This document discusses nanoparticulate drug delivery systems. It begins by defining nanotechnology and describing some applications in pharmaceuticals including nanoparticles, nanosuspensions, nanospheres, nanocapsules, and nanoemulsions. It then provides a brief history of using nanoparticles for drug delivery and defines different types of nanoparticles. The rest of the document discusses various types of nanoparticles in more detail, methods for their preparation, advantages of nanosizing drugs, and some limitations.