Over the past hundred years tablet manufacturers have developed materials and process that can produce compressed tablets contining a precise amount of an active pharmaceutical ingredient (API) at high speed and at relatively low cost. Current usage of the term " direct compression " is used to define the process by which tablets are compressed directly from the powder of active ingredient/s and suitable excipients. No pretreatment of the powder blends by wet or dry granulation is involved. Directly Compressible Grade materials are blend of Active Pharmaceutical Ingredients with suitable excipients and ready to compress into tablets. They are also referred as drum to hopper grade materials.