Diffusion model for drug release from suspensions II: release to a perfect sink.

Numerical mathematical methods are applied to a diffusion model based on physicochemical principles to predict drug release from suspensions of drug in semisolid vehicles. The predicted mass of drug released versus time curves using this model are in agreement with some reported experimental data but differ from predictions using the classical model for semisolid suspensions. The differences are discussed in relation to the drug dissolution rate and diffusion rate in the vehicle.