An electrochemical method for the determination of liposome–water partition coefficients of drugs

An electrochemical method for the determination of the liposome–water partition coefficients of drugs was developed. Interactions of liposomes and β-blockers were studied using square wave voltammetry (SWV) at a water–DCE interface created at the tip of a micropipette. Five different β-blockers, propranolol, timolol, carteolol, nadolol and metoprolol were encapsulated in liposomes prepared using the extrusion method. The liposomes were made in three different sizes by varying the size of the pores in the polycarbonate membrane used in extrusion. The partition of five β-blockers between the cavity and the membrane of the liposome was determined.