申请人:Rao Rammohan Davuluri
公开号:US20070244318A1
公开(公告)日:2007-10-18
The present invention relates to an improved process for preparation of Levofloxacin hemihydrate having single individual impurity not more than 0.1% and free from particulate matter & from the other enantiomer (R-form) which comprises dissolving levofloxacin technical grade in aqueous alkaline solution, treating the resulting solution with activated carbon at room temperature, removing the undissolved particulate matter filtration, bringing the pH of the aqueous alkaline levofloxacin solution to neutral using dilute mineral acid, removing the precipitated particulate matter by filtration, acidifying the resulting solution, treating the acidified solution with activated carbon at room temperature, filtering the undissolved particulate matter by filtration, neutralizing the acidic solution, filtering again to remove any particulate matter present and, extracting the resulting product with chlorinated solvent and concentrating under vacuum using aqueous tetrahydrofuran or in admixture with other organic solvents to get highly pure levofloxacin hemihydrate having single individual impurity is less than 0.1% and free from particulate matter & from the other enantiomer (R-form).
本发明涉及一种改进的制备左氧氟沙星半水合物的方法,该方法具有单个杂质不超过0.1%且不含颗粒物和其他对映体(R-型)的特点。该方法包括将左氧氟沙星技术级溶解在水性碱性溶液中,将所得溶液在室温下用活性炭处理,通过过滤去除未溶解的颗粒物,使用稀酸将水性碱性左氧氟沙星溶液的pH值调节至中性,通过过滤去除沉淀的颗粒物,使所得溶液酸化,将酸化的溶液在室温下用活性炭处理,通过过滤去除未溶解的颗粒物,中和酸性溶液,再次过滤去除任何存在的颗粒物,并用氯化溶剂提取所得产物,并在水合四氢呋喃或与其他有机溶剂混合物中使用真空浓缩,以得到单个杂质小于0.1%且不含颗粒物和其他对映体(R-型)的高纯度左氧氟沙星半水合物。