ABSTRACT
The pelleting operation is performed in what is described in the pharmaceutical industry as a pill-making machine. For satisfactory operation of the pilling process, the powder feed must have definite characteristics (specifications) of density, moisture content, particle size distribution, and compaction character and must contain die and punch lubricants. In order for a catalyst to pill satisfactorily, a primary requirement is that a lubricant, previously identified as graphite, Sterotex (a trade name for stearin), or other aids to be described. Densification on the laboratory scale can be brought about in a number of different ways. If there is nothing more suitable available, a large mortar and pestle can be used. When the mortar and pestle is used, the powder in question is put into the mortar along with a small amount of water. If the only purpose of the drying operation following densification is the removal of water, then the temperature is usually in the range of approximately 140–160°C.
