Wang, Pengfei published the artcileThe fingerprints of nifedipine/isonicotinamide cocrystal polymorph studied by terahertz time-domain spectroscopy, Recommanded Product: Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, the main research area is Cocrystal polymorph; Nifedipine; Quantum chemical calculations; Spectral fingerprints; Terahertz time-domain spectroscopy; Vibrational modes.
Cocrystal is constructed to improve physicochem. properties of active pharmaceutical ingredient and prevent polymorphism via intermol. interactions. However, recent examples on cocrystal polymorphs display significantly different properties. Even though some anal. techniques have been used to characterize the cocrystal polymorphic system, it remains unclear how intermol. interactions drive and stabilize the structure. In this work, we study the cocrystal polymorphs of nifedipine (NFD) and isonicotinamide (INA) using terahertz (THz) spectroscopy. Form I and form II of NFD-INA cocrystals show spectral fingerprints in THz region. Temperature-dependent THz spectra display distinguished frequency shifts of each fingerprint. Combined with solid-state d. functional theory (DFT) calculations, the exptl. fingerprints and their distinct responses to temperature are elucidated by specific collective vibrational modes. The vibrations of hydrogen bonding between dihydropyridine ring of NFD and INA are generally distributed below 1.5 THz, which play important roles in stabilizing cocrystal and preventing the oxidation of NFD. The rotations of Me group in NFD are widely distributed in the range of 1.5-4.0 THz, which helps the steric recognition. The results demonstrate that THz spectroscopy is a sensitive tool to discriminate cocrystal polymorphs. It has the potential to be used as a non-invasive technique for pharmaceutical screening.
International Journal of Pharmaceutics (Amsterdam, Netherlands) published new progress about Cocrystal polymorph; Nifedipine; Quantum chemical calculations; Spectral fingerprints; Terahertz time-domain spectroscopy; Vibrational modes. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Recommanded Product: Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.