New crystal form of moxifloxacino chlorhydrate.

New crystalline form of moxifloxacin hydrochloride. The present invention relates to a new stable crystalline form of moxifloxacin hydrochloride, the process of its preparation and its use in the preparation of pharmaceutical compositions. A process is provided comprising dissolving crude moxifloxacin hydrochloride in a methanol / water mixture by heating at reflux temperature; add acetone and the solution is brought to a temperature between 40 and 45 ° C; cooling the solution to a temperature between 15 and 25 ° C; separate the crystals formed by filtration; wash and dry the product obtained to constant weight.