1977 年 97 巻 11 号 p. 1168-1173
The powder of aspirin and sulfisomezole were sieved into three classes, L, M, and S in the order of their grain size, and used for making tablets. Disintegration time of these tablets was measured for containing various amounts of corn starch. The minimum content of corn starch (critical content) for tablet disintegration was determined and the distance between starch grains in a tablet was calculated from the critical content of disintegrant. The calculations for the distance were based on the following conditions of crystal size : (a) aspirin and sulfisomezole crystals are much larger than starch grains and (b) aspirin and sulfisomezole crystals are nearly the same with starch grains in size. The tablet of small particles required a larger amount of corn starch to disintegrate in water, i. e., tablets of crystal size S showed larger value of the critical content than those of the sizes L and M, but the calculated distance was nearly the same in tablets of L, M, and S size grains. The critical content and the distance were affected by the wetting of crystals. For the tablet of sulfisomezole, which was coated with Aerosol OT, the distance between starch grains necessary for tablet disintegration did not vary with particle size of sulfisomezole. The distance in the tablets of treated crystals was longer than those in tablets of intact crystals.