AN EVALUATION OF PROCESS VARIABLES IN WET GRANULATION

In wet granulation, determining the process variables which play an essential role in granule quality is crucial for optimizing the manufacturing process. An L16(2(5)) fractional factorial experimental design using the table of orthogonal arrays was employed in order to estimate the relative intensity of the influences of five process variables on granule quality in wet granulation using a high-speed mixer granulator. Total volume and formulation of binder solution, blade rotation speed, granulation time, and amount of powder supplied into the granulator were selected as decisive process variables in the formation of granules. Granule yield, geometrical mean granule size and uniformity of granule size were evaluated as representative properties of granule quality. Experimental results were analyzed according to the analysis of variance (ANOVA). The results of significance test and contribution ratio in ANOVA indicated that, within the experimental region, only binder solution had a critical effect on the three physical properties of the obtained granules. The effects of other variables were found to be minimal. Further, the contribution of sampling error to total variance was quite small.