Relating Compaction Performance & Behavior to Process Conditions

EPILOGUE TO THE PROJECT

density.

components and the individual components when compacted to the same pressure or the same

compacts. This work has clearly demonstrated the differences between a mixture of two

develop during compaction of powder mixtures as well as the residual stresses in the resulting

(2) We employed the Discete Element Method (DEM) to explore the distribution of forces that

pharmaceutical formulations) because it may replicate their interaction with moisture.

be considered as a model material for soluble crystalline components in mixtures (e.g., APIs in

of X with the appropriate properties (in this case matching of the elasticity modulus). NaCl can

controls strength in NaCl-X mixtures allows us to optimize their properties deliberate selection

material interactions. The most important result is that understanding the mechanism that

(1) The work in the NaCl system, in terms of in depth understanding of the mechanisms and the

In this report we present the results of the last year in particular:

paramount importance to the understanding of interacting mixtures.

In general, a mechanistic understanding of the ingredients and their interactions is of

the non-interacting mixtures.

received attention in the literature and was misinterpreted by studying it in the context of

this kind of behavior within the framework of the NaCl-Starch system, which had

during post compaction property evolution. We have attempted to demonstrate some of

stages of the processing of the mixtures, for example during milling of the mixture or

properties or the behavior of the others. This interaction can take place in any of the

• Indirect interactions, where the presence of one of the ingredients in the mixture alters the

such as those involving moisture transport, or local interdiffusion

• Direct interactions, such as chemical reactions between the powders, physical interactions

possible type of interactions. To begin with we attempt to classify them into:

- Directly interacting mixtures. This is a very broad category of problems because of the

mixtures is can be tricky.

high density regime. Therefore utilizing it to more complex problems such as the one of the

substantial effort (which was part of our project) is still relatively new and untested, in the

The problem here is that the DEM approach, even for single components, despite our

approach. We have presented this first order approach and have highlighted its weakness.

no trivial. This is the problem that we have attempted to address using the discrete element

Even in this case the direct comparison between the individual constituents and the mixture is

not the process of mixing affect the physical and chemical characteristics of the powders.

- Non interacting mixtures. This is the simplest case in which neither the powder themselves

mixtures according the possibility and the type of interaction between their constituents:

important concept that became obvious in the early days of the project is the classification of

some ideas that will provide the scientific basis for the exploration of this problem. The most

the years by the academic and scientific community. We attempted in the project to explore

The problem of compaction of powder mixtures and their properties has received attention over