“…The spray drying process usually includes four stages: atomization, droplet mixing with dry gas, solvent volatilization, and product separation, in which the technological conditions and parameters of the atomization process play a decisive role in the droplet size distribution (Ré, 2006 ; Liu et al, 2015 ; Deshmukh et al, 2016 ; Messa et al, 2020 ), such as the selection of atomizer, nozzle pressure, feed or air flow rate, etc (Bowey & Neufeld, 2010 ; Shi et al, 2020 ). The spray drying method can generate particles in one step quickly and continuously, eliminating the need for a separate drying process in other preparation methods (Helbling et al, 2020 ; Ozturk & Kiyan, 2020 ; Yurtdas & Ozturk, 2020 ). The entire preparation process is automated, and a relatively high encapsulation rate can be obtained (Calegari et al, 2020 ), which is suitable for the encapsulation of proteins or peptides (Aydin, 2020 ; Shi et al, 2020 ), plasmid DNA (Walter et al, 2001 ; Atuah et al, 2003 ; Jilek et al, 2004 ), and small molecule drugs (Waldron et al, 2014 ).…”