Spray dried powder downstream processing

Spray-dried powders often exhibit relatively small particles representing a large surface area, low bulk density, and often show poor flowability. Therefore, often a pre-compaction step is needed during downstream processing in order to increase the bulk density to a level which later allows tablet compression or capsule filling. At the same time, this reduces the surface area of the material which could have an impact on the drug release rate, especially when appropriate attention is not given to the formulation composition. 

For the sake of simplicity, the current case study will only focus in one of the manufacturing steps (the spray drying of the bulk powder, as previously introduced in Sect. 8.2.2) and, within this one, only show the application of the QbD methodology for two of the CQAs particle size (Dv50) and bulk density (BD). The considered specifications for these CQAs (31-57 p,m for particle size and 0.100-0.200 g/ml for BD) were set based on the interaction/interdependence with the downstream process... 

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