The 3-D model: Does time plasticity represent the influence of tableting speed?

Abstract

The objective of this study is to test the hypothesis that time plasticity (parameter d from 3-D modeling) is influenced by tableting speed. Tablets were produced at different maximum relative densities (rho(rel, max)) on an instrumented eccentric tableting machine and on a linear rotary tableting machine replicator. Some 3-D data plots were prepared using pressure, normalized time, and porosity according to Heckel. After fitting of a twisted plane, the resulting parameters were analyzed in a 3-D parameter plot. The materials used were dicalcium phosphate dihydrate (DCPD), spray-dried lactose, microcrystalline cellulose (MCC), hydroxypropyl methylcellulose (HPMC), kappa-carrageenan (CAR), and theophylline monohydrate (TheoM). The results show that tableting speed especially influences the parameter d (time plasticity) of the 3-D model for plastically and viscoelastically deforming materials such as MCC, HPMC, CAR, and TheoM. For more plastically deforming materials such as MCC, HPMC, and TheoM, a subtle influence on omega is also visible. The stages of higher densification are affected more than the stages of lower densification. Brittle materials such as DCPD exhibit no influence of tableting speed. The influence of speed on spray-dried lactose is minor. The results are valid for data obtained from an eccentric tableting machine and also for data from a linear rotary tableting machine replicator. Thus, the empirically derived parameter time plasticity d really represents the influence of time.

Evaluation of a new coprocessed compound based on lactose and maize starch for tablet formulation

“…It can be influenced by tableting speed. 25 With increasing time plasticity d, the powder deforms faster during tableting. 2,25 Therefore, with increasing densification time plasticity d increases.…”

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

“…The influence of speed on time plasticity (d) has been tested at different production rates on an eccentric tableting machine and also on a linear rotary tableting machine replicator. 9 The results showed that the empirically derived parameter time plasticity (d), represents the influence of time. The influence of varying production rates on the parameters d, e, and o as obtained with a rotary tableting machine is given in Figure 1.…”

“…The 3-D modeling technique is applicable to data from rotary and eccentric tableting machines and from tableting machine simulators 3 and the method has been successfully used in characterizing materials with very different deformation mechanisms, 4,5 as well as, those with similar deformation mechanisms. 6,7 This method has already been applied to characterize mixtures 8 and is a valuable tool in testing excipients for their usefulness in soft tableting, 9 that is for tableting pressure-sensitive materials without damage.…”

Evaluation of Tablet Formation of Different Lactoses by 3D Modeling and Fractal Analysis

“…Tableting speed can influence it (Picker, 2003b). Pressure plasticity e describes the relationship between density and pressure.…”

“…The method has been experimentally tested for its explanatory power and applicability, especially the parameters can be traced back in experiments. Time plasticity d is influenced by speed, pressure plasticity d correlates with microhardness, and the twisting angle, an indicator for elasticity, correlated with the elastic modulus (Picker, 2002(Picker, , 2003b. Furthermore, the results of 3D modeling have been validated by comparison with other well-established characterization techniques (Picker, 2002).…”