TQ-S

BACKGROUND: Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). The clinical efficacy and safety of an administered tofacitinib, either monotherapy or in combination with conventional synthetic disease-modifying anti-rheumatic drugs, mainly methotrexate (MTX), have been evaluated. The high plasma concentration with delayed medicine clearance may affect the liver and/or kidney functions. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC- MS/MS) method for the quantitative analysis of methotrexate, tofacitinib, and metabolite M9 in plasma of Sprague Dawley (SD) rats was developed, and its effectiveness was validated as well...

BACKGROUND: Ketamine is an NMDAR antagonist with aggregating use across many areas of medicine. P450 enzymes heavily metabolise ketamine where norketamine is a first pass formed metabolite following initial N-demethylation [1]. Serum ketamine monitoring is becoming increasingly important where a sensitive method is required with a robust lower limit of quantitation. METHODS: Samples were prepared using protein precipitation or solid phase extraction. Ion suppression was investigated to assess sample preparation technique, followed by reverse phase chromatography coupled with tandem mass spectrometry to analyse extractions using a Waters Xevo TQ-s and associated Acquity chromatography systems...

Mycophenolate mofetil (MMF) and sodium mycophenolate are commonly prescribed immunosuppressive drugs for patients who have undergone solid organ transplant. Therapeutic drug monitoring (TDM) of these drugs is performed by assessing mycophenolic acid (MPA) in plasma. Due to the large inter-individual variability and narrow therapeutic range, the precise determination of systemic MPA concentration carries great clinical significance. We present a rapid, sensitive, specific, and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitation of MPA in plasma...

BACKGROUND: Vericiguat, as a new stimulator of soluble guanylate cyclase (sGC), was recently approved as a first-in-class treatment for reducing risks in patients with ejection fraction less than 45 percent and heart failure (HF) in the USA. OBJECTIVE: The main aim of the present experiment was to establish an acceptable, sensitive assay based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for quantitatively analyzing the plasma concentration levels of vericiguat in rats, and to further evaluate the effect of apigenin on the metabolism of vericiguat in vivo...

Lavender ( Lavandula angustifolia Miller or Lavandula officinalis Chaix) is an ethnopharmacological plant commonly known as English lavender. Linalool and linalyl acetate are putative phytoactives in lavender essential oil (LEO) derived from the flower heads. LEO has been used in aroma or massage therapy to reduce sleep disturbance and to mitigate anxiety. Recently, an oral LEO formulation was administered in human clinical trials designed to ascertain its anxiolytic effect. However, human pharmacokinetics and an LC-MS/MS method for the measurement of linalool are lacking...

INTRODUCTION: Qingjin Yiqi granule (QYG) is a prescription medicine of traditional Chinese medicine which is widely used clinically for the recovery of coronavirus patients. However, there is currently limited research on the quality control of QYG. OBJECTIVE: To evaluate the quality of QYG qualitatively and quantitatively by making full use of advanced chromatography-mass spectrometry techniques. METHODS: Firstly, a multicomponent characterisation of QYG was performed by ultrahigh-performance liquid chromatography coupled with a Q Exactive™ hybrid quadrupole-Orbitrap mass spectrometry (UHPLC-Q-Orbitrap-MS) system using a rapid negative/positive switching mode...

Introduction: The aim of the present study was to establish a simple method for the determination of riluzole in human plasma by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and apply it for the determination of riluzole in amyotrophic lateral sclerosis (ALS) patients. Methods: Samples were prepared by protein precipitation and were then gradient-eluted on a column of ACQUITY UPLC® HSS T3 by using 0.1% formic acid acetonitrile and 0.1% formic acid water as the mobile phase...

CONTEXT: CYP2C19 is an important member of the human cytochrome P450 2C (CYP2C) family. Mavacamten is a novel treatment of patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM) which was metabolized mainly by CYP2C19. OBJECTIVE: In this study, we firstly reported and validated a quantitative analysis method of mavacamten in rat plasma based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), which was applied to the drug-drug interaction (DDI) study between mavacamten and CYP2C19 inhibitors (fluvoxamine, fluoxetine and fluconazole) in rats...

CONTEXT: Derazantinib-an orally bioavailable, ATP competitive, multikinase inhibitor-has strong activity against fibroblast growth factor receptors (FGFR)2, FGFR1, and FGFR3 kinases. It has preliminary antitumor activity in patients with unresectable or metastatic FGFR2 fusion-positive intrahepatic cholangiocarcinoma (iCCA). OBJECTIVE: This experiment validates a novel sensitive and rapid method for the determination of derazantinib concentration in rat plasma by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), and applies it to the study of drug-drug interaction between derazantinib and naringin in vivo ...

Periprosthetic joint infection is a challenging infection involving the joint prosthesis and adjacent tissue, such as synovial fluid, synovial tissue, and bone tissue. The current treatment consists of multiple surgical revisions and long-term antibiotic therapy. Treatment failure can cause poor functional outcome and reduced quality of life. Further research on the extent of antibiotic penetration into the infected tissues is of great importance. Our work aimed to develop and validate a novel ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of the commonly administered antibiotics vancomycin and clindamycin in plasma and synovial fluid...

