Abstract
This study explores microdynamic flowability as an innovative approach for early active pharmaceutical ingredient (API) characterisation, when compounds are often scarce and/or expensive. By incorporating small-scale flow measurements during the pre-formulation stage, we aim to support strategic decision-making in formulation development and process design. Laboratory-scale micronisation of the poorly water-soluble drug Palbociclib, while enhancing dissolution, was found to adversely affect flowability. Agglomeration driven by cohesive forces was quantitatively described for the first time via image analysis using sample quantities of less than 200 mg. Our findings demonstrate that microdynamic flow studies provide critical insights into the processability of APIs under low-stress conditions, such as those relevant to research and development (R&D) tablet presses. These results highlight the value of advanced flowability analysis in early-stage development, enabling improved understanding and control of powder processing in pharmaceutical manufacturing and particle engineering.