Determination of process variables affecting drug particle attrition within multi-component blends during powder feed transmission

Abstract

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
• image analysis
• particle size
• pharmaceuticals
• Raman spectroscopy

Acknowledgements

The authors would like to thank Rao Mantri, Peter Timmins and Patrick Wray (all Bristol-Myers Squibb) and Benson Kariuki (Cardiff University) for their support during this study.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.