Document Type


Date of Award


Degree Name

Master of Science in Chemical Engineering - (M.S.)


Chemical and Materials Engineering

First Advisor

Ecevit Atalay Bilgili

Second Advisor

Piero M. Armenante

Third Advisor

Murat Guvendiren


The aim of this study is to investigate the impact of stirrer speed (2000-4000 rpm) and bead loading (~20-60%) on the breakage kinetics-energy consumption during milling of griseofulvin, a poorly soluble drug, and compare the performance of crosslinked polystyrene (CPS) beads with that of yttrium-stabilized zirconia (YSZ) beads. Laser diffraction, SEM, viscometry, and XRPD were used for characterization. A microhydrodynamic model was used to interpret the breakage kinetics. An increase in stirrer speed led to faster breakage due to more frequent and forceful CPS bead-bead collisions. Despite causing slight decrease in maximum contact pressure, an increase in CPS bead loading caused a dramatic increase in frequency of drug particle compressions, which dominated the faster breakage. While YSZ beads required higher energy consumption than CPS beads, they achieved the same product fineness faster than CPS beads. Microhydrodynamic model rationalized the favorable use of YSZ over CPS beads.



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