Chromatography-tandem Mass Spectrometry Method Research Articles

Therapeutic drug monitoring of levetiracetam - Is dried blood spot sampling suitable?

Therapeutic drug monitoring helps prevent seizures and minimize side effects in epilepsy patients. Phlebotomy is the gold standard for blood collection but can be difficult for children, pregnant women, and patients in remote areas. We previously validated dried blood spot (DBS) sampling for carbamazepine, lamotrigine, levetiracetam (LEV), and valproic acid. Uncertainties in LEV comparisons from the previous validation were further investigated in this study by increasing sample numbers and comparing results using both immunochemistry and LC-MS/MS methods. Additionally, capillary and venous DBS were compared, and the stability of samples during mail transport was assessed. To compare LEV concentrations in capillary DBS and plasma, and to assess the stability of capillary DBS during transportation. Capillary and venous blood samples were collected from 40 LEV-treated patients. Concentrations were measured using immunochemistry and liquid chromatography tandem mass spectrometry methods. Comparisons between matrices and methods were analyzed with Passing-Bablok regression and Bland-Altman plots. No proportional bias was found in regression analysis and Bland-Altman plots showed no bias between methods. For capillary DBS versus plasma concentrations, 92.1 % of values were within 20 % of the mean. No bias was detected between capillary and venous DBS, with deviations within acceptable limits. Sample stability was maintained during mail transport. The concentrations obtained for LEV in capillary DBS versus plasma showed that therapeutic drug monitoring of LEV can be performed as at-home self-sampling with DBS mailed to the laboratory for analysis.

Wastewater-borne markers of neurodegenerative disease: β-methylamino-L-alanine and aminomethylphosphonic acid.

Wastewater-borne markers of neurodegenerative disease: β-methylamino-L-alanine and aminomethylphosphonic acid.

An ultra-sensitive liquid chromatography tandem mass spectrometry method for the simultaneous quantification of 2H6-alectinib and alectinib in human plasma to support a microtracer food-effect trial.

An ultra-sensitive liquid chromatography tandem mass spectrometry method for the simultaneous quantification of 2H6-alectinib and alectinib in human plasma to support a microtracer food-effect trial.

Interaction study between HIV protease inhibitors and alectinib in rats based on an ultra-performance liquid chromatography tandem mass spectrometry method.

Interaction study between HIV protease inhibitors and alectinib in rats based on an ultra-performance liquid chromatography tandem mass spectrometry method.

Evaluation of active substances in gamboge and their mechanisms for the treatment of colorectal cancer by UPLC-MS/MS integrated with network pharmacology.

Evaluation of active substances in gamboge and their mechanisms for the treatment of colorectal cancer by UPLC-MS/MS integrated with network pharmacology.

Comparisons of the bioavailability of icariin, icariside II, and epimedin C in rats after oral administration of total flavonoids of Epimedium brevicornu Maxim. and its three formulations.

Comparisons of the bioavailability of icariin, icariside II, and epimedin C in rats after oral administration of total flavonoids of Epimedium brevicornu Maxim. and its three formulations.

Analysis of (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol and (-)-11-nor-9-carboxy-Δ8-tetrahydrocannabinol in hair from a school-age population.

