Preparation and handling of raw and auxiliary materials before tablet pressing1

Raw materials and auxiliary materials for tableting must be crushed, sieved or dried before being blended. Generally, drugs are more suitable to pass through 80-100 mesh sieves. For poisonous drugs, valuable drugs and colored raw materials, they should still be made into fine powder and passed through a sieve of 120 mesh or larger. Because the fine powder is easy to mix. When mixing, it must be mixed with the main and auxiliary materials according to the equal increment method. It is also possible to dissolve a small amount of the main drug in a suitable solvent, absorb it with a small amount of thixotropic agent, mix it in equal increments, and then sieve it repeatedly. In short, it should be mixed thoroughly. Tinctures or liquid extracts included in prescriptions may first be concentrated into sugar