The use of energy indices in estimating powder compaction functionality of mixtures in pharmaceutical tableting

A series of binary powder blends comprising of microcrystalline cellulose (Avicel PH101), alpha-lactose monohydrate or theophylline anhydrous were prepared in order to investigate the densification of binary pharmaceutical powder mixes under compaction pressure. It is postulated that the use of derived energy parameters, as well as various evolved indices, calculated from the work expended during the fabrication and/or rupture of a compact can be employed to quantitatively predict the compaction properties of pharmaceutical powder mixes comprised of the same constituents. The relationship between the net work of compression normalized to powder volume and the resulting compact strength for mix constituents can be used to define a pharmaceutical formulation space in which compact mechanical properties can be estimated for other 'virtual mixes' of the same constituents in different proportions. The approach is successfully applied to the prediction of the mechanical properties of a ternary mix of these constituents.