PROBLEM TO BE SOLVED: To provide solid preparations suitable for use in the process of keratin fiber for dyeing the hair.SOLUTION: Disclosed is a solid formulation having a tablet form, comprising at least one water-insoluble superdisintegrant selected from the group consisting of carmellose, crospovidone, and crosslinked starch, as well as at least one active ingredient selected from the group consisting of a color imparting agent, alkalizer, an oxidizer, and a thickener, the superdisintegrant being characterized by a water absorption ratio of at least 0.5.SELECTED DRAWING: None【課題】毛髪の染色の為のケラチン繊維の処理における使用に好適な固形製剤の提供。【解決手段】タブレットの形態を有し、クロスカルメロース、クロスポビドン、及び架橋でんぷんで構成される群から選択される少なくとも1つの水不溶性の超崩壊剤、並びに、色付与剤、アルカリ化剤、酸化剤、及び増粘剤で構成される群から選択される少なくとも1つの活性剤を含み、前記超崩壊剤が少なくとも0.5の吸水率によって特徴付けられる固形製剤。【選択図】なし