Shuji Matsusaka

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Pharmaceutical powders are very prone to electrostatic charging by colliding and sliding contacts with walls and other particles. In pharmaceutical formulation processes, particle charging is often a nuisance and can cause problems in the manufacture of products, such as affecting powder flow, and reducing fill and dose uniformity. For a fundamental(More)
The phenomenon of electrostatic charge generation in a pneumatic conveying system was studied. The main parameters used for quantitative characterization of the phenomenon included induced current, particle charge density and equivalent current of the charged granular flow. These were measured using a Digital Electrometer, Faraday Cage and Modular(More)
Powder flowability of microcrystalline cellulose particles having different particle shapes, whose aspect ratios ranged from 1.8 to 6.4, was measured using the vibration shear tube method. Particles lubricated with magnesium stearate were also investigated in order to evaluate the effect of surface modification on powder flowability. Particles were(More)
We demonstrate that a vibration-induced air inflow can cause vigorous bubbling in a bed of fine particles and report the mechanism by which this phenomenon occurs. When convective flow occurs in a powder bed as a result of vibrations, the upper powder layer with a high void ratio moves downward and is compressed. This process forces the air in the powder(More)
Hiroaki Masuda, Shuji Matsusaka, and Koreyoshi Imamura Dept. of Chem. Eng., Kyoto Univ. * A new method has been developed to measure and evaluate the operational powder characteristics for fine particle processing based on the reentrainment phenomena. Experiments on particle reentrainment were carried out using an accelerated air flow for 21 different test(More)
BACKGROUND The evaluation of lubricity or flowability of pharmaceutical powders is important for consistent production and quality control of drug products. However, there have been only a few studies on quantitative measurements of the properties of lubricated powders. METHOD Magnesium stearate (MgSt) and sodium stearyl fumarate (SSF) were used as(More)
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