Figure 5.

Drug release curves $M^d\left(\theta \right)/M_{\infty }^d$ for different values of $De$ and $\alpha =D_d/D$. Arrows indicate increasing values of $De={10}^{-4},{10}^{-3},{10}^{-2},{10}^{-1},{10}^0$. Dot-dashed black lines represent the limiting case $De\to 0$. (A) $\alpha =1$; (B) $\alpha =0.1$; (C) $\alpha =0.01$.