Abstract: The invention is directed to a crystalline anhydrate solvate of loracarbef, and also is directed to a process for preparing a crystalline monohydrate form of the compound of formula (I) ##STR1## which comprises drying a crystalline isopropanolate form of the compound of formula (I) at a temperature of from about 50.degree. C. to about 100.degree. C. to provide a crystalline anhydrate form of the compound of formula (I); and exposing the crystalline anhydrate form of the compound of formula (I) to a relative humidity of from about 90 to about 100%.