PROBLEM TO BE SOLVED: To provide a preparation that can maintain anti-norovirus activity of a lysozyme modified product even after storage for a long period of time, and a method for producing the preparation.SOLUTION: There is provided lysozyme modified product-containing powder that contains a lysozyme modified product and/or salt thereof, and dextrin, in which anti-norovirus activity regulated below when the powder is stored for 4 weeks under the condition of 40°C and 75%RH is 2.0 or more, a reduction value of anti-norovirus activity before and after the storage is 3.0 or less, preferably 2.0 or more. Anti-norovirus activity: when norovirus mixture, which is obtained by mixing the equal amount of norovirus solution and the lysozyme modified product-containing powder solution containing a lysozyme modified product by 2 wt.% in terms of the solid content, is left to stand for 1 minute at 25°C, a value obtained by subtracting a logarithm of an infectivity titer after leaving to stand from a logarithm of an infectivity titer before leaving to stand.SELECTED DRAWING: NoneCOPYRIGHT: (C)2019,JPO&INPIT【課題】長期間保存後もリゾチーム変性物の抗ノロウィルス活性を維持しうる製剤、及びその製造方法の提供。【解決手段】リゾチーム変性物及び/又はその塩と、デキストリンを含む、リゾチーム変性物含有粉末であって、40℃、75%RHの条件下で4週間保存されたときの以下に規定される抗ノロウィルス活性が2.0以上であり、かつ前記保存前後における抗ノロウィルス活性の低下値が3.0以下であり、好ましくは、2.0以上である、リゾチーム変性物含有粉末。抗ノロウィルス活性:ノロウィルス液と、リゾチーム変性物を固形分換算で2質量%含有する上記リゾチーム変性物含有粉末水溶液とを等量混合して得られたノロウィルス混合液を25℃で1分間放置した時の、放置前の感染価の対数から放置後の感染価の対数を引いた値。【選択図】なし
