Designing enhanced spray dried particles for inhalation: A review of the impact of excipients and processing parameters on particle properties

Spray drying is a constructive single-step manufacturing technique used to produce dry powder. Spray drying plays a remarkable role in producing inhalable powder formulations due to its ability to engineer particles with optimized characteristics for inhalation. However, the complexity of drying kinetics and particle formation process coupled with the specificity of the targeted physicochemical characteristics of inhalable particles makes it a very interesting area of research. This review will discuss various aspects of spray drying such as configurations and functions, drying kinetics, component distribution and particle solidification. Furthermore, the review will focus on the functionality and behavior of excipients during drying. Finally, characterization techniques used to investigate components distribution within dried particles will be highlighted with research thrust in this area.