PROBLEM TO BE SOLVED : To provide pharmaceutical tablets containing as an active ingredient erlotinib or a pharmaceutically acceptable salt thereof that can suppress the initial elution of an active ingredient in water and avoid rapid elution of an active ingredient. SOLUTION : The present inventor found that a pharmaceutical tablet containing erlotinib or a pharmaceutically acceptable salt thereof as an active ingredient enables suppression of the initial elution of an active ingredient in water by containing an amino group modification macromolecular additive inside thereof, and completed the invention. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT