Encapsulation offers drug developers a number of commercial and medical advantages. E.g., it can be used for the sustained release of some antibiotics reducing dosage requirements. By preventing drug concentration peaks, encapsulation is also an effective way to treat chronic illness – e.g., cancer or AIDS – with reduced side effects. This encapsulation technique is also widely employed for physical protection of the API against oxidation, humidity or other compounds in the formulation.
Spray drying makes it possible to engineer particles in order to create specific release patterns and other desired properties. For encapsulation, the API and biodegradable excipients are dissolved and/or suspended. Subsequently the feed is atomized and dried into a powder.
An interesting alternative approach is spray congealing, where the API is melted or mixed with molten excipients and the powder particles produced by atomization and cooling.
Another reason for encapsulation may be “taste masking” used for masking strong taste in medicines for oral delivery, e.g. in syrups or chewing tablets for children