scholarly journals Development and Validation of an Analytical Method for Quantitation of Monobutylphthalate, a Metabolite of Di-n-Butylphthalate, in Rat Plasma, Amniotic Fluid, Fetuses and Pups by UPLC-MS/MS

2020 ◽  
Vol 44 (4) ◽  
pp. 370-377 ◽  
Author(s):  
Melanie A Rehder Silinski ◽  
Reshan A Fernando ◽  
Veronica G Robinson ◽  
Suramya Waidyanatha
Keyword(s):  
Amniotic Fluid ◽  
Endocrine System ◽  
Rat Plasma ◽  
Consumer Products ◽  
Negative Ion ◽  
Laboratory Animals ◽  
Sprague Dawley ◽  
Simple Method ◽  
Toxicological Studies ◽  
Relative Standard

Abstract Phthalates have been used for decades as softening agents in the production of plastics, but in recent years have been extensively investigated for their potential hazards to human health and the environment. Di-n-butyl phthalate (DBP), with widespread exposure occurring through a variety of consumer products such as cosmetics and pesticides, is a suspected carcinogen and an endocrine system disruptor in both humans and laboratory animals. Its predominant metabolite is the monoester, monobutyl phthalate (MBP), which can serve as a marker of exposure. To support toxicological studies of DBP in pregnant and lactating rats and their offspring, a novel ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for quantitation of MBP in rat plasma, amniotic fluid, fetuses and whole pup samples. Plasma samples were extracted using a simple protein precipitation with acetonitrile. Extraction and delipidation of pup homogenate was performed using acetonitrile and then submerging the vials in liquid nitrogen. Extracts were analyzed by UPLC-MS/MS in the negative ion mode. The method was successfully validated over the concentration ranges 25–5,000 ng/mL in female Sprague Dawley (SD) rat plasma and 50–5,000 ng/g in SD pup homogenate. Matrix calibration curves were linear (r ≥ 0.99), and the percent relative error (%RE) values were ≤ ±15% for standards at all levels. Absolute recoveries were > 92% in both matrices. The limits of detection (LODs) were 6.9 ng/mL in plasma and 9.4 ng/g in pup homogenate. Acceptable intra- and interday accuracy and precision were demonstrated by mean %RE ≤ ±7.5 and relative standard deviation (%RSD) ≤ 10.1%. Extract stability was demonstrated for ~6 days at various temperatures and freeze–thaw stability was demonstrated after 3 cycles over 3 days. Secondary matrix evaluation was performed for MBP in amniotic fluid and pooled fetus homogenate (mean %RE ≤ ±11.5 and %RSD ≤ 13.7). These data demonstrate that this simple method is suitable for determination of MBP in plasma, amniotic fluid, fetus and pup samples from toxicological studies of DBP.

scholarly journals Development of an Analytical Method for Quantitation of 2,2ʹ-Dimorpholinodiethyl Ether (DMDEE) in Rat Plasma, Amniotic Fluid and Fetal Homogenate by UPLC–MS-MS for Determination of Gestational and Lactational Transfer in Rats

2020 ◽  
Author(s):  
Melanie A Rehder Silinski ◽  
Teruyo Uenoyama ◽  
Reshan A Fernando ◽  
Veronica G Robinson ◽  
Georgia Roberts ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Dose Range ◽  
Rat Plasma ◽  
Protein Precipitation ◽  
Sprague Dawley ◽  
Range Finding ◽  
Sprague Dawley Rat ◽  
Relative Standard ◽  
Significant Difference ◽  
Lactational Transfer

