Reversed-phase thin-layer chromatography technique for the comparison of the lipophilicity of selected non-steroidal anti-inflammatory drugs.

The chromatographic behavior of a series of coxibs and oxicams, drugs from a group of non-steroidal anti-inflammatory drugs, was studied by reversed-phase thin-layer chromatography with binary mobile phases containing water and the organic modifiers: methanol, acetone, 1,4-dioxane, acetonitrile and 2-propanol. Linear relationships were obtained between the retention RM values of the compounds and the concentration of organic modifier in the mobile phase. Values of RM0, represent the theoretical RM values at 0% organic solvent in the mobile phase were calculated by extrapolation. These experimental lipophilicity values were correlated with lipophilicity (logP) from databases. The obtained results show that reversed-phase chromatography (experimental parameters) may be a good instrument for analytics in describing the lipophilic nature of investigated compounds as well as the activity.