title: Batch-specific discrimination using nuclear quadrupole resonance spectroscopy.
abstract: In this paper, we report on the identification of batches of analgesic paracetamol (acetaminophen) tablets using nitrogen-14 nuclear quadrupole resonance spectroscopy ((14)N NQR). The high sensitivity of NQR to the electron charge distribution surrounding the quadrupolar nucleus enables the unique characterization of the crystal structure of the material. Two hypothesis were tested on batches of the same brand: the within the same batch variability and the difference between batches that varied in terms of their batch number and expiry date. The multivariate analysis of variance (MANOVA) did not provide any within-batches variations, indicating the natural deviation of a medicine manufactured under the same conditions. Alternatively, the statistical analysis revealed a significant discrimination between the different batches of paracetamol tablets. Therefore, the NQR signal is an indicator of factors that influence the physical and chemical integrity of the material. Those factors might be the aging of the medicine, the manufacturing, or storage conditions. The results of this study illustrate the potential of NQR as promising technique in applications such as detection and authentication of counterfeit medicines.
authors.affiliation: †Department of Informatics, King's College London, Strand, London WC2R 2LS, United Kingdom.
authors.forename: Georgia
authors.initials: G
authors.lastname: Kyriakidou
authors.affiliation: ‡Department of Mathematical Statistics, Lund University, Lund SE-221 00, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jakobsson
authors.affiliation: †Department of Informatics, King's College London, Strand, London WC2R 2LS, United Kingdom.
authors.forename: Kaspar
authors.initials: K
authors.lastname: Althoefer
authors.affiliation: †Department of Informatics, King's College London, Strand, London WC2R 2LS, United Kingdom.
authors.forename: Jamie
authors.initials: J
authors.lastname: Barras
mesh_terms: D000082:Acetaminophen / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D015999:Multivariate Analysis; D009584:Nitrogen / Q000737:chemistry; D013607:Tablets
chemical_list: D013607:Tablets; D000082:Acetaminophen; D009584:Nitrogen