Simultaneous analysis of amphetamine-type stimulants in plasma by solid-phase microextraction and gas chromatography-mass spectrometry.

Brazil is considered one of the countries with the highest number of amphetamine-type stimulant (ATS) users worldwide, mainly diethylpropion (DIE) and fenproporex (FEN). The use of ATS is mostly linked to diverted prescription stimulants and this misuse is widely associated with (ab)use by drivers. A validated method was developed for the simultaneous analysis of amphetamine (AMP), DIE and FEN in plasma samples employing direct immersion-solid-phase microextraction, and gas chromatographic/mass spectrometric analysis. Trichloroacetic acid 10% was used for plasma deproteinization. In situ derivatization with propylchloroformate was employed. The linear range of the method covered from 5.0 to 100 ng/mL. The detection limits were 1.0 (AMP), 1.5 (DIE) and 2.0 ng/mL (FEN). The accuracy assessment of the control samples was within 85.58-108.33% of the target plasma concentrations. Recoveries ranged from 46.35 to 84.46% and precision was <15% of the value of relative standard deviation. This method is appropriate for screening and confirmation in plasma forensic toxicology analyses of these basic drugs.

Trends in counterfeits amphetamine-type stimulants after its prohibition in Brazil.

Brazil is one of the world's highest users of anorectic drugs, mainly diethylpropione, fenproporex and sibutramine. The present work focuses on physical and chemical characteristics of 17 counterfeited capsules containing amphetamine-type stimulants (ATS) from three seizures conducted by Brazilian Federal Police. The physical profile was useful in indicating forgery, bring complementary information, but the use of this data singly was not sufficient to distinguish between authentic and counterfeited medicines. The chemical analysis revealed that the seizures capsules labeled as Desobesi-M (fenproporex 25mg), actually contained the active pharmaceutical ingrediente (API) sibutramine. The amount of this API ranged from 1/3 to 2 times the amount of drug found in commercial product, may reach twice the recommended daily dose. Multivariate analysis with application of principal component analysis on data from spectroscopy attenuated total reflectance Fourier transform infrared classified the samples according to their similarities, indicating that two seizures had common origin. This study represents the first step in the elucidation of falsification of ATS in Brazil. Considering the forensic intelligence these information are valuable in order to develop and establish a database that enables correlate samples from different locations and/or suppliers and to map the profile and trends of trafficking.

Which amphetamine-type stimulants can be detected by oral fluid immunoassays?

INTRODUCTION: The use of oral fluid for monitoring drug consumption on roads has many advantages over conventional biological fluids; therefore, several immunoassays have been developed for this purpose. In this work, the ability of 3 commercial immunoassays to detect amphetamine-type stimulants (ATSs) in oral fluid was assessed. In addition, it was reviewed the main controlled ATSs available worldwide, as well as the oral fluid immunological screening tests that have been used for identifying ATSs in drivers. MATERIALS AND METHODS: The analytical specificity of amphetamine direct enzyme-linked immunosorbent assay (ELISA), methamphetamine direct ELISA (Immunalysis Corporation), and Oral-View saliva multidrug of abuse test (Alfa Scientific Designs) was evaluated using ATS-spiked oral fluid. Legislation and published articles that report the use of immunological screening tests to detect ATS consumption in conductors were reviewed, including the kit's technical information, project reports, police and drug databases. RESULTS AND DISCUSSION: Even at high concentrations, the tested assays were not able to detect methylphenidate, fenproporex, or diethylpropion, controlled ATSs legally marketed in many countries. CONCLUSIONS: This evidences the need to develop new kits that enable one to control the misuse of prescription ATSs on roads through oral fluid immunoassays.

Determination of amphetamine-type stimulants in oral fluid by solid-phase microextraction and gas chromatography-mass spectrometry.

A method for the simultaneous identification and quantification of amphetamine (AMP), methamphetamine (MET), fenproporex (FEN), diethylpropion (DIE) and methylphenidate (MPH) in oral fluid collected with Quantisal™ device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL(-1) (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL(-1). The detection limits were 0.5 ng mL(-1) (MET), 1 ng mL(-1) (MPH) and 2 ng mL(-1) (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with Quantisal™ device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid.