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Lumateperone is a novel agent approved by FDA for treatment of schizophrenia in adults. To elucidate the species differences in the of biotransformation of lumateperone and its pharmacokinetic (PK) characteristics in rats, the metabolite identification of lumateperone was carried out in rat, dog and human liver microsomes, and rat plasma after oral administration using UPLC-Q Exactive Orbitrap high-resolution mass spectrometry HRMS. Furtherly, the PK characteristics of lumateperone and its N-demethylated metabolite (M3) in rat plasma were investigated using a validated LC-MS/MS method following intravenous and oral administration. Fourteen phase I metabolites were found in liver microsomes and ten of them were observed in rat plasma. N-demethylation, carbonylation, dehydrogenation, and piperazine ring cleavage were main metabolic pathway of lumateperone. No unique metabolites were formed in human liver microsomes. After rapid absorption in rats, lumateperone was quickly metabolized and eliminated with bioavailability of less than 5%. The exposure level of M3 was about 1.5-fold higher than that of lumateperone in rat plasma. Lumatperone underwent extensive metabolism and was absorbed rapidly in rats. Metabolite M3 had equivalent or slightly higher exposure levels than lumateperone. This study provides essential PK information to facilitate further pharmacodynamic researches of lumateperone., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Therapeutic drug monitoring (TDM) using cyclin-dependent kinase inhibitors (CDK4/6is) is a novel approach for optimizing treatment outcomes. Currently, palbociclib, ribociclib, and abemaciclib are the available CDK4/6is and are primarily coadministered with letrozole. This study aimed to develop and validate an LC-MS/MS method for the simultaneous analysis of CDK4/6is, 2 active metabolites of abemaciclib (M2 and M20), and letrozole in human plasma for use in TDM studies., Methods: Sample pretreatment comprised protein precipitation with methanol and dilution of the supernatant with an aqueous mobile phase. Chromatographic separation was achieved using a reversed-phase XBridge BEH C18 column (2.5 μm, 3.0 × 75 mm XP), with methanol serving as the organic mobile phase and pyrrolidine-pyrrolidinium formate (0.005:0.005 mol/L) buffer (pH 11.3) as the aqueous mobile phase. A triple quadrupole mass spectrometer was used for the detection, with the ESI source switched from negative to positive ionization mode and the acquisition performed in multiple reaction monitoring mode., Results: The complete validation procedure was successfully performed in accordance with the latest regulatory guidelines. The following analytical ranges (ng/mL) were established for the tested compounds: 6-300, palbociclib and letrozole; 120-6000, ribociclib; 40-800, abemaciclib; and 20-400, M2 and M20. All results met the acceptance criteria for linearity, accuracy, precision, selectivity, sensitivity, matrix effects, and carryover. A total of 85 patient samples were analyzed, and all measured concentrations were within the validated ranges. The percent difference for the reanalyzed samples ranged from -11.2% to 7.0%., Conclusions: A simple and robust LC-MS/MS method was successfully validated for the simultaneous quantification of CDK4/6is, M2, M20, and letrozole in human plasma. The assay was found to be suitable for measuring steady-state trough concentrations of the analytes in patient samples., Competing Interests: F. Puglisi has received honoraria from Amgen, AstraZeneca, Daiichi Sankyo, Celgene, Eisai, Eli Lilly, Exact Sciences, Gilead, Ipsen, Menarini, MSD, Novartis, Pierre Fabre, Pfizer, Roche, Seagen, Takeda, and Viatris. F. Puglisi is currently receiving research grants from AstraZeneca, EISAI, and Roche. L. Gerratana has received honoraria from AstraZeneca, Daiichi Sankyo, Eli Lilly, GlaxoSmithKline, Incyte, Novartis, Pfizer, Menarini Stemmline, and AbbVie. L. Gerratana is currently receiving research grants from Menarini Silicon Biosystems. S. Corsetti has received a travel grant from AstraZeneca. The remaining authors declare no conflict of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology.)

Despite its effectiveness, combination antiretroviral treatment (cART) has a limited effect on HIV DNA reservoir, which establishes early during primary HIV infection (PHI) and is maintained by latency, homeostatic T-cells proliferation, and residual replication. This limited effect can be associated with low drug exposure in lymphoid tissues and/or suboptimal adherence to antiretroviral drugs (ARVs). The aim of this study was to assess ARV concentrations in plasma, peripheral blood mononuclear cells (PBMCs) and lymph nodes (LNs), and their association to HIV RNA and HIV DNA decay during PHI. Participants were randomised to receive standard doses of darunavir/cobicistat (Arm I), dolutegravir (Arm II) or both (Arm III), with a backbone of tenofovir alafenamide and emtricitabine. Total HIV DNA was measured using digital-droplet PCR in PBMCs at baseline, 12 and 48 weeks. Drug concentrations in plasma and PBMCs were determined at 2, 12 and 48 weeks (LNs at 12 weeks) by UHPLC-MS/MS. Seventy-two participants were enrolled, mostly male (n=68), with a median age of 34 years and variable Fiebig stages (V-VI 57.7%, I-II 23.9%, and III-IV 18.3%). Twenty-six patients were assigned to Arm I, 27 to Arm II and 19 to Arm III. After 48 weeks, most patients had undetectable viremia, with minor differences in HIV RNA decay between arms. Patients with Fiebig I-II showed faster HIV RNA and HIV DNA decay. Intracellular tissue penetration was high for nucleoside analogues and low-moderate for darunavir and dolutegravir. Only tenofovir diphosphate concentrations in PBMCs showed correlation with HIV DNA decay. Overall, these results indicate that the timing of treatment initiation and intracellular tenofovir penetration are primary and secondary factors, respectively, affecting HIV reservoir., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Poor adherence to ART and pre-exposure prophylaxis (PrEP) can impact patient and public health. Point-of-care testing (POCT) may aid monitoring and adherence interventions., Objectives: We report the pharmacokinetics of tenofovir [dosed as tenofovir disoproxil (TDF) and tenofovir alafenamide (TAF)], emtricitabine (FTC), lamivudine (3TC) and dolutegravir (DTG) in plasma and urine following drug cessation to evaluate adherence targets in urine for POCT., Methods: Subjects were randomized (1:1) to receive DTG/FTC/TAF or DTG/3TC/TDF for 15 days. Plasma and spot urine were collected on Day 15 (0-336 h post final dose). Drug concentrations were quantified using LC-MS, and non-linear mixed-effects models applied to determine drug disposition between matrices and relationship with relevant plasma [dolutegravir protein-adjusted 90% inhibitory concentration (PA-IC90 = 64 ng/mL) and minimum effective concentration (MEC = 324 ng/mL)] and urinary thresholds [tenofovir disoproxil fumarate 1500 ng/mL]., Results: Of 30 individuals enrolled, 29 were included (72% female at birth, 90% Caucasian). Median (range) predicted time to plasma dolutegravir PA-IC90 and MEC were 83.5 (41.0-152) and 49.0 h (23.7-78.9), corresponding to geometric mean (90%) urine concentrations of 5.42 (4.37-6.46) and 27.4 ng/mL (22.1-32.7). Tenofovir in urine reached 1500 ng/mL by 101 h (58.6-205) with an equivalent plasma concentration of 6.20 ng/mL (4.21-8.18)., Conclusions: These data support use of a urinary tenofovir threshold of <1500 ng/mL (tenofovir disoproxil fumarate-based regimens) as a marker of three or more missed doses for a POCT platform. However, due to low dolutegravir concentrations in urine, POCT would be limited to a readout of recent dolutegravir intake (one missed dose)., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)

