Mycophenolic acid, is a milky white powder that is soluble in methanol and ethanol, slightly soluble in ether and chloroform, and insoluble in benzene, toluene, and cold water. Mycophenolic acid ester, as a primary immunosuppressant, has been widely used domestically and internationally for the prevention and treatment of acute rejection in organ transplantation. Mycophenolic acid is the first antibiotic discovered by humans, but its most important value lies in its immunosuppressive activity. Novartis, a US company, has developed an enteric-coated sustained-release tablet of mycophenolic acid sodium, marketed as Myfortic, which was launched in many countries including the US and Europe in 2004 and is mainly used to treat rejection reactions in organ transplantation. The enteric-coated tablet of mycophenolic acid sodium does not dissolve and release mycophenolic acid in the acidic environment of the stomach (pH 5), but only dissolves and is absorbed in the neutral environment of the small intestine, thereby avoiding upper gastrointestinal side effects and improving patient tolerance.