Tracking NPS in Portugal: the case of MTMP

A New Psychoactive Substance (NPS), is a “substance of abuse, either in a pure form or preparation, that is not controlled by the 1961 Convention of Narcotic Drugs or the 1971 Convention on Psychotropic Substances, but which may pose a public health threat”. NPS initially appeared on the market as legal substitutes to illicit drugs. However, the health risks associated with the consumption of NPS led to the publication of new legislation in different countries, aiming to overcome the concerns related to these risks. In Portugal, NPS are control by Decree-Law 54/2013 which prohibits the production and commercialization of 159 NPS.

One of the main challenges in the early control of NPS, either in seized material or biological matrices, is related to their correct identification using reliable and rapid analytical methods, even in the absence of standards. To tackle the problem of accurate and unambiguous identification of NPS in Portugal, a collaboration was established between the Faculty of Sciences (University of Lisbon) and the Forensic Laboratory of Portuguese Criminal Police (LPC/PJ). Between 2014 and 2019, working on 71 selected cases chosen by the LPC/PJ, a methodology was achieved based on the combination of data from complementary analytical techniques, allowing the detection in 117 seized samples of 106 NSP: 22 NPS detected for the first time in Portugal, the new cathinone 4F-PBP1 for the first time in Europe and several amphetamines (pre)precursors, being synthetic cathinones the major class of the NPS detected.

It is worth highlighting the case study of a package, seized in 2016 by the Portuguese Criminal Police, containing 7 samples, that were proved to contain 5 different cathinones. The structural elucidation carried out, using several analytical techniques (GC-MS, NMR, HRMS and IC), allowed the unequivocal identification of the cathinones 4-CEC (1), clephedrone (2), dibutylone (3), 4-MEAP (4), MTMP (5) (Fig.1).

Fig.1 – Structure of cathinones

Cathinones 1 to 4 were already found as NPS in several European countries but, however, in Portugal the substances 1 to 3 were detected for the first time in this study. Five samples contained the cathinones as hydrochloride salts with high purity. MTMP was found in 2 samples, one in the free base form and the other as a mixture of free base and hydrochloride salt in the molar ratio of 8:2. MTMP (MMMP or Caccure 907), in the free base form, is a photoinitiator commonly used in photopolymerization systems considered by the European Chemical Agency as having acute oral toxicity. However, MTMP detection as hydrochloride salt, in the seized package with other cathinones, suggested its use as recreational substance. These facts seem to bear the suspicion that the detection of this substance in seized samples and body fluids2 is due to its ingestion as a recreational substance and not to contamination by the packaging.