A sensitive liquid chromatography tandem mass spectrometry method for the detection of (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol and (-)-11-nor-9-carboxy-Δ8-tetrahydrocannabinol in hair with a cutoff of 1 pg/10 mg of hair and a limit of quantitation of 0.2 pg/10 mg of hair for both analytes was developed and is herein described. A subset of samples collected from a school-age population between December 2022 and February 2023 was analyzed by this method after having screened presumptive positive by enzyme immunoassay out of a total pool of approximately 5300 samples. Of these presumptive positive samples, 66% showed the presence of one or both analytes at a concentration ≥1 pg/10 mg of hair. Of the 213 positive samples, 57% contained more (-)-11-nor-9-carboxy-Δ8-tetrahydrocannabinol than (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol, and 6% contained more than 50-fold higher Δ8 isomer than Δ9 isomer. Of the 197 samples that were reportable for (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol ≥1 pg/10 mg cutoff, 53% of them contained more (-)-11-nor-9-carboxy-Δ8-tetrahydrocannabinol than (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol. Of the 197 samples that were reportable for (-)-11-nor-9-carboxy-Δ8-tetrahydrocannabinol ≥1 pg/10 mg cutoff, 15.7% exceeded the upper limit of linearity of the method (200 pg/10 mg). These results suggest a high level of (-)-Δ8-tetrahydrocannabinol usage in this population relative to (-)-Δ9-tetrahydrocannabinol usage. They further suggest the possibility that the (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol reported for some of these samples may only have been present due to (-)-Δ9-tetrahydrocannabinol contamination of (-)-Δ8-tetrahydrocannabinol products being consumed in large quantities. Thus, reported results for (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol alone may give a false picture of the extent of the cannabis product being consumed by a test subject.

Gas and liquid chromatography-tandem mass spectrometry methods for the analysis in food of 110 chemicals from printing inks and adhesives used in food contact materials.

Gas and liquid chromatography-tandem mass spectrometry methods for the analysis in food of 110 chemicals from printing inks and adhesives used in food contact materials.

Postmortem redistribution of carbofuran and benzofuranol in rats determined using solid phase extraction by HPLC-MS/MS.

Postmortem redistribution of carbofuran and benzofuranol in rats determined using solid phase extraction by HPLC-MS/MS.

Serum 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D are decreased in dogs with sinonasal aspergillosis.

Serum 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D are decreased in dogs with sinonasal aspergillosis.

Development of a Liquid Chromatography–Tandem Mass Spectrometry Method for the Determination of Puberulic Acid in Red Yeast Rice Supplements

Development of a Liquid Chromatography–Tandem Mass Spectrometry Method for the Determination of Puberulic Acid in Red Yeast Rice Supplements

Pharmacokinetics and Tissue Distribution of Enavogliflozin in Mice Using a Validated Liquid Chromatography–Tandem Mass Spectrometry Method

Pharmacokinetics and Tissue Distribution of Enavogliflozin in Mice Using a Validated Liquid Chromatography–Tandem Mass Spectrometry Method

A multicenter, randomized, open label, two formulation, crossover bioequivalence trial of doxorubicin hydrochloride liposomal injection in Chinese patients with metastatic breast cancer

PurposeThe primary objectives of this trial were aimed at exploring the pharmacokinetic profiles and the human bioequivalence of an intravenous liposomal injection of doxorubicin hydrochloride in comparison with a reference formulation in Chinese patients diagnosed with metastatic breast cancer.MethodsTo achieve these goals, the trial employed a randomized, open-label, two-formulation crossover dosing strategy among Chinese patients with metastatic breast cancer. Pharmacokinetic (PK) evaluation was conducted through the collection of blood samples, and the liquid chromatography tandem mass spectrometry (LC/MS/MS) method was leveraged to quantify plasma concentrations of both liposome-encapsulated doxorubicin and non-encapsulated doxorubicin in patients. Throughout the trial, all adverse events observed in the patients were meticulously assessed.ResultsThe results indicated that the maximum concentration (Cmax), AUC from time zero to the last measurable concentration (AUC0-t), and AUC extrapolated to infinity (AUC0-∞) of in vivo non-encapsulated doxorubicin after administration of both formulations fell within the 80.00%–125.00% range at a 90% confidence interval.ConclusionThese findings strongly indicated that the tested formulations were bioequivalent to the reference formulation. The results also demonstrated that both formulations were well-tolerated, further establishing their safety profile in the context of metastatic breast cancer treatment.Trial registrationChinadrugtrials.org.cn Identifier: CTR20200878.

