COMPRESSION PHYSICS OF PHARMACEUTICAL POWDERS: A REVIEW

Due to various advantages such as high-precision dosing, manufacturing efficiency and patient compliance helped making tablets the most popular dosage forms among all available dosages forms. Compaction, which is an essential manufacturing step in the manufacture of tablets, mainly includes compression (i.e. reduction of volume of the powder under consideration and particle rearrangement)  and consolidation (i.e., formation of interparticulate bond to facilitate stable compaction). The success of the compaction process depends not only on the physico-technical properties of drugs and excipients, but also on the instrument settings with respect to rate and magnitude of force transfer. Tablet manufacturing speed and pre/main compression force profile also have an influence on the quality of the final tablet. Mechanical aspects of tablet formation can be studied using, instrumented punches/dies, instrumented tablet punching machines, and compaction simulators. These have potential application in pharmaceutical research and development, such as studying basic compaction mechanism, various process variables, scale-up parameters,  trouble shooting problems, creating compaction data library, and fingerprinting of new active pharmaceutical ingredients (APIs) or excipients. Mathematical models, force-time, force-distance, and die-wall force parameters of tablet manufacturing are used to describe work of compaction, elasticity/plasticity, and time dependent deformation behavior of pharmaceuticals powder under consideration.