Pharmacie Globale International Journal of Comprehensive Pharmacy Recent Research on Co-processed Excipients for Direct Compression-a Review

INTRODUCTION Direct compression is the process of tabletting of a blend of ingredients, the compression mix, without a preliminary granulation or aggregation process. The compression mix contains the active pharmaceutical ingredient blended with one or more excipients.1 It has been estimated that less than 20 percent of pharmaceutical materials can be compressed directly into tablets. The rest of the materials lack flow, cohesion or lubricating properties necessary for the production of tablets by direct compression. The use of directly compressible excipients may yield satisfactory tablets for such materials. Although simple in terms of unit processes involved, the direct compression process is highly influenced by powder characteristics such as flowability, compressibility, and dilution potential. Tablets consist of active drugs and excipients, and not one drug substance or excipient possesses all the desired physicomechanical properties required for the development of a robust direct‐compression manufacturing process, which can be scaled up from laboratory to production scale smoothly. Most formulations (70–80%) contain excipients at a higher concentration than the active drug. Consequently, the excipients contribute significantly to a formulation’s functionality and processability. In simple terms, the direct‐compression process is directly influenced by the properties of the excipients. The physicomechanical properties of excipients shall ensure a robust and successful process are good flowability, good compressibility, low or no moisture sensitivity, low lubricant sensitivity, and good machineability even in high‐speed tabletting machinery with reduced dwell times. The majority of the excipients that are currently available fail to live up to these functionality requirements,