norfloxacin ep impurity b norfloxacin ethylenediamine analog 7-[(2-aminoethyl)amino]-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hcl价格
norfloxacin ep impurity b norfloxacin ethylenediamine analog 7-[(2-aminoethyl)amino]-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hcl价格共:1条