Tablet processing dimensional analysis

Scale-up of the tableting process in the pharmaceutical industry is still an empirical process. Dimensional analysis, a powerful method that has been successfully used in other applications, can provide a solid scientific basis for tableting scale-up. It is a method for producing dimensionless numbers that completely describe the process. The analysis should be carried out before the measurements are made, because dimensionless numbers essentially condense the frame in which the measurements are performed and evaluated. It can be applied even when the equations governing the process are not known. 

It was demonstrated that dimensional analysis of the tableting process can produce a scientifically reliable way of predicting tablet properties across the range of materials and with diverse compaction mechanisms. A theoretically sound scale-up method is thus readily available for tableting equipment of different capacity. The method can be readily expanded to include other materials and tablet presses and other target quantities, such as tablet stability (disintegration) and bioavailability (dissolution). 

Levin, M. and Zlokarnik, M., Dimensional analysis of the tableting process,Pharmaceutical Process Scale-Up, M. Levin (Ed.), Marcel Dekker, New York, (2002). 

Levin, M. and M. Zlokamik Dimensional Analysis of Tableting Process, in Pharmaceutical Process Scale-Up, Marcel Dekker, Inc. New York, Basel 2002... 

Several predictive methods have been applied to the tablet compaction process on a small scale to envisage what will happen on a large scale. Dimensional analysis has been described by Levin as a method of developing functional relationships that describe any given process in a dimensionless form to facilitate modeling and scale-up (or scale down). Although, theoretically, dimensional analysis can be applied to tablet manufacture, no examples are found in the literature. 

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