A relationship between diffusional transport in lipid membranes and a lipophilic-eutectic parameter.
A theoretical model has been developed to relate passive diffusional transport with a parameter termed the lipophilic-eutectic coefficient, Le. Based on this parameter it is proposed that the lipophilicity of a substance can be estimated. The method is based on the melting point lowering of a pure substance in the presence of an impurity of similar structure. Cholesterol was chosen as a model biological lipid because it is a neutral lipid that is found in relatively high concentrations in a variety of membranes. Transdermal absorption in humans and intestinal absorption in the rat both show a high degree of correlation with respect to Le. For our studies, Le appears to be as satisfactory as the partition coefficient for estimating lipophilicity and its determination is less demanding analytically.
Schultz
T W
TW
Philadelphia College of Pharmacy and Science, PA 19104.
Ando
H Y
HY
D000818:Animals; D001692:Biological Transport; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002784:Cholesterol / Q000378:metabolism; D004058:Diffusion; D006801:Humans; D007408:Intestinal Absorption; D008563:Membrane Lipids; D008566:Membranes / Q000378:metabolism*; D008954:Models, Biological; D051381:Rats; D012869:Skin Absorption; D012997:Solvents; D013256:Steroids / Q000378:metabolism; D013816:Thermodynamics
D008563:Membrane Lipids; D012997:Solvents; D013256:Steroids; D002784:Cholesterol