Although antiretroviral therapy (ART) is highly effective for the treatment of HIV-1 infection to suppress virus in the blood, HIV persists in tissues. HIV persistence in the tissues is due to numerous factors, and one of those factors are antiretroviral (ARV) concentrations. ARV concentrations in tissues must be adequate to suppress HIV at the sites of action. While therapeutic drug monitoring in the plasma is well-known, drug monitoring in the tissues provides local assessments of adequate ARV exposure to prevent localized HIV resistance formation. Towards these efforts, we validated an ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) method in human tissues (cervical, rectal, and vaginal tissues) for the simultaneous quantification of five ARVs: bictegravir, cabotegravir, dolutegravir, doravirine, and raltegravir. For this assay, protein precipitation with acetonitrile with stable, isotopically-labeled internal standards followed by supernatant pre-concentration was performed. Analyte separation was accomplished using a multistep UPLC gradient mixture of 0.1 % formic acid in water (A) and acetonitrile (B) with a Waters Cortecs T3 (2.1x100 mm) column. The assay was extensively validated as per the United States Food and Drug Administration Bioanalytical Method Validation Guidance over a clinically observed range (0.05-50 ng/mL) with superb linearity (R2 > 0.99 across all ARVs). The assay run time was 8.5 min. This analytical method achieves appropriate performance of trueness (85.5-107.4 %), repeatability, and precision (CV < 15 %). Our method will be employed for the therapeutic monitoring of guideline-recommended ARVs in human tissues for monitoring therapeutic efficacy in HIV treatment and prevention research efforts., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Sharon A. Riddler reports a relationship with Gilead Sciences Inc that includes: funding grants. Sharon A. Riddler reports a relationship with Merck & Co Inc that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aim: The relationship between CYP1A2 polymorphisms and the steady-state plasma levels of aripiprazole and its active metabolite, dehydroaripiprazole, were investigated in Japanese schizophrenic patients., Background: It has been implied that cytochrome P450 (CYP) 1A2 may play a role in the metabo-lism of aripiprazole. Genetic variations in the CYP1A2 gene have been reported., Objective: The authors investigated the relationship between 2 CYP1A2 polymorphisms, CYP1A2*C (-3860G>A) and CYP1A2*F (-163C>A) , and the steady-state plasma levels/dose (C/D) ratios of aripiprazole and dehydroaripiprazole in Japanese schizophrenic patients., Methods: All 89 subjects (46 males and 43 females) had been receiving 2 fixed daily doses of aripiprazole (24 mg; n=56 and 12 mg: n=33) for more than 2 weeks. No other drugs were used except flunitrazepam and biperiden. The plasma drug levels were determined by LC/MS/MS. These CYP1A2 polymorphisms were detected using polymerase chain reaction analysis., Results: The mean C/D ratios of dehydroaripiprazole were significantly (P < 0.05) lower in patients with the A/A allele of CYP1A2*F than in those without the allele. No differences were found in the values of aripiprazole and the combination of aripiprazole and dehydroaripiprazole among the CYP1A2 *F genotype. There were no differences in the values of aripiprazole, dehydroaripiprazole, or the combination of the 2 compounds among the CYP1A2 *C genotype. The absence of the A allele of CYP1A2 *F was correlated with the mean C/D ratios of dehydroaripiprazole (standardized partial correlation coefficient = 0.276, P < 0.01) by multiple regression analysis., Conclusion: The findings of this study suggest that the CYP1A2 *F polymorphism contributes at least partially to the variability in the steady-state plasma levels of dehydroaripiprazole., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Palbociclib is an oral inhibitor of cyclin-dependent kinases 4 and 6 used in the treatment of locally advanced and metastatic breast cancer, and is extensively metabolized by cytochrome P450 enzyme 3A4 (CYP3A4). A pharmacokinetic/pharmacodynamic relationship between palbociclib exposure and neutropenia is well known. This study aimed to investigate the effects of the moderate CYP3A4 inhibitor erythromycin on the pharmacokinetics of palbociclib. We performed a randomized crossover trial comparing the pharmacokinetics of palbociclib monotherapy 125 mg once daily (q.d.) with palbociclib 125 mg q.d. plus oral erythromycin 500 mg three times daily for seven days. Pharmacokinetic sampling was performed at steady-state for both dosing schedules. Eleven evaluable patients have been enrolled. For palbociclib monotherapy, geometric mean area under the plasma concentration-time curve from zero to infinity (AUC 0-24h ), maximum plasma concentration (C max ), and minimum plasma concentration (C min ) were 1.46 × 10 3  ng•h/mL (coefficient of variation (CV) 45.0%), 80.5 ng/mL (CV 48.5%), and 48.4 ng/mL (CV 38.8%), respectively, compared with 2.09 × 10 3  ng•h/mL (CV 49.3%, P = 0.000977), 115 ng/mL (CV 53.7%, P = 0.00562), and 70.7 ng/mL (CV 47.5%, P = 0.000488) when palbociclib was administered concomitantly with erythromycin. Geometric mean ratios (90% confidence intervals) of AUC 0-24h , C max , and C min for palbociclib plus erythromycin vs. palbociclib monotherapy were 1.43 (1.24-1.66), 1.43 (1.20-1.69), and 1.46 (1.30-1.63). Minor differences in adverse events were observed, and only one grade ≥ 3 toxicity was observed in this short period of time. To conclude, concomitant intake of palbociclib with the moderate CYP3A4 inhibitor erythromycin resulted in an increase in palbociclib AUC 0-24h and C max of both 43%. Therefore, a dose reduction of palbociclib to 75 mg q.d. is rational, when palbociclib and moderate CYP3A4 inhibitors are used concomitantly., (© 2021 The Authors. Clinical Pharmacology & Therapeutics © 2021 American Society for Clinical Pharmacology and Therapeutics.)

This study aimed at assessing 2-methoxyphenyl piperazine derivative for its binding specificity and suitability in mapping metabotropic glutamate receptor subtype 1, which is implicated in several neuropsychiatric disorders. N-(2-(4-(2-Methoxyphenyl)piperazin-1-yl)ethyl)-N-methylpyridin-2-amine was synthesised and evaluated for brain imaging subsequent to radiolabelling with [ 11 C] radioisotope via methylation process in 98.9% purity and 52 ± 6% yield (decay corrected). The specific activity was in the range of 72-93 GBq/µmol. The haemolysis of blood was 2-5% for initial 4 hr and remained < 10% after 24 h of incubation indicating low toxicity. In vitro autoradiograms after coincubation with unlabelled ligand confirmed the high uptake of the PET radioligand in the mGluR1 receptor rich regions. The PET as well as biodistribution studies also showed high activity in the brain with a direct correlation between receptor abundance distribution pattern and tracer activity. The biodistribution analyses revealed initial high brain uptake (4.18 ± 0.48). The highest uptake was found in cerebellum (SUV 4.7 ± 0.2), followed by thalamus (SUV 3.5 ± 0.1), and striatum (SUV 3 ± 0.1). In contrast, pons had negligible tracer activity. The high uptake observed in all the regions with known mGluR1 activity indicates suitability of the ligand for mGluR1 imaging., (Copyright © 2021. Published by Elsevier Inc.)

Background: Bictegravir coformulated with emtricitabine and tenofovir alafenamide as a fixed-dose combination (BIC/FTC/TAF 50/200/25 mg) is recommended as an initial regimen in patients who are antiretroviral (ARV)-naïve or virologically suppressed on a stable ARV regimen. However, no real-world pharmacokinetic (PK) data are available in treatment-experienced patients with antiretroviral resistance receiving BIC/FTC/TAF plus a boosted protease inhibitor., Setting/methods: This prospective, single-center, nonrandomized pharmacokinetic study enrolled adult treatment-experienced persons with HIV and creatinine clearance >30 mL/min receiving BIC/FTC/TAF + DRV/c as part of routine clinical care. Steady-state PK profiles of BIC, TAF, tenofovir (TFV), and DRV after daily dosing of BIC/FTC/TAF + darunavir/cobicistat (DRV/c) were obtained with samples at predose and 0.5, 1, 2, and 4 hours postdose. The AUC0-24 at steady state was extrapolated by imputing C0 for C24 for each participant (AUC0-tau,exp)., Results: Nine participants were enrolled with a median age of 59 years (range 54-67) and median number of years on ART of 19 (range 5.8-30). The median (interquartile range [IQR]) BIC AUC0-tau,exp and Cmax values were 128.9 µg*h/mL (78.1-159.5) and 6.9 µg/mL (5.1-9.8), respectively. The median (IQR) TAF AUC0-tau,exp and Cmax values were 0.376 µg*h/mL (0.199-0.430) and 0.276 µg/mL (0.149-0.543), respectively. Predose concentrations of TFV and DRV were comparable with historical data., Conclusion: Treatment-experienced persons with HIV receiving BIC/FTC/TAF + darunavir/cobicistat (DRV/c) had BIC exposures (AUC0-tau) that were increased by approximately 26% compared with historical PK data. Although TAF exposures were substantially increased, plasma TFV was only modestly higher. These results suggest that BIC/TAF/FTC + DRV/c is a viable antiviral regimen option for treatment-experienced persons., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Therapeutic drug monitoring (TDM) is strongly suggested to define the proper drug dosage to overcome inter- and intra-patient variability in drug exposure, which is typically observed with oral anticancer agents, such as palbociclib (PALBO), ribociclib (RIBO) and letrozole (LETRO), all approved for the treatment of HR+, HER2- locally advanced or metastatic breast cancer (BC). Optimal TDM implementation requires a blood sampling organization that can be hampered by limited availability of health and laboratory personnel. Dried Blood Spot (DBS) sampling is proposed to overcome such limitations. The aim of this work was the development of a new LC-MS/MS method to analyze DBS samples containing PALBO, RIBO, and LETRO. Analytes extraction from DBS was performed by adding a methanolic solution containing the corresponding internal standards. LC-MS/MS analysis was performed using a LC Nexera (Shimadzu) system coupled with an API 4000 QTrap (SCIEX) mass spectrometer. The chromatographic separation was performed on a Luna Omega Polar C18 column (Phenomenex). The method was applied to 38 clinical samples collected by finger prick. The influence of hematocrit and spot size, sample homogeneity, stability, and correlation between finger prick and venous DBS measurement were assessed. The analytical validation was performed according to EMA and FDA guidelines. The analytical range of the method was 1 to 250 ng/mL for PALBO, 40 to 10000 ng/mL for RIBO, and 2 to 500 ng/mL for LETRO, where linearity was assessed, obtaining mean coefficients of determination (R 2 ) of 0.9979 for PALBO, 0.9980 for RIBO, and 0.9987 for LETRO). The LC-MS/MS method runtime was 6.6 min. Incurred sample reanalysis demonstrated reproducibility, as the percentage difference between the two quantifications was lower than 20% for 100% of PALBO, 81.8% of RIBO, and 90.9% of LETRO paired samples. Intra- and inter-day precision (CV (%)) was lower than 11.4% and intra- and inter-day accuracy was between 90.0 and 106.5%. DBS sample stability at room temperature was confirmed for 2.5 months. A positive correlation was observed between DBS and plasma concentrations for the 3 drugs, Lin's concordance correlation coefficients obtained by DBS normalization applying a selected strategy were 0.958 for PALBO, 0.957 for RIBO, and 0.963 for LETRO. In conclusion, a fast, easy, and reproducible DBS LC-MS/MS method for the simultaneous quantification of palbociclib; ribociclib and letrozole was developed to be used in clinical practice., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Blonanserin is an atypical antipsychotic drug with high affinity and selective antagonism for dopamine D 2 and D 3 and serotonin 5-HT 2A receptors. Blonanserin transdermal patch is the first transdermal formulation developed for the treatment of schizophrenia. The purpose of this population pharmacokinetic (PPK) analysis was to evaluate the characteristics of blonanserin pharmacokinetics after transdermal patch application, to estimate the daily fluctuation in blonanserin plasma concentration, and to evaluate the impact of patch application noncompliance to support usage in clinical settings. A total of 3747 plasma blonanserin concentrations from 9 clinical studies (93 healthy volunteers and 348 patients with schizophrenia) were used in the PPK analysis. The plasma concentration was predicted using the final PPK model, and dopamine D 2 receptor occupancy was estimated on the basis of the results of a separately reported positron emission tomography study. A 2-compartment, parallel zero-order absorption with a lag time and first-order elimination model was developed to describe the pharmacokinetics of blonanserin, including the change in absorption rate during patch application. The maximum/minimum ratio of plasma concentration was estimated as 1.10 at steady state, indicating minimal fluctuation. In the case of failure to remove the previous patch or a missing application, the increase or decrease in plasma concentration and dopamine D 2 receptor occupancy was <20%. These results indicated that the plasma blonanserin concentration and dopamine D 2 receptor occupancy were stable after blonanserin transdermal patch application, which may lead to improved tolerability during the treatment of patients with schizophrenia., (© 2021, The American College of Clinical Pharmacology.)

