Preparation, characterization and in vivo evaluation of 2-methoxyestradiol-loaded liposomes

This study systematically investigated the intravenous injection formulation of liposomes loaded with 2-methoxyestradiol (2-ME), a poor water soluble anti-tumor drug. The objective of this study was to design passive targeting nanoliposome which could improve therapeutic efficacy and liver first pass effect. Based on the optimized conditions of single-factor and orthogonal design, 2-ME-loaded liposomes were prepared by the aether injection method. The formulated liposomes were found to be relatively uniform in size with a negative zeta potential. The average drug entrapment efficiency and loading were 85% and 8%, respectively. The overall targeting efficiency (TEC) of the 2-ME-loaded liposomes was enhanced from 40.29% to 88.32% in the lung. The lung damage caused by liposomes was less severe than that by solution. These results indicated that 2-ME liposomes could mainly deliver the drug to the lungs and make the drug accumulate in the lungs, which changed the disposition behavior in vivo, decreased the toxic and side effects on other tissues and reduced the severity of damage to lungs following intravenous injection. (C) 2009 Elsevier B.V. All rights reserved.