ERYTHROMYCIN DERIVATIVE HAVING NOVEL CRYSTAL STRUCTURES AND PROCESSES FOR THEIR PRODUCTION

摘要

The present invention provides an E-type crystal of N-demethyl-N-isopropyl-12-methoxy-11-oxo-8,9-anhydroerythromycin A-6,9-hemiacetal fumarate having strong diffraction peaks at diffraction angles (2&thetas;) of 5.6 DEG and 10.4 DEG as measured by powder X-ray diffractometry, which is prepared by treating a C-type crystal of the compound in a mixed solvent of ethyl acetate and water at 20 DEG C to 40 DEG C, and a D-type crystal prepared via the E-type crystal. These crystals have a reduced content of residual solvent and high suitability for formulation. <IMAGE>