Heparin sodium is the sodium salt product of heparin. It is a kind of acid mucopolysaccharide natural anticoagulant, containing sulfate group. It can be widely used in the prevention and treatment of various cardiovascular and cerebrovascular diseases, and is widely favored in clinical application. It is widely found in the mucous membranes of the intestines, lungs and liver of mammals, especially in the small intestine of pigs. At present, the main raw material extracted in China is the small intestine mucosa of pigs. Because it exists in the form of protein complex in animal body, a certain amount of protein will remain in crude product, affecting the quality of the product.

　　The purification process of heparin mainly includes deproteinization, purification and decolorization of crude products, which meets the requirements of pharmacopoeia standards. In China, heparin purification is mostly performed by two-step oxidation of potassium permanganate and hydrogen peroxide or secondary oxidation with the addition of hydrogen peroxide in stages. Meanwhile, it has been reported that heparin purification is performed by enzymolysis combined with oxidation.