Real-time assessment of granule and tablet properties using in-line data from a high-shear granulation process

A method for real-time assessment of granule and tablet properties was investigated. A mixture of microcrystalline cellulose: mannitol:povidone (78.5:18.5:3) was used in the study and granulated with five different water amounts and two impeller speeds. This represents a full-factorial design with two factors, thus giving a causal structure to the variation between the experiments. Process data (power consumption, temperature and in-line near-infrared spectra) were collected during the granulations. In addition to the in-line process data, critical granule and tablet quality properties (such as particle size, porosity and tablet hardness) were measured in order to achieve in-depth process understanding. Neither power consumption nor temperature gave information that could be directly attributable to tablet properties, and these techniques were also heavily dependent on the speed of the impeller. In contrast, when using the first NIR overtone band for water (1460 nm), in-line real-time assessment of dry granule and tablet properties could be achieved. (C) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.