Hard capsules are probably the second most common dosage form for oral drug delivery. They are generally easier to develop than tablets and they have some patient benefits such as ease of swallowing and they automatically provide taste masking. A modern capsule machine can fill more than one component into a capsule shell (for example an immediate release powder and extended release beads) allowing for a high degree of flexibility of product characteristics in a simple filling operation.
Many capsule formulations are produced by simple dry blending of components, although other techniques may be required such as: