Production, applications and in vivo fate of drug nanocrystals

Today, drug nanocrystals are frequently used as a formulation strategy for improving the solubility and dissolution of poorly soluble drug materials. It is well known that when drug particles are in the nanometer size range their dissolution rate and saturated solubility can both be substantially increased. However, turning the superior dissolution in vitro into bioavailability benefits in vivo, can be problematic. Various in vivo conditions, such as changes in pH in the GI tract, as well as rapid transit through the GI tract may cause problems for permeability. Accordingly, after successful nanocrystallization, it is of the utmost importance to perform the formulation studies carefully. In this review, the production of nanocrystals and their most commonly studied delivery routes are discussed, while keeping in mind in vitro in vivo correlation.