Erythromycin Tablets, USP are an antibacterial product containing erythromycin, USP in a unique, nonenteric film coating for oral administration. Erythromycin Tablets are available in two strengths containing 250 mg or 500 mg erythromycin base.
Erythromycin is produced by a strain of Saccharopolyspora erythraea (formerly Streptomyces erythraeus) and belongs to the macrolide group of antibiotics. It is basic and readily forms salts with acids. Erythromycin is a white to off-white powder, slightly soluble in water, and soluble in alcohol, chloroform, and ether. Erythromycin is known chemically as (3R*, 4S*, 5S*, 6R*, 7R*, 9R*, 11R*, 12R*, 13S*, 14R*)-4-[(2,6-dideoxy-3-C-methyl-3-O-methyl-α-L- ribo-hexopyranosyl)oxy]-14-ethyl-7,12,13-trihydroxy-3,5,7,9,11,13-hexamethyl-6-[[3,4,6-trideoxy-3-(dimethylamino)- β-D- xylo–hexopyranosyl]oxy]oxacyclotetradecane-2,10-dione. The molecular formula is C 37H 67NO 13, and the molecular weight is 733.94.