Chapter 29. Solid State Organic Chemistry and Drug Stability

Abstract

Publisher Summary This chapter discusses the basic principles of solid state organic chemistry and its role to bear on the pharmaceutical problems, such as drug stability. Solid state organic chemistry generally emphasizes the study of crystalline solids because the geometric arrangement of molecules in the reacting solid can be determined. The general steps in a solid state reaction are different from those of a solution reaction. Solid state reactions begin at one or more nucleation sites in the solid and spread through the crystal. The known solid state organic reactions can be classified as either physical transformations or chemical reactions. Physical transformations are solid state reactions, in which no new covalent bonds are formed or broken, but instead the nature and structure of their crystal is altered. There are two types of physical transformations: polymorphic transformations and desolvations. Chemical reactions include solid-gas reaction, solid state photochemical reactions, solid state thermal reactions, solid-solid reactions etc. A variety of methods are available for the study of solid state organic chemistry and the solid state chemistry of drugs. The use of these techniques has been discussed in the chapter. Other potential applications for solid state nuclear magnetic resonance (NMR) spectroscopy include the study of amorphous forms, solid state reactions, and drug-polymer interactions. The future directions of the field of solid state organic chemistry and drug stability mostly involve the careful investigation of other solid state reactions.