Codried products of microcrystalline cellulose (MCC) with saccharides (glucose, mannitol and sorbitol) and low-substituted hydroxypropylcellulose (L-HPC) of various grades (LH11, -20, -21, -22 and -31) were prepared. Their characteristics were evaluated and compared with the corresponding physical mixtures (PM) and dried product of MCC slurry (MCC-S). Improvement in flowability and Carr's index was demonstrated for codried products. Tablets prepared from most of the codried products showed a lower yield pressure and a shorter disintegration time, but a lower tensile strength. The E-0 value of MCC-S was the highest among all MCC products tested. Further, all codried products demonstrated a lower E0 value than that of the corresponding physical mixtures. The extent of modification on the stiffness of MCC by L-HPC was larger than that by saccharides. K-ic0 values for physical mixtures were larger than those of the corresponding codried products and MCC-S. On the other hand, K-ic0 values for codried products of MCC with saccharides were in a comparable range of 0.63-1.10 MPa m(1/2), whereas that for codried products of MCC with L-HPC increased with increasing particle size (LH11>LH21>LH31). R-0 was larger for physical mixtures than for the corresponding codried products. Most physical mixtures had a larger value of R-0 than MCC-S except that for PMS, whereas values for most of codried products were smaller than that of MCC-S except for CD11 and CD21. The values of sigma(T0) for the codried products were lower than those for the physical mixtures, and both were lower than that for MCC-S. In terms of physical mixtures, the extent of decrease by mixing MCC with L-HPC was lower than that when mixing MCC with saccharides. However, the extent of decrease by codrying MCC with saccharides was greater than that with L-HPC. In conclusion, rounder, smoother particles with fewer free-moving fibers on the surface are the determining factor influencing the mechanical performance of the resulting codried products.