Investigation of the Enantioseparation of Basic Drugs with Erythromycin Lactobionate as a Chiral Selector in CE

Abstract

The macrocyclic antibiotics including ansamycins, glycopeptides, aminoglycosides and polypeptides have been demonstrated to exhibit powerful enantioselectivity towards numerous chiral compounds. By comparison with the four classes of antibiotics, macrolides are another type of macrocyclic antibiotics. In this study erythromycin lactobionate belonging to the group of macrolides is first used as a chiral selector in CE for the enantiomeric separations of basic drugs. As observed, erythromycin lactobionate allowed excellent separation of the enantiomers of N,N-dimethyl-3-(2-methoxyphenoxy)-3-propylamine, propranolol and duloxetine, as well as partial enantioresolution of primaquine, chloroquine and nefopam. In addition, erythromycin lactobionate possesses advantages such as high solubility and low viscosity in the solvent and very weak UV absorption. Among several experimental factors including buffer pH, BGE and erythromycin lactobionate concentrations, capillary temperature and applied voltage, we found that the enantioseparations of basic drugs above-mentioned strongly depended on the pH of BGE and the concentration of the chiral additive. The optimum pH was in the neutral or weak basic region but varied among drugs. An erythromycin lactobionate concentration of about 10% (w/v) and a low capillary temperature of 16 °C were recommended for the practical analysis.