601347 Disclosed is a crystalline polymorph of a compound of formula (I) also known as 3-[[[6- Deoxy-4-O-(3,5-dichloro-2-ethyl-4,6-dihydroxybenzoyl)-2-O-methyl-?-Dmannopyranosyl] oxy]-methyl]-12(R)-[[6-deoxy-5-C-methyl-4-O-(2-methyl-1-oxopropyl)-?-DIyxo- hexopyranosyl]oxy]-11(S)-ethyl-8(S)-hydroxy-18(S)-(1(R)hydroxyethyl)-9,13,15-trimethyloxacyclooctadeca-3,5,9,13,15-pentaene-2-one characterized by a powder x-ray diffraction pattern with at least peaks at diffraction angles 2? of 7.6°, 15.4°, and 18.8° ± 0.1 and a Differential Scanning Calorimetry (DSC) endothermic curve starting at about 150°C and with a peak at about 158 °C. Also disclosed are pharmaceutical compositions comprising the polymorph. The compositions are useful in preventing or treating a bacterial infection in particular Clostridium difficile infection.
