Development and Application of Laboratory Tools To Predict Particle Properties upon Scale-Up in Agitated Filter-Dryers

Agitated filter-dryers (AFDs) are commonly used for performing both filtration and drying operations in the manufacture of active pharmaceutical ingredients (APIs) and intermediates. Successful scale-up from the laboratory to manufacturing AFD equipment requires that physical properties specifications such as particle size be consistently met in addition to chemical purity specifications. Depending on the API–solvent system and equipment operational parameters, undesired attrition or agglomeration may occur, so an improved understanding of these phenomena upon scale-up is of key importance. In this paper, we describe recent advances in laboratory methods, based on material characterization methods common to drug product formulation development, to better assess the risk of agglomeration and attrition potential upon scale-up. These methods provide data to evaluate solid behavior, in both wet and dry states, associated with processing in an AFD. For agglomeration prediction, the application of mixer torque ...