We have developed an easily swallowed film formulation that swells and turns into a jelly instantaneously upon absorption of a small amount of saliva. The formulation's structure comprises a gelating layer on both faces of a drug-containing layer, and this structure restrains the elution of a drug in the mouth. Swelling experiments confirmed the instantaneous gelation when the gelating layer absorbs purified water. Fifteen seconds after immersion in purified water, the bulk modulus of the film formulation was less than 500N/m2, which is an appropriate value for easy swallowing by elderly people. A dissolution study confirmed the delayed dissolution of glimepiride as a model drug. In a clinical study, although the stagnation at the upper esophagus was observed with a gelatin capsule, the film formulation passed the esophagus and reached the stomach quickly.