Binder-substrate interactions in wet granulation. 3: The effect of excipient source variation

The effect of excipient source variation on the interactions during wet granulation between microcrystalline cellulose and aqueous solutions of two molecular weight grades of two polymer binders has been studied using an instrumented mexer torque rheometer. The wet massing data confirmed previous observations that dissimilar polymers interact differently with cellulose substrates during the wet massing process. In addition, for a second cellulose material, variations were also observed in the pattern of interaction between the binders and the excipient. An examination of particulate and surface energetic properties revealed differences in the cellulose materials which were then related to the observed rheological behaviour.