Prediction of suitable amount of water addition for wet granulation

The purpose of this study was to predict the amounts of water addition suit able for pharmaceutical formulations in wet granulation, using a high-speed mixer or a fluidized bed granulator, before granulation trials. In order t o determine the suitable amount of water addition, each excipient was first subjected to kneading with water in a mortar and a refractive near-infrare d moisture sensor (IR sensor) measured the amount of water at the powder su rface. Further by analysis the plot (output value of the IR sensor vs. amou nt of added water) for each excipient, the amount of water addition for gra nulation was determined for it. As a second step, two model formulations we re designed and suitable amounts of water for granulation were predicted by summation of the obtained excipient values. The predicted value was compar ed with the experimental value for high-speed mixer granulation. The predic ted and experimental amounts of water addition corresponded for the two mod el formulations, suggesting that the above method is useful for estimating suitable amounts of addition of water for formulations before granulation t rials. (C) 2000 Elsevier Science B.V. All rights reserved.