INTERACTION OF ENROFLOXACIN WITH PHOSPHOLIPID MONOLAYER AND BILAYER

In the present paper interactions between enrofloxacin and phosphatidy lcholine, dipalmitoylphosphatidylcholine, and mixtures of these lipids with cholesterol were studied by different techniques. Hydrophobic in teractions were determined by differential scanning calorimetry, carbo xyfluorescein leakage from liposomes, and compression isotherms of mix ed monolayers. The penetration kinetics as well as the polarization ch anges of the anilinonaphthalene sulfonate probe inserted into liposome s were used to study the effect of the drug in the lipid polar head mo tion. The drug was unable to form monolayers and compression isotherms showed a low level of drug interaction with phospholipids. This was a lso confirmed by differential scanning calorimetry measurements in whi ch no change in the main transition temperature was observed but a sli ght broadening of the peaks. However, a strong influence in the fluidi ty of the polar part of the bilayers after incubation of liposomes wit h enrofloxacin was found.