FLUOROQUINOLONE-BIOMEMBRANE INTERACTIONS - MONOLAYER AND CALORIMETRICSTUDIES

The interaction of two 6-fluoroquinolones, ciprofloxacin and its penty l derivative, with model membranes was studied as a function of drug h ydrophobicity as reflected in the pentyl side chain at position 4 in t he piperazinyl group, by epifluorescence surface balance technique and differencial scanning calorimetry. In the first part of this study dr ug incorporation in dipalmitoylphosphatidylcholine monolayers was inve stigated using epifluorescence microscopy, In the second part, the inf luence of the presence of the hydrophobic chain and fluoroquinolone co ntent on the thermotropic behavior of liposomes was investigated. Both monolayer and calorimetric studies demonstrated that hydrophobicity o f the drug had a role in determining the nature of drug-membrane inter action as seen in greater perturbations of the lipid packing by pentyl ciprofloxacin.