Cantor et al. evaluated the physicochemical properties of high drug load formulations manufactured using conventional wet or foam granulation process. Acetaminophen (APAP), Metformin HCL (Met), and Aspirin were used as model APIs (80% w/w). According to their results, foam granulation improved the plasticity of granulates containing a brittle drug such as APAP. On the other hand, foam granulation did not enhance the plasticity for viscoelastic material such as Met [5].
Barot et al. described the feasibility of directly compressing Met by the spray-drying process in the presence of polymer. Their results showed that the use of polyvidone (PVP) during the spray-drying process resulted in better properties of the Met formulation [1].