||Abstract: "Both the permeability coefficients (Pd's) through lipid bilayer membranes of varying composition (lecithin [L], lecithin:cholesterol [LC], and spingomyelin:cholesterol [SC]) and the n-hexadecane:water partition coefficients (Knc's) of H2O and seven nonelectrolytes (1,6 hexanediol, 1,4 butanediol, n-butyramide, isobutyramide, acetamide, formamide, and urea) were measured."
||P.129 bottom paragraph: "Results: Table I summarizes [investigators’] findings. Column 1 lists the molecules investigated in the order of decreasing values of Khc [The partition coefficient], which are given in column 2. They span a range from 1,6 hexanediol (Khc=5.4×10^-4), the most lipophilic, to urea (Khc=3.5×10^-6), the least lipophilic. (Even the most lipophilic, hexanediol, is very hydrophilic.) Column 3 gives their diffusion constants (D) in water (at 25°C). Columns 4, 5, and 6 list the values for Pd [permeability coefficient] on lecithin membranes (L), lecithin:cholesterol membranes (LC), and sphingomyelin:cholesterol membranes (SC), respectively. (For L membranes, Pd's were not measured for hexanediol, n-butyramide, and isobutyramide, because unstirred layer corrections were too large: for SC membranes, Pd was not measured for urea, because its value was too small.) Column 7 gives Pd(n-butyramide) and Pd(H20) on SC membranes at 14.5°C. Columns 8, 9, and 10 list values of Pd/(DKhc/Δx) for L, LC, and SC membranes, where Δx, the thickness of the hydrocarbon interior of the membrane, is taken as 50Å." See notes beneath table