Exclusion of poly(ethylene glycol) from liposome surfaces.

The electrophoretic mobility of vesicles is measured for concentrations of poly(ethylene glycol) from 0 wt.% to 10 wt.%.

Interaction of electrically charged drug molecules with phospholipid membranes.

Model membranes (egg-yolk PC liposomes) were exposed to the cationic form of amphiphilic drugs. Microelectrophoresis was used to measure the change of the electrokinetic potential as a function of the drug concentration. By use of the Gouy-Chapman theory the surface potential and surface charge density were calculated.