Solvents are heavily used throughout many pharmaceutical processes. Solvents are used for cleaning, for forming azeotropes, in crystallizations and liquid extractions. The proper selection of solvents is thus critical to the development of a successful process.
In this paper we will present an overview of various techniques for selecting solvents. We will start by examining the thermodynamic, process design and environmental sources of the physical property constraints needed to guide the selection process. We will then present some of the computational techniques used for the selection process. Finally, an example will be shown to demonstrate how these techniques can be used to select crystallization solvents.