Erythromycin-Benzoyl Peroxide Topical Gel contains erythromycin
[(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-hexa-methyl-6-[[3,4,6-trideoxy-3-(dimethylamino)-β-D-xylo-hexopyranosyl]oxy]oxacyclotetradecane-2,10-dione].
Erythromycin is a macrolide antibiotic produced from a strain of Saccharopolyspora erythraea (formerly Streptomyces erythreus). It is a base and readily forms
salts with acids.
Chemically, erythromycin is (C37H67NO13). It has the following structural
formula:
Erythromycin has the molecular weight of 733.94. It is a white crystalline
powder and has a solubility of approximately 1 mg/mL in water and is soluble in
alcohol at 25°C.
Erythromycin-Benzoyl Peroxide Topical Gel also contains benzoyl peroxide for
topical use. Benzoyl peroxide is an antibacterial and keratolytic agent.
Chemically, benzoyl peroxide is (C14H10O4). It has the following structural
formula:
Benzoyl peroxide has the molecular weight of 242.23. It is a white granular
powder and is sparingly soluble in water and alcohol and soluble in acetone,
chloroform and ether.
Each gram of Erythromycin-Benzoyl Peroxide Topical Gel contains, as
dispensed, 30 mg (3%) of erythromycin and 50 mg (5%) of benzoyl peroxide in a
base of purified water USP, carbomer, alcohol 20%, sodium hydroxide NF, docusate
sodium and fragrance.