1. Heparin sodium is soluble in water and easy to add; Add to water phase, add at the last stage of formulation, temperature lower than 40℃;

　　2. The stability of heparin sodium is best when the pH value is between 7.0 and 7.5；

　　3. Light and antioxidant VC have no significant effect on its stability;

　　4. Oxidant and strong electrolyte have a great influence on the stability of heparin sodium;

　　5. Heparin sodium is anion polysaccharide, which is not compatible with cationic components. Compatibility test should be conducted.