Liquid Chromatography Combined With Tandem Mass Spectrometry for the Pharmacokinetic and Metabolism Studies of PROTAC ARV‐471 in Rats

ABSTRACTProteolysis targeting chimera (PROTAC) is emerging as a promising medicinal modality, which has aroused widespread interest among the field of pharmaceutical manufacturing in the recent years. ARV‐471 is an orally active PROTAC estrogen receptor degrader against breast cancer, which leads to the ubiquitylation and subsequent degradation of estrogen receptors via the proteasome. In this study, we developed a highly sensitive liquid chromatography tandem mass spectrometry method (LLOQ = 0.5 ng/mL) for the measurement of ARV‐471 in rat plasma. The acetonitrile precipitated sample was separated on ACQUITY BEH C18 column using acetonitrile‐0.1% formic acid as mobile phased with gradient elution. Multiple reactions monitoring in positive ESI mode was employed for the quantification of ARV‐471 (m/z 724.4 → 396.2). The assay showed good linearity over the concentration range of 0.5–1000 ng/mL with correlation coefficient > 0.996. The assay was validated according to FDA guidance, and all the validation parameters were within the predefined acceptance criteria. After validation, the assay was applied to the pharmacokinetic study of ARV‐471 in rats. Additionally, the metabolites in rat plasma were identified using liquid chromatography–high resolution mass spectrometry. Four metabolites were identified and characterized. Hydrolysis, glucuronidation and deamination were the main metabolic pathways of ARV‐471 in rats.

Validated LC-MS/MS methodology for the quantification of CBD, trace level THCA and UK controlled cannabinoids (Δ9-THC, Δ8-THC, CBN and THCV) in food samples.

Products containing cannabidiol (CBD) have become increasingly popular due to consumer-perceived benefits of improving health and well-being. More specifically in the United Kingdom (UK), CBD food products are categorised as novel foods. For these products to remain on the market, they must have authorisation from the Food Standards Agency on the basis that they are safe, correctly labelled, and do not contain substances classified under controlled drugs legislation in accordance with any existing or future Home Office guidance. This demands for analytical laboratories to be able to accurately measure the CBD concentration using validated methods to confirm correct labelling, as well as the controlled cannabinoid content to ensure the products comply with legislation. To address some of these challenges, this work describes two similar liquid chromatography tandem mass spectrometry (LC-MS/MS) methods which were developed and validated for measuring CBD and trace level controlled cannabinoids in CBD containing foods. The accuracy of the methods developed were tested for the first time through an interlaboratory comparison involving expert laboratories. The methods were applied to a comprehensive study of 148 CBD edible products. In 13 of the products tested (9% of the total) CBD was found below the limit of quantification. Of the remaining 135 products (91% of the total), 66% were found to have detectable amounts of one or more controlled cannabinoids. Of the 13 samples that did not contain detectable levels of CBD, two did contain quantifiable levels of controlled cannabinoids. The validation and sample analysis results reveal intriguing sets of data which help gauge the ongoing narrative surrounding CBD analysis and CBD products available in the UK. The research contributes to the global effort to keep unsafe products off the market.

Impact of Methotrexate and 7-Hydroxymethotrexate Exposure on Renal Toxicity in Pediatric Non-Hodgkin Lymphoma.

