Use of UPLC-HRMS/MS for In Vitro and In Vivo Metabolite Identification of Three Methylphenidate-derived New Psychoactive Substances

2019 ◽  
Vol 44 (2) ◽  
pp. 156-162
Author(s):  
Sascha K Manier ◽  
Sophia Niedermeier ◽  
Jan Schäper ◽  
Markus R Meyer

Abstract The distribution of so-called new psychoactive substances (NPS) as substitute for common drug of abuse was steadily increasing in the last years, but knowledge about their toxicodynamic and toxicokinetic properties is lacking. However, a comprehensive knowledge of their toxicokinetics, particularly their metabolism, is crucial for developing reliable screening procedures and to verify their intake, e.g., in case of intoxications. The aim of this study was therefore to tentatively identify the metabolites of the methylphenidate-derived NPS isopropylphenidate (isopropyl 2-phenyl-2-(2-piperidyl) acetate, IPH), 4-fluoromethylphenidate (methyl 2-(4-fluorophenyl)-2-(piperidin-2-yl) acetate, 4-FMPH) and 3,4-dichloromethylphenidate (methyl 2-(3,4-dichlorophenyl)-2-(piperidin-2-yl) acetate, 3,4-CTMP) using different in vivo and in vitro techniques and ultra-high performance liquid chromatography–high-resolution mass spectrometry (UHPLC-HRMS/MS). Urine samples of male rats were analyzed, and the transfer to human metabolism was done by using pooled human S9 fraction (pS9), which contains the microsomal fraction of liver homogenisate as well as its cytosol. UHPLC-HRMS/MS analysis of rat urine revealed 17 metabolites for IPH (14 phase I and 3 phase II metabolites), 13 metabolites were found for 4-FMPH (12 phase I metabolites and 1 phase II metabolite) and 7 phase I metabolites and no phase II metabolites were found for 3,4-CTMP. pS9 incubations additionally indicated that all investigated substances were primarily hydrolyzed, resulting in the corresponding carboxy metabolites. Finally, these carboxy metabolites should be used as additional analytical targets besides the parent compounds for comprehensive mass spectrometry–based screening procedures.

2011 ◽  
Vol 57 (12) ◽  
pp. 1748-1756 ◽  
Author(s):  
Andrea E Schwaninger ◽  
Markus R Meyer ◽  
Allan J Barnes ◽  
Erin A Kolbrich-Spargo ◽  
David A Gorelick ◽  
...  

BACKGROUND 3,4-Methylendioxymethamphetamine (MDMA) is excreted in human urine as unchanged drug and phase I and II metabolites. Previous urinary excretion studies after controlled oral MDMA administration have been performed only after conjugate cleavage. Therefore, we investigated intact MDMA glucuronide and sulfate metabolite excretion. METHODS We used LC–high-resolution MS and GC-MS to reanalyze blind urine samples from 10 participants receiving 1.0 or 1.6 mg/kg MDMA orally. We determined median Cmax, tmax, first and last detection times, and total urinary recovery; calculated ratios of sulfates and glucuronides; and performed in vitro–in vivo correlations. RESULTS Phase II metabolites of 3,4-dihydroxymethamphetamine (DHMA), 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-dihydroxyamphetamine (DHA), and 4-hydroxy-3-methoxyamphetamine were identified, although only DHMA sulfates, HMMA sulfate, and HMMA glucuronide had substantial abundance. Good correlation was observed for HMMA measured after acid hydrolysis and the sum of unconjugated HMMA, HMMA glucuronide, and HMMA sulfate (R2 = 0.87). More than 90% of total DHMA and HMMA were excreted as conjugates. The analyte with the longest detection time was HMMA sulfate. Median HMMA sulfate/glucuronide and DHMA 3-sulfate/4-sulfate ratios for the first 24 h were 2.0 and 5.3, respectively, in accordance with previous in vitro calculations from human liver microsomes and cytosol experiments. CONCLUSIONS Human MDMA urinary metabolites are primarily sulfates and glucuronides, with sulfates present in higher concentrations than glucuronides. This new knowledge may lead to improvements in urine MDMA and metabolite analysis in clinical and forensic toxicology, particularly for the performance of direct urine analysis.


