Tracking the distribution of “ecstasy” tablets by Raman composition profiling: A large scale feasibility study

Abstract

Here we report the results of the largest study yet carried out on composition profiling of seized "ecstasy" tablets by Raman spectroscopy. Approximately 1500 tablets from different seizures in N. Ireland were analysed and even though practically all the tablets contained MDMA as active constituent, there were very significant differences in their Raman spectra, which were due to variations in both the nature and concentration of the excipients used and/or the degree of hydration of the MDMA. The ratios of the peak heights of the prominent drug bands at 810 cm(-1) and 716 cm(-1) (which vary with hydration state of the drug), and the drug band at 810 cm(-1) against the largest clearly discernible excipient band in the spectrum were measured for all the samples. It was found that there was sufficient variation in composition in the general sample population to make any matches between batches of tablets taken from different seizures significant, rather than the result of random chance. Despite the large number of different batches of tablets examined in this study, only two examples of indistinguishable sets of tablets were found and in only one of these had the two batches of tablets been seized at different times. Finally, the fact that there are many examples of batches of tablets (particularly in different batches taken from single seizures) in which the differences between each set are sufficiently small that they appear to arise only from random variations within a standard manufacturing method implies that, with more extensive data, it may be possible to recognize the "signature" of tablets prepared by major manufacturers.

Recent applications of Chemical Imaging to pharmaceutical process monitoring and quality control

“…It was demonstrated that the eigenvalue-based criteria for choosing principal components was ineffective for these Raman Chemical Images, and the author remarked that the basic postulates of PCA could pose a significant problem when applied to Raman mapping spectra. For NIR mapping spectra, interpretation of PCA proved difficult; problems were associated with associating pure component spectra Bell et al [51] , [55], [56] and [57] published findings on the development of quantitative analytical methods for Raman analysis of solid dosage forms. In one paper, this research team reported results on Raman mapping of seized ecstasy tablets [51].…”

Electrochemical and spectroscopic characterisation of amphetamine-like drugs: Application to the screening of 3,4-methylenedioxymethamphetamine (MDMA) and its synthetic precursors

“…Although there are some reported studies on the Raman analysis of amphetamine-like compounds [14][15][16][17][18][19][20][21], these experiments have only focused on particular regions of the vibrational spectra.…”

Development of sampling methods for Raman analysis of solid dosage forms of therapeutic and illicit drugs

“…It was assumed, rather than explicitly demonstrated, that the large surface area from which the signal was collected ensured that this spectrum was representative of the average composition of the sample. 1,3 Although this rotating tablet arrangement is widely used, it is typically only applied in situations where manually loading tablets one at a time is acceptable because it is difficult to combine sample rotation with automated high-throughput analysis of large numbers of tablets. In the work here, the approach taken was to mount sets of tablets on a motorized sample stage and to record data from a grid of points on each tablet (and from each tablet in the sample holder) by stepping the stage in the x and y directions.…”