Compression shear strength and tableting behavior of microcrystalline cellulose agglomerates modulated by a solution binder (polyethylene glycol)

Purpose. To investigate the possibility of modulating the compression shear strength of agglomerates by the incorporation of a solution binder and to study the subsequent effect on the deformation behavior and tablet forming ability of the agglomerates. Method Various concentrations (0.5 to 10%) of polyethylene glycol were inco rporated as a solution binder into microcrystalline cellulose agglomerates of different porosity (10 and 20%) and the shear strength of the agglomerat es, as evaluated by the lib value of the Kawakita equation, and the permeab ility to air and tensile strength of tablets formed from them were determin ed. Results. Increased agglomerate porosity and concentration of polyethylene g lycol reduced the lib values, which led to the formation of tablets with a lower permeability. A decreased tablet permeability corresponded to an incr eased tablet tensile strength except that the highest binder content was as sociated with a drop in the tablet tensile strength. Conclusions. The solution binder reduced the agglomerate shear strength, wh ich was expressed as an increased degree of agglomerate deformation during compression. The latter seemed to be controlled by both agglomerate porosit y and shear strength. The main role of the solution binder in improving the agglomerate compactability was to increase the degree of deformation of ag glomerates during compression.