A medicinal preparation for oral administration which has a multilayer structurecomprising a drug-containing layer and a gel-forming layer. The multilayerstructure includes the gel-forming layer disposed as each surface layer. Thegel-forming layer contains a gel-forming agent which upon absorption of an aqueousliquid swells to thereby form a gel. The gel-forming layer has a rate of 37°Cwater absorption of 0.5 g/(g s) or higher and comes to have a gel content, as determinedthrough immersion in 0.9 mass% aqueous sodium chloride solution having a temperatureof 37°C, of 20 mass% or higher.
