Mechanism for translocation of fluoroquinolones across lipid membranes

► Ciprofloxacin diffuses in water as concerted stacks. ► Stacks of ciprofloxacin dissolve as they enter lipid membranes. ► Translocation of ciprofloxacin through lipid membranes takes place in monomeric form. ► Ciprofloxacin diffuses through a lipid membrane in its neutral form.