Effect of various cryoprotectants on freeze-drying of liposomes containing na methotrexate

摘要

The use of liposomes for the delivery of therapeutic agents, such as enzymes, hormones and anti-cancer drugs, is well established. In general, the proposed types of liposomes do not meet the required standards for long-term stability of pharmacentical preparations if they are stored as aqueous dispersions. The encapsulated drug tends to leak out of the bilayer structure and the liposome might aggregate or fuse on storage. The leakage problem is one of the limiting factors in commercial development of liposome products. Nevertheless, limited success was attained to improve the long-term retention of encapsulated solutes by freeze-drying. Crowe et al. found that only trehalose provided satisfactory cryoprotection in their laboratory experiments. The purpose of this study was teo examine the ability of different cryoprotectants to protect Na methotrexate liposomes vesicles from leakage during freeze-drying process.