Stabilized adhesive preparation containing donepezil

A donepezil-containing adhesive preparation which has a pressure-sensitive adhesive layer containing donepezil on at least one side of a support is provided, whereby the formation of donepezil-related substances in a pressure-sensitive adhesive layer is inhibited. The pressure-sensitive adhesive layer is obtained by film-forming of a mixture comprising a pressure-sensitive adhesive, donepezil and a stabilizer, wherein the stabilizer contains one or more species selected from the group consisting of ascorbic acid, a metal salt or an ester thereof, isoascorbic acid or a metal salt thereof, ethylenediamine tetraacetic acid or a metal salt thereof, 2-mercaptobenzimidazole, 2,6-di-t-butyl-4-methylphenol, tetrakis[3-(3',5,-di-t-butyl-4'-hydroxyphenyl)propionic acid]pentaerythritol, tocopherol acetate, rutin, a metal sulfite salt and a metal thiosulfate salt.