Security screening for the detection of counterfeit medicines and illegal drugs using X-ray diffraction and multivariate analysis

Research Institution / Organisation

University College London

In Collaboration With

Home Office; UK Border Force; Defence Science and Technology Laboratory (DSTL)

Principal Researcher

Peter Kenny

Level of Research

PhD

Project Start Date

September 2014

Research Context

The trade in counterfeit medicine and illegal recreational drugs remains prevalent along with the damaging consequences for consumers and society. Technology is sought which reliably detects illicit materials during security screening while causing minimal disruption to legal activity and without causing damage to traded goods.

Energy dispersive x-ray diffraction (EDXRD) is a technology in an advanced stage of research and development which has shown potential for non-destructive, fast, and reliable screening. It has been demonstrated in experiments to identify illicit drugs concealed in courier parcels and to determine accurately the chemical composition of pharmaceutical formulations.The diffraction signals which result from EDXRD are fingerprints from which we deduce the chemical composition of a sample under investigation. However, detection of materials of interest is made difficult by signal contributions from other materials as well as from extraneous physical effects. Moreover, a high level of data noise is inherent in rapid screening systems, which further inhibits material detection.

This research focuses on statistical methodology to identify the relevant materials from these complex signals and to develop an analytical framework for screening procedures which use EDXRD.

Research Methodology

This research uses data from two contexts:

  • Medicine: analysis of packaged pharmaceutical formulations to determine the chemical composition of the active ingredients and the excipients within the tablets.
  • Fast parcel systems: analysis of typical couriered parcels through volume imaging in EDXRD. Objective is to identify presence and location of illicit drugs concealed within and amongst a variety of other common materials within parcels.

We model data from both EDXRD experiments within a multivariate analysis framework and generalise the methodology to be extended to other screening contexts. Through the combination of soft spectral unmixing algorithms and physical hard-modelling we recover the characteristic EDXRD profiles of the materials of interest as well as the quantity or concentrations in which they are present.

Inspiration for the statistical methodology is taken from the fields of analytical chemistry and spectroscopy, referred to as chemometric methods. Screening for food, agriculture and medicine quality is common and technologies such as Near Infra-Red spectroscopy and Raman spectroscopy are often employed in these applications. We extend such analytical methods to EDXRD, incorporating relevant contextual and physical insights, in order to extract relevant information from our screening experiments to inform detection.

Interim reports and publications

I. Drakos, P. S. Kenny, T. Fearn, R. D. Speller, Multivariate analysis of energy dispersive X-ray diffraction data for the detection of illicit drugs in border control, J. Crime Sci. 6 (2017)

C. Crews, P. S. Kenny, D. O'Flynn, R. D. Speller, Multivariate calibration of energy-dispersive X-ray diffraction data for predicting the composition of pharmaceutical tablets in packaging, Journal of Pharmaceutical and Biomedical Analysis (2018)

Date due for completion

March 2019
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