COMPARATIVE COMPACTION PROPERTIES OF VARIOUS MICROCRYSTALLINE CELLULOSE TYPES AND GENERIC PRODUCTS

The purpose of this review is to compare the tableting properties of conventional microcrystalline cellulose (MCC) with those of other common direct compression diluents and of the numerous new MCC grades and brands recently made available. After a brief discussion of the mechanisms of consolidation involved in the formation of MCC tablets, the first section deals with the basic mechanical properties of powders important for compression. Values of parameters describing ductility, brittleness, elasticity and viscoelasticity are presented and discussed in relation with the degree of polymerization, the crystallinity, the moisture content and the morphological properties of the materials. The tableting properties of the powders during the compression process (densification behavior, work of compression) and the mechanical strength of the finished products (compactibility) are examined. Special attention is given to the effects of moisture content, lubricants and other added substances on the performances of MCC products. Comparative tablet weight variation data are provided for several MCC types from different supplies. Finally, aging of the MCC compacts is discussed in relation to environmental conditions, before warning the user in the conclusion on the considerable variability of MCC products currently available on the market.