Lipophilicity study of eight cephalosporins by reversed-phase thin-layer chromatographic method

The lipophilicity (R-M0) and specific hydrophobic surface area for the representatives of four generation cephalosporins have been determined by reversed-phase thin-layer chromatography, and the effect of different mobile-phase modifiers (such as methanol, acetonitrile, acetone, 1,4-dioxane and 2-propanol) on the retention has been studied. The compounds studied showed typical retention behavior; their R-M values decreased linearly with increasing concentration of the organic modifier in the eluent. The linear correlations between the volume fraction of the organic solvent and the R-M values over a limited range were established for each solute, resulting in high values of correlation coefficients (>0.95 in most cases). R-M values were determined by various concentrations of organic modifier, and the correlation obtained was extrapolated to 0% of organic modifier. Chromatographically established logP (R-M0) parameters were compared with computationally calculated partition coefficients values (AClogP, ALOGP, KOWWIN, ALOGPs, XLOGP2, MLOGP and XLOGP3) and experimental octanol-water logP values (measured by the shake flask method). The received results demonstrate that RP-TLC may be a good alternative technique for analytics in describing the lipophilic nature of investigated cephalosporins as well as the activity. Copyright (c) 2015 John Wiley & Sons, Ltd.