Effect of the particle shape on the particle dynamics in a spheronization process

Abstract

Abstract. Spherical granules with a narrow size distribution are widely used in many pharmaceutical applications. Extrusion-spheronization is a well-established process to produce such pharmaceutical pellets. The cylindrical extrudates from the extrusion step are rounded in the spheronizer. The formation mechanisms inside of a spheronizer depend strongly on the particle dynamics. To describe the complex particle flow and interactions, the Discrete Element Method can be used. In our previous works the spherical particles during the last part of the spheronization process were studied. Since the pellets have a cylindrical shape at the beginning and undergo different stages of deformation during the rounding process, the objective of this study was the description of the influence of the particle shape on the particle dynamics. To predict the interactions of the pellets, their dominant plastic behaviour was described with an appropriate contact model and the material parameters were calibrated with compression and impact tests.

Contact Behavior of Microcrystalline Cellulose Pellets Depending on their Water Content

“…However, the measured breakage forces are in a critical region regarding stresses occurring in a spheronization process. In our previous work , the forces acting on cylindrical as well as spherical MCC pellets with a water content of 37.2 % during the spheronization process were obtained by simulation. Due to the different mass and shape of the extrudates compared to the spherical pellets, different average values of the collision force were obtained, namely, 0.13 N for the cylindrical extrudates and 0.06 N for the spherical pellets.…”

Particle Kinematics in Spheronization of Pharmaceutical Pellets

“…Die Partikelkinematik im Sphäroniser wurde in vorherigen Studien für verschiedene Partikelsysteme untersucht , wobei das Materialverhalten der verwendeten Modellpartikeln deutlich vom tatsächlichen Verhalten der feuchten Pellets abwich. Auch Bouffard et al untersuchten die Partikelbewegung in einem Sphäroniser unter besonderer Berücksichtigung der Entmischung bereits mittels Simulationen.…”