ABSTRACT
In the production of pharmaceutical dosage forms, granulation is one of the most com-
mon unit operation employed to improve the flow and compressibility of particulate
material by size enlargement and densification. Granulation can be divided into wet and
dry methods. Wet granulation methods are more often chosen over dry granulation
because of dust elimination, single-pot processing and obtaining predictable granulation
end-point determination. Examples of wet granulation methods include fluid bed, high
shear, pelletization techniques such as extrusion-spheronization, spray drying, rotary
processing and so forth. In wet granulation, a liquid is used to agglomerate powder
particles with constant agitation into a coherent mass which is subsequently dried and
sized for subsequent processing. Despite their advantages, wet granulation methods are
not suitable for thermo-labile and moisture sensitive materials or materials that are highly
cohesive. In such instances, dry granulation or granulation by compression become the
method of choice as it eliminates the need for an extra drying step which is detrimental to
actives that degrade or convert to a less stable form under elevated temperatures.