AIM: A simple and sensitive method using in vivo microdialysis coupled with UPLC-MS/MS was established to evaluate the pharmacokinetics of Shuang Hu tincture (SHZTN). METHOD: Xevo TQ-S was used to analyze the active ingredients of mesaconitine, hypaconitine, 4-hydroxycinnamic acid, ferulic acid, N-(2, 3- dimethyl phenyl) -2- aminobenzoic acid (DPA) of SHZTN. Samples were prepared by methanol precipitation method, and internal standard (IS) lannaconitine and p-Hydroxybenzoic acid were added...

The primary objective of this study was to develop and validate an efficient and accurate ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach as a means to detect tropifexor plasma concentrations in beagle dogs and to study its pharmacokinetic profile in beagle dogs. The chromatographic separation of tropifexor and oprozomib (internal standard, ISTD) on the column, with the addition of acetonitrile for rapid precipitation and protein extraction, was achieved with 0.1% formic acid aqueous solution-acetonitrile for the mobile phase...

RATIONALE: Ionization by atmospheric pressure gas discharge has been employed for a long time in mass spectrometry. Inductively coupled plasma mass spectrometry is an exemplar, and widely used for elemental analysis. The technique has less uptake in organic mass spectrometry. We describe a simple source design that can be readily implemented in most atmospheric pressure ionization (API) systems and compare its performance with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI)...

Background: Utilising stable isotope labelled internal standards (SIL-IS) in quantitative LC-MS/MS drug analysis is the most widely used approach to normalise for variability during sample quantification processes. However, compounds containing atoms such as Sulphur, Chlorine or Bromine, could potentially cause cross-signal contribution to the SIL-IS from the naturally occurring isotopes, resulting in non-linear calibration curves. A simple, novel method of mitigating the effect is presented here...

A novel mass spectrometry based analytical method for simultaneous analysis of the antiviral drugs acyclovir, its metabolite 9-carboxymethoxymethylguanine, ganciclovir and penciclovir in serum is described. These antiviral drugs are active against herpes virus infections. Acyclovir and penciclovir are regarded as safe and effective medicines with mild side effects such as headache and gastrointestinal discomfort, ganciclovir is regarded as more toxic and is known to cause e.g., bone marrow suppression. Acyclovir main metabolite 9-carboxymethoxymethylguanine is a presumptive neurotoxin and should be monitored in patients with impaired renal function or in cases with neurotoxic symptoms...

The hallmarks of cancer include metabolism with deregulating cellular energetics. Dysfunctions in succinate dehydrogenase (SDH) metabolic enzyme activity, leading to an abnormal accumulation of succinic acid has been described in solid tumors but also in inflammation and ischemia reperfusion injury. Succinic acid is a potential biomarker of SDH related pathologies for diagnostic, evaluation of treatment response and follow-up of the disease. We developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) method allowing a rapid, accurate and precise quantification of succinic acid levels in clinical (serum, urine) and preclinical (cellular pellets, supernatants) samples...

Upadacitinib, as a selective and reversible Janus kinase (JAK) inhibitor, has been widely used in the treatment of atopic dermatitis, ulcerative colitis and other inflammatory bowel diseases and other immune-mediated diseases. The combination of methotrexate and upadacitinib is a common clinical treatment strategy for rheumatoid arthritis (RA) in recent years. In this study, we established an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) assay for quantitative measurement of upadacitinib and methotrexate, by which we successfully determined pharmacokinetic parameters of them in rat plasma...

Introduction: C-peptide is used as a marker of endogenous insulin secretion in the assessment of residual β-cell function in diabetes and in the diagnostic workup of hypoglycemia. Previously developed LC-MS/MS methods to quantify serum concentrations of C-peptide have monitored intact peptide, which ionizes poorly. As a result, methods have leveraged immunoaffinity enrichment or two-dimensional chromatography. In this study, we aimed to use proteolysis during sample preparation to enhance the sensitivity of traditional LC-MS/MS...

A valid method based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with a chiral stationary phase was established for the determination of myclobutanil enantiomer residue in wheat grain and its processed products (flour, bran, pasta, steamed bun, noodle, and cooking water). The wheat grain and processed product samples were extracted with acetonitrile and purified with primary secondary amine (PSA) and C18. The enantiomers of myclobutanil were separated by Chiral column Lux Cellulose-1 (150 mm×2...

Antimicrobials premixes are the presentation of choice to administer drugs simultaneously to groups of animals in intensive husbandry systems that require treatment for pathologies of bacterial origin. Among the premixes available for use in poultry, florfenicol and oxytetracycline are commonly administered via food or water. However, their actual concentration in premixes must meet on-label statements to ensure plasma concentrations reach effective therapeutic levels. Hence, this work was designed for the purpose of verifying whether the concentration of antimicrobial present in five premixes matched their on-label statement...