ABSTRACT
Objective To establish an innovative methods for the identification of nimodipine polymorphs. Methods Nimodipine of two crystal forms were prepared by rapid solvent removal and identified by powder X-ray diffraction, infrared spectroscopy and Raman spectroscopy.The dissolution study of the powder samples were carried out in six different mediums. Results Powder X-ray diffraction patterns of crystal form A and B could be used for the identification of crystal forms of nimodipine.Crystal form B has characteristic diffraction peaks at 2θ=5° and 2θ=13° in the pattern,while crystal form A has characteristic diffraction peaks at 2θ=27° distinguishing two crystal forms effectively. Raman spectrum could be used to identify the crystal forms.Compared with Raman spectra of crystal form B, there exists characteristic scattering peak at 500 cm-1 in crystal form A. According to the position and intensity of the peaks of crystal form A and B, it could distinguish two crystal types effectively.The results of dissolution tests showed that the solubility of crystal form A is better than crystal form B. Conclusion Various analysis techniques in different principle were used in the research, such as Powder X-ray diffraction, Infrared spectroscopy and Raman Spectroscopy etc.Crystal forms were confirmed in several aspects according to the properties of different crystal form, and the solubility of crystal form A is better than crystal form B.
ABSTRACT
Objective To establish an innovative methods for the identification of nimodipine polymorphs. Methods Nimodipine of two crystal forms were prepared by rapid solvent removal and identified by powder X-ray diffraction, infrared spectroscopy and Raman spectroscopy.The dissolution study of the powder samples were carried out in six different mediums. Results Powder X-ray diffraction patterns of crystal form A and B could be used for the identification of crystal forms of nimodipine.Crystal form B has characteristic diffraction peaks at 2θ=5° and 2θ=13° in the pattern,while crystal form A has characteristic diffraction peaks at 2θ=27° distinguishing two crystal forms effectively. Raman spectrum could be used to identify the crystal forms.Compared with Raman spectra of crystal form B, there exists characteristic scattering peak at 500 cm-1 in crystal form A. According to the position and intensity of the peaks of crystal form A and B, it could distinguish two crystal types effectively.The results of dissolution tests showed that the solubility of crystal form A is better than crystal form B. Conclusion Various analysis techniques in different principle were used in the research, such as Powder X-ray diffraction, Infrared spectroscopy and Raman Spectroscopy etc.Crystal forms were confirmed in several aspects according to the properties of different crystal form, and the solubility of crystal form A is better than crystal form B.