The major purpose of this work was to study the effect of various liposome formulations on transdermal iontophoretic transport of enoxacin through excised rat skin. The electrochemical stability of these liposomes was also evaluated. The enoxacin encapsulation percentage was significantly enhanced after 6h incubation in electric field, whereas the fusion of enoxacin liposomes was inhibited by application of electric current. The results of iontophoretic transport showed that the permeability of enoxacin released from liposomes was higher compared with that of free drug form. The iontophoretic permeability of enoxacin released from liposomes increased with a decrease in fatty acid chain lengths of phospholipid, which can be due to the various phase transition temperature of phospholipids. Incorporation of charged phospholipid in liposomes resulted in an alteration of transdermal behavior of enoxacin: the iontophoretic permeation as well as enoxacin amount partitioned in skin were greatly reduced after incorporation of stearyl amine in liposomes, which can be attributed to the competitive ion effect. The stratum corneum-based liposomes showed the highest amount of enoxacin partitioned into skin depot. The results of employing cathodal iontophoresis on negative charged liposomes suggested that liposomal vesicles or phospholipids may carry enoxacin into deeper skin strata via follicular route.
