title: Partitioning of flunitrazepam into model membranes studied by temperature controlled gel filtration chromatography.
abstract: The use of gel filtration chromatography with Sephadex as a separation medium was used in order to study flunitrazepam (FNTZ) partitioning into artificial model membranes consisting of dipalmitoyl-phosphatidylcholine (dpPC) vesicles, under controlled temperature conditions. In this system two phenomena are taking place simultaneously: the ligand-liposome interaction and the lipid self-aggregation to form the liposome. The liposome-FNTZ interaction was evidenced by the non-enantiography of the first derivative of FNTZ elution peak in frontal chromatography through Sephadex G-75. On the other hand, the presence of FNTZ reduced liposomes mean size and increased their size dispersion as evidenced by molecular filtration through Sephadex G-200. The dpPC-buffer FNTZ partition coefficient determined in zonal chromatography through Sephadex G-10 increased about 33% when the temperature rose above the temperature of dpPC transition from the liquid crystalline to the fluid phase. Gel filtration chromatography seems a suitable technique to study lipid liposome-FNTZ interactions at a qualitative level. In addition, this technique has the advantage over other methods of giving the possibility of observing the mutual effects exerted between the drug and the self-aggregating structure.
authors.affiliation: Cátedra de Química Biológica, Facultad de Ciencias Exactas, Físicas y Naturales, Córdoba, Argentina.
authors.forename: D A
authors.initials: DA
authors.lastname: García
authors.forename: M A
authors.initials: MA
authors.lastname: Perillo
mesh_terms: D002850:Chromatography, Gel / Q000379:methods*; D005445:Flunitrazepam / Q000737:chemistry*; D018757:GABA Modulators / Q000737:chemistry*; D008081:Liposomes; D008567:Membranes, Artificial; D013696:Temperature; D014316:Tritium
chemical_list: D018757:GABA Modulators; D008081:Liposomes; D008567:Membranes, Artificial; D014316:Tritium; D005445:Flunitrazepam