To provide a preparation for oral administration in which silodosin being a medicine having extremely bitter taste can be ingested without a feeling of a foreign object and even without water, and which is equipped with leachability capable of reproducing blood concentration effective for treating urinary disturbance or the like associated with prostatic hypertrophy.SOLUTION: There are provided masking particles obtained by granulating or coating drug grains containing fine powder of silodosin by a coating agent containing non-enteric polymer, in which the content of non-enteric polymer is 80 pts.mass to 400 pts.mass with respect to 100 pts.mass of silodosin. In the masking particles, an elution ratio of preparation for oral administration containing masking particles after 15 minutes at pH 6.8 is 85% or more. In the masking particles, time at which bitter taste is beginning to be sensed in a human bitter taste sensory test of the preparation for oral administration containing masking particles is 30 seconds or more.SELECTED DRAWING: None【課題】極めて苦味の強い薬剤であるシロドシンを、異物感なく、水なしでも服用でき、かつ前立腺肥大症に伴う排尿障害等の治療に有効な血中濃度を再現できる溶出性を備えた、経口投与製剤の提供。【解決手段】シロドシンの微粉末を含有する薬物粒子を、非腸溶性高分子を含有するコーティング剤で造粒又は被覆して得られるマスキング粒子であって、非腸溶性高分子含量が、シロドシン100質量部に対して80質量部～400質量部である、マスキング粒子。マスキング粒子を含有する経口投与製剤のpH6.8における１５分後の溶出率が、85％以上である、マスキング粒子。マスキング粒子を含有する経口投与製剤のヒト苦味官能試験における苦味を感じ始める時間が、３０秒以上である、マスキング粒子。【選択図】なし