Sotorasib is a KRAS inhibitor with promising anticancer activity in phase I clinical studies. This compound is currently under further clinical evaluation as monotherapy and combination therapy against solid tumors. In this study, a liquid chromatography-tandem mass spectrometric method to quantify sotorasib in mouse plasma and eight tissue-related matrices (brain, liver, spleen, kidney, small intestine, small intestine content, lung, and testis homogenates) was developed and validated. Protein precipitation using acetonitrile was utilized in 96-well format to extract sotorasib and erlotinib (internal standard) from mouse plasma and tissue homogenates. Separation of the analytes was performed on an Acquity UPLC® BEH C18 column by gradient elution of methanol and 0.1% formic acid in water at a flow rate of 0.6 ml/min. Sotorasib was detected by a triple quadrupole mass spectrometer with positive electrospray ionization in selected reaction monitoring mode. A linear calibration range of 2-2,000 ng/ml of sotorasib was achieved during the validation. Accuracy values were in the range of 90.7-111.4%, and precision values (intra- and interday) were between 1.7% and 9.2% for all tested levels in all investigated matrices. The method was successfully applied to investigate the plasma pharmacokinetics and tissue accumulation of sotorasib in female wild-type mice., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

AMG 510 is the first-in-class KRAS G12C inhibitor, currently in phase 2 clinical trials as an orphan drug to treat non-small cell lung cancer patients. We developed and validated a sensitive, selective, and high-throughput HPLC-MS/MS method for the quantitation of AMG 510 in mouse plasma per the regulatory guideline of the US Food and Drug and Administration. AMG 510 and the IS (MRTX-1257) were extracted from mouse plasma using tert-butyl methyl ether and chromatographed using an isocratic mobile phase (0.2% formic acid:acetonitrile; 25:75, v/v) at a flow rate of 0.65 mL/min on an Atlantis dC 18 column. AMG 510 and the IS eluted at ~0.95 and 0.73 min, respectively. AMG 510 and the IS were detected by positive electrospray ionization in multiple reaction monitoring using transition pair (Q1 → Q3) m/z 561.1 → 134.1 and m/z 566.5 → 98.2, respectively. Excellent linearity was achieved in the concentration range of 1.08-5040 ng/mL (r > 0.0996). No matrix effect and carryover were observed. Intra- and inter-day accuracies and precisions were within the acceptance range. AMG 510 was demonstrated to be stable under the tested storage conditions. This novel method has been applied to a pharmacokinetic study in mice., (© 2020 John Wiley & Sons, Ltd.)

Dolutegravir (DTG) is an integrase inhibitor, whose gastrointestinal absorption is impaired by the formation of chelates with multivalent metal cation preparations. However, little is known regarding the interactions of DTG with preparations containing other multivalent metal cations or with polycation polymer preparations. This study examined how the pharmacokinetics of DTG are affected by co-administration with Al(OH) 3 , LaCO 3 , and the polycation polymers bixalomer (Bxl) and sevelamer (Svl). Prior to oral administration of DTG (5 mg/kg), rats were orally administered Al(OH) 3 (150 or 300 mg/kg), LaCO 3 (50 or 75 mg/kg), Bxl (250 or 500 mg/kg), or Svl (300 or 600 mg/kg). Serum concentrations of DTG were then measured over the next 24 h. Compared to the administration of DTG alone, its co-administration with Al(OH) 3 , LaCO 3 , Bxl, and Svl led to reduced serum concentration of DTG, and consequently, a significantly reduced area under the curve. These comparisons also revealed a considerable reduction in the maximum concentration, suggesting that the interactions of these agents with DTG in the intestinal tract inhibit absorption of DTG. The above results demonstrate that Al(OH) 3 , LaCO 3 , Bxl, and Svl affect the pharmacokinetics of DTG and indicate the need for caution when combining any of the above preparations with DTG., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2020 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.)

Therapeutic drug monitoring (TDM) is used in certain clinically selected cases and in research settings to optimize the response to antiretroviral therapy. Plasma of blood is commonly used for TDM, but blood sampling is invasive and at risk for transmission of infectious agents. On the other hand, saliva sampling is noninvasive, safe, cheap, and easily performed compared to blood. Dolutegravir (DTG) is now widely prescribed as a key component of antiretroviral therapy for HIV infection. In this study, we examined the relationship between DTG concentrations in plasma and saliva of treated patients to explore the possibility of using saliva as an alternative body fluid of TDM. A total of 17 pairs of blood and saliva samples were obtained from 15 consented HIV-1-infected subjects treated with DTG containing regimens for more than one month. Both blood and saliva samples were collected within 1 h of each other. Drug concentrations were determined by liquid chromatography-tandem mass spectrometry using DTG-d5 as an internal standard. The LLOQ was 0.5 ng/mL. The calibration curves were prepared with pooled plasma or saliva containing DTG in a range of 0.5-100 ng/mL with precision of <14.4% and accuracy within ±14.7%. The DTG concentrations in the plasma and saliva were significantly correlated (Pearson's correlation coefficient r = 0.76, p < 0.001). The median ratio of the drug concentration in saliva to those in plasma was 0.0056, which is close to the rate of non-protein-bound DTG in plasma (0.70%), suggesting that only free DTG in plasma is transported to the salivary glands and secreted into saliva. The present study demonstrates that DTG concentration in saliva reflects the pharmacologically active drug concentration in plasma and may provide an easily accessible alternative for monitoring effective antiretroviral treatment., Competing Interests: The authors have read the journal’s policy and declare the following competing interests: KS and SK are employees of Hanah Meditech Co. Ltd. However, this company was established after this study concluded, and KS and SK were employees of Keio University, Tokyo, Japan at the time the study was conducted. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: People living with human immunodeficiency virus are ageing under combination antiretroviral treatments but data on drug exposure in serum and cerebrospinal fluid are limited. Dolutegravir is a widely used second-generation integrase strand transfer inhibitor: conflicting data suggest that neuropsychiatric side effects may present at a higher frequency in patients with higher dolutegravir serum concentrations., Methods: We performed a retrospective analysis of our therapeutic drug monitoring registry identifying patients receiving once-daily dolutegravir without concomitant interacting drugs and significant clinical conditions. Data were analysed stratifying time after drug dose intake (maximum concentration 0.5-4 and trough concentration 21-27 h). Cerebrospinal fluid samples from patients enrolled in neurological studies and receiving dolutegravir were analysed for dolutegravir cerebrospinal fluid concentrations and cerebrospinal fluid-to-plasma ratios. Serum and cerebrospinal fluid concentrations were measured through validated chromatographic methods., Results: We included 207 (providing 457 serum samples) and 41 patients (providing 41 cerebrospinal fluid samples). Participants were mostly male (68.2-72.8%) of median age of 50 years (50-53 years). Non-significant changes in dolutegravir maximum concentration and trough concentration were observed with age at Spearman's test (p values > 0.05); linear logistic regression showed a significant effect of age on dolutegravir trough concentration (p = 0.0013) (Fig. 1). Dolutegravir maximum concentration [3830 ng/mL (2311-5057) vs 4230 ng/mL (2919-5272), p = 0.311] and trough concentration [838 ng/mL (362-1587) vs 966 ng/mL (460-2085), p = 0.056] were non-significantly or borderline higher in patients aged > 50 years. Cerebrospinal dolutegravir concentrations were associated with plasma concentrations (ρ = 0.374, p = 0.016) and age (ρ = 0.537, p = 0.003); cerebrospinal fluid dolutegravir concentrations (13.8 vs 7.3 ng/mL, p = 0.015) and cerebrospinal fluid-to-plasma ratios (0.57 vs 0.32%, p = 0.017] were higher in participants aged > 50 years., Conclusions: We observed an increase in dolutegravir exposure in serum and in cerebrospinal fluid in older patients living with human immunodeficiency virus.

Objective: Ethanol and zopiclone are both sedating drugs that impair traffic relevant skills, but that show vast differences in epidemiological traffic risk. One explanation for this could be that they impair various kinds of skills differently, but this is less previously studied. The aim of this study was to compare effects of zopiclone and ethanol on a large battery of computerized psychomotor and cognitive tests according to different test classifications. Methods: Ethanol (50 grams), zopiclone 5 mg, zopiclone 10 mg or placebo was administered in a randomized trial with a cross-over design. Blood was sampled nine times after administration and analyzed for zopiclone and ethanol using fully validated methods. The computerized tests Connors Continuous Performance Test (CPT), Stockings of Cambridge (SOC) and choice reaction time (CRT) was performed at baseline and after administration. The three tests yielded fifteen different test components, which were categorized according to the three well-known behavior levels (automative behavior, control behavior and executive planning). Secondly, they were categorized into tests measuring "reaction time", "impulsivity" and "attention/cognition". Results: On all tests belonging to behavior level 1 and on all tests measuring "reaction time", more subjects were impaired by zopiclone than ethanol. On all tests measuring "impulsivity", more subjects were impaired by ethanol than zopiclone. Conclusion: Zopiclone and ethanol both lead to impairment, but have a different profile on what kind of tests and neurocognitive functions they mostly impair. This could be important in the understanding of the differences in traffic risk connected to these two drugs.

