Effect of surface modification with silicon compounds on flowability of granulated lactose

Abstract

The effect of surface modification on powder flowability was experimentally investigated in the present study. The powder sample was granulated lactose with 147 μm mass median diameter, which is used as an excipient for direct compression. The surface of the granulated lactose was modified by mechanical dry coating with silicon compound glidants, namely magnesium aluminometasilicate, aluminum silicate, magnesium silicate, and silicon dioxide, which were 3 to 13 μm in mass median diameter. Powder flowability was evaluated by a vibrating tube method, which can characterize both the static and dynamic friction properties, and by conventional methods, i.e., measuring the angle of repose and compressibility. Finally, effective surface modification agents that improve powder flowability were selected from the tested silicon compounds.