Direct enantiomeric separation of cis-(±)diltiazem in plasma by high-performance liquid chromatography with ovomucoid column

Abstract

A method is proposed for the direct enantiomeric separation of cis-(±)diltiazem in plasma. The method is based on a commercial Ultron ES-OVM column with a mobile phase of different mixtures of ethanol—phosphate buffer. The degree of extraction of the enantiomers was more than 86%. The detection limit of the method used was 5 ng of racemic mixture on column (coefficient of variation = 13%), corresponding to 3.2 ng for cis-(+)diltiazem and 1.8 ng for cis-(−)diltiazem.