PROBLEM TO BE SOLVED: To provide a needle-shaped substance composed of a polymer originated from a natural product such as a polysaccharide to which attention is paid as a substitute because a needle-like substance composed of a metal, silicon, a synthetic polymer or the like accompanies risk when the needle-shaped substance remains in the skin at paracentesis by any chance, and to provide a method for producing the substance by which the water resistance is improved because many natural polysaccharides are water-soluble, and such the many problems as deformation by moisture absorption after molding, deterioration when preserved for a long period, impossibility of coating of an aqueous medicament, and smell are present.SOLUTION: The polysaccharide having a carboxy group and/or an amino group in the molecular structure, and derived from a natural product is dissolved in water by forming a salt in many cases. Accordingly, the molded product obtained by drying and solidifying the solution is soaked in water containing an acid or an alkali, or a hydrophilic organic solvent containing a little amount of the water to desalt the molded product to provide the needle-shaped substance having the water resistance. The method for producing the needle-shaped substance is also provided.COPYRIGHT: (C)2011,JPO&INPIT【課題】金属やシリコン、合成高分子などからなる針状物体は穿刺時に万が一皮膚内に残存した場合に危険性を伴うため、代替物として注目されている多糖類などの天然物由来の高分子からなる針状物体を提供することにある。多くの天然多糖類は水溶性であり、成形後に吸湿による変形、長期保存の場合の劣化、水性薬剤が塗布出来ない、におい等の問題があり、耐水性を向上させる製造方法を提供する。【解決手段】分子構造内にカルボキシル基および、またはアミノ基を持つ天然物由来の多糖類は多くの場合、塩を形成して水に溶解する。そこで乾燥固化した成形体を、酸またはアルカリを含む水もしくは、水を少量含む親水性有機溶媒に浸漬して脱塩して耐水性を持たせてなることを特徴とする針状物体とその製造方法。【選択図】なし
