PHYSICOCHEMICAL PROPERTIES AND BIOLOGICAL-ACTIVITIES OF ERYTHROMYCIN NALIDIXATE

Erythromycin nalidixate was prepared by combining nalidixic acid with erythromycin base. Thin-layer chromatographic studies and infrared abs orption spectrum confirmed homogeneity of the new salt. The salt is ve ry soluble in nonpolar solvent and freely soluble in polar solvent. Th e salt is quite stable at room temperature (30 +/- 1 degrees C). The a ntimicrobially active dose of the salt was found to be 820 mu g/mg. Se rum protein binding amounted to 85% and was reversible LD(50) in mice was found to be 371.5 mg/kg when the intraperitoneal route was used.