1990 ◽  
Vol 47 (4) ◽  
pp. 831-837 ◽  
Author(s):  
Kenneth A. Gill ◽  
Patrick J. Walsh

Prior in vivo studies of the effects of temperature on uptake, metabolism and excretion of benzo[a]pyrene (BaP) by the gulf toadfish (Opsanus beta) suggested that metabolism of BaP may be partially temperature insensitive under certain conditions. In the present study, hepatocytes were isolated from toadfish acclimated to 18 or 28 °C, and then cells were exposed to BaP at 18, 23, and 28 °C in vitro to more directly examine the effects of temperature on metabolism. Toadfish hepatocytes metabolized BaP to a variety of Phase I and Phase II metabolites in similar proportions to toadfish in vivo, with the exception that fewer Phase I metabolites were detected. A marked temperature dependence of metabolism of BaP to Phase II metabolites was noted between 18 and 28 °C at near saturating concentration of BaP (13 μg∙mL−1). Warm-acclimated toadfish displayed a lower temperature sensitivity than cold-acclimated toadfish (Q10, the ratio of the rate at T + 10 °C: rate at T = 1.85 and 2.65, respectively). However, at a lower, subsaturating concentration of BaP (5 μg∙mL−1), production of all metabolites showed a marked temperature independence. We speculate that this independence is the result of temperature effects on the kinetic properties of the enzymes of xenobiotic metabolism.


1996 ◽  
Vol 30 (5) ◽  
pp. 469-472
Author(s):  
Tsong-Mei Tsai ◽  
Brian F Shea ◽  
Paul F Souney ◽  
Fred G Volinsky ◽  
Joseph M Scavone ◽  
...  

OBJECTIVE: TO study the effects of ofloxacin on the reliability of urine glucose testing. DESIGN: Open-label, nonrandomized. SETTING: A university-affiliated tertiary care hospital, ambulatory clinic. PARTICIPANTS: Ten healthy volunteers (8 men and 2 women) aged 22-39 years. MAIN OUTCOME MEASURES: Phase I (in vitro) involved the addition of selected amounts of ofloxacin to a set of standard 50-mL urine samples prepared to simulate glycosuria. Phase II (in vivo) involved the oral administration of ofloxacin 400 mg to 10 subjects. Urine was collected: (1) immediately predose, (2) pooled 0–4 hours postdose, and (3) pooled 4–8 hours postdose. Known glucose concentrations were then added to these samples. Clinitest and Diastix tests were performed on all samples. The accuracy of these tests in determining glucose concentrations was compared among urine samples taken before and after ofloxacin dosing. RESULTS: None of the ofloxacin concentrations in phase I (0,25,50, 100, 200,400, and 800 μg/mL) influenced these testing methods at the urine glucose concentrations of 0.0%, 0.5%, 1%, and 2%. Likewise, the accuracy of these two tests was unaffected by ofloxacin administration in phase II. CONCLUSIONS: In single-dose administration, ofloxacin does not interfere with Clinitest or Diastix for determining urine glucose concentrations. Supported by a grant from the RW Johnson Pharmaceutical Research Institute. Presented in abstract form at the American College of Clinical Pharmacy 1994 Winter Practice and Research Forum, February 6–9, 1994, San Diego. CA.


1989 ◽  
Vol 72 (4) ◽  
pp. 649-659
Author(s):  
Virlyn W Burse ◽  
Margaret P Korver ◽  
Larry L Needham ◽  
Chester R Lapeza ◽  
Elizabeth L Chester R ◽  
...  

