| Abstract: | Interaction of cephalosporin antibiotics with flat bilayer lipid membranes (BLM) composed of vegetative or bacterial phospholipids was studied with respect to their effect on electroconductivity, capacity for binding to the bilayers and capacity for transmembrane transfer through the bilayers. By their effect on conductivity, the investigated cephalosporins could be divided into three groups: those having no effect on conductivity at the maximum concentrations (up to 1 mg/ml) i.e. cefoperazone, cefotaxime and ceftizoxime, those having an effect on conductivity at concentrations of 0.2 to 0.5 mg/ml i.e. cephalexin and cephalothin and those having a significant effect on conductivity at concentrations of 10 to 60 micrograms/ml i.e. N-acyl derivative of 7-ACA (substance 64) and 7-ACA derivative (substance 71). The cephalosporins had a capacity for binding to the bilayers and for incorporation into the bilayers. They penetrated to some extent through the bilayers composed of either vegetable or bacterial phospholipids. The lower rate of penetration through the BLM as compared to that of penicillins must be due to lower hydrophobicity of the cephalosporin molecules as compared to that of penicillins. |
