Powder Rheology Of Lactose: Impacts Of Powder Morphology On Performance Of Pharmaceutical Excipients

Powder flow measurements are increasingly important in pre-formulation and formulation stages as pharmaceutical developers continue to push towards quality-by-design approaches. TA Instruments Powder Rheology Accessory includes two cells for powder measurements: the Flow Cell and the Shear Cell. In this note, the processing behavior of two lactose excipients is studied by measuring shear and flowability of milled and spray-dried lactose. Milled lactose was found to have higher cohesion, yield strength, confined and unconfined flow energies when compared to spray-dried lactose. Additionally, milled lactose flow energy exhibited a dependence on impeller tip speed and more variability than spray-dried lactose. The multiple powder rheology measurements presented indicate better processability with spray-dried lactose than with milled lactose.