Liposomal formulations of anticancer drugs: selectivity and effectiveness.

After a delay of roughly 30 years, liposomes are becoming important as drug-targeting systems especially in anticancer therapy. Two liposomal anthracycline formulations are now available for cancer treatment and more are in preclinical tests or in clinical trials. This review summarizes the possibilities to improve the anticancer activity of certain drugs by entrapment in liposomes. We will briefly examine the problems and limitations of liposomal systems, from a pharmacokinetic as well as from a manufacturing viewpoint. Moreover, the anticancer properties of the two new liposomal anthracycline formulations will be discussed with regard to anticancer activity and side effects and compared with the properties of the respective free drugs. Copyright 2000 Harcourt Publishers Ltd.