7-Hydroxymethotrexate (7-OHMTX) is the main metabolite in plasma following high-dose MTX (HD-MTX), which may result in activity and toxicity of the MTX. Moreover, 7-OHMTX could produce crystalline-like deposits within the renal tubules under acidic conditions or induce renal inflammation, oxidative stress, and cell apoptosis through various signaling pathways, ultimately leading to kidney damage. The objectives of this study were thus to explore the exposure-safety relationship of two compounds and search the most reliable marker for predicting HDMTX nephrotoxicity. A total of 280 plasma concentration data (140 for MTX and 140 for 7-OHMTX) for 60 pediatric patients with non-Hodgkin lymphoma (NHL) were prospectively collected. Plasma MTX and 7-OHMTX concentrations were determined using a high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method. A nonlinear mixed effect model approach was used to build a joint population pharmacokinetic (PopPK) model. After validation, the model estimated the peak concentration (Cmax) and area under the curve within the initial 48 h (AUC0-48h) of the patients after drug administration by Bayesian feedback. The receiver operating characteristic (ROC) curves were generated to identify an exposure threshold associated with nephrotoxicity. A three-compartment chain model (central and peripheral compartments for MTX and central compartment 7-OHMTX) with the first-order elimination adequately characterized the invivo process of MTX and 7-OHMTX. The covariate analysis identified that the aspartate aminotransferase (AST) was strongly associated with the peripheral volume of distribution of MTX. Moreover, the Cmax of MTX and 7-OHMTX showed significant differences (p < 0.0001, p = 0.0472, respectively) among patients with or without nephrotoxicity. Similarly, individuals with nephrotoxicity also exhibited substantially higher ratio of 7-OHMTX to MTX peak concentration and the sum of MTX + 2.25 times the concentration of 7-OHMTX (p < 0.0001, p = 0.0426, respectively). By ROC analysis, the Cmax of MTX and 7-OHMTX had the greatest area under the curve (AUC) values (0.769 and 0.771, respectively). A Cmax threshold of 9.26 μmol/L for MTX or a Cmax threshold of 0.66 μmol/L for 7-OHMTX was associated with the best sensitivity/specificity for toxicity events (MTX: sensitivity = 0.886; specificity = 0.70; 7-OHMTX: sensitivity = 0.886; specificity = 0.70). We demonstrated that the Cmax of MTX and 7-OHMTX were the most reliable markers associated with nephrotoxicity and proposed a Cmax threshold of 9.26 μmol/L for MTX and 0.66 μmol/L for 7-OHMTX as the point with a high risk of nephrotoxicity. Altogether, this study may contribute to crucial insights for ensuring the safe administration of drugs in pediatric clinical practice.

Identification of a novel imidazole-derived GABA agonist isopropoxate: simultaneous detection and quantification of imidazole-derived analogs from human hairs in abused cases by LC-MS/MS.

Distribution and abuse of imidazole-derived γ-aminobutyric acid (GABA) agonists, such as etomidate and metomidate, and their analogs have been encountered frequently especially in China. The aim of this study was to identify etomidate, metomidate, propoxate, and isopropoxate more accurately by establishing a gas chromatography-mass spectrometry (GC-MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS) method and applying it to real forensic cases. Onemg of the seized powder was dissolved in 1mL of methanol, and subjected to GC-MS and LC-MS/MS. Hair samples were washed and cut into approximately 2mm sections, then ground to powder by a low-temperature grinder. Twenty mg of the hair powder was extracted with 1mL of methanol, and the supernatant was subjected to LC-MS/MS. Etomidate, metomidate, propoxate, and isopropoxate were chromatographically separated and each mass spectrum was obtained by GC-MS. For LC-MS/MS, tested validation data were all satisfactory. The seized powder samples contained isopropoxate, with an approximate content of 30.9%. Etomidate, etomidate acid, metomidate, and isopropoxate could be determined in the submitted hairs, ranging from 2.89 to 8.09ng/mg, 0.0591-0.177ng/mg, 0.342-2.77ng/mg, and 33.2-130ng/mg, respectively. Mass spectra and ion chromatograms of etomidate, metomidate, isopropoxate, and propoxate were obtained by GC-MS. We have also established a simultaneous and reliable analytical method for etomidate, etomidate acid, metomidate, and isopropoxate in human hair by LC-MS/MS. This is the first report to present analytical results of a novel imidazole-derived GABA agonist isopropoxate in drug abuse cases.

Development of a UPLC-MS/MS method for the determination of sulfatinib and its no interaction with myricetin in rats.

