NCIt definition : The ethylsuccinate salt form of erythromycin, a broad-spectrum, topical macrolide
antibiotic with antibacterial activity. Erythromycin ethylsuccinate diffuses through
the bacterial cell membrane and reversibly binds to the 50S subunit of the bacterial
ribosome. This prevents bacterial protein synthesis. Erythromycin ethylsuccinate may
be bacteriostatic or bactericidal in action, depending on the concentration of the
drug at the site of infection and the susceptibility of the organism involved.;