THERMAL-BEHAVIOR AND SOLUBILITY OF FENOPROFEN CALCIUM

The thermotropic mesomorphism and the solubility of the supercooled th ermotropic mesophase of the nonsteroidal antiinflammatory drug fenopro fen calcium are investigated, The thermotropic mesophase is investigat ed by different methods, including SEM, ODSC, FTIR, WAXD and TEM. The mesophase formation is found to be basically due to the loss of the cr ystalline bound water, and does not lead to a true melt (SEM, ODSC). T he mesophase is determined to be of thermotropic (reversed) hexagonal type, which for the first time could be visualized by transmission ele ctron microscopy (WAXD, TEM). The structure of the supercooled mesopha se which can be obtained by cooling the mesophase to room temperature, is identical with the structure of the thermotropic liquid crystal (W AXD). The solubility and the dissolution rate of the supercooled mesop hase in water is higher than that of the crystalline dihydrate. The su percooled mesophase however, can only be used to increase the pharmace utical availability of fenoprofen calcium, if water contact during sto rage is avoided.