Rheological characterization of microcrystalline cellulose and silicified microcrystalline cellulose wet masses using a mixer torque rheometer

The rheological properties of silicified microcrystalline cellulose (Prosol v 50) were compared with those of standard grades of microcrystalline cellu lose (Emcocel 50 and Avicel PH 101). Cellulose samples were analyzed using nitrogen adsorption together with particle size, flowability, density and s welling volume studies. The rheological behaviour of the wet powder masses was studied as a function of mixing time using a mixer torque rheometer (MT R). Silicified microcrystalline cellulose exhibited improved flow character istics and increased specific surface area compared to standard microcrysta lline cellulose grades. Although the silicification process affected the sw elling properties and, furthermore, the mixing kinetics of microcrystalline cellulose, the source of the microcrystalline cellulose had a stronger inf luence than silicification on the liquid requirement at peak torque. (C) 19 99 Elsevier Science B.V. All rights reserved.