[Object] The amounts of donepezil-related substances formed in a donepezil-containing adhesive preparation are reduced.[Solution] One type or two or more types of combinations of compounds selected from the groups of combinations of compounds of th efollowing (a) to (j) are blended in a donepezil-containing pressure-sensitive adhesive layer:(a) isoascorbic acid or metal salts thereof and 2-mercaptobenzimidazole(b) isoascorbic acid or metal salts thereof and 2,6-di-t-butyl-4-methylphenol(c) isoascorbic acid or metal salts thereof and metal salts of hydroxymethanesulfinic acid(d) isoascorbic acid or metal salts thereof and rutin(e) 2-mercaptobenzimidazole and 2,6-di-t-butyl-4-methylphenol(f) 2-mercaptobenzimidazole and metal salts of hydroxymethanesulfinic acid and(g) 2-mercaptobenzimidazole and rutin(h) 2,6-di-t-butyl-4-methylphenol and metal salts of hydroxymethanesulfinic acid and(i) 2,6-di-t-butyl-4-methylphenol and rutin and(j) metal salts of hydroxymethanesulfinic acid and rutin.
