The 3-D model: Experimental Testing of the Parameters d, e, and ω and Validation of the Analysis

The aim of the study was to evaluate the parameters d, e, and ω for their significance in compression data analysis. Materials with predominantly different compression properties were used and tableting data were obtained with an instrumented eccentric and rotary tableting machine. The parameters time plasticity (d), pressure plasticity (e), and the twisting angle (ω), an indicator of fast elastic decompression, were derived by 3-D modeling. The Peak-Offset-Time, the pressure–time function parameters, the Heckel slope, normalized compaction (E2norm) and elastic energy (E3norm), and fast elastic recovery (FER), which are well known tableting parameters, were calculated from the tableting data. The plastic microhardness of the tablets was determined from using microindentation. The results revealed that d is influenced by speed, e correlates with microhardness, and ω correlates with the Elastic modulus (E). Thus, for all three 3-D model parameters an experimental basis is given. The validation showed that d correlates with the Peak-Offset-Time and the pressure–time function parameters, e correlates with the Heckel slope and E2norm, and ω correlates with E3norm and FER of the tablets. The significance of the three parameters is fully given. It is no longer necessary to use two separate methods to differentiate between time- and pressure-dependent deformations. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 1408–1417, 2007