Discoloration or discoloration of the press

Discoloration or discoloration of the press

Reasons for discoloration or surface coloration and corresponding measures are as follows:

(1) The excipients used in the compound preparation have a large color difference and are not overfinely ground or mixed, which is easy to produce freckles. This needs to be redone. The lubricants used for stamping can only be improved if they are carefully screened and mixed with the particles.

(2) The particles are very hard, or when the particles of the color plate are not uniformly dense, it is easy to produce spots. In this case, the granules must be looser. The colored pellets are made of ethanol without starch as a wetting agent. The granules are uniform in thickness, fixed, and the tablets are not prone to blemishes.

(3) In the compaction process, too much scaling will fall on the particles and move along with scaling, resulting in oil spots. The upper punch can be fitted with a layer of rubber band to prevent oil dirt from entering the particles and should be wiped frequently.

(4) Drugs that are susceptible to moisture, such as some tablets, change colour when exposed to metal under damp conditions. Can control air humidity, reduce contact with metal.

(5) During granulation, ethanol is used to make granulation, which increases the temperature of the oven rising too fast or the rotation time is too long, and the surface color of the particles changes. The surface color of the particles is a little dark, and there will be color spots during tablet pressing. It can be heated slowly or reduced by the first rotation time.