Is there an alternative to erythrocin syrup, because it lacks a lab?

Erythrocin syrup contains erythromycin ethylsuccinate equivalent to 250 mg/5 ml of erythromycin. One has chosen this erythromycin derivative because erythromycin is not Resistant to the acid of the stomach. This raw material cannot be purchased; Ankle erythromycin. You could prepare erythromycin capsules and make them gastro-resistant with CAP. I hope the patiênt can take these capsules. There is currently a syrup, which facilitates the intake of capsules in children and elderly people. The brand name is Gloup.