Investigation of the effect of type and source of microcrystalline cellulose on capsule filling

Abstract

The influence of the type and source of 8 microcrystalline cellulose samples on the capsule filling performance has been investigated. Different sources of fine, medium and coarse grade microcrystalline cellulose have been used. Several properties of the powders such as particle size, packing and flow were determined and related to the capsule filling behaviour and the capsule disintegration time. A fine grade microcrystalline cellulose such as Avicel® PH105 cannot be used in capsule filling because of unsatisfactory flow properties. Medium and coarse grade microcrystalline cellulose can be classified as a good capsule filling excipient, but not all sources are suitable. The Ludde-Kawakita constant a (Ludde and Kawakita, 1966) and Hausner's ratio (Hausner, 1967) are good indicators of the capsule filling performance, especially in terms of interchangeability of different sources, possibility of filling above maximum bulk density and flow problems producing large coefficients of fill weight variation.