Dissolution profiles in column dissolution.

A self-consistent model for open-ended column dissolution is presented. It is shown that when the concentration of the efflux stream from the column is plotted versus time, then the profile is fairly level at first and then drops rapidly, in the form of an inverse sigmoid profile. The model assumes that the particles are isometric and that they adhere to a Levich type particulate dissolution, and it is based on plug flow with a given residence time. Consistency is shown between the plug flow parameter (Q2) and experimental data. Good correlation is found between predicted and experimental profiles.