A compressibility and compactibility study of real tableting mixtures: the effect of granule particle size.

This study investigates the effect of particle size on the compression characteristics of wet- (fluid-bed granulation - FBG) and dry-granulated (slugging - DGS) tableting mixtures. Particle-size distribution, flowability, compressibility, using the Heckel and Walker model, compactibility and elastic recovery as well as friability and disintegration were determined and compared between the two particle size fractions (180-400 μm, 400-710 μm) and initial unsieved mixtures. The results showed that the particle size of granules had no effect on the compressibility of the FBG and DGS mixtures, due to the high fragmenting nature of the formulation used in this study. On the other hand, compactibility was particle size dependent, as larger-sized fractions showed higher crushing strength, lower friability, and lower elastic recovery. This was attributed to increased fragmentation of larger particles, allowing stronger bonding between uncontaminated surface areas. As a result of better rearrangement of particles, both initial tableting mixtures showed lower compressibility and lower compactibility compared to their sieved fractions.