spray drying serves as a microencapsulation technique when an active material is dissolved or suspended in a melt or polymer solution and becomes trapped in the dried particle. the main advantages are the ability to handle labile materials because of the short contact time in the dryer and the operation is economical. in modern spray dryers the viscosity of the solutions to be sprayed can be as high as 300 mpa·s. applying this technique, along with the use of supercritical carbon dioxide, sensitive materials like proteins can be encapsulated.