8. Amorphous Solid Dispersions (ASD) of a PA in a polymer

Amorphous forms of PAs provide potentially interesting ways of improving the dissolution mechanisms and bioavailability of poorly water-soluble PAs. However, solid amorphous compounds (glasses) are thermodynamically unstable and can crystallize over time, which negates their advantage. What's more, the supersaturated state achieved by dissolving an amorphous compound, which is the source of interest for bioavailability, is often interrupted by crystallization of the PA from solution (figure 19 b). The use of Amorphous Solid Dispersions (ASDs) of PA with other compounds, mainly polymers, has in many cases...