FORMATION AND PROPERTIES OF HCO-10 VESICLES

The characteristics of poly(oxyethylene) hydrogenated easter oil ether (HCO-IO) vesicles were studied for the standpoints of encapsulation e fficiency, stability, solubilization and permeability or barrier effic iency. The vesicles of 5% HCO-10 had 6.24% of calcein-entrapment effic iency and 240 nm of mean diameter. The stability of HCO-10 vesicle sus pensions was dependent on their concentrations. In the vesicle suspens ions of 10% HCO-10 or more, both the size of the vesicles and the flui dity of the suspensions obviously varied with incubation time, indicat ing that a flocculation occurred; whereas, the vesicle suspension of 5 % HCO-10 was relatively stable. The solubilization process of HCO-10 v esicles by SDS was similar to that of EggPC liposomes. The rate consta nts for permeation of Cl ion and calcein were 2.46 x 10(-3) s(-1) and 5.79 x 10(-5) s(-1), respectively, suggesting that HCO-10 vesicles pos sessed some barrier potential for Cl ion and calcein although they wer e smaller than those of liposomes. Furthermore, the efflux of the solu te such as calcein from HCO-10 vesicles was maximum at 37 degrees C, w here the vesicle membrane was presumably destabilized by dehydration o f EOs in HCO-10 molecules.