Solid-State Nuclear Magnetic Resonance Spectroscopy

The Use of 13C Labeling to Enhance the Sensitivity of 13C Solid-State CPMAS NMR to Study Polymorphism in Low Dose Solid Formulations

“…13 C CPMAS NMR would result in prohibitively long measuring times in our case. Therefore, we undertook 13 C labeling of those 13 C nuclei, which give resonances diagnostic for the crystal form in solid-state 13 C CPMAS NMR. Org OD 14 was labeled both at the 19-and 20-ethynyl and the 21-methyl positions as indicated in Figure 1.…”

“…The 13 C labeling of Org OD 14 was carried out as reported elsewhere. 15 Mass spectrometric analysis showed an isotope incorporation of >95%.…”

“…1,3-13 Solid-state 13 C CPMAS NMR spectroscopy has also been used to study the polymorphism in solid dosage forms for several compounds.…”

“…Solid-state 13 C CPMAS NMR is widely used to study polymorphism either qualitatively and quantitatively.…”

Characterization of Prednisolone in Controlled Porosity Osmotic Pump Pellets using Solid-State NMR Spectroscopy

“…Because of its strength in the characterization of pharmaceutical formulations, solid-state NMR spectroscopy was chosen as the primary analytical technique to characterize PDL in the solid state following different formulation conditions. [20][21][22][23][24][25][26][27][28][29][30] The objective of this research was to investigate the effects of formulation and processing variables on PDL in the solid state. The parameters studied included mixing time, water, drying conditions, and excipient ratios.…”