Liposomes and lipid membranes in capillary electromigration and liquid chromatography techniques in studies of beta blockers

In the literature part, different analytical techniques for investigating drug-lipid interactions were reviewed, with the emphasis being on capillary electromigration and liquid chromatog-raphy techniques involving the use of artificial lipid vesicles called liposomes. Special interest was reserved for studies on beta blockers, a class of cardiovascular drugs. In addition, com-mercial intravenous lipid emulsions were introduced and in vivo and in vitro research on them was reviewed, mainly focusing on studies of their application in treatment of drug over-doses. Other methods for studying drug-lipid interactions were also briefly discussed and compared to electrophoretic and chromatographic techniques. In the experimental part, the interactions of seven beta blockers with a commercial intrave-nous lipid emulsion, Intralipid, were studied by a capillary electrophoresis technique called liposome electrokinetic chromatography. Electrophoretic mobilities of the analytes in a capil-lary filled with Intralipid solution were determined. From the mobilities of the analytes and Intralipid solution, retention factors and distribution coefficients for the beta blockers were determined. The values were compared with literature octanol/water partition coefficients and experimentally determined partition coefficients from previous research. The particle sizes of the lipid emulsion were studied by dynamic light scattering and flow field-flow fractionation. Other capillary electromigration techniques such as partial-filling electrokinetic chromatog-raphy and capillary electrophoresis frontal analysis were also briefly performed, and the results were compared with liposome electrokinetic chromatography. Also, interactions of the In-tralipid solution with the silica capillary wall were studied