抄録
Crystals of chloramphenicol obtained from about 30 kinds of solvents were analyzed by differential scanning calorimetry (DSC) for the detection of solvate formation. It was found that heterocyclic solvents such as pyridine and picolines formed solvates with chloramphenicol. Thermal behaviours of these solvates were further investigated by DSC under various conditions, by gas evolution analysis and by thermogravimetric analysis. The one-to-one solvate with pyridine was found most suitable to the size reduction by solvation and desolvation. The specific surface area of the desolvated chloramphenicol was 3.0-3.1m2/g. The heat of desolvation and the heat of transformation from the pyridinate to the desolvated chloramphenicol were 6.3±0.5 kcallmole and 5.0±0.5kcal/mole, respectively. Also, the activation energy for the desolvation reaction was estimated by boththe methods of ozawa and Kissinger to be 20.6±1.6 kcallmole and 20.0±0.8 kca1/mole, respectively.
