The construction and uses of factorial designs in the preparation of solid dosage forms. Part 2: Granulation in a fluidized bed.

With the help of a factorial design of experiments, the optimum conditions for preparing aminophenazone granules in a fluidized bed were established by which high quality tablets were obtained with a minimum energy expenditure. Granules with given technological properties could be prepared by controlling the regime of the granulation process. By varying the experimental conditions, a reproducible correlation was found between the parameters of optimization (mean granule diameter and work of compression) and the factors controlling the granulation process (pressure of compressed air, velocity and temperature of fluidizing air and binder concentration). The effect of the granule quality on tablet physical properties was discussed. Recommendations were given for the exploitation of fluidized bed units in the practice of granulation and tableting.