Kinetic study on hemipenta hydrate risedronate monosodium in batch crystallization by cooling mode

The crystallization kinetics of hemipenta hydrate risedronate monosodium (RS) were investigated in cooling mode. The solubility, induction time, mechanism of nucleation and crystal growth in the crystallization of hemipenta hydrate RS in water as a solvent were determined by the in situ measurement using focused beam reflectance measurement (FBRM). The relationship between induction time and the supersaturation was obtained for understanding mechanism of nucleation. The nucleation mechanism including homogeneous and heterogeneous nucleation was grasped with respect to the supersaturation. From the results of nucleation experiments, the interfacial tension of hemipenta hydrate RS was determined. Furthermore, the kinetics of crystal growth was also obtained. The crystal growth of hemipenta hydrate RS was controlled by the combination of one and two-dimensional growth mechanisms.