Abstract 2,2ʹ-Dimorpholinodiethyl ether (DMDEE) is a specialty amine catalyst used in the production of flexible foams, adhesives and coatings. The potential for occupational exposure to DMDEE is high, but toxicity data are very limited. The objective of this work was to develop a method to quantitate DMDEE in biological matrices to assess gestational and lactational transfer of DMDEE in rats following exposure of dams The method used protein precipitation, followed by removal of phospholipids and analysis of supernatant by ultra-performance liquid chromatography-tandem mass spectrometry. Rat fetuses were homogenized in water prior to protein precipitation and delipidation procedures. The method was evaluated in male Sprague Dawley rat plasma over the concentration range 5 to 1000 ng/mL. The method was linear (r ≥ 0.99), accurate (mean relative error (RE) ≤ ±11.9%) and precise (relative standard deviation (RSD) ≤ 2.7%). The mean absolute recovery was 106%. The limit of detection was 0.262 ng/mL. Standards as high as ∼100,000 ng/mL could be successfully diluted into the calibration range (mean %RE = −14.9; %RSD = 0.5). The method was evaluated in Sprague Dawley rat dam plasma, post-natal day 4 pup plasma, gestational day (GD) 18 amniotic fluid and fetal homogenate (mean %RE ≤ ±11.9; %RSD ≤ 2.3). Concentrations of DMDEE in rat dam plasma, amniotic fluid and fetal homogenate stored for at least 29 days and in pup plasma for at least 18 days at −80°C were within 87.7 to 99.5% of Day 0 concentrations, demonstrating that DMDEE is stable in these matrices. The method was used to quantitate DMDEE in rat plasma, amniotic fluid and fetus samples from a dose range finding toxicology study in which dams were dosed via gavage with DMDEE from GD 6 at doses of 0 (control), 62.5 and 250 mg/kg/day. DMDEE concentration increased with the dose in all matrices examined. The concentration in GD 18 fetuses was almost 2-fold higher than GD 18 dams demonstrating gestational transfer of DMDEE. However, the concentration in post-natal day 4 pup plasma was more than an order of magnitude lower than corresponding dam plasma suggesting less potential for transfer of DMDEE from dams to pups via lactation. There was no significant difference in concentration for male and female pup plasma.

scholarly journals A Pathology Review of the Lower Gastrointestinal Tract in Relation to Ulcerative Colitis in Rats and Cynomolgus Macaques Treated With Ammonium Perfluorooctanoate

2020 ◽  
Vol 48 (4) ◽  
pp. 593-602 ◽  
Author(s):  
Sue Chang ◽  
George A. Parker ◽  
Sarah E. Kleinschmidt ◽  
Geary W. Olsen ◽  
Carol A. Ley ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Gastrointestinal Tract ◽  
Laboratory Animals ◽  
Ohio River ◽  
Positive Trend ◽  
Sprague Dawley ◽  
Toxicological Studies ◽  
Chronic Inflammatory Condition ◽  
Cynomolgus Macaques ◽  
Rigorous Treatment

Among many short-term, subchronic, and chronic toxicology studies with ammonium perfluorooctanoate (PFOA), the gastrointestinal tract has not been identified as a target organ for PFOA-related toxicity in laboratory animals where the corresponding serum PFOA concentrations typically approach several orders of magnitude higher than the general human population. These lack of gastrointestinal tract-related findings were in direct contrast to an epidemiological observation where a positive trend was observed for ulcerative colitis, an idiopathic chronic inflammatory condition of the gut, in a Mid-Ohio River community whose drinking water contained higher levels of PFOA. This study was conducted to perform a histological reevaluation of large intestine sections in laboratory animals from 2 long-term toxicological studies: one was with Sprague Dawley rats that received ammonium PFOA in their diet for 2 years and the other one was with cynomolgus macaques that received daily capsules of ammonium PFOA for 6 months. In both studies, there was a lack of histological evidence of treatment-related inflammatory lesions that was suggestive of the occurrence of ulcerative colitis in these laboratory animals even under the most rigorous treatment schedules. These findings do not offer support for the biological plausibility of the epidemiological associations reported.

scholarly journals Development and Validation of an Analytical Method for Quantitation of Sulfolane in Rat and Mouse Plasma by GC–MS

2019 ◽  
Vol 43 (6) ◽  
pp. 477-481 ◽  
Author(s):  
Melanie A Rehder Silinski ◽  
Teruyo Uenoyama ◽  
Stephen D Cooper ◽  
Reshan A Fernando ◽  
Veronica G Robinson ◽  
...  
Keyword(s):  
Analytical Method ◽  
Limit Of Detection ◽  
Rat Plasma ◽  
Oil Refining ◽  
Gas Chromatography Mass Spectrometry ◽  
Sprague Dawley ◽  
Mouse Plasma ◽  
Sd Rat ◽  
Relative Standard ◽  
Development And Validation

