Kinetic study on the hydrolysis of erythromycin ethyi succinate

The stability of erythromycin ethyl succinate in prepared aqueous and pharmaceutical suspensions was investigated. The released free erythromycin base has been monitored by derivative spectrophotometric measurement of the yellow color formed after dilution with 9 N hydrochloric acid. The proposed analytical method has been optimized and validated. The activation energy for the hydrolysis of the ester in buffer [pH 7] was found to be 2.0839 Kcal./mole. In oral suspension for pediatric use, the ester was found to be stable for at least 15 days after reconstitution