(1) Reason:

The amount of adhesive or smoothing agent is small or inappropriate, so that the particles are unevenly distributed, and the coarse and fine particles are stratified. Even if the pressure is increased, the tablet cannot be restrained.

(2) Reason:

The damage of the drug is not sufficient, and the content of the drug or oily ingredient with rich fibrous, elastic drug or oil is not evenly mixed.

(3) Reason:

The water content is not suitable, too little water or dry particles are more elastic, because the drug containing crystal water loses more crystal water when the particles are dry, becoming brittle and easy to crack. However, the hardness becomes smaller if it is excessive.

(4) Reason:

the physical properties of the drug itself. Determined by brittleness, plasticity, elasticity, and hardness, for example, elastic materials become smaller when compressed, and shrink due to elasticity after decompression, so the tablet becomes loose.

(5) Reason:

mechanical elements. If the length of the punch is not the same, or the pressure adjustment is different, the speed of the tablet press machine is too fast or the particles in the hopper are sometimes too small.