AbstractSulfolane is an industrial solvent commonly used for extraction of aromatic hydrocarbons in the oil refining process, as well in the purification of natural gas. Its wide use and high solubility in water has led to contamination of groundwater. The objective of this work was to develop and validate an analytical method to quantitate sulfolane in rodent plasma in support of the National Toxicology Program toxicology and toxicokinetic studies of sulfolane. The method uses extraction of plasma with ethyl acetate and analysis by gas chromatography–mass spectrometry with electron ionization. The method was validated in male Sprague Dawley (SD) rat plasma over the concentration range of 20–100,000 ng/mL. The method was linear (r ≥ 0.99), accurate (mean relative error (RE) ≤ ±5.1%) and precise (relative standard deviation (RSD) ≤ 2.9%). The absolute recovery was ≥74%. The limit of detection was 0.516 ng/mL. Standards as high as ~2.5 mg/mL could be successfully diluted into the calibration range (mean %RE ≤ ±4.5; %RSD ≤ 4.6). Extracted samples were stable for at least 3 days at ambient and refrigerated temperatures, and freeze/thaw stability in matrix was demonstrated after three cycles over 3 days (calculated concentrations within 90.8–102% of Day 0 concentrations). Sulfolane was stable in frozen plasma for at least 75 days at −80°C (calculated concentrations within 93.0–98.1% of Day 0 concentrations). Matrix evaluation was performed for sulfolane in female SD rat plasma and male and female B6C3F1 mouse plasma (mean %RE ≤ ±4.9; %RSD ≤ 3.3). These data demonstrate that the method is suitable for determination of sulfolane in rodent plasma.

Risk assessment of dietary exposure to methylmercury in fish in the UK

2007 ◽  
Vol 26 (3) ◽  
pp. 185-190 ◽  
Author(s):  
B J Maycock ◽  
D J Benford
Keyword(s):  
Risk Assessment ◽  
Dietary Exposure ◽  
Epidemiological Studies ◽  
Consumer Products ◽  
Laboratory Animals ◽  
Human Data ◽  
Toxicological Studies ◽  
Assessment Approach ◽  
Nutritional Data ◽  
The Uk

Risk assessment of chemicals in food is generally based upon the results of toxicological studies in laboratory animals, allowing for uncertainties relating to interspecies differences, human variability, and gaps in the database. Use of quantitative human data is preferable if available, as in the example of methylmercury. Methylmercury is a neurotoxic environmental contaminant, for which fish is the main source of dietary exposure. Human data from poisoning incidents and epidemiological studies have been used by expert committees to derive a guideline intake level for methylmercury, based on the susceptibility of the most sensitive lifestage, the developing fetus. In the UK, an expert group of nutritionists and toxicologists was formed to review the benefits and risks associated with fish consumption. A formal risk–benefit analysis was not possible because the nutritional data were not sufficiently quantitative. The Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT), therefore, modified the risk assessment approach to derive different guideline intake levels for different subgroups of the population. The COT opinion was used to provide targeted advice on how much fish can be consumed without undue risk from the contaminants. Consumption by adults of one weekly portion (140 g) of shark, swordfish or marlin, would lead to an exceedance of the guideline intake for methylmercury of 40–90%, set to protect the developing fetus, without considering intake from the rest of the diet. Pregnant women and women who may become pregnant within 1 year were, therefore, advised to avoid consumption of these species. Intakes in other adults would be within a higher guideline intake, set to protect groups of the population other than the developing fetus. However, consumption by children of one weekly portion of these species could lead to an exceedance of this guideline intake by up to 60%, without considering intake from the rest of the diet. It was, therefore, advised that consumption of these species by children should be avoided.

