Liposomes with alpha-tocopherol membrane

Abstract

Liposomes, closed spherical structures formed by phospholipid bilayers, have been recognized as a controlled drug delivery system. We have studied the preparation and biocompatibility of liposomes based on soya phospholipids encapsulated with alpha-tocopherol. The binding efficiency of alpha-tocopherol was analysed by comparing two methods for liposome preparation: a) dry film (DFM) and b) solvent infusion method (SIM). The degree of encapsulation achieved (88-93%) suggested a high affinity of alpha-tocopherol for liposome membrane binding. The initial concentration of alpha-tocopherol had a significant effect on the degree of encapsulation, while the effect of method used was less pronounced. In general, a higher degree of encapsulation was achieved with smaller liposome size fractions. Based on an experimentally obtained size distribution function, it can be concluded that if smaller liposomes are used, SIM seems to be more efficient due to the higher content of smaller vesicles. The in vivo application of the liposomes to CBA mice confirmed the biocompatibility and nontoxicity of such preparations. The analysis of hematological parameters in peripheral blood (determination of mature blood cells with differential count) revealed that liposomes did not express cytotoxic effects on any of the parameters tested.