ABSTRACT
The stability of liposomes and efforts to improve them by physical and chemical means are extremely important issues, especially with the commercialization of liposome products. Stability of liposomes depends on intraliposomal and interliposomal forces, including intrinsic tensions, interactions with other liposomes, extrinsic particles, and agents. Liposome structure and its stability are due to several forces and energy contributions from hydration of polar heads and their electrostatic/dynamic interactions with solvents and solutes, hydrophobic interaction, and attractive London-van der Waals dispersive forces between hydrocarbon chains. In the broadest sense liposome stability involves the stability of the particle and its constituents including the entrapped molecules in any, including liposomicidal, environment. In addition to some theoretical considerations there are many practical aspects of liposome colloidal stability. The stability of colloidal particles against aggregation is normally described by the Derjaguin-A. I. Landau-E. J. Verwey-J. T. G. Overbeek theory. Commercial application of liposomes require also the stability of liposomes on the shelf.
