A review of the newly identified impurity profiles in methamphetamine seizures

Pharmacological Treatments for Methamphetamine Use Disorder: Current Status and Future Targets

The illicit use of the psychostimulant methamphetamine (METH) is a major concern, with overdose deaths increasing substantially since the mid-2010s. One challenge to treating METH use disorder (MUD), as with other psychostimulant use disorders, is that there are no available pharmacotherapies that can reduce cravings and help individuals achieve abstinence. The purpose of the current review is to discuss the molecular targets that have been tested in assays measuring the physiological, the cognitive, and the reinforcing effects of METH in both animals and humans. Several drugs show promise as potential pharmacotherapies for MUD when tested in animals, but fail to produce long-term changes in METH use in dependent individuals (eg, modafinil, antipsychotic medications, baclofen). However, these drugs, plus medications like atomoxetine and varenicline, may be better served as treatments to ameliorate the psychotomimetic effects of METH or to reverse METH-induced cognitive deficits. Preclinical studies show that vesicular monoamine transporter 2 inhibitors, metabotropic glutamate receptor ligands, and trace amine-associated receptor agonists are efficacious in attenuating the reinforcing effects of METH; however, clinical studies are needed to determine if these drugs effectively treat MUD. In addition to screening these compounds in individuals with MUD, potential future directions include increased emphasis on sex differences in preclinical studies and utilization of pharmacogenetic approaches to determine if genetic variances are predictive of treatment outcomes. These future directions can help lead to better interventions for treating MUD.

Changes in methamphetamine impurity profiles induced by tert-butoxycarbonylation

Analysis of impurities in methamphetamine (MA) can be used to characterize MA seizures, investigate the relationship among MA seizures, and provide information on their synthetic routes. Recently, chemically derivatized MA, such as tert-butoxycarbonyl (t-Boc) MA, has been seized and attracted attention because routine forensic analysis methods may fail to correctly identify them. Chemical derivatization is a simple method for protection and deprotection of a compound, and protection of MA using t-Boc can be used to mask the MA. Although t-Boc derivatization might alter the impurity profile of MA, the actual changes in the impurity profile have not been investigated. In this study, changes in the MA impurity profile with tert-butoxycarbonylation were explored. MA and some typical impurities were derivatized using di-tert-butyl dicarbonate and water. Analysis of the impurities in five MA samples by gas chromatography showed that peaks both appeared and disappeared for the deprotected MA compared with the original MA. However, typical impurities important for characterizing MA seizures were conserved after derivatization and deprotection. Most of the new peaks were speculated to be contaminants introduced during derivatization and deprotection. A peak giving a mass spectrum similar to that of t-Boc MA was detected in the chromatograms of t-Boc MA and deprotected MA. Although the origin of this peak was not determined, it might be a marker for the MA involving tert-butoxycarbonylation. These results indicate that tert-butoxycarbonylation can alter the MA impurity profile; therefore, care is needed when interpreting results for derivatized MA.

Changes in drug availability patterns on Tanzanian mainland: The effects of the surge operations deterrent strategy

This study investigated the recent changes in illegal substances availability on the Tanzanian mainland as a result of the government's surge operations as a deterrent approach against illicit drug production, trafficking and usage from 2017 to 2020, as well as the consequences of the COVID-19 pandemic on the drug market. Overall, 247467 seizures of illegal substances weighing 25357.9 kg were tested at The Government Chemist Laboratory Authority (GCLA), an average of 6339.5 kg annually. According to the findings, cannabis was the most frequently encountered substance, accounting for 80.6%, 88.2%, and 83% of all incidents, samples, and weight, respectively. Heroin came in second with 12.6% of the total incidents and 7.4% of the total number of samples, while khat came in second with 15.2% of the weight of the seized illegal substances during the period under study. Apart from a 202 and 4709 decline in heroin incidents and samples, the weight jumped from 15.3 kg in 2017 to 303.5 kg in 2020. Generally, the overall weight of the seizures decreased by 67.3% from 13036.4 kg in 2017-3890.7 kg in 2020. The results were particularly noticeable in the case of cannabis, which plunged by 76.5% from 11771.1 kg in 2017-2727 kg in 2020. Despite the eruption of the COVID-19 pandemic and associated lockdowns and travel limitations, heroin seizures increased by 67.4% in 2020 compared to the preceding three years combined.