Antipsychotic drugs (AP) are widely prescribed for the treatment of schizophrenia and psychosis. The pharmacological treatment of schizophrenia is often performed with the simultaneous use of two or more antipsychotic agents to achieve the desired control of psychotic symptoms Available AP include both conventional (typical) and new (atypical) antipsychotic medications. Atypical AP, such as quetiapine, now account for the vast majority of AP prescriptions. In forensic toxicology, AP are of considerable interest because of their potential abuse and their involvement in intoxications and suicides. The authors retrospectively examined AP positive cases detected in samples collected during autopsies performed in the Forensic Clinical and Pathology Service of National Institute of Legal Medicine and Forensic Sciences Centre Branch or in other autopsies carried out in the central region of Portugal, between January 2016 and December 2018. A quantitative liquid chromatography-tandem mass spectrometry assay was developed for the simultaneous determination of 16 AP (amisulpride, aripiprazole, chlorpromazine, clozapine, cyamemazine, fluphenazine, haloperidol, levomepromazine, melperone, olanzapine, paliperidone, promethazine, quetiapine, risperidone, sulpiride and ziprasidone) in blood samples of postmortem cases. The Laboratory of Forensic Chemistry and Toxicology received 3,588 requests for toxicological analysis: 1,413 cases were positive for drugs from which 351 (24.8%) cases were positive for AP, 60.1% from male individuals and 39.9% from female. Quetiapine was the most prevalent AP (36.5%) followed by olanzapine (20.8%). During this period, there were 25 postmortem cases with AP blood concentrations above therapeutic range, in which 36% of those are in agreement with the information received (psychological history or acute intoxication suspicion) and the manner of death was suicide. Our results point that antipsychotics are an increasingly prevalent class of drugs. AP must be measured not only in toxic concentrations but also in therapeutic levels in postmortem cases; therefore, it is important to come up with a sensitive method to cover the low therapeutic range in which AP are usually present., (© The Author(s) 2020. Published by Oxford University Press on behalf of Society of Forensic Toxicologists, Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

An analytical method for the detection of 40 benzodiazepines, (±)-zopiclone, zaleplon and zolpidem in blood and urine by solid-phase extraction liquid chromatography-tandem mass spectrometry was developed and validated. Twenty-nine of 43 analytes were quantified in 0.5 mL whole blood for investigating postmortem, drug-facilitated sexual assault (DFSA) and driving under the influence of drugs cases (DUID). The four different dynamic ranges of the seven-point, linear, 1/x weighted calibration curves with lower limits of quantification of 2, 5, 10 and 20 μg/L across the analytes encompassed the majority of our casework encountered in postmortem, DFSA and DUID samples. Reference materials were available for all analytes except α-hydroxyflualprazolam, a hydroxylated metabolite of flualprazolam. The fragmentation of α-hydroxyflualprazolam was predicted from the fragmentation pattern of α-hydroxyalprazolam, and the appropriate transitions were added to the method to enable monitoring for this analyte. Urine samples were hydrolyzed at 55°C for 30 min with a genetically modified β-glucuronidase enzyme, which resulted in >95% efficiency measured by oxazepam glucuronide. Extensive sample preparation included combining osmotic lysing and protein precipitation with methanol/acetonitrile mixture followed by freezing and centrifugation resulted in exceptionally high signal-to-noise ratios. Bias and between-and within-day imprecision for quality controls (QCs) were all within ±15%, except for clonazolam and etizolam that were within ±20%. All 29 of the 43 analytes tested for QC performance met quantitative reporting criteria within the dynamic ranges of the calibration curves, and 14 analytes, present only in the calibrator solution, were qualitatively reported. Twenty-five analytes met all quantitative reporting criteria including dilution integrity. The ability to analyze quantitative blood and qualitative urine samples in the same batch is one of the most useful elements of this procedure. This sensitive, specific and robust analytical method was routinely employed in the analysis of >300 samples in our laboratory over the last 6 months., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

A rapid, sensitive, and reliable liquid chromatography-tandem mass spectrometric method was developed to quantify ipatasertib in dog plasma. The dog plasma sample was deproteinated by using acetonitrile with ulixertinib as an internal standard followed by separation on a Spursil C 18 -EP column with a gradient mobile phase comprising 2 mM ammonium acetate containing 0.1% formic acid and acetonitrile. Positive ion electrospray was used, and multiple reaction monitoring transitions were m/z 458.2 > 387.2 for ipatasertib and m/z 433.1 > 262.1 for the internal standard. The developed method was validated with a linear range of 0.3-1500 ng/mL, and with correlation coefficient greater than 0.9989. The lower limit of quantification was 0.3 ng/mL. The intra- and inter-day precision ranged from 3.58 to 14.32%, whereas the intra- and inter-day accuracy was in the range of -2.50-13.25%. No carry-over and matrix effects were observed under the current conditions. The extraction recovery was demonstrated to be greater than 85.43%. Ipatasertib was stable during the storage, processing, and determination. The validated assay was further successfully applied to a pharmacokinetic study of ipatasertib in dogs after oral and intravenous administrations. The bioavailability of ipatasertib was determined to be 19.3%., (© 2020 John Wiley & Sons, Ltd.)

Background The PARP inhibitor olaparib has shown acceptable toxicity at doses of up to 400 mg twice daily (bid; capsule formulation) with encouraging signs of antitumor activity. Based on its mode of action, olaparib may sensitize tumor cells to DNA-damaging agents. This Phase I trial (NCT00516724) evaluated the safety, pharmacokinetics (PK) and preliminary efficacy of olaparib combined with carboplatin and/or paclitaxel. Methods Patients with advanced solid tumors received olaparib (capsule bid) plus carboplatin (Part A), carboplatin and paclitaxel (Part B), or paclitaxel (Part C). In each part of the study, different drug doses were given to define the most appropriate dose/drug combination to use in further studies. Safety assessments included evaluation of dose-limiting toxicities (DLTs; cycle 1 only), adverse events (AEs) and physical examinations. PK assessments of olaparib, carboplatin and paclitaxel were performed. Tumor responses (RECIST) were assessed every two cycles. Results Fifty-seven patients received treatment. DLTs were reported in two patients (both receiving olaparib 100 mg bid and carboplatin AUC 4; Part A, cohort 2): grade 1 thrombocytopenia with grade 2 neutropenia lasting for 16 days, and grade 2 neutropenia lasting for 7 days. Non-hematologic AEs were predominantly grade 1-2 and included fatigue (70%) and nausea (40%). Bone marrow suppression, mainly neutropenia (51%) and thrombocytopenia (25%), frequently led to dose modifications. Conclusions Olaparib in combination with carboplatin and/or paclitaxel resulted in increased hematologic toxicities, making it challenging to establish a dosing regimen that could be tolerated for multiple cycles without dose modifications.

Background In the first part of this extensive phase I study (NCT00516724), continuous olaparib twice daily (bid) with carboplatin and/or paclitaxel resulted in myelosuppression and dose modifications. Here, we report the safety, tolerability, and efficacy of intermittent olaparib dosing combined with carboplatin and paclitaxel. Methods Patients with advanced solid tumors (part D) and enriched for ovarian and breast cancer (part E) received olaparib (capsule and tablet formulations) using intermittent schedules (2 to 10 days of a 21-day cycle) combined with carboplatin/paclitaxel. Safety assessments included evaluation of dose-limiting toxicities (DLTs; cycle 1 only), adverse events (AEs), and physical examinations. Pharmacokinetic assessments of olaparib capsule and tablet combined with carboplatin/paclitaxel were performed. Tumor responses (RECIST) were assessed every 2 cycles. Results In total, 132 heavily pre-treated patients were included. One DLT of grade 3 elevated alanine aminotransferase lasting for 8 days was reported (olaparib tablet 100 mg bid days 3-12, carboplatin area under the curve 4 and paclitaxel 175 mg/m 2 ). The most common hematological AEs were neutropenia (47%) and thrombocytopenia (39%), which frequently led to dose modifications. Non-hematological AEs were predominantly grade 1-2, including alopecia (89%) and fatigue (84%). Overall objective response rate was 46%. Conclusions Discontinuous dosing of olaparib resulted in significant myelosuppression leading to dose interruptions and/or delays. Anti-tumor activity was encouraging in patients enriched with BRCA-mutated breast and ovarian cancer. The most appropriate olaparib tablet dose for use in further studies evaluating olaparib in combination with carboplatin and paclitaxel is 50 mg bid (days 1-5).

This study investigated the kinetics of quetiapine and its metabolite 7-hydroxyquetiapine in guinea pig blood and hair roots during the whole time course of absorption and elimination after intragastric administration of three dosages (25 mg/kg, 50 mg/kg, 100 mg/kg). The mean maximum concentration (C max ) values of quetiapine in the blood of the low-, medium- and high-dose groups were 334.4, 849.0, and 2751.1 ng/mL, respectively, and those of 7-hydroxyquetiapine were 75.6, 175.5, and 173.7 ng/mL, respectively. The corresponding mean Cmax values of quetiapine in hair roots were 2.0, 5.9, and 14.7 ng/mg, and those of 7-hydroxyquetiapine were 1.0, 1.8, and 6.4 ng/mg. The mean half-lives of quetiapine at the three dosages in blood were 3.8 h, 5.0 h, and 6.0 h, and those in hair roots were 48.2 h, 41.5 h, and 162.3 h; for 7-hydroxyquetiapine, the values were 2.9 h, 4.1 h, and 4.2 h in blood and 77.1 h, 103.6 h, and 385.9 h in hair roots. The levels of quetiapine in blood and hair roots were higher than those of 7-hydroxyquetiapine, and there were significant positive correlations (p<0.05) between the concentrations of quetiapine and 7-hydroxyquetiapine in hair roots and the respective doses within 24 h and 48 h. Quetiapine and 7-hydroxyquetiapine could still be detected in some guinea pigs even after 28 days, which means that drugs remain in the hair roots longer than in the blood. This finding shows that hair roots could be a good alternative or supplemental matrix to common biological samples such as blood and urine, as hair roots substantially extend the detection window from days to months. Moreover, quetiapine and 7-hydroxyquetiapine were detected within 15min after administration in hair roots, which also suggests that the drug enters the hair roots quickly. Therefore, hair root analysis may be a good choice to detect acute poisoning and single-dose administration if other matrices are unavailable or to provide complementary information for other matrices., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Bariatric surgery is increasingly performed in morbidly obese HIV patients. Limited data exist regarding antiretroviral drug exposure after bariatric surgery. We report a case of a morbidly obese HIV patient who underwent sleeve gastrectomy. Abacavir, lamivudine, and dolutegravir therapeutic drug monitoring was performed at several time points pre- and postsurgery. Significantly increased levels were measured, particularly for abacavir, whose levels increased ∼12-fold. Several mechanistic explanations for these findings are discussed., (Copyright © 2020 American Society for Microbiology.)

The aim of the present study was to develop a liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method for the determination of olaparib in rat plasma. The plasma samples were processed using one-step protein precipitation with acetonitrile and then separated on Waters Acquity BEH C 18 column (50 × 2.1 mm, particle size 1.7 μm) using water containing 0.1% formic acid and acetonitrile as mobile phase with optimized gradient elution. Mass spectrometric detection was carried out by selective reaction monitoring mode via positive ESI mode with precursor-to-product transitions of m/z 435.3 > 367.1 and m/z 443.1 > 375.2 for olaparib and 2 H 8 -olaparib (internal standard). The method was linear over the concentration range 0.1-2000 ng/ml with correlation coefficient >0.9987. The lower limit of quantitation was 0.1 ng/ml. The method showed excellent accuracy and precision, negligible matrix effect and high extraction recovery. The validated method was subsequently utilized to determine the concentration of olaparib in rat plasma and further applied to the pharmacokinetic study of olaparib in rat plasma. Our results demonstrated that olaparib showed gender-dependent pharmacokinetics in rats. Compared with that in males, olaparib showed high plasma exposure, long half-life, low clearance and high bioavailability in females., (© 2020 John Wiley & Sons, Ltd.)

Recently, there has been an increase in overdose deaths due to novel synthetic opioids (NSO). Due to backlogs experienced by many forensic laboratories, it is important to understand drug stability in a variety of storage conditions. The objective of this study was to investigate the stability of AH-7921, U-47700, U-49900, U-50488, MT-45, W-15, and W-18 in blood at various temperatures over a 36-week period. NSO were generally stable over the 36-week period (66%-118%) at low and high concentrations when blood samples were stored in the refrigerator or freezer. Most analytes were stable for at least 2 weeks at room temperature (77%-120%). At the elevated temperature (35°C), analytes were generally stable for at least 14 days (75%-109%). This study has determined the stability of several NSO at various temperatures over a 36-week period. These results reflect the forensic significance of keeping samples stored at proper temperatures. Blood samples suspected to contain synthetic opioids should be stored refrigerated or frozen, when possible, in order to preserve analyte stability, especially at low concentrations., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The serine hydrolase monoacylglycerol lipase (MAGL) is the rate-limiting enzyme responsible for the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG) into arachidonic acid and glycerol. Inhibition of 2-AG degradation leads to elevation of 2-AG, the most abundant endogenous agonist of the cannabinoid receptors (CBs) CB1 and CB2. Activation of these receptors has demonstrated beneficial effects on mood, appetite, pain, and inflammation. Therefore, MAGL inhibitors have the potential to produce therapeutic effects in a vast array of complex human diseases. The present report describes the pharmacologic characterization of [1-(4-fluorophenyl)indol-5-yl]-[3-[4-(thiazole-2-carbonyl)piperazin-1-yl]azetidin-1-yl]methanone (JNJ-42226314), a reversible and highly selective MAGL inhibitor. JNJ-42226314 inhibits MAGL in a competitive mode with respect to the 2-AG substrate. In rodent brain, the compound time- and dose-dependently bound to MAGL, indirectly led to CB1 occupancy by raising 2-AG levels, and raised norepinephrine levels in cortex. In vivo, the compound exhibited antinociceptive efficacy in both the rat complete Freund's adjuvant-induced radiant heat hypersensitivity and chronic constriction injury-induced cold hypersensitivity models of inflammatory and neuropathic pain, respectively. Though 30 mg/kg induced hippocampal synaptic depression, altered sleep onset, and decreased electroencephalogram gamma power, 3 mg/kg still provided approximately 80% enzyme occupancy, significantly increased 2-AG and norepinephrine levels, and produced neuropathic antinociception without synaptic depression or decreased gamma power. Thus, it is anticipated that the profile exhibited by this compound will allow for precise modulation of 2-AG levels in vivo, supporting potential therapeutic application in several central nervous system disorders. SIGNIFICANCE STATEMENT: Potentiation of endocannabinoid signaling activity via inhibition of the serine hydrolase monoacylglycerol lipase (MAGL) is an appealing strategy in the development of treatments for several disorders, including ones related to mood, pain, and inflammation. [1-(4-Fluorophenyl)indol-5-yl]-[3-[4-(thiazole-2-carbonyl)piperazin-1-yl]azetidin-1-yl]methanone is presented in this report to be a novel, potent, selective, and reversible noncovalent MAGL inhibitor that demonstrates dose-dependent enhancement of the major endocannabinoid 2-arachidonoylglycerol as well as efficacy in models of neuropathic and inflammatory pain., Competing Interests: All authors were employees of Janssen Research and Development at the time the research was conducted., (Copyright © 2020 by The American Society for Pharmacology and Experimental Therapeutics.)

Within the family of serotonin (5-HT) receptors, the 5-HT 1A subtype is particularly interesting as it may be involved in various physiological processes or psychological disorders. The p-[ 18 F]MPPF, a highly selective 5-HT 1A antagonist, is used for in vivo studies in human or animal by means of positron emission tomography (PET) [1]. In order to selectively extract p-[ 18 F]MPPF and its main metabolites from plasma, molecularly imprinted polymer (MIP) was prepared against these compounds by using the p-MPPF as template. For the control of the selectivity, non-imprinted polymer (NIP) was also synthesized without template. The MIP sorbent, packed in disposable extraction cartridges (DECs), was then evaluated as molecularly imprinted solid-phase extraction (MISPE) prior to the LC determination. The conditions of extraction were evaluated in order to obtain the highest selective retention of the p-[ 18 F]MPPF and its metabolites on this MIP. The MIP selectivity was exploited in the loading and washing steps by adjusting the pH of plasma samples at a suitable value and by selecting mixtures for the washing step to limit the contribution of non-specific interactions. Other important parameters involved in the conditioning and elution steps were also studied. Finally, a pre-validation was carried out with optimal extraction conditions to demonstrate the performance of this MISPE-LC method as a generic method in the context of evaluation of new MISPE for p-[ 18 F]MPPF and its potential for metabolites extraction from human plasma., Competing Interests: Declaration of Competing Interest Not applicable, (Copyright © 2019 Elsevier B.V. All rights reserved.)

TM5441, a furan-containing drug, is an inhibitor of plasminogen activator inhibitor-1 (PAI-1), which can induce intrinsic apoptosis of human cancer cell lines. The aim of this study was to identify the reactive metabolites of TM5441 and to reveal the bioactivation pathways that are associated with its hepatotoxicity. The reactive metabolites were trapped by using glutathione (GSH) or N-acetyl-lysine (NAL) in rat, dog, and human liver microsomal incubation system after exposure to TM5441. Two metabolic activation pathways were disclosed. The first bioactivation pathway was dominated by Cytochrome P450 enzymes (CYP450s); TM5441 was metabolized into cis-2-butene-1,4-dial derivative dependent on NADPH, which can be trapped in the liver microsomal incubations fortified with GSH or NAL as trapping agents. Five metabolites (M1, M2, M9, M12 and M13) associated with GSH and three metabolites (M4, M7 and M14) associated with NAL were identified by liquid chromatography-high resolution mass spectrometry. The second bioactivation pathway was catalyzed by UDP-glucuronosyltransferases (UGTs); TM5441 was conjugated with glucuronide to form acyl-glucuronide (M10), which further reacted with GSH, resulting in the identification of a TM5441-S-acyl-GSH adduct (M11) in liver microsomal incubations fortified with uridine-5'-diphosphoglucuronidc acid (UDPGA) and GSH. M9, M10, M11, M12 and M13 were also detected in bile samples of rats given TM5441. Compared with rat, dog would display closer bioactivation profiles to human. The CYP450 enzyme responsible for the bioactivation of TM5441 was mainly identified as CYP3A4, using human recombinant CYP450 enzymes and specific inhibitory studies. The UGT enzymes responsible for the bioactivation of TM5441 mainly involved UGT2B7, 1A1 and 1A4. These results facilitate the understanding of the bioactivation of TM5441 and potential toxicological implications., (Copyright © 2019. Published by Elsevier B.V.)

A novel LC-MS/MS method was developed for the quantification of the new cyclin dependent kinase inhibitors (CDKIs) palbociclib and ribociclib and the aromatase inhibitor letrozole used in combinatory regimen. The proposed method is appropriate to be applied in clinical practice due to the simple and fast sample preparation based on protein precipitation, the low amount of patient sample necessary for the analysis (10 μL) and the total run time of 6.5 min. It was fully validated according to FDA and EMA guidelines on bioanalytical method validation. The linearity was assessed (R2 within 0.9992-0.9983) over the concentration ranges of 0.3-250 ng/mL for palbociclib, 10-10000 ng/mL for ribociclib and 0.5-500 ng/mL for letrozole that properly cover the therapeutic plasma concentrations. A specific strategy was implemented to reduce the carryover phenomenon, formerly known for these CDKIs. This method was applied to quantify the Cmin of palbociclib, ribociclib and letrozole in plasma samples from patients enrolled in a clinical study. The same set of study samples was analysed twice in separate runs to assess the reproducibility of the method by means of the incurred samples reanalysis. The results corroborated the reliability of the analyte concentrations obtained with the bioanalytical method, already proved by the validation process. The percentage differences were always within ±10% for all the analytes and the R2 of the correlation graph between the two quantifications was equal to 0.9994., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: Dr. Fabio Puglisi reports grants from Astrazeneca and from Roche, outside the submitted work. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Purpose: Tailoring medication dosing for the individual patient is complex, and many factors can influence drug exposure. We investigated the effect of age and CYP2D6 genotype on aripiprazole and dehydroaripiprazole exposure in patients using long-acting injectable (LAI) or oral aripiprazole., Methods: Matched data on serum concentration of aripiprazole and CYP2D6 genotype of patients using oral or LAI aripiprazole were included retrospectively from a therapeutic drug monitoring service. The patients were divided into the following CYP2D6 genotype-defined categories: poor metabolizers (PMs), intermediate metabolizers (IMs), normal metabolizers (NMs), and ultrarapid metabolizers (UMs). Linear mixed model analyses were used to evaluate the impact of CYP2D6 genotype on dose-adjusted serum concentrations of the active moiety of aripiprazole+dehydroaripiprazole in relation to age and formulation., Results: We identified 635 patients (mean age = 40.1 years, 9.4% ≥ 65 years, 53.7% females) using LAI (n = 166) or oral formulation (n = 469). The genotype-predicted CYP2D6 phenotype subgroups were 2.4% UMs, 82.0% NMs, 8.0% IMs, and 7.2% PMs. Age did not significantly affect exposure of the active moiety of aripiprazole+dehydroaripiprazole in the LAI (p = 0.071) or oral (p = 0.14) subgroups. Compared with CYP2D6 NMs, PMs and IMs had significantly increased exposure of the active moiety of aripiprazole+dehydroaripiprazole in the LAI (1.7-fold higher, p < 0.001, and 1.5-fold higher, p < 0.001) and oral (1.7-fold higher, p < 0.001, and 1.6-fold higher, p < 0.001) subgroups., Conclusions: In conclusion, doses should be adjusted according to CYP2D6 genotype when initiating treatment with aripiprazole LAI or tablets, while advanced age do not affect the exposure of the active moiety of aripiprazole treatment regardless of formulation.

Background: Pharmacokinetic (PK) changes can affect antiretroviral (ARV) systemic exposure for critically ill patients living with HIV (CI-PLWH). Studies to guide ARV adjustments in this population are limited., Methods: A PK analysis was conducted in a 44-year-old CI-PLWH who presented for a heart and lung transplant on veno-arterial extracorporeal membrane oxygenation (VA ECMO). Home ARV therapy (ART) of co-formulated abacavir/lamivudine/dolutegravir (ABC/3TC/DTG) was continued. ARV serum concentrations were obtained during and after VA ECMO. Two blood levels were drawn at 1 h, for maximum serum concentration (C max ) and a serum trough (C t ). ARVs were given as a single tablet crushed via nasogastric tube., Results: Area under the concentration-time curve (AUC 0-t ) was calculated using non-compartmental analysis. C max and AUC 0-t were higher during VA ECMO compared with post-decannulation. The C max of ABC was >2.5-fold higher than the mean in the reference. C max and C t post VA ECMO were within range of referenced literature for all ARVs. C max and AUC 0-t of DTG post VA ECMO was approximately four- to fivefold lower than referenced literature. HIV virological suppression was maintained throughout the hospitalization., Conclusions: ART adjustments would not be required for this patient. Additional studies are needed to assess effects of VA ECMO and crushed tube administration of ARVs in CI-PLWH.

Objective: To investigate whether the use of recommended therapeutic doses of medicinal drugs has led to suspicion of driving under the influence of drugs (DUID) after implementation of legislative limits for illicit and medicinal drugs in 2012. Methods: Data from suspected drug-impaired drivers apprehended by the police from 2013 to 2015 were selected from the Norwegian Forensic Toxicology Database. The blood samples had been analyzed for benzodiazepines (BZDs), z-hypnotics, opioids, stimulants, certain hallucinogens, and alcohol. Drivers who tested positive for one BZD or a z-hypnotic only, were included in the study. Drug concentrations measured in their blood samples were compared to the maximal obtainable steady state concentrations if the drug had been used in accordance with the recommendations set by the Norwegian Directorate of Health. Results: BZDs or z-hypnotics were found in 10 248 samples, representing 59.6% of the total number of drivers arrested for suspected DUID (n = 17 201). Only one BZD or z-hypnotic with a blood drug concentration above the legislative limit was detected in 390 (2.3%) of the total number of samples. Clonazepam was the most frequently detected BZD (n = 4656), while as a single drug above the legislative limit, it was detected in only 3.6% (n = 168) of the clonazepam-positive blood samples. For drivers testing positive for only one z-hypnotic, drug concentrations above the legislative limit were found in 27% (n = 55) of the blood samples that tested positive for zolpidem and 12.4% (n = 53) of the samples that tested positive for zopiclone. In total, 155 subjects out of 10 248 testing positive for BZDs or z-hypnotics displayed concentrations above the legislative limit but within the concentration ranges that are expected when taking recommended therapeutic drug doses, and 77 below the legislativel limit. Conclusions: The results show that the implementation of legislative limits for BZDs and z-hypnotics may have contributed to DUID suspicion for a small group of patients using therapeutic drug doses; only 1.3% of the suspected DUID offenders had concentrations of only one of those drugs in-line with recommended therapeutic dosing.

An innovative open-label, crossover clinical study was used to investigate the excretion balance, pharmacokinetics, and metabolism of nemiralisib-an inhaled phosphoinositide 3-kinase delta inhibitor being developed for respiratory diseases. Six healthy men received a single intravenous microtracer of 10 µ g [ 14 C]nemiralisib with a concomitant inhaled nonradiolabeled 1000 µ g dose followed by an oral 800 µ g dose of [ 14 C]nemiralisib 14 days later. Complementary methods including accelerator mass spectrometry allowed characterization of a range of parameters including oral absorption (F abs ), proportion of nemiralisib escaping gut wall metabolism (F g ), hepatic extraction (E h ), fraction of dose absorbed from inhaled dose (F lung ), and renal clearance. Intravenous pharmacokinetics of nemiralisib were characterized by low blood clearance (10.0 l/h), long terminal half-life (55 hours), and high volume of distribution at steady state (728 l). Nemiralisib exhibited moderate inhaled and oral bioavailability (38% and 35%) while F lung was 29%. Absorption and first-pass parameters were corrected for blood renal clearance and compared with values without correction. Any swallowed nemiralisib was relatively well absorbed (F abs , 0.48) with a high fraction escaping gut wall metabolism and low extraction by the liver (F g and E h being 0.83 and 0.10, respectively). There were no major human plasma metabolites requiring further qualification in animal studies. Both unchanged nemiralisib and its oxidative/conjugative metabolites were secreted in bile, with nemiralisib likely subject to further metabolism through enterohepatic recirculation. Direct renal clearance and metabolism followed by renal clearance were lesser routes of elimination. SIGNIFICANCE STATEMENT: A number of innovative features have been combined into one small clinical study enabling a comprehensive description of the human pharmacokinetics and metabolism of an inhaled molecule. Design elements included an intravenous 14 C tracer administration concomitant with an inhalation dose that enabled derivation of parameters such as fraction absorbed (F abs ), the proportion of drug escaping first-pass extraction through the gut wall and liver (F g and F h ) and hepatic extraction (E h ). Entero-test bile sampling enabled characterization of biliary elimination pathways., Competing Interests: A.W.H., R.W., Y.L.M., E.J., G.Y., R.C., A.G., A.P., D.K., C.B., W.A.F. are GSK employees and hold GSK shares. K.R., M.M. are GSK employees. E.M.H. is a GSK employee and holds GSK shares and is on patents pertaining to the research discussed in the manuscript. L.C., D.W. have no conflicts of interest to disclose. Availability of data and materials., (Copyright © 2019 The Author(s).)

A rapid, sensitive and selective liquid chromatography-tandem mass spectrometry method for the detection of tandospirone (TDS) and its active metabolite 1-[2-pyrimidyl]-piperazine (1-PP) in Sprague-Dawley rat plasma is described. It was employed in a pharmacokinetic study. These analytes and the internal standards were extracted from plasma using protein precipitation with acetonitrile, then separated on a CAPCELL PAK ADME C 18 column using a mobile phase of acetonitrile and 5 mm ammonium formate acidified with formic acid (0.1%, v/v) at a total flow rate of 0.4 mL/min. The detection was performed with a tandem mass spectrometer equipped with an electrospray ionization source. The method was validated to quantify the concentration ranges of 1.000-500.0 ng/mL for TDS and 10.00-500.0 ng/mL for 1-PP. Total time for each chromatograph was 3.0 min. The intra-day precision was between 1.42 and 6.69% and the accuracy ranged from 95.74 to 110.18% for all analytes. Inter-day precision and accuracy ranged from 2.47 to 6.02% and from 98.37 to 105.62%, respectively. The lower limits of quantification were 1.000 ng/mL for TDS and 10.00 ng/mL for 1-PP. This method provided a fast, sensitive and selective analytical tool for quantification of tandospirone and its metabolite 1-PP in plasma necessary for the pharmacokinetic investigation., (© 2019 John Wiley & Sons, Ltd.)

Mefunidone (MFD) is a promising anti-fibrotic candidate molecule with greater anti-fibrotic activity than pirfenidone (PFD). However, there has been no report on the methodology used for the quantification of MFD or on any investigation of its pharmacokinetics. In this study, an efficient and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to assay MFD in monkey plasma. This assay method was validated and applied to a pharmacokinetics study in monkeys. The lower limit of quantification of this assay was 0.1 μg·mL -1 , and the linear calibration curve was acquired with R 2  > 0.99 between 0.1 and 60 μg·mL -1 . The intra-day and inter-day precision were evaluated with coefficient of variations of 1.5%-5.8%, whereas the mean accuracy ranged from 91.7% to 106.9%. A negligible matrix effect and good recovery were obtained using this assay, with average extraction recoveries of MFD and the internal standard (IS) in the range of 85.5%-124.8% and 84.1%-94.0%, respectively. The precision of the absolute matrix effect of MFD and the IS was 1.2-3.0% and 1.2-7.3%, respectively. The samples were stable under all experimental conditions. Linear pharmacokinetics were observed for MFD in monkeys, where the exposures of MFD increased proportionally with increasing MFD doses at the range of 10-90 mg·kg -1 . Moderate elimination of MFD from the body was observed, with t 1/2 of 5-7 h, and the elimination rate of MFD was stable during multiple dosing. In conclusion, this method provides an reliable analytical approach for quantification of MFD in plasma and was successfully applied to a pharmacokinetics study in monkeys., (© 2019 John Wiley & Sons, Ltd.)

