HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ANALYSIS OF ERYTHROMYCIN

Liquid chromatographic analysis can provide a simpler and superior alt ernative to microbial assay of antibiotics. A number of liquid chromat ographic methods for the analysis of erythromycin have been published in the past 17 years. However, many of these methods are complex and l ack the selectivity needed for the assay of erythromycin in the presen ce of erythromycin derivatives and impurities. We examined several C-1 8 based stationary phase columns and developed a significantly improve d C-18 liquid chromatographic method for the assay of erythromycin. In comparison to a recently published polymer (poly(styrene-divinylbenze ne)) stationary phase LC method, our method is simpler, more rugged, f aster, and more sensitive. The developed method has been successfully used for the analysis of erythromycin in commercial bulk samples. The chromatographic assay results correlate with microbiological assay.