(457q) Mechanical Property Characterization of Active Pharmaceutical Ingredients

Crystallization and drying are key unit operations that determine the physical attributes of API. These attributes can significantly affect the performance of the formulation process itself, and the final drug product. Recently, we have examine agitated dryers and studied particle breakage (fracture or shattering) due to the application of shear forces. We find that mechanical properties such as elastic modulus, hardness and fracture toughness under impact stress are important parameters to be measured when establishing better drying protocols in order to minimize attrition and/or agglomeration during the drying operation.

In this presentation, we will discuss characterization techniques we have explored to evaluate these mechanical properties of API. Using a rotary shear cell, API samples are subjected to very high consolidation stress in order to study plastic deformation and flow functions of the bulk material. Properties such as the cohesion and particle breakage can be derived. The Instron Universal Tester can be used to quantify the crystal fracture strength in the bulk powder bed using Heckel analysis. The ultimate goal in this approach is to predict the impact of compression and shear to the API bulk powder, especially during the drying process.