Nemiralisib (GSK2269557), a potent inhaled inhibitor of phosphoinositide 3-kinase δ (PI3K δ ), is being developed for the treatment of respiratory disorders including chronic obstructive pulmonary disease. Determining the pharmacokinetic (PK) and pharmacodynamic (PD) responses of inhaled drugs early during drug development is key to informing the appropriate dose and preferred dose regimen in patients. We set out to measure PD changes in induced sputum in combination with drug concentrations in plasma and bronchoalveolar lavage (BAL) taken from healthy smokers ( n = 56) treated for up to 14 days with increasing doses of inhaled nemiralisib (0.1-6.4 mg). Induced sputum analysis demonstrated a dose-dependent reduction in phosphatidylinositol-(4,5)-trisphosphate (PIP3, the product of PI3K activation), with a maximum placebo-corrected reduction of 23% (90% confidence interval [CI], 11%-34%) and 36% (90% CI, 11%-64%) after a single dose or after 14 days of treatment with nemiralisib, respectively (2 mg, once daily). Plasma analysis suggested a linear PK relationship with an observed accumulation of ∼3- to 4.5-fold (peak vs. trough) in plasma exposure after 14 days of nemiralisib treatment. The BAL analysis at trough confirmed higher levels of the drug in the lungs versus plasma (32-fold in the BAL fluid component, and 214-fold in the BAL cellular fraction). A comparison of the drug levels in plasma and the reductions in sputum PIP3 showed a direct relationship between exposure and PIP3 reduction. These results demonstrated target engagement upon treatment with inhaled nemiralisib and provide confidence for a once-daily dosing regimen., (Copyright © 2019 The Author(s).)

Purpose: Nemiralisib, a phosphoinositide 3-kinase δ inhibitor, is being investigated as an immunomodulatory agent with anti-inflammatory properties in chronic obstructive pulmonary disease. This study evaluated the pharmacokinetic (PK) properties and safety of a new formulation of nemiralisib that contains 0.4% magnesium stearate., Methods: In this randomized, double-blind, parallel-group study, healthy individuals received a single dose of 500 or 750 μg of nemiralisib administered via the Ellipta dry powder inhaler (DPI) (n = 6 in each treatment group). Aerodynamic particle size distribution (APSD) data comparing previous and new formulations were available before the study. Serial PK analyses for plasma exposure and safety assessments were performed during the first 24 h after dosing, with follow-up measurements on days 3 and 6 in clinic., Findings: APSD had increases of approximately 6-fold and 2-fold in very fine particle mass and fine particle mass over the previous (Diskus) formulation. In humans, systemic exposure (AUC) was greater after inhalation of 750 versus 500 μg of nemiralisib (AUC 0-t : 17,200 h∙pg/mL; 95% CI, 10,900-27,200 h∙pg/mL and 13,100; 95% CI, 8130-21,000 h∙pg/mL, respectively). A low frequency of individual adverse events and no serious adverse events were reported after both doses., Implications: After single-dose inhalation of 500 and 750 μg of nemiralisib from the Ellipta DPI in healthy individuals, plasma PK data were well defined, and as predicted based on previous PK and APSD data, exposure was increased with the new formulation. Nemiralisib was well tolerated with no new safety issues identified. These data supported progression of nemiralisib to a Phase IIb study in patients with chronic obstructive pulmonary disease. ClinicalTrials.gov identifier: NCT03189589., (Copyright © 2019. Published by Elsevier Inc.)

The emergence of Mycobacterium tuberculosis strains resistant to current first-line antibiotic regimens constitutes a major global health threat. New treatments against multidrug-resistant tuberculosis (MDR-TB) are thus eagerly needed in particular in countries with a high MDR-TB prevalence. In this context, macozinone (PBTZ169), a promising drug candidate with an unique mode of action and highly potent in vitro tuberculocidal properties against MDR Mycobacterium strains, has now reached the clinical phase and has been notably tested in healthy male volunteers in Switzerland. To that endeavor, a multiplex UHPLC-MS/MS method has been developed for the sensitive and accurate human plasma levels determination of PBTZ169 along with five metabolites retaining in vitro anti-TB activity. Plasma protein precipitation with methanol was carried out as a simplified sample clean-up procedure followed by direct injection of the undiluted supernatant for the bioanalysis of the six analytes within 5 min, using 1.8 μm reversed-phase chromatography coupled to triple quadrupole mass spectrometry employing electrospray ionization in the positive mode. Stable isotopically-labelled PBTZ169 was used as internal standard (ISTD), while metabolites could be reliably quantified using two unlabeled chemical analogues selected as ISTD from a large in-house analogous compounds library. The overall methodology was fully validated according to current recommendations (FDA, EMEA) for bioanalytical methods, which include selectivity, carryover, qualitative and quantitative matrix effect, extraction recovery, process efficiency, trueness, precision, accuracy profiles, method and instrument detection limits, integrity to dilution, anticoagulant comparison and short- and long-term stabilities. Stability studies on the reduced metabolite H2-PBTZ169 have shown no significant impact on the actual PBTZ169 concentrations determined with the proposed assay. This simplified, rapid, sensitive and robust methodology has been applied to the bioanalysis of human plasma samples collected within the frame of a phase I clinical study in healthy volunteers receiving PBTZ169., Competing Interests: The authors have declared that no competing interests exist.

Background: Olaparib is a first-in-class potent oral poly(ADP-ribose) polymerase inhibitor., Objectives: The aims of this analysis were to establish an integrated population pharmacokinetic (PK) model of olaparib in patients with solid tumors and to bridge the PK of olaparib between capsule and tablet formulations., Methods: The population PK model was developed using plasma concentration data from 659 patients in 11 phase I, II, and III studies of olaparib tablets/capsules monotherapy. Relative bioavailability between the tablet and capsule formulations was estimated and the relative exposure between olaparib tablet and capsule therapeutic doses was further assessed., Results: The concentration-time profile was described using a two-compartment model with sequential zero- and first-order absorption and first-order elimination for both capsules and tablets with different absorption parameters. Multiple-dose clearance compared with single-dose clearance was reduced by approximately 15% (auto-inhibition). Disease severity had an impact on olaparib clearance, and tablet strength had an impact on K a . The olaparib geometric mean area under the curve (AUC) and maximal concentration (C max ) following a single 300 mg tablet were 42.1 μg h/mL and 5.8 μg/mL, respectively, and the steady-state geometric mean AUC and C max following a 300 mg tablet twice daily were 49.0 μg h/mL and 7.7 μg/mL, respectively. The relative exposure (AUC) of the 300 mg tablet formulation is 13% higher than the 400 mg capsule formulation., Conclusion: This analysis bridged the olaparib capsule and tablet formulation PK and provided key assessment to support the approval of the olaparib tablet formulation in patients with ovarian cancer, regardless of their BRCA mutation status.

The development and full validation of a sensitive and selective ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method are described for the simultaneous analysis of afatinib, alectinib, crizotinib and osimertinib in human lithium heparinized plasma. Afatinib-d6, crizotinib-d5 and erlotinib-d6 were used as internal standards. Given osimertinib's instability in plasma and whole blood at ambient temperature, samples should be solely processed on ice (T = 0 °C). Chromatographic separation was obtained on an Acquity UPLC ® BEH C18; 2.1 × 50 mm, 1.7 μm column, which was eluted with 0.400 mL/minute flow on a linear gradient, consisting of 10 mM ammonium formate (pH 4.5) and acetonitrile. Calibration curves for all compounds were linear for concentration ranges of 1.00 to 100 ng/mL for afatinib and 10.0 to 1000 ng/mL for alectinib, crizotinib and osimertinib, herewith validating the lower limits of quantification at 1.00 ng/mL for afatinib and 10.0 ng/mL for alectinib, crizotinib and osimertinib. Within-run and between-run precision measurements fell within 10.2%, with accuracy ranging from 89.2 to 110%., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Green tea extracts (GTE) has been reported to be a kinase inhibitor and modulator for various drug metabolizing enzymes. It may give synergetic antioncogenic effect, but with a possibility of pharmacokinetic interactions with various co-administered anticancer agents like palbociclib (PAL), a selective inhibitor of CDK-4/6 primarily metabolized by CYP3A enzyme. To explore the impact of GTE on PAL pharmacokinetics in Sprague-Dawley rats, a rapid and sensitive UHPLC-QTOF-MS method was established. Chromatographic separation was carried out on an Acquity UPLC BEH C 18 (100 × 2.1 mm, 1.7 μm) column using a gradient mobile phase system consisting of 0.1% formic acid and acetonitrile. Sample preparation was based on a simple protein precipitation method. Estimation of target ions [M + H] + at m/z 448.2455 for PAL and m/z 441.2044 for ibrutinib (IS) was performed in selective ion mode ESI-HRMS. Good sensitivity (1.0 ng/mL) and linearity over a wide concentration range of 1-2000 ng/mL was exhibited by the method. The results indicated that the administration of GTE resulted in decreased oral bioavailability of PAL in both short- and long-term conditions. However, when both conditions were compared, the variation was less for the peak concentration and area under the concentration-time curve level of PAL., (© 2018 John Wiley & Sons, Ltd.)

: Freeze-drying is an effective means of storing platelets. In this study, we investigated the effects of a protective agent on freeze-dried platelet-rich plasma (FD-PRP) after a 12-week preservation period. Platelet structure was measured by transmission electron microscopy (TEM), and the expression levels of procaspase activating compound (PAC)-1 and CD62P were measured by flow cytometry. The levels of transforming growth factor-beta (TGF-β), platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) were determined by ELISA. The effect of FD-PRP on cell proliferation was measured by cell counting. TEM revealed that most platelets were intact, and their internal structure was evident. The expression levels of the platelet activation marker CD62P in FD-PRP and fresh PRP were 36.83% ± 8.21 and 35.47% ± 4.11, respectively, without a significant difference (P > 0.05). The expression levels of PAC-1 in FD-PRP and fresh PRP were 3.23% ± 0.49 and 2.83% ± 0.44, respectively, without a significant difference (P > 0.05). Upon activation of FD-PRP and fresh PRP by thrombin, the levels of TGF-β, PDGF and VEGF were not significantly decreased in FD-PRP. Moreover, FD-PRP promoted cell proliferation in a manner similar to that of fresh PRP. The protective agent maintained the biological activity of FD-PRP after a 12-week preservation period.

