Batch production of pharmaceutical granulations in a fluidized bed I: Effects of process variables on physical properties of final granulation

The investigation concerns the effects of process variables associated with the fluidized bed granulation technique on the physical properties of the final granulation. The process variables investigated include binder solution addition rate, air pressure to the binary nozzle, inlet air temperature during the granulation cycle, and binary nozzle position with respect to the fluidized solids. When the rate at which the aqueous binder solution added to the fluidized bed of powders was increased, the ability of the solution to wet and penetrate the solids was enhanced, resulting in: (a) a larger average granule size, (b) a less friable granulation, (c) a more fluid granulation, and (d) a decreased granulation bulkiness. Similar results, also traceable to enhanced binder solution efficiency, occurred with a decrease either in the binary nozzle air pressure or in the inlet air temperature during the granulation cycle. The position of the binary nozzle with respect to the fluidized powders had significant effects upon the average granule size and granule friability. The effects upon the granulation flow properties and bulkiness, however, were slight.