The Bioavailability of Erythromycin Stearate versus Enteric-Coated Erythromycin Base When Taken Immediately before and after Food

Abstract

Erythromycin plasma concentrations were determined in twenty subjects after a single dose, immediately before food, of erythromycin, 500 mg, as: erythromycin stearate (Erythrocin®, 500 mg, ovaloid tablets), and erythromycin base (Eryc®, 250 mg, capsules containing enteric-coated pellets). Plasma concentrations were again determined in eighteen of the original subjects with the same dose given immediately after food. Maximum Plasma Concentrations (mcg/ml) Erythromycin stearate was more bioavailable than erythromycin base when administered immediately before food. The preparations were bioequivalent when given immediately after food. Erythromycin stearate was more bioavailable than erythromycin base when administered immediately before food. The preparations were bioequivalent when given immediately after food.