Medicines authentication by quadrupole resonance

Start date December 2012

Client King's College London

Dr David Nugent


Counterfeit and substandard medicines constitute a serious threat to public health. The scale of the problem is already great – particularly in the developing world – and is still growing. Funded by the Wellcome Trust, King's College London researchers have developed a prototype portable medicines authentication device based on quadrupole resonance (QR) spectroscopy. Employing innovative parametric data processing techniques developed in association with Lund University, the system provides non-invasive non-desructive and quantitative inspection of packaged medicines. A prototype authenticator has been developed and is presented for commercialisation.


QR spectroscopy can identify and quantify different polymorphs of pharmaceutical agents. It is important to emphasize that QR measurements could be carried out with the presence of excipients in the sample without modifications in most cases. The properties of QR permit the study of both raw materials and different mixtures, such as several active agents, different polymorphs, and amorphous or crystalline mixture. For this reason, QR could be a powerful technique to detect soild-state uniformity content in intermediate and final products.

The first-generation system is targetted at nitrogen- and/or chlorine-containing medicines in blister packs and bottles without the need to remove these items from their packaging. Initial studies have been based on a database consisting of the QR "fingerprints" of a select list of essential medicines as defined by the World Health Organisation and that are commonly counterfeited in developing countries.


Table 1: Capabilities of QR medicine authentication

What can QR do? What can't QR do?

Analyse crystalline solids included in pills, powders and oral suspensions

Look at liquids or amorphous solids
Target the API uniquely Assay the complete pill
Be quantitive as well as qualitative Target medicines with no quadrupole nucleus
See through optically opaque non-metallic packaging See through fully metallic packaging
Discriminate between different polymorphs Easily identify an unknown medicine
Provide information that can be related to the source of the API

Work quickly when the sample mass is very low



A portable medicines authentication machine has been constructed. A simple four-step process is used to authenticate the contents of the sealed medicine packet:

Step 1: Scan the barcode of the medicine package

Step 2: Drop the packet into the scanner - no need to discard packaging

Step 3: Press "go" - the system is fully automated

Step 4: A green/red light indicates whether the packet is authentic or not


Documents available for download


Tate E, Althoefer K, Barras J, Rowe MD, Smith JA, Pearce GE, Wren SA, "Quantitative 35Cl nuclear quadrupole resonance in tablets of the antidiabetic medicine Diabinese", Anal Chem. 2009 Jul 1;81(13):5574-6
Elizabeth Balchin, David J. Malcolme-Lawes, Iain J. F. Poplett, Michael D. Rowe, John A. S. Smith, Gareth E. S. Pearce, Stephen A. C. Wren, "Potential of Nuclear Quadrupole Resonance in Pharmaceutical Analysis", Analytical Chemistry 2005 77 (13), 3925-3930
Jakobsson, A.; Mossberg, M.; Rowe, M.D.; Smith, J.A.S., "Frequency-selective detection of nuclear quadrupole resonance signals," Geoscience and Remote Sensing, IEEE Transactions on , vol.43, no.11, pp. 2659- 2665, Nov. 2005

Barras J, Katsura S, Sato-Akaba H, Itozaki H, Kyriakidou G, Rowe MD, Althoefer KA, Smith JA., "Variable-Pitch Rectangular Cross-section Radiofrequency Coils for the Nitrogen-14 Nuclear Quadrupole Resonance Investigation of Sealed Medicines Packets", Anal Chem. 2012 Nov 6;84(21):8970-2. doi: 10.1021/ac3015643. Epub 2012 Oct 26.

J. Barras, K. Althoefer, M. D. Rowe, I. J. Poplett, J. A. S. Smith, "The emerging field of medicines authentication by nuclear quadrupole resonance spectroscopy", Appl Magn Reson (2012) 43:511-529
J. Barras, K. Althoefer, M. D. Rowe, I. J. Poplett, J. A. S. Smith, "The emerging field of medicines authentication by nuclear quadrupole resonance spectroscopy", KCL MRDE 2011 presentation

Frequency selective detection of NQR signals in the presence of multiple polymorphic forms, Samuel Somasundaram, Andreas Jakobsson, John. A. S. Smith, 14th European Signal Processing Conference (EUSIPCO 2006), Florence, Italy, September 4-8, 2006.