concentrations between 20% and 40%, whereas there are very aggressive nail treatments, for example, using creams with 50% urea.
Dosage:

- 0.5 - 1%: keratoplastic action, useful in cleaning and healing wounds and ulcers.

- At 5-25%: keratoplastic and moisturizing action, useful in hyperkeratotic moderately itching and dry skin.

- By 10-40%%: keratolytic action useful in psoriasis, ichthyosis, eczema, ringworm, hyperkeratosis, etc ...

- 40%: proteolytic action, used for painless removal of nails by a bandage soaked with the preparation.

Side effects: Topical application can cause irritation to sensitive skin. In long treatments can be sensitizing.

Incompatibility: Nitric acid, nitrate, formaldehyde, and alkalis. At very high concentrations (> = 10%) may compromise the stability of non-ionic emulsions, as they give a basic pH.

Observations: It is hygroscopic. In the presence of moisture can develop a slight ammoniacal odor. Warning in the package insert "May cause skin irritation."

Storage: in closed containers. PROTECT FROM LIGHT AND MOISTURE.