Cross-polarization/magic-angle spinning NMR studies of polymorphism: Androstanolone

Characterization of Lycopene Nanoparticles Combining Solid-State and Suspended-State NMR Spectroscopy

“…All NMR spectra were obtained on a Bruker DSX 200 NMR spectrometer. 13 C suspended-state NMR measurements were conducted by suspending the micronizates in D2O. Magic angle spinning was carried out with 4-mm double-bearing rotors of ZrO2 and a spinning rate of 4000 Hz at a probe temperature of 295 K. The 13 C 90°pulse length was 4.7 µs.…”

“…Magic angle spinning was carried out with 4-mm double-bearing rotors of ZrO2 and a spinning rate of 4000 Hz at a probe temperature of 295 K. The 13 C 90°pulse length was 4.7 µs. A total of 10K transients were accumulated at a time domain size of 3K data points with an acquisition time of 78 ms and a delay time of 10 s. 13 C solid-state NMR spectra were obtained with the cross-polarization/magic angle spinning (CP/MAS) technique. Magic angle spinning was carried out with 4-mm double-bearing rotors of ZrO2 and a spinning rate of 10 000 Hz at a probe temperature of 295 K. The proton 90°p ulse length was 4.7 µs, and the contact time and delay time were 3 ms and 3 s, respectively.…”

NMR studies of organic polymorphs & solvates

“…Most NMR studies of stoichiometric hydrates make a point of reporting their 13 C spectra (sometimes of several compositions) and comparing them to those of anhydrous forms 23,47,49,54,69,72,105,107,110,113,128,140,154,160,[185][186][187]189,193,[199][200][201][202][203] but without any study of the hydration/dehydration process. Table 4 contains some relevant information.…”

Solid-State Nuclear Magnetic Resonance Spectroscopy-Pharmaceutical Applications

“…In a series of publications by Harris and Fletton, solid‐state NMR spectroscopy was used to investigate the structures of several polymorphs 151–155. The majority of these studies included X‐ray diffraction and IR techniques and also addressed the possibility of quantitative measurements of polymorphic mixtures.…”

“…In addition to the hydrogen bonding explanation of the crystallographic splittings, the use of NMR spectroscopy to quantitatively determine the amount of each pseudopolymorph present in a mixture was addressed. In the study of androstanolone,152 high‐quality 13 C NMR spectra were obtained by the CP/MAS technique, which permitted the characterization of the anhydrous and monohydrate forms. In this case, the crystallographic splittings were noted for the two forms and were correlated with hydrogen bonding.…”