Analysis of the retention behavior of selected antiarrhythmics by means of thin-layer chromatography

The retention behavior of ivabradine, its 11 related compounds, diltiazem and verapamil has been examined by thin-layer chromatography using non-polar stationary phase (RP-18) and the following mobile phases: methanol-6.25% aqueous ammonia, tetrahydrofuran - 6.25% aqueous ammonia, and also polar stationary phase (silica gel) with tetrahydrofuran - 6.25% methanolic ammonia as mobile phase. In the examined chromatographic systems, linear relationships were established between the retention coefficients, R-M(0) and m, and molecular properties of the investigated antiarrhythmic drugs. The Quantitative Structure Retention Relationship (QSRR) modeling was performed with use of the stepwise multiple linear regression, in order to select the most important molecular properties which influence the retention behavior. The developed models revealed that apart from lipophilicity also the molecular volume (V), and the hydrogen bond basicity (B) of the tested compounds are the most important for the retention behavior in the examined chromatographic systems.