Sulfatinib is a novel oral tyrosine kinase inhibitor (TKI) with selective inhibition of fibroblast growth factor (FGFR), colony-stimulating factor 1 receptor (CSF-1R) and vascular endothelial growth factor receptor (VEGFR) 1, 2, and 3. It has been approved for the therapy of neuroendocrine tumors arising in the non-pancreatic (December 2020) and pancreatic (June 2021) glands. Until now, there has no research on the determination of sulfatinib in biological medium by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. The current study validated a sensitive and reliable quantitative detection of sulfatinib in plasma using UPLC-MS/MS for the first time, and investigated the interaction with myricetin in rats. Acetonitrile was used to precipitate the plasma protein, and lenvatinib was employed as the internal standard (IS). The method demonstrated that sulfatinib presented high linearity over the concentration of 11-2,000ng/mL with the lower limit of quantification (LLOQ) of 1ng/mL. It was validated methodologically that the precision, matrix effect, stability, accuracy and extraction recovery were all within the allowable values. Moreover, male Sprague-Dawley (SD) rats were assigned randomly to assess the interaction between sulfatinib (30mg/kg) and myricetin (50mg/kg). Nevertheless, no significant differences of the main pharmacokinetic parameters were revealed. This may be due to insufficient doses of myricetin, or failure of myricetin to act in a timely manner in vivo. The findings contributed to a better understanding of the metabolism and drug-drug interaction of sulfatinib, but the presence or absence of interactions needs to be confirmed by further studies.

Rapid LC-MS/MS Evaluation of Collagen and Elastin Crosslinks in Human and Mouse Lung Tissue with a Novel Bioanalytical Surrogate Matrix Approach.

Alterations to post-translational crosslinking modifications in the extracellular matrix (ECM) are known to drive the pathogenesis of fibrotic diseases, including idiopathic pulmonary fibrosis (IPF). Thus, the methodology for measuring crosslinking dynamics is valuable for understanding disease progression. The existing crosslinking analysis sample preparation and liquid chromatography tandem mass spectrometry (LC-MS/MS) methods are typically labor-intensive and time-consuming which limits throughput. We, therefore, developed a rapid approach minimizing specialized equipment and hands-on time. The LC-MS/MS sample analysis time was reduced to two minutes per sample. We then improved the analytical integrity of the method by developing a novel surrogate matrix approach for the dihydroxylysinonorleucine (DHLNL) crosslink. By modifying sample preparation, we prepared a tissue-based surrogate matrix with undetectable levels of endogenous DHLNL, providing a strategy for quantifying this crosslink with a more relevant standard matrix. We then applied this rapid methodology to evaluating crosslinking in lung fibrosis. We showed an increase in DHLNL in human IPF lung relative to healthy donors, as well as in a fibrotic mouse model. Finally, we demonstrated that this increase in DHLNL could be mitigated with an anti-fibrotic compound, suggesting that this assay has potential for evaluating pharmaceutical compound efficacy.

Development of a straightforward direct injection UHPLC-MS/MS method for quantification of plastic additive chemicals in roadside retention ponds

There is growing interest in road pollution that enters surface waters. Additive chemicals used in the manufacture of plastics, including tyre rubber, are mobile pollutants that pose a threat to aquatic life. Therefore, an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was developed to measure 25 plastic additive chemicals in road runoff and water of retention ponds used to manage road runoff. A straightforward direct injection methodology was adopted to minimise sample handling and risk of contamination. Using this approach, the method quantitation limits (MQLs) ranged from 4.3 × 10−3 to 13 µg/L. These were adequate to determine most chemicals at or below their freshwater predicted no-effect concentration (PNEC). Method trueness ranged from 18 to 148% with most chemicals being within 80–120%. The method was applied to water from four retention ponds in series to measure additive chemicals entering the ponds (i.e., in road runoff) and passing through each pond. Greatest concentrations were observed in road runoff during heavy rainfall following dry weather. Here, 1,3-diphenylguanidine (DPG) exceeded its current PNEC of 1.05 µg/L. Notably, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-quinone) was determined at 0.13 µg/L which is greater than its lowest acute toxicity threshold (0.095 µg/L). Similarity in additive chemical concentrations throughout the retention ponds during steady flow suggests little or no removal occurs. However, further studies are needed to assess the fate and removal of plastic additive chemicals in retention ponds and the risk posed to aquatic environments. Such research can be facilitated by this newly developed UHPLC-MS/MS method.Graphical