Size-induced segregation during pharmaceutical particle die filling assessed by response surface methodology using discrete element method

The Challenge of Die Filling in Rotary Presses—A Systematic Study of Material Properties and Process Parameters

“…The strong improvement in the filling result due to suction fill, which can take place in a rotary press, was detected by Jackson et al [2]. Besides the experimental investigations, CFD/DEM-Simulations focused on the die filling process and analyzed air effects [13][14][15][16][17][18][19][20][21][22][23][24]. A rotational filling device with gravity fill equipped with moved dies and a stationary feeder, mimicking a rotary press more realistically, was used to correlate die filling performance and critical material attributes [25].…”

“…In addition, the flowability of lubricated powders was improved due to overlubrication caused by increasing feed frame speed. In addition to the approaches with filling devices, computer modeling was used to investigate the flow behavior of powders in feed frames and into dies [19][20][21][22].…”

Size-induced segregation during die filling

“…This value, however, does not provide any indication about the distribution of API particles within a single tablet, which in turn is affected by the distribution of the API within the powder blend deposited into the die during die filling. It is desirable to have a uniform distribution of API and excipient particles in the die, as a non-uniform component distribution might lead to such tableting issues as lamination and sticking (Furukawa et al, 2016).…”

“…The influence of die velocity and particle size on the segregation of binary blends was also assessed numerically (DEM) by Furukawa et al (2016). The authors observed that small particles tend to flow toward the bottom corner of the die in the moving direction of the shoe.…”

“…Despite detailed numerical investigations of segregation during die filling (Furukawa et al, 2016, Guo et al, 2011a, Guo et al, 2011b, Mateo-Ortiz et al, 2014), the issue is not fully understood. The present study aims to experimentally explore size-induced segregation of binary blends with various fine-to-coarse ratios during die filling.…”