Pharmacokinetics of Picroside I, II, III, IV in Rat Plasma by UPLCMS/ MS

2020 ◽  
Vol 16 (4) ◽  
pp. 438-445 ◽  
Author(s):  
Haili Xie ◽  
Xiaojie Lu ◽  
Weiqiang Jin ◽  
Hua Zhou ◽  
Dongxin Chen ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Multiple Reaction Monitoring ◽  
Gradient Elution ◽  
Ultra Performance Liquid Chromatography ◽  
Rat Plasma ◽  
Negative Ion ◽  
Protective Effects ◽  
Sprague Dawley ◽  
Picroside Ii ◽  
Bone Injury

Background: Modern pharmacological studies show that rhizoma coptidis has protective effects on the liver, gallbladder, kidney, cerebral ischemia-reperfusion, local hypoxia injury, antiinflammatory, bone injury, nerve cells and myocardial cells. The effective components have been isolated from picroside I, II, III and IV. Introduction: A selective and sensitive ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed for the simultaneous quantitative determination of picroside I, II, III and IV in rat plasma to aid the pharmacokinetics studies. Method: Sprague-Dawley (SD) rats were orally administered with 10 mg/kg, intravenously injected with 1 mg/kg for the mixture of picroside I, II, III and IV. The biological samples were collected at 0.083 3 h, 0.25 h, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h, 24 h. A UPLC BEH C18 column (2.1 mm×50 mm, 1.7 μm) was used for chromatographic separation with the mobile phase consisting of acetonitrile and 0.1% formic acid by gradient elution. The flow rate was 0.4 mL/min. Multiple reaction monitoring (MRM) transitions were m/z 491.1→147.1 for picroside I, m/z 511.1→234.9 for picroside II, m/z 537.3→174.8 for picroside III and m/z 507.3→163.1 for picroside IV in negative ion mode. Result: The inter-day precision was less than 13%, the intra-day precision was less than 15%. The accuracy ranged from 89.4% to 111.1%. Recovery was higher than 79.1%, and the matrix effect ranged from 96.2% to 109.0%. Conclusion: The sensitive, rapid and selective UPLC-MS/MS method can be applied to the pharmacokinetic study of picroside I, II, III and IV in rats.

scholarly journals UPLC-MS/MS Method for the Simultaneous Quantification of Eight Compounds in Rat Plasma and Its Application to a Pharmacokinetic Study after Oral Administration of Veratrum (Veratrum nigrum L.) Extract

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yuqi Fan ◽  
Lulu Zhao ◽  
Xuhua Huang ◽  
Jiayuan Shen ◽  
Wei Wang ◽  
...  
Keyword(s):  
Oral Administration ◽  
Internal Standard ◽  
Rat Plasma ◽  
Negative Ion ◽  
Pharmacokinetic Parameters ◽  
Relative Standard ◽  
Antifungal Effects ◽  
The Matrix ◽  
The Stability

Veratrum nigrum L. is a well-known traditional Chinese medicine with a lot of pharmacological activities including antihypertensive, anticancer, and antifungal effects. In the current experiment, a rapid and sensitive UPLC-MS/MS method that takes only 7 min run time has been established and validated for simultaneous determination of eight bioactive compounds including cyclopamine, jervine, veratramine, polydatin, quercetin, apigenin, resveratrol, and veratrosine in rat plasma. The chromatographic separation of analytes and internal standard was performed on a Phenyl-Hexyl column ( 2.1 × 100   mm , 1.7 μm) with the mobile phase consisting of water (0.1% formic acid) and acetonitrile at a flow rate of 0.3 mL/min. An electrospray ionization (ESI) source was used to detect the samples in both positive and negative ion modes. The intra- and interday precisions of the compounds were less than 9.5% and the accuracy ranged from -10.8% to 10.4%. The extraction recoveries of the compounds were in the range of 85.1 ± 1.5 % to 102.6 ± 8.0 % , and the matrix effect ranged from 91.2 ± 4.5 % to 113.8 ± 1.5 % . According to the results of the stability test, the eight compounds have good stability under various conditions and the relative standard deviation (RSD) less than 13.2%. The pharmacokinetic parameters of the eight compounds in rat plasma after oral administration of Veratrum nigrum L. extract were successfully determined by the established UPLC-MS/MS method.

