Evaluation of a convective diffusion drug dissolution rate model.

A recently introduced drug dissolution rate model based on convective diffusion was evaluated by experimentally determining dissolution rates. Alkyl p-aminobenzoates were used as the test compounds in a dissolution cell which promoted laminar flow of the liquid past the dissolving surface. The parameters evaluated were diffusivity, solubility, rate of shear, dissolving surface shape, and orientation of the surface relative to flow. The agreement between theory and experiment was quite satisfactory with respect to the functional dependence of the rate on these parameters as well as the actual magnitude of the rates.