Spray drying

Abstract

Pharmaceutical spray drying has become a valuable tool in the general formulation toolbox known as “particle engineering” in which the active pharmaceutical ingredients can be co‐sprayed with excipients to enable precise control of the particle size, density, surface energy, solid‐state form, and residual solvents. This chapter discusses the spray drying process for pharmaceutical powder production processes. The final product particle size is controlled predominantly by the initial liquid droplet size and to a lesser degree by the feedstock concentration, along with the feed solution to particle density ratio. The chapter outlines several atomizer design and performance parameters that should be considered when developing a spray‐drying process for a target set of powder properties. The impact of nozzle selection propagates into the drying environment by dictating the initial droplet size and trajectory.