Microscale granulation in a fluid bed powder processor using electrostatic atomisation

The aim of this study was to use the electrostatic atomisation in miniaturised fluid bed granulation process and define the effect of process parameters. The process parameters included in the study were granulation liquid flow rate, atomisation voltage and binder concentration in the granulation liquid. Altogether 22 batches were granulated in Multichamber Microscale Fluid bed powder Processor (MMFP). Granule size distributions were measured with both sieves and image analyses. With these process conditions, the atomisation liquid flow rate had a strong positive correlation with the granule size. Increasing the atomisation voltage increased the granule size, which is contradictory with the expectations. The effect of the binder concentration remained unclear. Although it is challenging to model the fluid bed granulation process in micro-scale, multivariate methods such as principal component analysis (PCA) are helpful in studying the most important phenomena.