Treatment of tumour bearing mice with liponsome-entrapped actinomycin D prolongs their survival.

The possibility of employing liposome-entrapped actinomycin D for the treatment of AKR mice inoculated with AKR-A cells was examined. It was found that injection of actinomycin D after its entrapment in liposomes prolonged the survival of such mice to a greater extent than did similar amounts of free actinomycin D. Data from in vitro experiments suggest that entrapped actinomycin D could localize in the nucleus of AKR-A cells presumably following endocytosis of the liposomal carrier and subsequent liberation of the drug in, and its diffusion from, the lysosomes.