Abstract
Difference in the apparent density between the core and peripheral portion of a tablet was measured in order to observe the behavior of powder compressed into various shapes of tablets. In another experiment, double cylindrical tablets of various shapes were made by compressing colored powder in concentric circles to observe the movement of powder caused by compression in cross-sections of the double cylindrical tablets. Movement of a powder due to compression was not observed in tablets with a flat surface, whereas the movement of powder from the peripheral portion to the core was observed in tablets with a curved surface. Abnormal behavior of a powder, such as excessive movement toward the core, was observed in tablets with a flat surface on one side. A larger difference in the apparent density and movement of a powder caused by compression was observed in tablets with a smaller radius of curvature and thickness. These results supported the previous findings concerning the influence of tablet shape on the distribution of hardness inside the tablets.
