Controlled Release with Finite Dissolution Rate

We consider a two-phase generalization of the classical Higuchi model for controlled drug release. The drug is assumed to be prepared in a stent in its solid phase by immersion in a polymeric matrix, which eventually delivers the drug when it reaches the free end. We derive a single effective evolution equation, which we prove to be equivalent to the original system of two coupled PDEs. We provide analytical estimates for the asymptotic regimes...