The flow properties of pharmaceutical powders have a great importance in the manufacturing of solid dosage forms. In order to ensure the performance in the production line this parameter must be determined. There are several methods described in European Pharmacopeia that are used to measure these properties. Some of them were used in this study and the results obtained from conventional methods (Conv) and shear cell using the powder flow tester (PFT) showed differences that were more evident in fractions with smaller particle size (F < 63) and for bulk powder (FTotal). The various powder behaviors showed to be related with the size of the particles. An increase of the ffc (Flow Index) was observed with the increase of the particle size. It was also found for the different fractions that the ffc always increases with increasing major principal consolidation stress (σ1). This study shown to be predictive because it also allowed the behavior profiles of other LactMN fractions to be known by interpolation of the median size (Dv50) or σ1 values ranged between the studied intervals. Furthermore, it was also observed that ffc of the FTotal was similar to the F < 63, showing the same behavior under σ1. The occurrence of caking was not observed.
Keywords: Flow index; diluent; excipient; flowing; shear cell.