[Comparison of the bioavailabilities of erythromycin estolate and erythromycin ethylsuccinate dry suspension preparations in steady state].

Relative bioavailability of erythromycin was determined after multiple-dose administration of erythromycin estolate in comparison to erythromycin ethylsuccinate both given as oral suspensions to twelve healthy volunteers. The daily erythromycin dose of erythromycin ethylsuccinate was 50% higher than the respective dose of erythromycin estolate; the dosage interval tau was 12 h for erythromycin estolate and 8 h for erythromycin ethylsuccinate. This scheme was planned in accordance to advices of the respective manufactures. Results of the study confirm the differences in extent of bioavailability of both erythromycin derivatives known from single-dose investigations. Furthermore, the experimental data show that a twice daily administration of 1000 mg erythromycin as erythromycin estolat resulted in sufficiently high plasma concentration of the active compound.