20.500.12556/RUL-133626 Nuclear Quadrupole Resonance (NQR) a useful spectroscopic tool in pharmacy for the study of polymorphism Nuclear Quadrupole Resonance (NQR) spectroscopy has been known for 70 years. It is suitable for the study of measured (poly)crystalline chemical compounds containing quadrupole nuclei (nuclei with spin I ≥ 1) where the characteristic NQR frequencies represent the fingerprints of these compounds. In several cases, $^{14}$N NQR can distinguish between the polymorphic crystalline phases of active pharmaceutical ingredients (APIs). In order to further stimulate $^{14}$N NQR studies, we review here several results of API polymorphism studies obtained in Ljubljana laboratories: (a) In sulfanilamide, a clear distinction between three known polymorphs (α, β, γ) was demonstrated. (b) In famotidine, the full spectra of all seven different nitrogen positions were measured; two polymorphs were distinguished. (c) In piroxicam, the $^{14}$N NQR data helped in confirming the new polymorphic form V. (d) The compaction pressure in the tablet production of paracetamol, which is connected with linewidth change, can be used to distinguish between producers of paracetamol. We established that paracetamol in the tablets of six different manufacturers can be identified by $^{14}$N NQR linewidth. (e) Finally, in order to get an extremely sensitive $^{14}$N NQR spectrometer, the optical detection of the $^{14}$N NQR signal is mentioned. NQR Nuclear Quadrupole Resonance spectroscopy $^{14}$N NQR relaxation drug polymorphism crystal polymorphism X-ray powder diffraction (XRPD) powder mixture quantification NQR with optically pumped magnetometer true false true Angleški jezik Ni določen Članek v reviji 2021-12-06 12:24:59 2021-12-06 12:25:04 2023-05-04 13:06:01 0000-00-00 00:00:00 2020 0 0 22 str. iss. 6, art. 450 Vol. 10 2020 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 53:543.42 2073-4352 10.3390/cryst10060450 17705475 RAZ_Trontelj_Zvonko_2020.pdf RAZ_Trontelj_Zvonko_2020.pdf 1 F5D95FAE63EB4DFD88C7FA5EC0189339 df975c54b2333242813b1aeac4e1bf45d4afd216ff7d3602cef524b2faa9da5e 59b796ae-5687-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=151840 https://www.mdpi.com/2073-4352/10/6/450 1 0e292506-5687-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=151839 Fakulteta za farmacijo Fakulteta za elektrotehniko 0 0 0