Stabilization of amorphous paracetamol based systems using traditional and novel strategies.

There is a special interest in having pharmaceutical active ingredients in the amorphous state due to their increased solubility and therefore, higher bioavailability. Nevertheless, not all of them present stable amorphous phases. In particular, paracetamol is an active ingredient widely known for its instability when prepared in the amorphous state. In the present work thermally stable amorphous binary paracetamol based systems were obtained showing stability on a wide range of temperatures: below its glass transition temperature (Tg) as amorphous solids in the glassy state and above their glass transition temperature, where these materials exist as stable supercooled liquids. To achieve stabilization of the binary paracetamol based system several strategies were applied and optimized, being the selection of the container material a key and novel approach to control the mechanical stress during cooling, eliminating cracks which act as nucleation centers leading to crystallization.