Drying of the Product
For handling and storage, the purified product needs to be dried. This can be achieved by any one of the following methods: (i) Vaccum drying . It involves drying in a vacuum drier. (ii) Spray drying. It involves atomization of the solution or slurry through a nozzle or a rotating disc, using a current of hot air (150-2500C). It is used for enzymes, antibiotics and food products. (iii) Freeze-drying. It involves freezing of the solution, so that the water is sublimed from the frozen mass. The method is used for many pharmaceutical products, like vaccines, enzymes, plasma fractions, etc.