Generally, powdered drugs need to be pelletized before they can be tableted because of:

(1) There is a certain amount of air in the pores between the powders. When the punch is pressurized, part of the air in the powder cannot escape in time, and is pressed into the tablet. When the pressure is reduced, the air inside the tablet expands. , causing the tablet to rupture.

(2) The fine powder of some drugs is relatively easy, the friction is large, the accumulation is easy, and the fluidity is poor. It cannot be smoothly flowed into the die hole by the feed bucket, thus affecting the weight of the tablet and making the tablet content inaccurate.

(3) If there are several kinds of raw materials in the prescription, the difference in the proportion of the raw materials is large. In the process of tableting, due to the vibration of the tableting machine, the heavy one will sink and the lighter will rise, resulting in stratification, so that the film The dosage of the agent is not allowed.

(4) The airflow formed during the tableting process tends to cause the fine powder to fly, and the viscous fine powder easily adheres to the surface of the punch, which is liable to cause sticking.

In view of the above reasons, it is necessary to reasonably select the materials according to the different properties of the drugs, equipment conditions and climate, and to make certain thickness and elastic particles to overcome them.