Identification and Quantification by NMR Spectroscopy of the 22 and 22 Epimers in Budesonide Pharmaceutical Forms.

The authors developed four variants of the qNMR technique (H or C nucleus, DMSO-d6 or CDCl solvent) for identification and quantification by NMR of 22 and 22 epimers in budesonide active pharmaceutical ingredient and budesonide drugs (sprays, capsules, tablets). The choice of the qNMR technique version depends on the drug excipients. The correlation of H and C spectra signals to molecules of different budesonide epimers was carried out on the basis of a comprehensive analysis of experimental spectral NMR data (H-H gCOSY, H-C gHSQC, H-C gHMBC, H-H ROESY).