英文名称:13-Ethyl-17-hydroxy-18,19-dinorpregn-5(10)-en-20-yn-3-one; 17-Ethinyl-17-hydroxy-18-methylestr-5(10)-en-3-one; 13-Ethyl-17a-ethynyl-17-hydroxygon-5(10)-en-3-one; 13-Ethyl-17-hydroxy-18,19-dinor-17a-pregn-5(10)-en-20-yn-3-one(Levonorgestrel Impurity B); EP Levonorgestrel Impurity B