To provide a method for easily producing a water-insoluble molded body that is safe and useful as a medical material, a food material, a cosmetic material and the like and has a low water-swelling factor while keeping essential characteristics of raw material polyanionic polysaccharides.SOLUTION: In a production method of a water-insoluble molded body, a raw material molded body composed of a water-soluble salt of polyanionic polysaccharides is made water-insoluble while keeping a shape of the raw material molded body to obtain a water-insoluble molded body. The method includes a step for making the raw material molded body water-insoluble a plurality of times by alternately bringing the raw material molded body into contact with first and second processing solutions to obtain the water-insoluble molded body of a water-swelling factor of 160% or less. The second processing solution is more hydrophobic than the first processing solution.SELECTED DRAWING: None【課題】原料であるポリアニオン性多糖類本来の特性が保持されているとともに、安全性が高く、医療用材料、食品用材料、及び化粧品用材料等として有用な、水による膨潤率が低い水不溶性成形体を簡便に製造する方法を提供する。【解決手段】ポリアニオン性多糖類の水溶性塩からなる原料成形体を、前記原料成形体の形状を維持したまま水不溶して水不溶性成形体を得る水不溶性成形体の製造方法である。原料成形体を、酸無水物を含有する第１の処理液及び第２の処理液に順次接触させて複数回水不溶化処理し、膨潤率１６０％以下の水不溶性成形体を得る工程を有し、第１の処理液に比して第２の処理液の疎水性が高い。【選択図】なし