scholarly journals An Accurate and Reproducible Method for the Quantitative Analysis of Isoflavones and Their Metabolites in Rat Plasma Using Liquid Chromatography/Mass Spectrometry Combined with Photodiode Array Detection

2006 ◽  
Vol 89 (4) ◽  
pp. 1158-1167 ◽  
Author(s):  
Estatira Sepehr ◽  
Patrick Robertson ◽  
G Sarwar Gilani ◽  
Gerard Cooke ◽  
Benjamin Pui-Yan Lau
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Rat Plasma ◽  
Biochanin A ◽  
Array Detector ◽  
Plasma Samples ◽  
Simple Method ◽  
Potential Health ◽  
Relative Standard ◽  
Photodiode Array

Abstract To study the safety and potential health benefits of soy isoflavones, a rapid and simple method based on liquid chromatography combined with mass spectrometry (LC/MS) and photodiode array detector (PDA) was developed for the determination of isoflavones in rat plasma. The analytes included daidzein, genistein, glycitein, equol, 4-ethyl phenol, and biochanin A over a concentration range of 1.04320.0 nM using 75 L of rat plasma. Rat plasma samples were hydrolyzed by adding an enzyme mixture from Helix pomatia containing glucuronidase and sulfatase to convert the isoflavone -glycosides daidzin, genistin, and glycitin to their active aglycone forms. A liquidliquid extraction method using ethyl acetate as the extraction solvent was used to extract aglycones and the internal standards (phenolphthalein -d glucuronide, 4-methylumbelliferyl sulfate, and apigenin) from digested plasma samples. The extract was evaporated to dryness under a nitrogen stream, reconstituted with 0.1%formic acid in wateracetonitrile (85 + 15), and injected into a Zorbax SB-CN reversed-phase column (4.6 75 mm, 3.5 m particle size). The Micromass ZQ detector was operated in the positive ion selected-ion monitoring mode. The flow rate for LC was 1.0 mL/ min, with a split where 25% of the effluent was introduced into the electrospray ionization probe of the MS instrument and 75% into the PDA. The chromatographic run time was 16.0 min, with delay of 10 min/injection. The interday precision and accuracy of the standard samples were <2.6% relative standard deviation and <10% relative error, respectively. Recovery of the reported isoflavones with this method varied from 86 to 100%.

scholarly journals Pharmacokinetic Study of Thirteen Ingredients after the Oral Administration of Flos Chrysanthemi Extract in Rats by UPLC-MS/MS

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Qi Jia ◽  
Xuhua Huang ◽  
Guangzhe Yao ◽  
Wenjuan Ma ◽  
Jiayuan Shen ◽  
...  
Keyword(s):  
Oral Administration ◽  
Bioactive Compounds ◽  
Pharmacokinetic Study ◽  
Rat Plasma ◽  
Negative Ion ◽  
Pharmacokinetic Parameters ◽  
Phase System ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Acquity Uplc

A rapid and reliable UPLC-MS/MS method was developed and validated for the simultaneous quantification of thirteen bioactive compounds (luteolin, cynaroside, luteolin 7-O-glucuronide, isochlorogenic acid C, chlorogenic acid, cryptochlorogenic acid, apigenin, apigenin 7-glucoside, acacetin, hyperoside, isoquercitrin, tilianin, and hesperidin) in rat plasma. The compounds were separated on an ACQUITY UPLC BEH C18 column (2.1×100 mm, 1.7 μm) with a gradient mobile phase system of acetonitrile and 0.1% (v/v) formic acid aqueous solution at a flow rate of 0.3 mL/min. All compounds were quantitated using Agilent Jet Stream electrospray ionization (AJS ESI) in a negative ion mode. The lower limit of quantification (LLOQ) for all compounds was below 5 ng/mL. The intra- and interday accuracy ranged from -13.0% to 14.0%, and precisions were less than 12.2%. The extraction recoveries of the compounds were in the range of 56.9% to 95.0%, and the matrix effect ranged between 71.6% and 109.3%. Stability studies proved that the thirteen compounds were stable under tested conditions, with a relative standard deviation (RSD) of less than 11.4%. This developed method was successfully applied to the pharmacokinetic study of the 13 bioactive compounds after oral administration of Flos Chrysanthemi extract in rat by UPLC-MS/MS. Pharmacokinetic parameters of 8 out of the 13 compounds investigated are presented in this paper.

