Name: Erythromycin Ethylsuccinate USP

T.S.No.: SPEC/API/HEES-007/D/01
Issue Date: 01/03/2006


CAS: 1264-62-6

Storage: Preserve in tight containers.

Supersede: SPEC/API/HEES-007/D
Date: 01/04/2002

M.F.:  C43 H75 NO16

M.W.: 862.05g/mole







White or slightly yellow crystalline powder. Is should be odorless or practically odorless, and should practically tasteless.



Very slightly soluble in water; freely soluble in alcohol, in chloroform and in polyethylene glycol 400.

Identification      (By IR)


The Infra red absorption spectrum should concordant with the spectrum obtained from working std of Erythromycin Ethylsuccinate or with the reference Infra red spectrum graph.



Meets the requirements, except that when it is labeled as being in the amorphous state is does not meet the requirement.

X ray diffraction


Where labeled as being in the amorphous state in the x ray diffraction state performed at high sensitivity for angles of diffraction between 20 and 200 exhibits no reflection, and between 70 and 100 exhibits a more intense hachured baseline, creation a halo.

Water Content


Not more than 3.00%w/w.

Residue on Ignition


Not More Than 1.00%w/w.

Related Compounds


Any individual compound should not be more than 3.00%.
Erythromycin-A enol ether should not be more than 3.00%.

Erythromycin N- ethylsuccinate should not be more than 3.00%.

Residual solvents


Acetone: Not more than 5000.00 ppm.

Methylene Chloride: Not more than 600.00 ppm.



Sum of Erythromycin A, Erythromycin B and Erythromycin C is not less than 76.5% calculated on the anhydrous basis. The percentage of Erythromycin B should not more than 12.00% and the percentage Erythromycin C should not more than 5.00%.

End of specification