It was found that 1/5 PPZ/PEG was the most stable dispersion under elevated temperature and/or humidity. FDTs containing 60% of mannitol, 15% of calcium silicate, 15% of crospovidone, and 10% of 1/5 PPZ/PEG solid dispersion exhibited fast disintegration times (37 +/- 3), sufficient hardness (1.28 +/- 0.06 MPa), and fast onset of drug dissolution (34% of PPZ dissolved in 4 minutes), and these properties were found to be retained with storage. Thus, by optimizing the drug/excipient ratio of the solid dispersion and tablet composition, it was possible to produce FDTs that possessed fast disintegration and satisfactory drug dissolution in addition to adequate tensile strength, so that they can be handled and packed normally.