Excipients, in addition to the main drug in the drug preparation of additional substances, can also be called excipients. Such as adhesives, fillers, disintegrants, lubricants in tablets; Chinese medicine pills in wine, vinegar, juice, etc.; semi-solid preparations of ointments, creams in the matrix part; liquid preparations of preservatives, antioxidants, flavoring agents, aromatics, co-solvents, emulsifiers, solubilizers, osmotic pressure regulators, coloring agents can be called excipients. The general requirements for excipients are stable nature, no contraindications with the main drug, no side effects, does not affect the efficacy, at room temperature is not easy to deformation, dry crack, mold, insects, harmless to humans, no physiological effects, no chemical or physical effects with the main drug, does not affect the determination of the content of the main drug. A medicinal mixture (e.g. syrup, lard or liquid petroleum jelly) that does not react chemically, to which a drug with therapeutic effect is added or by which other components are glued together. An inactive substance (such as gum arabic, molasses, lanolin or starch) that constitutes an excipient of a drug or antigen; in particular, a substance added to a drug mixture to give the mixture a viscosity for the preparation of pills or tablets when there is a sufficient amount of liquid in the mixture.