Figure 1.
Three kinds of models of tablet kernels with different shapes. (a) The first model has four cylinder cavities placed in a sphere (Cylinder model). (b) The second model has four horn cavities placed in a sphere (Horn model). (c) The third model has four reversed horn cavities placed in a sphere (R-Horn model). The blue part represents the exposed area of the drug kernel. Along with the decrease of height, the surface area (S) will change in three kinds of models.