Radiopaque liposomes for computed tomography opacification

A low-osmolality tri-iodinated hydrosoluble uro-angiographic contrast medium (iopromide) was encapsulated into sonicated liposomes. Following in vitro experiments, the authors observed the kinetics and targeting of these radiopaque liposomes (ROL) in vivo (dogs) by scannography. The preliminary step was to investigate some of the factors which can influence the encapsulation efficiency and permit the best ratio iopromide/lipids. Systematic evaluations of encapsulation rates were assumed. Computed tomography (CT) enabled a linear relationship to be established between the concentration of ROL and contrast enhancement (r=0.996). CT scans were obtained after intravenous administration and contrast enhancement in different organs was investigated. It is concluded that liposome encapsulation of iopromide leads to hepatic uptake, local contrast enhancement and persistant opacification because of delayed renal elimination.<>