Reversed-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their active metabolites

Abstract

The chromatographic behaviour of some ACE inhibitors and their active metabolites was examined under conditions of reversed-phase thin-layer chromatography on RP-18 silica using water-methanol, water-ethanol and water-acetone as binary solvent systems. The relationship between the R M values and the concentration of organic modifier in the mobile phases was linear. It was found that an increase in the content of the organicmodifier in the employed solvent systems led to a decrease of the R M values, i.e., of the retention. Also, the more hydrophobic compounds had a longer retention. Based on regression analysis of the plots, the lipophilicity parameters RM0 and c0 were calculated. The chromatographically obtained lipophilicity parameters were correlated with the calculated log P values.