CONTROLLED-RELEASE OF THEOPHYLLINE FROM WATER-SWOLLEN SCLEROGLUCAN MATRICES

A two-phase model for diffusion and drug release through swollen polym eric matrices is presented and solved. This model explains the non-Fic kian release behaviour experimentally found for the system constituted by theophylline in a water-swollen scleroglucan matrix in a slab form . The exponential nature of the temporal behaviour of the drug in the stationary phase is confirmed by means of Green function analysis. The boundary conditions deriving from the non-self-sustaining nature of t he polymeric gel and from the presence of a net are investigated in de tail.