Characterization of melt-quenched and milled amorphous solids of gatifloxacin.
The objectives of this study were to characterize and investigate the differences in amorphous states of gatifloxacin. We prepared two types of gatifloxacin amorphous solids coded as M and MQ using milling and melt-quenching methods, respectively. The amorphous solids were characterized via X-ray diffraction (XRD), nonisothermal differential scanning calorimetry (DSC) and time-resolved near-infrared (NIR) spectroscopy. Both the solids displayed halo XRD patterns, the characteristic of amorphous solids; however, in the non-isothermal DSC profiles, these amorphous solids were distinguished by their crystallization and melting temperatures. The Kissinger-Akahira-Sunose plots of non-isothermal crystallization temperatures at various heating rates indicated a lower activation energy of crystallization for the amorphous solid M than that of MQ. These results support the differentiation between two amorphous states with different physical and chemical properties.
a Faculty of Pharmacy , Research Institute of Pharmaceutical Sciences, Musashino University , Nishitokyo-shi , Tokyo , Japan.
Yusuke
Y
Hattori
a Faculty of Pharmacy , Research Institute of Pharmaceutical Sciences, Musashino University , Nishitokyo-shi , Tokyo , Japan.
Ayumi
A
Suzuki
a Faculty of Pharmacy , Research Institute of Pharmaceutical Sciences, Musashino University , Nishitokyo-shi , Tokyo , Japan.
Makoto
M
Otsuka
D002152:Calorimetry, Differential Scanning / Q000379:methods*; D003460:Crystallization; D004355:Drug Stability; D024841:Fluoroquinolones / Q000737:chemistry*; D000077734:Gatifloxacin; D019265:Spectroscopy, Near-Infrared; D044366:Transition Temperature; D014961:X-Ray Diffraction
D024841:Fluoroquinolones; D000077734:Gatifloxacin
Amorphous solid; X-ray diffraction; gatifloxacin; non-isothermal DSC; time-resolved near-infrared spectroscopy