Abstract: The present invention aims to provide a solid pharmaceutical composition comprising: (a) an effective antibacterial quantity of antibiotic from the quinolone family, preferably, moxifloxacin or a pharmaceutically acceptable salt thereof; and (b) a pharmacologically acceptable carrier or excipient compatible with the active ingredient, said excipient being lactose-free. The invention also includes a process for obtaining a solid pharmaceutical composition comprising, as an active ingredient, an antibiotic from the quinolone family, with said process comprising the steps of: (a) mixing and homogenizing the active ingredient and dry excipients in the granulator, i.e.