A cross-polarization magic-angle spinning 13C NMR characterization of the stable solid-state forms of cimetidine.
Proton decoupled, cross-polarization magic-angle spinning 13C NMR spectra of four polymorphic forms (A, B, C, and D) and a monohydrate form (M1) of the histamine H2 antagonist cimetidine were obtained, and the chemical shifts of the various forms were tabulated. A modified polarization inversion pulse sequence was used to distinguish quaternary, methine, methylene, and methyl carbon resonances and thereby assist spectral assignment. It is also shown that the solid-state form of cimetidine in a commercial formulation can be reliably ascertained by NMR, despite the presence in the spectrum of signals from organic excipients that are much more intense than those from the compound.
Middleton
D A
DA
Analytical Sciences Department, SmithKline Beecham Pharmaceuticals, Welwyn, Herts., Great Britain.
Le Duff
C S
CS
Berst
F
F
Reid
D G
DG
D002247:Carbon Isotopes; D002927:Cimetidine / Q000737:chemistry*; D003460:Crystallization; D005079:Excipients; D006635:Histamine H2 Antagonists / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods
D002247:Carbon Isotopes; D005079:Excipients; D006635:Histamine H2 Antagonists; D002927:Cimetidine