High‐resolution 13C and 43Ca solid‐state NMR and computational studies of the ethylene glycol solvate of atorvastatin calcium

We report 43Ca and 13C solid‐state nuclear magnetic resonance (NMR) spectroscopic studies of the ethylene glycol solvate of atorvastatin calcium. The 13C and 43Ca chemical shift and 43Ca quadrupolar coupling tensor parameters are reported. The results are interpreted in terms of the reported X‐ray diffraction crystal structure of the solvate and are compared with the NMR parameters of atorvastatin calcium trihydrate, the active pharmaceutical ingredient in Lipitor®. Hartree–Fock and density functional theory calculations of the NMR parameters based on a cluster model derived from the optimized X‐ray diffraction crystal structure of the ethylene glycol solvate of atorvastatin calcium are in reasonable agreement with the experimental 43Ca and 13C NMR measurables. We report 43Ca and 13C solid‐state NMR spectroscopic studies of the ethylene glycol solvate of atorvastatin calcium. The 13C and 43Ca chemical shift and 43Ca quadrupolar coupling tensor parameters are measured and interpreted in terms of the reported X‐ray diffraction crystal structure of the solvate. The NMR parameters of the ethylene glycol solvate are also compared with those of atorvastatin calcium trihydrate.