Abstract A gas chromatographic-electron capture detection method for determining the concentration of polychlorinated biphenyls (PCBs) as Aroclor 1254 (AR 1254) in serum was evaluated through a 2-phase collaborative study. In Phase I, each collaborator's lot of Woelm silica gel (70-150 mesh) was evaluated for elution and recovery of AR 1254, which had been added in vitro at 25 ng/mL to a serum extract. In Phase II, each collaborator analyzed a series of bovine serum samples that contained the following: (1) in vitro-spiked AR 1254; (2) in vivo AR 1254 and 8 in vitro-spiked chlorinated hydrocarbons; (3) in vivo AR 1254 only; (4) 8 in vitro-spiked chlorinated hydrocarbons only; and (5) neither AR 1254 nor chlorinated hydrocarbons above the detection limit of the method. In Phase I, the average recovery of AR 1254 from silica gel for the 6 collaborators was 87.9 ± 15.44% (mean ± 1 SD; N = 18; range = 52.3-105.8%). In Phase II, the analysis of in vitro spikes of AR 1254 in serum at 8.58,16.8, 41.8, and 84.3 ppb gave mean (X) interlaboratory recoveries of 89.0, 83.3, 79.4, and 76.9%, respectively, with within-laboratory (repeatability) relative standard deviations (RSDr) of 18.8, 20.5, 10.2, and 14.1%, respectively, and among-laboratory (reproducibility) relative standard deviations (RSDR) of 21.5, 21.1, 14.6, and 20.8%, respectively. The determination of in vivo AR 1254 in samples containing approximately 10, 25, 50, and 100 ng/mL of AR 1254 resulted in interlaboratory means of 10,22,39, and 79 ng/mL, respectively, with RSDr = 6.7,9.7,6.4, and 5.8%, respectively, and RSDR = 20.6,16.0, 10.9, and 10.3%, respectively. The precision of the method for incurred AR 1254 showed a maximum RSDr of less than 10% and a maximum RSDR of less than 21% for a concentration range of 10-100 ng/mL. The accuracy of the method as demonstrated by the mean recovery of in vitro-spiked AR 1254 over a concentration range of 8.58-84.3 ng/mL was 82.2%. The method has been approved interim official first action.


Chirality ◽  
2001 ◽  
Vol 13 (10) ◽  
pp. 754-759 ◽  
Author(s):  
Vladimír Wsól ◽  
Radim Král ◽  
Lenka Skálová ◽  
Barbora Szotáková ◽  
František Trejtnar ◽  
...  
Keyword(s):  
Phase I ◽  

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 8501-8501 ◽  
Author(s):  
I. Lossos ◽  
M. D. Craig ◽  
M. S. Tallman ◽  
R. V. Boccia ◽  
P. R. Conkling ◽  
...  

8501 Background: Darinaparsin (ZIO-101) is a novel organic arsenical active against diverse cancers in vitro, and in vivo. Darinaparsin i.v. activity in lymphoma is being evaluated in a phase II study. Darinaparsin is orally bioavailable; the oral form is being investigated in two phase I studies in patients with advanced malignancies. Methods: Phase II trial is being conducted in patients diagnosed with advanced lymphomas who had ≥ 1 prior therapy. Patients receive 300 mg/m2/day of darinaparsin i.v. for 5 consecutive days every 28 days. Efficacy and safety are evaluated by standard criteria. Phase I oral dose escalation studies are being conducted in patients with advanced malignancies and explore safety, MTD, DLTs and preliminary efficacy of continuous and intermittent dosing schedules. Starting continuous dose is 100 mg BID for 3 weeks with 1 week rest, starting intermittent dose is 300 mg twice weekly for 3 weeks followed by 1 week rest. Results: The phase II study has accrued 28 lymphoma patients (21 non-Hodgkin's, 7 Hodgkin's); median age at baseline 61 years, ECOG ≤2, median number of prior therapies 3. Seventeen subjects have received at least 2 cycles of darinaparsin and are evaluable for efficacy. Of these, 1 subject (PTCL) has achieved a complete response, 3 - partial responses (2 marginal zone, 1 Hodgkin's), and 4 stable disease (2 PTCL, 1 DLBCL, 1 Hodgkin's). A total of 63 cycles of darinaparsin have been administered to subjects with lymphoma. No Gr. 3 or higher drug-related AEs were reported. Two SAEs were considered possibly drug-related (fall; neutropenic fever). Phase I studies accrued 35 patients; median age at baseline 58 years, ECOG ≤2, median number of prior therapies 3. Predominant tumor types include: colorectal (17), pancreatic (3), NHL (3). Current darinaparsin dose levels: continuous 200 mg BID, 2× weekly 900 mg. Of 18 patients evaluable for efficacy, 10 demonstrate SD ≥ 3 cycles. Oral darinaparsin bioavailability is 58%. Drug-related AEs include nausea/vomiting, fatigue, decreased appetite/anorexia. Conclusions: Darinaparsin is active in heavily pretreated patients with advanced lymphoma and has been very well tolerated. Oral darinaparsin is also well tolerated, and shows early activity. [Table: see text]


2018 ◽  
Vol 485 ◽  
pp. 144-151 ◽  
Author(s):  
Mohamed W. Attwa ◽  
Adnan A. Kadi ◽  
Hany W. Darwish ◽  
Sawsan M. Amer ◽  
Haitham AlRabiah

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