Determination of lipophilicity of some non-steroidal anti-inflammatory agents and their relationships by using principal component analysis based on thin-layer chromatographic retention data

The relative lipophilicity of ten non-steroidal anti-inflammatory agents have been determined by reversed-phase thin layer chromatography using different reversed-phase high-performance thin-layer chromatography plates and water–methanol mixtures as eluents. The compounds studied showed regular retention behavior, their R M values decreasing linearly with increasing concentration of methanol in the eluent. Principal component analysis allowed a more rational and objective estimation and comparison of lipophilicity determined by reversed-phase thin-layer chromatography. It also affords a useful graphical tool, since scatterplots of the scores onto the plane described by the first two components will have the effect of separating compounds from each other most effectively, thus obtaining a “congeneric lipophilicity chart”.