A comparison of cellactose with two ad hoc processed lactose-cellulose blends as direct compression excipients

Three processed lactose-cellulose blends of similar composition, particle s ize and true density were compared as direct compression excipients: one wa s prepared by dry granulation, one by extrusion-spheronization, and the com mercial product Cellactose, Differences among their flow properties depende d solely on their different sphericities, Unlike those of the other blends. Cellactose particles exhibited numerous macropores, The mean yield pressur es of all three blends were similar to those of direct compression lactoses , Cellactose tablets prepared at a punch pressure that largely eliminated m acropores (pores >1 mu m) had better mechanical properties hut much poorer disintegration than tablets of the other blends prepared at the same punch pressure. However, the tensile strength and disintegration time of Cellacto se tablets both fell rapidly as macropore volume was increased by reducing punch pressure, while the enthalpy of wetting/dissolution rose, The strengt h and water-resistance of well-compacted Cellactose tablets is attributed t o the spatial distribution of lactose and cellulose in Cellactose particles , rather than to beta-lactose content or extra-particular structural featur es.