Isolation and solid-state characteristics of a new crystal form of indomethacin
β Scribed by Shan-Yang Lin
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 506 KB
- Volume
- 81
- Category
- Article
- ISSN
- 0022-3549
No coin nor oath required. For personal study only.
β¦ Synopsis
A new polymorphic crystal form of indomethacin was precipitated from an aqueous solution of indomethacin and beta-cyclodextrin by titration with a 0.5 N HCl aqueous solution. Three polymorphs (alpha, beta, and gamma forms) and a new crystal form were differentiated with thermal analysis, infrared spectroscopy, powder X-ray diffractometry, thin-layer chromatography, elemental analysis, and Fourier transform infrared (FTIR) spectroscopy with a newly developed FTIR microscope equipped with a thermal analyzer. The new crystal polymorph of indomethacin exhibited endo- and exothermic peaks near 102.8 and 104.1 degrees C, respectively, because of phase transitions without weight loss, followed by two additional endothermic peaks at 151 and 158.9 degrees C, because of fusion. The differential scanning calorimetry-FTIR system can be used to examine the correlation between structural change of C = O stretching bands of this new polymorph and its thermal response. The new crystal form contained some gamma-form crystals, determined with an FTIR microscope equipped with a mapping option. Solid-state carbon-13 nuclear magnetic resonance spectra of the polymorphs of indomethacin were also examined.
π SIMILAR VOLUMES
LY334370 HCl, a 5HT1f agonist investigated for the treatment of migraines, was identified in five crystal forms: three anhydrates (I-III), a dihydrate, and an acetic acid solvate. The identification and characterization of these crystal forms by optical microscopy, differential scanning calorimetry,
Single crystals of a new form of \(\mathrm{K}_{2} \mathrm{FeF}_{5}\) have been grown by hydrothermal synthesis in concentrated HF solutions. The structure is established from single crystal X-ray diffraction data: space group Pbam, \(Z=8, a=7.3591\) (4) \(\AA, b=23.0897\) (10) \(\AA\), and \(c=5.705