Journal of pharmaceutical sciences (2019).
Amorphous solid dispersions (ASDs) are commonly used to enhance the oral absorption of drugs with solubility or dissolution rate limitations. While the ASD formulation is typically constrained by physical stability and in vivo performance considerations, ASD particles can be engineered using the spray drying process to influence mechanical and flow properties critical to tableting. Using the ASD formulation of 20% w/w felodipine dispersed in polyvinyl pyrrolidone vinyl acetate (PVP VA), spray drying atomization and drying conditions were tuned to achieve four different powders with varying particle properties. The resulting particles ranged in volume moment mean diameter from 4 to 115 μm, bulk density from 0.05 to 0.38 g cm-3, and morphologies of intact, collapsed, and fractured hollow spheres. Powder flowability by shear cell ranged from poor to easy flowing, while mechanical property tests suggested all samples will produce strong tablets at reasonable solid fractions and compression pressures. Additionally, Hiestand dynamic tableting indices showed excellent dynamic bonding for three powders, and low viscoelasticity with high brittleness for all powders. This work demonstrates the extent spray-dried ASD particle morphologies can be engineered to achieve desired powder flow and mechanical properties to mitigate downstream processing risks and increase process throughput.
