The relevance of glass transition temperature for the process of tablet formation

The aim was to determine the relevance of the glass transition temperature (T_g) on the compressibility and compactibility of different excipients as celluloses, cellulose derivatives, lactoses, starch, maltodextrin and carrageenan. Their T_g was determined, they were tableted on an instrumented eccentric tableting machine and crushing force was analyzed. Using force, time and displacement tableting behavior was analyzed by 3D modeling. The parameters obtained, d (time plasticity), e (pressure plasticity) and w (fast elastic decompression), show different deformation mechanisms for the materials in relation to their T_g. Further, if the T_g can be reversibly exceeded during tableting, crushing force is high, otherwise crushing force is lower. This revised version was published online in July 2006 with corrections to the Cover Date.