All4Nutra
Shear cell tests have been conducted on twenty different lactose powders, most of which commercially available for oral or inhalation purposes, spanning a wide range of particle sizes, particle morphologies, production processes. The aims of the investigation were: i) to verify the reliability of the technique in evaluating and classifying the flowability of powders; ii) to understand the connection between the flowability of a powder and the morphological properties of its particles; iii) to find a general mathematical relationship able to predict the yield locus shape given the particle size, shape and consolidation state of a lactose powder. These aspects and their limitations are detailed in the manuscript together with other interesting findings on the stick-slip behavior observed in most of the lactose powders examined.
Highlights
• 16 different lactose powders investigated in detail using shear cell tests.• The variability of the shear cell results was investigated and reduced.
• A formula to predict the yield locus at a given consolidation state was provided.
• Stick-slip oscillations in lactose powders were detected and analyzed in detail.
Table 1. Particle size (dv50), lactose grade and number code for each powder analyzed in the present paper.
