theoretical study of diffusional release of a dispersed solute from a hollow cylindrical polymeric matrix

The present study proposes an exact solution for the release kinetic of a solute from inside a hollow cylindrical polymeric matrix into an inifnite medium when the initial concentration of the solute (a) is greater than the solubility limit (cs). a combination ofanalytical and numerical methods was used to calculate the solute concentration profile andthe release rate. the model was developed for two dierent conditions including: (1) therelease medium was owing through the hollow cylinder in which the boundary layer maybe neglected, and (2) the release medium inside the hollow cylinder was stagnant where theboundary layer needed to be considered. the results indicated that the release pro iles were close to the constant release rate after a typical burst release. also, the release profile from a solid cylindrical matrix was compared to that of a hollow cylinder. the results indicated that the hollow cylindrical matrix was a promising carrier when the zero-order release wasdesirable. the present model demonstrated the potential of the hollow cylindrical matrix as a suitable geometry for sustained drug delivery systems.