Chapter Three - Electron Microscopy of Pharmaceutical Systems

Abstract

Numerous nanosized drug delivery systems, such as nanoparticles and nanofibers, have been developed during the past few decades. To characterize the morphology and physicochemical properties of both dry and hydrated systems, sophisticated methods of analysis are required. Electron microscopy (EM) represents a versatile and reliable method of doing this. Conventional transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are established techniques for analyzing solid systems, especially in tandem with analytical electron microscopic techniques. The growing number of hydrated colloidal drug delivery systems requires more complex methods, such as cryoelectron or freeze-fracture (FF) electron microscopy. This chapter provides an introduction to drug delivery systems of current research interest and presents strategies for their analysis by EM techniques. Advantages and limitations of the different approaches are discussed and selected findings of interest are presented. Since analytical EM techniques such as electron energy loss spectroscopy are rarely employed in pharmaceutical studies, an additional focus is placed on these methods to encourage future research.