ABSTRACT
This chapter presents the most relevant physicochemical properties of drug nanocrystals and methods for their preparation. Drug nanocrystals, according to the most common concept within the scientific community, are particles of nanometric size composed of the active pharmaceutical ingredient arranged in a crystalline structure. Compared with other nanomedicines, the main distinguishing characteristic of drug nanocrystals results from the fact that their composition is almost 100% drug without additional matrix materials. The most special physicochemical properties of nanocrystals are their increased surface area and the resulting increased saturation solubility, both of which affect dissolution rates. Nanocrystals are an attractive formulation strategy for poorly water-soluble drugs and those for which dissolution is the rate-limiting step for drug absorption as size reduction to the nanometric scale has both thermodynamic and kinetic implications. Wet milling is used to produce nanosized crystals as dry milling is not efficient enough.
