Although less popular, it gained increased interest in the recent years for creating modified released products.

It involves the compaction of granular materials around a preformed tablet core using specially designed tableting equipment. Compression coating is a dry process.

This type of tablet (compression coated tablet) has two parts, internal core and surrounding coat. The core is small porous tablet and prepared on one turret. For preparing final tablet, a bigger die cavity in another turret is used in which first the coat material is filled to half and then core tablet is mechanically transferred, again the remaining space is filled with coat material and finally compression force is applied.

Mechanically, it is a complex process, as the tablet may be tilted when transferred to the second die cavity.

Mostly, the coat is water soluble and disintegrates easily after swallowing, in order to achieve immediate release product}.

This tablet readily lend itself in to a repeat action tablet as the outer layer provides the initial dose while the inner core release the drug later on. But, when the core quickly releases the drug, entirely different blood level is achieved with the risk of over dose toxicity. To avoid immediate
release of both the layers, the core tablet is coated with enteric polymer so that it will not release the drug in stomach while, the first dose is added in outer sugar coating. Even so, coating operation requires interpretation while manufacturing and dawdling the manufacturing process. Sometimes, inner core may be of liquid formulation to provide immediate release of core after the coat gets dissolved.

The Purpose of Compression Coated Tablet
  1. Traditionally, to separate incompatible materials (one in the core and the other in the coat). There is an interface between the two layers and thus compromise product stability. It is possible to apply an inert placebo coating layer first, to separate the core from the final coat more effectively. Example : The manufacturing of Artesunate and Amodiaquine Tablet Formulation 
  2. May be used to create modified-release products such as Delayed Release (Release in intestinal)