Optimizing the Preparation, Analysis and Formulation of Liposomes for Drug Delivery Applications

Abstract

Liposomes, and other lipid based carriers, are useful vehicles for drug delivery applications because they are relatively simple to make, are biocompatible and their size, chemical functionality and stability can be modulated to optimize the drug delivery process. Additionally, targeting moieties can be added to the surface of liposomes that enable specific targeting of tumor or other tissues and help to maximize drug delivery to the targeted area and to reduce non-specific delivery and toxicity.However, liposome size, stability and surface chemistry are all susceptible to changes in the surrounding environment including changes in pH, salt concentration, temperature and storage time. Thus it is critically important to optimize liposome preparation, analysis techniques and storage conditions to ensure that the final liposome formulation will be effective in its desired application.Here we discuss liposome preparation, analysis and formulation using light scattering techniques to assess liposome size and zeta potential, under a wide range of environmental conditions, including variations in temperature, salt concentration, lipid/liposome concentration. It is observed that variations in these parameters significantly affect both liposome size and zeta potential outcomes.