The Granulation Mechanism of a Tapered-fluidized Bed.

The fluidized bed granulation is used widely in the manufacturing process of solid drug products. It is known that the optimum condition of granulation is not decided simply because of the complexity of the operation factors. In this study, the effects of manufacturing factors on the physical properties of granules are investigated to clarify the granulation mechanism. From the experimental results, it is found that the average particle size is determined by the moisture content of the granule. From the theoretical consideration of the physical properties of the granule, a granulation model is proposed. The granule density and bulk density are found to be simulated by this granulation model. At the same time, the scale effects of experimental apparatus on the physical properties of the granule are discussed.