Hepatocellular carcinoma (HCC) is a fatal oncogenic disorder with few therapeutic options. Novel therapeutic strategy with combination of a selective CDK4/6 inhibitor palbociclib (PAL) with a tyrosine kinase inhibitor (TKI) sorafenib (SOR) is reported to impair tumour growth and significantly increased survival in various preclinical models of HCC. In the current work a sensitive and rapid UHPLC-QTOF-MS method was established for the concurrent quantification of PAL and SOR in rat plasma using ibrutinib as internal standard (IS). Chromatographic separation was carried out on an Agilent Poroshell EC C18 (50 mm × 3 mm, 2.7 μm) using gradient mobile phase consisting of 0.1% formic acid and acetonitrile. Flow rate of 0. 45 mL/min with a run time of 5 min was used for separation. A simple sample preparation approach of protein precipitation was used in the current study. The mass spectrometric analysis of selective ions at [M + H] + m/z 448.2455 for PAL, m/z 465.0936 for SOR and m/z 441.2034 for IS was monitored with extracted ion chromatography. The LC-MS method meets the regulatory bio-analytical guidelines, exhibited good sensitivity and linearity over the range of 1.0-2000.0 ng/mL for PAL and SOR. The pharmacokinetic parameters of PAL remained unchanged when SOR was co-administered with PAL. The study pointed out that the co-intake of PAL with SOR resulted in a slight increment of C max (11.21%) and AUC (7.95%) levels of SOR when co-administered with PAL when compared to individual oral intake in SD rats. The current method provides a modern rapid and sensitive tool for pharmacokinetic studies of PAL and SOR in a pre-clinical set up., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The aim of the study was to assess the safety, tolerability, and pharmacokinetics of single and repeat doses of nemiralisib administered via a dry powder inhaler to healthy Japanese subjects. This was a single-center, double-blind, randomized, placebo-controlled, parallel, single- and repeat-ascending-dose study. Thirty-six healthy Japanese male subjects were randomized to receive either 1 dose strength of nemiralisib or placebo. The study consisted of a screening period, a single-dose session (session 1), a repeat-dose session (session 2), a 10-day washout period between the sessions, and then a follow-up visit 10 ± 1 days after the last dose of session 2. No serious adverse events were reported. No clinically significant abnormalities were found in clinical laboratory results, vital signs, or spirometry results. Generally, exposure (maximum observed plasma concentration [C max ] and area under the concentration-time curve [AUC]) increased with dose in an approximately proportional manner. Plasma T max was achieved rapidly at approximately 0.08 hours, and the terminal elimination half-life (T 1/2 ) was approximately 40 hours. T max and T 1/2 did not change between days or doses in the single- and repeat-dose sessions. Following 10 daily doses of 200, 500, and 700 μg nemiralisib, accumulation was observed, and the ratios (session 2, day 10:session 1) for Ro(AUC 0-24 ) and R(C max ) were 2.4-3.0 and 1.5-1.7, respectively. Steady state was achieved by 6-7 days, based on trough observed plasma drug concentration (C trough ) values., (© 2018, The American College of Clinical Pharmacology.)

L-3,4-Dihydroxyphenylalanine (L-DOPA) is the most effective therapy for motor symptoms of Parkinson's disease (PD); however, with repeated administration, as many as 94% of PD patients develop complications such as L-DOPA-induced dyskinesia. We previously demonstrated that EMD-281,014, a highly selective serotonin 2A (5-HT 2A ) receptor antagonist, reduces the severity of dyskinesia in the parkinsonian marmoset, without interfering with L-DOPA anti-parkinsonian benefit. Here, we assessed the effects of EMD-281,014 on L-DOPA-induced abnormal involuntary movements (AIMs) in the 6-hydroxydopamine (6-OHDA)-lesioned rat. We first determined the pharmacokinetic profile of EMD-281,014, to administer doses leading to clinically relevant plasma levels in the behavioural experiments. Dyskinetic 6-OHDA-lesioned rats were then administered EMD-281,014 (0.01, 0.03 and 0.1 mg/kg) or vehicle in combination with L-DOPA and AIMs severity was evaluated. We also assessed the effect of EMD-281,014 on L-DOPA anti-parkinsonian action with the cylinder test. We found that the addition of EMD-281,014 (0.01, 0.03 and 0.1 mg/kg) to L-DOPA did not reduce AIMs severity (P > 0.05), when compared to vehicle. EMD-281,014 did not compromise L-DOPA anti-parkinsonian action. Our results suggest that the highly selective 5-HT 2A receptor antagonist EMD-281,014 is well-tolerated by parkinsonian rats, but does not attenuate L-DOPA-induced AIMs. Our results highlight differences between rodent and primate models of PD when it comes to determining the anti-dyskinetic action of 5-HT 2A receptor antagonists.

Osimertinib (AZD9291) is a highly selective irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) designed to treat nonsmall-cell lung cancer patients with EGFR active and T790 M resistant mutations. A rapid and sensitive method for quantitative analysis by ultra-performance liquid chromatography-tandem mass spectrometry of osimertinib and its metabolite AZ5104 in human plasma was developed and validated. The samples were prepared by protein precipitation and separated on a BEH C 18 column (2.1 × 50 mm, 1.7 μm) by gradient elution with 0.1% (v/v) formic acid and 10 mm ammonium acetate in water and acetonitrile as the mobile phase. Electrospray ionization in positive ion mode and multiple reaction monitoring were used to monitor the ion transitions at m/z 500.4 → 385.3 and 486.3 → 371.1. The results indicated that the method had excellent sensitivity and specificity. The validation was performed in a range from 0.5 to 100 ng/mL. Intra-day and inter-day precisions (in terms of RSD) were all <15%, and the accuracies (in terms of RE) were within ±15%. The lower limit of quantification, matrix effect, extraction recovery, stability and dilution integrity were also validated and satisfied the validation criteria. Finally, this method was successfully applied in a retrospective analysis, and the predose samples of 52 nonsmall-cell lung cancer patients who were enrolled in a novel third EGFR TKI clinical trial were analyzed for screening regardless of whether they had previously received osimertinib treatments., (© 2018 John Wiley & Sons, Ltd.)

Osimertinib, a new-generation inhibitor of the epidermal growth factor, has been used for the clinical treatment of advanced T790M mutation-positive tumors. In this research, an original analysis method was established for the quantification of osimertinib by ultra-performance liquid chromatography with time of flight mass spectrometry (UPLC-TOF-MS) in rat plasma. After protein precipitation with acetonitrile and sorafinib (internal standard, IS), they were chromatographed through a Waters XTerra MS C 18 column. The mobile phase was acetonitrile and water (including 0.1% ammonia). The relative standard deviation (RSD) of the intra- and inter-day results ranged from 5.38 to 9.76% and from 6.02 to 9.46%, respectively, and the extraction recovery and matrix effects were calculated to range from 84.31 to 96.14% and from 91.46 to 97.18%, respectively. The results illustrated that the analysis method had sufficient specificity, accuracy and precision. Meanwhile, the UPLC-TOF-MS method for osimertinib was successfully applied into the pharmacokinetics of SD rats.

1. Although drug interactions between epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and gastric acid-suppressing medications (AS) are considered clinically significant, there is limited data regarding the influence of various gastric pH conditions on the pharmacokinetics of EGFR-TKIs. We aimed to clarify the changes in the pharmacokinetics of the EGFR-TKIs, gefitinib, erlotinib and osimertinib, due to the changes in gastric pH after administration of omeprazole or vonoprazan. 2. Omeprazole (10-100 mg/kg, p.o.) and vonoprazan (1-5 mg/kg, p.o.) led to a significant and dose-dependent increase in gastric pH. 3. AUC 0-3 of gefitinib and erlotinib (5 mg/kg, p.o.) started to decrease at gastric pH 3.3 and 5.6, respectively, reached a plateau at pH > 6, and then significantly decreased up to 47 and 59% of control levels, respectively. AUC 0-3 of osimertinib (5 mg/kg, p.o.) was not significantly changed by omeprazole and vonoprazan. 4. Although there are some issues regarding the extrapolation of the results of our rat study to humans, careful monitoring of patients treated with gefitinib and erlotinib is needed in cases in which the gastric pH increases from 3 to 5 and especially when the gastric pH is >5 in patients who are co-administered both the EGFR-TKIs and AS.

A fast and easy-to-use liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination and quantification of a novel antifungal drug, olorofim (F901318), a member of the novel class of orotomides, in human plasma and serum was developed and validated. Sample preparation was based on protein precipitation with acetonitrile and subsequent centrifugation. An isotope-labeled analogue of F901318 was employed as an internal standard. Chromatographic separation was achieved using a 50-mm by 2.1-mm, 1.9-μm, polar Hypersil Gold C 18 column and isocratic mobile phase consisting of 0.1% formic acid-acetonitrile (60%-40%, vol/vol) at a flow rate of 330 μl/min. The analyte was detected using a triple-stage quadrupole mass spectrometer operated in selected reaction monitoring (SRM) mode with positive heated electrospray ionization (HESI + ) within a single runtime of 2.00 min. The present LC-MS/MS method was validated according to the international guidelines of the International Conference on Harmonisation (ICH) and the U.S. Food and Drug Administration (FDA). Linearity of F901318 concentration ranges was verified by the Mandel test. The calibration curve was tested linear across the range and fitted using least-squares regression with a weighting factor of the reciprocal concentration. The limit of detection was 0.0011 mg/liter, and the lower limit of quantitation was 0.0033 mg/liter. Intraday and interday precisions ranged from 1.17% to 3.23% for F901318, and intraday and interday accuracies (percent bias) ranged from 0.75% to 5.01%. In conclusion, a method was established for the rapid quantitation of F901318 concentrations in serum and plasma samples in patient trials, and it optimizes therapeutic drug monitoring in applying an easy-to-use single method., (Copyright © 2018 American Society for Microbiology.)