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Title:	Impact of stirrer speed and media type-loading on the breakage kinetics during wet stirred media milling of griseofulvin
Author:	Parker, Nathaniel
View Online:	njit-etd2019-072 (xi, 78 pages ~ 3.1 MB pdf)
Department:	Department of Chemical and Materials Engineering
Degree:	Master of Science
Program:	Chemical Engineering
Document Type:	Thesis
Advisory Committee:	Bilgili, Ecevit Atalay (Committee chair) Armenante, Piero M. (Committee member) Guvendiren, Murat (Committee member)
Date:	2019-12
Keywords:	Griseofulvin milling Stirrer speed impact Bead loading impact Breakage kinetics Energy consumption
Availability:	Unrestricted
Abstract:	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.