Abstract: 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?) of 5.6° and 10.4° 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° C. to 40° 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.

Abstract: Crystal form F of [2S, 4R, 5R, 8R, 9S, 10S, 11R, 12R]-9-[(2,6-dideoxy-3-C-methyl-3-O-methyl-?-L-ribo-hexopyranosyl)oxy]-5-ethyl-4-methoxy-2,4,8,10,12,14-hexamethyl-11-[[3,4,6-trideoxy-3-(isopropylmethylamino)-?-D-xylo-hexopyranosyl]oxy]-6,15-dioxabicyclo[10.2.1]pentadec-14(1)-ene-3,7-dione (E)-2-butenedioic acid salt (2:1) showing strong X-ray diffraction peaks at diffraction angles 2?=6.6° and 8.5°, Crystal form D anhydrate of said compound showing strong X-ray diffraction peaks at diffraction angles 2?=7.1°, 13.5° and 14.2°, Crystal form D X-hydrate of said compound showing strong X-ray diffraction peaks at diffraction angles 2?=7.1° and 14.2° but not showing a strong X-ray diffraction peak at a diffraction angle 2?=13.5°, Solvate Crystal forms G1, G2 and G3 of said compound characterized by 2-theta angle positions in the powder X-ray diffraction pattern of 5.4°, 10.4°, 10.7° and 12.1°.

Abstract: 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&thgr;) of 5.6° and 10.4° 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° C. to 40° 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.