Mucosal surface-coat-forming film dosage units containing a water-soluble hydrocolloid, an effective dose of an active agent and a mucosal adhesion enhancer; wherein the active agent is encapsulated within a polymer which is chemically or physically distinct from the hydocolloid; wherein the mucosal adhesion enhancer is a starch graft copolymer; wherein the film exhibits a dry tack value of less than 3.5 g, a wet tack of greater than 35 g, a gelation temperature that is greater than 70° C. for a 2% polymer solution, a dry film thickness of less than 20 mil, a water content of 0.5 to 10%, a tensile strength greater than 1500 psi, a modulus in the range of 35,000 to 300,000 psi, a % elongation of less than 20%, a tear probagation resistance of 0.001 to 1 N, and a dissolution time in the range of 1 to 600 seconds upon application to an oral mucosal surface.