Preparation method of high-quality low-molecular-weight heparin calcium

The invention relates to a preparation method of high-quality low-molecular-weight heparin calcium, which comprises the following steps: dissolving heparin sodium by using a glacial acetic acid solution, reducing by using sodium borohydride, precipitating by using ethanol, dissolving by adding a calcium chloride solution, carrying out fractional precipitation by using a low-temperature solvent, carrying out gradient elution by using a DEAE column, precipitating filtrate by using the solvent, and drying. The production efficiency is improved, and the high-quality low-molecular-weight heparin calcium product which is high in anti-Xa factor titer and anti-Xa/anti-IIa ratio, stable in molecular weight and distribution, low in nitrite content and good in solution color and clarity is prepared. 本发明涉及一种高质量低分子量肝素钙的制备方法，用冰醋酸溶液溶解肝素钠，使用硼氢化钠还原后用乙醇沉淀，加入氯化钙溶液溶解，再经低温溶媒分级沉淀，最后采用DEAE柱进行梯度洗脱，滤液经溶媒沉淀后，干燥。本发明在提高生产效率的同时，制备出抗Xa因子效价及抗Xa/抗IIa比值高，分子量及分布稳定，亚硝酸盐含量低，溶液颜色及澄清度好的高质量低分子量肝素钙产品。