UREA

UREA

Brand Names : Carbamide, Carbonyldiamide; Aquacare; Aquadrate; Basodexàn; - Kerainamin; Nutraplus; Pastaron; Ureaphil; Ureophil; Urepearl.

Urea is a product of protein metabolism. It is present in human urine in about 3 per cent amount. In laboratory urea is prepared by evaporating a solution of ammonium cyanate to dryness when nearly 95% of ammonium cyanate is converted into urea.

Urea is also prepared from cyanamide by hydrolysis and from carbon dioxide by ammonolysis. One mole of carbon dioxide reacts with two moles of ammonia to yield ammonium carbamate. The carbamate then decomposes to form urea and Water.

Urea is also prepared from ammonia, carbon monoxide and sulphur in methanol .

Urea, m.p. 132-133°, occurs as colourless, transparent, slightly hygroscopic, odourless, prismatic crystals or white crystalline powder or pellets with cooling saline taste. It may gradually develop a slight odour of ammonia on prolonged standing. It is soluble in water, alcohol and methanol; practically insoluble in chloroform and ether; stored in airtight containers.Solutions in water are neutral to litmus and decompose on heating, giving off some ammonia.

When ammonia is evolved, the residue is dissolved in water and treated with a few drops of sodium hydroxide and then copper sulphate solution. A distinct violet colour is obtained.

Uses: Urea is a diuretic and antiseptic, used to treat acute increases in intracranial pressure, to maintain the output of urine during surgical procedures and to decrease intra-ocular pressure in acute glaucoma. It is also used to treat infected wounds, to promote granulation and healing and to promote the bacteriostatic activity of sulpha drugs. In industries, urea is used as fertilizer; in animal feeds; it reacted with aldehydes to carbon prepare resins and plastics; condenses with malonic ester to form barbituric acid; used extensively in the paper industry; in ammoniated dentifrices.

Side Effect

Urea may cause gastric irritation with nausea and vomiting when given by mouth. Intravenous administration may cause headache, nausea, vomiting, confusion and a fall in blood pressure. Topical applications may be irritant to sensitive skin.