Definition: It is a preparation containing the sodium salt of a sulphated glucosaminoglycan present in mammalian tissues. On complete hydrolysis, it liberates D-glucosamine, D-glucuronic acid, L-iduronic acid, acetic acid and sulphuric acid. It has the characteristic property of delaying the clotting of freshly shed blood. The potency of heparin sodium intended for parenteral administration is not less than 150 IU/mg, calculated with reference to the dried substance. The potency of heparin sodium not intended for parenteral administration is not less than 120 IU/mg, calculated with reference to the dried substance.