Impurity profiling of methamphetamine synthesized from methyl α-acetylphenylacetate

The group of P2P precursors including α-phenylacetoacetonitrile (APAAN), α-phenylacetoamide (APAA) and methyl α-acetylphenylacetate (MAPA) has become increasingly popular in Europe and other parts of the world in the last decade. Previous investigations have reported the use of APAAN in the synthesis of amphetamine and methamphetamine and identified a range of characteristic impurities. This research has expanded upon the current literature by investigating the use of MAPA in the synthesis of methamphetamine. In this study methamphetamine was synthesized via three common clandestine methods: the Leuckart synthesis and two reductive amination methods. We report the identification of seven impurities, four of which are methyl ester equivalents of impurities previously reported for the detection of APAAN. These are methyl 2-phenylbut-2-enoate, methyl 2-phenyl-3-hydroxybutanoate, methyl 3-(methylamino)-2-phenylbut-2-enoate and methyl 3-(methylamino)-2-phenylbutanoate. The other impurities identified are ethyl ester compounds formed via transesterification of the methyl ester due to the reaction solvent. This susceptibility for transesterification suggests that identification of the pre-precursor used may not always be straightforward and may be dependent on the reaction conditions employed. Of the impurities reported, methyl 3-(methylamino)-2-phenylbutanoate was deemed to be a potentially reliable impurity for detection of the use of MAPA; however, it is expected that lower levels of characteristic impurities may be detected in methamphetamine synthesized from MAPA than that from APAAN.

Impurity profiling of methamphetamine synthesised from α-phenylacetoacetonitrile (APAAN)

The rise in popularity of 'designer' precursor compounds for the synthesis of amphetamine-type stimulants poses a significant challenge to law enforcement agencies. One such precursor is α-phenylacetoacetonitrile (APAAN). APAAN emerged in Europe in 2010 and quickly became one of the most popular precursors for amphetamine synthesis in that region. Previous literature has identified four APAAN-specific impurities formed in the synthesis of amphetamine; however, there is currently no research on the use of APAAN in the synthesis of methamphetamine, which is more likely to be employed in a non-European market. In this study methamphetamine was synthesised via three common clandestine methods: the Leuckart method and two reductive amination methods. We report the identification of five new impurities and two previously identified impurities characteristic for the use of APAAN in the synthesis of methamphetamine. The newly identified impurities were characterised by MS and NMR and determined to be (E)-3-(methylamino)-2-phenylbut-2-enenitrile, 3-(methylamino)-2-phenylbutanenitrile, 3-methyl-2,4-diphenylpentanedinitrile, 2-phenylbutyronitrile and 3-hydroxy-2-phenylbutanenitrile.

Trends in illicit drugs based on the analysis of seizures from the Tanzania mainland drugs market

This study aimed at investigating the pattern of confiscated illegal drugs in the Tanzania mainland drug market from 2011 to 2016. The samples used in this study were seized by the police force and other law enforcement agents and were analysed at the Government Chemist Laboratory Authority, GCLA. A total of 90,366 samples weighing 17961.5 Kg were seized and analysed during the six years, an average of 15,061 samples corresponding to 2993.6 Kg per year. The overall results indicated cannabis to be the leading drug in terms of number of cases, number of samples and weights with 51.02%, 60.50% and 56.90%, respectively, but from 2011 to 2015 heroin had the highest percentage of both number of cases and samples by 58.46% and 55.91% of all seizures, respectively followed by cannabis. In terms of weight, heroin accounted for 67.55% and 26.32% in 2011 and 2012, respectively, whereas, the rest of the years' percentage weights were between 0.50 and 6.00% of the total seizures. The trend indicated a steady decrease in heroin seizures over the six years and an increased cannabis seizure. In 2016 cannabis was 78.28% and 80.89% of the total number of cases and samples, respectively. The results also indicated the decrease of cocaine cases and a significant increase in the amount khat. The year 2016 recorded the highest number of cases and number of samples with a total of 1212 and 48,440, respectively, which resulted from the increase in cannabis seizures by 72.28% and 80.89% of the total number of cases and samples, respectively, as compared to 2015. The second and third highest years were 2013 and 2014, respectively. The least was 2011 with 3493 samples. The trend also indicated heroin seizures were highest in 2011 (62.04%), 2014 (75.31%) and 2015 (79.26%) whereas cocaine seizures kept on decreasing gradually from 31.12% in 2011 to 0.05% in 2016. Khat (Catha edulis) had the highest weight in 2014 and 2016 and ranked second after cannabis with 43.63% of the total weight during 2011-2016 period. Benzodiazepines and amphetamine type stimulants (ATS) accounted the least in terms of number of cases and number of samples.