Actual issues of hygienic regulation and creation of safe working conditions at pharmaceutical manufacturing enterprises

2020 ◽  
Vol 60 (10) ◽  
pp. 640-644
Author(s):  
Vadim M. Vasilkevich ◽  
Ruslan V. Bogdanov ◽  
Elena V. Drozdova
Keyword(s):  
Pharmaceutical Industry ◽  
Working Conditions ◽  
Experimental Studies ◽  
Pharmaceutical Products ◽  
Laboratory Animals ◽  
Production Environment ◽  
Basic Principles ◽  
Toxicological Studies ◽  
Health Disorders ◽  
Safe Working

Introduction. The working conditions of pharmaceutical industry workers are characterized by the combined effect of unfavorable factors of the production environment, among which the leading one is chemical. The aim of study is to substantiate the basic principles and criteria for hygienic regulation of pharmaceutical products in their production to ensure safe working conditions for employees based on the results of their own research and existing requirements of technical regulations. Materials and methods. Analysis of working conditions and the prevalence of health disorders in pharmaceutical workers (according to literature data), toxicological studies of pharmaceutical substances on laboratory animals, scientific justification of hygiene standards in the air of the working area. Results. Among employees of the pharmaceutical industry, the predominant forms of production-related health disorders are diseases of the respiratory system, as well as skin dermatitis of allergic origin, liver and biliary tract diseases. Based on the results of experimental studies of domestic pharmaceutical products for the treatment of cardiovascular, oncological and mental diseases that have priority socio-economic significance, the basic principles and features of the practice of justifying the hygienic standards of medicines in the air of the working area are developed and systematized. Conclusions. During hygienic rationing of medicines, it is necessary to use a differentiated approach that allows, based on the analysis of information about the chemical structure, physical and chemical characteristics, production conditions, pharmacotherapeutic activity, and the results of studying the toxic effect in an experiment on laboratory animals, to determine the maximum permissible content in the air of the working area of medicines or to justify the prohibition of isolation with reasoned recommendations for their safe production.

scholarly journals Investigating Molecular Mechanisms of Immunotoxicity and the Utility of ToxCast for Immunotoxicity Screening of Chemicals Added to Food

2021 ◽  
Vol 18 (7) ◽  
pp. 3332
Author(s):  
Olga V. Naidenko ◽  
David Q. Andrews ◽  
Alexis M. Temkin ◽  
Tasha Stoiber ◽  
Uloma Igara Uche ◽  
...  
Keyword(s):  
Immune System ◽  
High Throughput ◽  
Environmental Protection Agency ◽  
High Throughput Screening ◽  
Molecular Mechanisms ◽  
Specific Activity ◽  
Laboratory Animals ◽  
In Vitro Assays ◽  
Toxicological Studies

The development of high-throughput screening methodologies may decrease the need for laboratory animals for toxicity testing. Here, we investigate the potential of assessing immunotoxicity with high-throughput screening data from the U.S. Environmental Protection Agency ToxCast program. As case studies, we analyzed the most common chemicals added to food as well as per- and polyfluoroalkyl substances (PFAS) shown to migrate to food from packaging materials or processing equipment. The antioxidant preservative tert-butylhydroquinone (TBHQ) showed activity both in ToxCast assays and in classical immunological assays, suggesting that it may affect the immune response in people. From the PFAS group, we identified eight substances that can migrate from food contact materials and have ToxCast data. In epidemiological and toxicological studies, PFAS suppress the immune system and decrease the response to vaccination. However, most PFAS show weak or no activity in immune-related ToxCast assays. This lack of concordance between toxicological and high-throughput data for common PFAS indicates the current limitations of in vitro screening for analyzing immunotoxicity. High-throughput in vitro assays show promise for providing mechanistic data relevant for immune risk assessment. In contrast, the lack of immune-specific activity in the existing high-throughput assays cannot validate the safety of a chemical for the immune system.

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