STABLE CRYSTAL OF ?-LACTAM COMPOUND

摘要

A stable crystal (I-form crystal) of (4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-({4-[(5S)-5- methyl-2,5-dihydro-1H-pyrrol-3-yl]-1,3-thiazol-2-yl}thio)-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid that has desirable characteristics as the active ingredient of drugs, and a method of producing the I-form crystal characterized by comprising desolvating the solvated crystal of the above compound.