結晶セルロースの流動性におよぼす充塡率の影響

抄録

When manufacturing pharmaceutical tablets by direct compression, the relationship between powder flowability and packing fraction must be evaluated to ensure that an appropriate excipient is selected. In this study, three types of microcrystalline cellulose with different particle sizes and shapes were evaluated by using the vibration shear tube method, which characterizes static and dynamic friction properties. First, to obtain the flowability profiles under quasi-steady-state conditions, the effects of an increasing rate of vibration acceleration on the mass flow rate were studied. Next, to analyze the effects of the initial packing fraction on powder flowability, the powder samples were subjected to vibration for different periods; then, experiments to evaluate powder flowability were conducted. The results demonstrated that the flowability related to static friction was strongly correlated with compressibility; this was evidenced by the packing-fraction variation. Because pre-consolidation of the powder suppressed flushing, the mass flow rate was directly proportional to compressibility. The proportional coefficient was used to evaluate the flowability related to dynamic friction.