Separation of erythromycin and related substances on base-deactivated reversed-phase silica gel columns

An official liquid chromatographic method for the analysis of erythromycin and related substances, which is based on a polymer reversed-phase, is desc ribed in the European Pharmacopoeia and in the United States Pharmacopeia. The pH of the mobile phase used in this system is 9.0. Recent advanced tech nology has led to the introduction of a new generation of silica-based reve rsed-phase column packings, which are claimed to be much more stable toward s bases. They are useful for the analysis of basic compounds. Studies to ve rify the separation of erythromycin and related substances on Hypersil BDS C-18, Luna C-18(2), Inertsil ODS-2 and Supelcosil ABZ+ have been performed and the results are presented. It is shown that these base-deactivated phas es give a better sensitivity and selectivity towards erythromycins than me polymer phase, provided that an adapted mobile phase is used. This is the f irst liquid chromatographic method described for the separation of erythrom ycin D from erythromycin A. (C) 2000 Elsevier Science BN. All rights reserv ed.