Figure 2. Histograms representing the measured permeability coefficients of fleroxacin, pefloxacin and enrofloxacin across DPhPC lipid vesicle membranes as a function of pH.

The counts provided here are normalised to the total number of vesicles detected in each case, to enable direct comparison of the permeability coefficients across the different conditions. For all three fluoroquinolones, the permeability increases as we increase the pH from acidic (pH 5) to neutral values. The mean permeability coefficients are reported in Table 1. From the histograms, we observe that fleroxacin has the lowest permeability of the three drugs, and enrofloxacin the highest. Separate histograms and the experimental scatter plots for each condition are provided in the Supplementary Information.