The aim of this study was to determine the location of attrition of formulated API particles within a powder feed system using a Morphologi G3-ID system, an image analyzer with integrated Raman capability enabling classification of particles with respect to their chemistry, to extract the API size distribution from the blended sample. The study also aimed to investigate the impact of other process variables, such as feed screw speed, on the extent of attrition observed. The study demonstrated that attrition occurs in two zones of the powder feed system, at the bottom of the hopper at the interface with the feed screw, and also within the feed screw itself. In the situation of the attrition at the bottom of the hopper variations in the hopper fill level were not observed to change the extent of attrition observed. Variation of the feed screw speed was observed to affect the extent of API attrition, with the particle size within the formulation observed to decrease with increasing speed. The findings highlight that an understanding of the impact of unit processes, and variations in the associated processing conditions, is vital in order to fully understand the behavior and performance of pharmaceutical dosage forms.
Keywords: Attrition; Raman spectroscopy; image analysis; particle size; pharmaceuticals.