Evaluation on the Drug–Polymer Mixing Status in Amorphous Solid Dispersions at the Early Stage Formulation and Process Development

Drug and polymer mixing status in amorphous solid dispersions, an important aspect with regard to the physical stability and in vivo performance of such systems, was evaluated in this report with two case studies. In the first case study, the mixing between the drug and the polymer in an amorphous solid dispersion was assessed at both particulate and bulk levels to ensure that a homogeneous solid dispersion was obtained. In the second study, drug–polymer distribution evaluation in amorphous solid dispersions facilitated the selection of an optimal drug loading and a robust manufacturing process at the early stage of formulation development. Through these two case studies, it is suggested that establishing a multi-faceted characterization approach for amorphous solid dispersions is key to achieve a better understanding of these complex systems and successful delivery of stable and efficacious amorphous formulations.