Solid-state properties

Abstract

Solid-state properties affect the development of every drug product. Solid-state properties have a profound impact on the development of a drug candidate at all stages. This chapter covers the basic concepts of physical forms related to early drug development including solid form screening and form selection process. It discusses the impact of physical properties, namely, particle habit and particle size. Stability of the drug substance is another key concern during the development of drug products. Other than solubility and stability, the variance of molecular structure may also affect the mechanical properties of the material, such as compressibility, elasticity, hardness, and flowability. Well-known examples in the inorganic realm include the hardness difference between graphite and diamond - two polymorphs of carbon - or between glass and quartz, amorphous and crystalline silicon dioxide.