(3S)-10-Fluoro-3-methyl-9-(4-methylpiperazin-1-yl)-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid;(S)-10-fluoro-3-methyl-9-(4-methylpiperazin-1-yl)-7-oxo-3,7-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid ; Levofloxacin 9-Piperazinyl Isomer ; 10-Fluoro Impurity;