The present invention provides a sterile alginate aqueous solution preparation which is ready-to-use and has storage stability, and a method for producing the same, the sterile alginate aqueous solution preparation containing (a) a monovalent metal salt of low endotoxin alginic acid having a weight average molecular weight of 50,000 to 400,000 by GPC-MALS method, (b) a salt selected from monovalent metal salt and ammonium salt and (c) water, the concentration of component (a) being 1.5 mass% or more, the concentration of component (b) being 0.5 to 2 mass%, and the viscosity measured at 20℃ by using a rotational viscometer being 2700 mPa ． s or more, the sterile alginate aqueous solution being filled in a sealed container or an airtight container. This alginate aqueous solution preparation is a ready-to-use low-endotoxin alginate monovalent metal salt aqueous solution preparation.本發明提供一種海藻酸鹽水溶液製劑及其製造方法，前述海藻酸鹽水溶液製劑係無菌且充填於密封容器或氣密容器，可即時使用且具有保存安定性，前述海藻酸鹽水溶液係含有：(a)藉由GPC-MALS法所得的重量平均分子量為5萬至40萬的低內毒素海藻酸的1價金屬鹽、(b)由1價金屬鹽及銨鹽選出的鹽及(c)水，成分(a)的濃度在1.5質量%以上，成分(b)的濃度為0.5至2質量%；使用旋轉黏度計在20℃測定的黏度為2700mPa‧s以上。此海藻酸鹽水溶液製劑是係可即時使用的低內毒素海藻酸的1價金屬鹽水溶液製劑。
