The present invention relates to an injectable pharmaceutical formulation comprising a compound of formula (I) said formulation being buffered to a pharmaceutically acceptable pH-value, especially a pH-value of from 2 to 6, in particular a pH value of from 3 to 5.5, preferred a pH-value of about 4 to 5, particularly preferred about 5.本發明關於包含式(I)之化合物的可注射藥學調配物該調配物係經緩衝至藥學可接受之pH值,尤其是2至6之pH值,特別是3至5.5之pH值,較佳為約4至5之pH值,特佳為約5。