A device for delivery of a therapeutic agent to a surgical cavity, including: a porous, mucoadhesive, freeze-dried polymeric matrix having first and second opposed surfaces, the matrix formed by a composition including chitosan； a plurality of particles embedded within the matrix, the particles containing the therapeutic agent and having a coating around the therapeutic agent, the coating including chitosan； and an additive selected from the group consisting of a hydration promoter, a particle adhesion inhibitor, a particle aggregation inhibitor, and combinations thereof. The first surface of the matrix is configured to be applied to the surgical cavity； the device releases the particles through the first surface； the device is also sterilized and provides release of approximately 20% to 100% of the therapeutic agent within 20 minutes of application to the surgical cavity.
