Evaluation of cilnidipine-loaded self-micro-emulsifying drug delivery system (SMEDDS) by quantification of comparative pharmacokinetic parameters using validated LC-ESI-MS/MS bioanalytical method and pharmacodynamic assessment.

OBJECTIVE: Regardless of having desired therapeutic properties many of the recently approved drugs are removed from the developmental pipeline for their clinical use due to low solubility and permeability. Conventional dosage forms are found relatively unsuitable for achieving desired pharmacokinetic and pharmacodynamics profiles. Cilnidipine is 1,4 dihydropyridine derivative calcium channel blocker used for the treatment of hypertension. METHOD: The aim and objective of this study was to develop a precise and significant method in LC-MS/MS for quantification of pharmacokinetic parameters of a cilnidipine-loaded self-micro-emulsifying drug delivery system in rat plasma and simultaneously assessed pharmacodynamic characters in comparison with the marketed cilnidipine tablet. Another potential aim of this study is to reduce the dose of the drug in order to counter the dose-dependent toxicities related to chronic use. In the present study, the parent and product ion of cilnidipine was m/z 491.3\237.1. RESULT: The plasma was extracted by protein precipitation technique. The calibration standard concentrations were 1.875, 3.75, 7.50, 15.00, 30.00, 60.00ng/mL and LLOQ, low-quality control, middle-quality control and high-quality control were 1.87, 5.62, 22.50, 45.00ng/mL, respectively. The mobile phase composition was 0.1% formic acid in Milli Q water with 10mM Ammonium acetate as an aqueous solvent and 0.1% formic acid in methanol as an organic solvent. Following oral administration of optimized formulation Cmax (peak plasma concentration) was achieved 21.02±3.17ng/mL at 0.866±0.11h (Tmax), whereas in the case of marketed tablet Cmax (peak plasma concentration) was achieved 10.16±0.89ng/mL at 0.93±0.11h (Tmax). DISCUSSION: The in-vivo characterizations of the optimized SMEDDS showed significantly better pharmacokinetic parameters in Wistar rats and showed almost 2.4 times enhanced relative bioavailability as compared to the marketed tablet of cilnidipine which was observed to be correlating to our findings with noninvasive blood pressure parameter of Wistar rats.

Bioactivity of silverleaf nightshade (Solanum elaeagnifolium Cav.) berries parts against Galleria mellonella and Erwinia carotovora and LC-MS chemical profile of its potential extract.

Natural products received much attention as an environmentally beneficial solution for pest management. Therefore, the extracts of invasive silverleaf nightshade (Solanum elaeagnifolium Cav.) weeds using their berries parts (seeds, peels and mucilage) supported by bioassay-guided fractionation were tested against both the greater wax moth (Galleria mellonella) and Erwinia carotovora pv. carotovora causes of the blackleg of potatoes. The seeds and peels of S. elaeagnifolium were successively extracted by maceration using dichloromethane (DCM), ethyl acetate (EtOAc), and ethanol (EtOH), respectively. While, its mucilage was extracted using EtOAc. The successive EtOH extract of the plant seeds had promising inhibition efficacy and the best minimal inhibition concentration (MIC) of 50 µg/ml against E. Carotovora amongst other extracts (DCM and EtOAc of the plant berries parts). Depending on dose response activity, EtOH extract had G. mellonella larval mortality and pupal duration rates (LC50; 198.30 and LC95; 1294.73 µg/ml), respectively. Additionally, this EtOH extract of seeds was fractionated using preparative TLC to three characteristic bands. The insecticidal and bacterial activities of these isolated bands (SEA, SEB, and SEC) were evaluated at a dose of 100 µg/ml, causing mortality by 48.48, 62.63 and 92.93% (G. mellonella larvae) and inhibition by 15.22, 0.00 and 31.66 mm (E. carotovora), respectively. Moreover, the separated major three bands were tentatively identified using LC-ESI-MS analysis revealing the presence of two phenolic acids; chlorogenic acid (SEA) and dicaffeoyl quinic acid (SEB) in addition to one steroidal saponin (SEC) annotated as borassoside E or yamoscin. Finally, the plant seeds' successive EtOH extract as well as its active constituents, exhibited potential broad-spectrum activity and the ability to participate in future pest management initiatives. A field study is also recommended to validate its bio-efficacy against selected pests and to develop its formulations.

Targeted multiplex validation of CSF proteomic biomarkers: implications for differentiation of PCNSL from tumor-free controls and other brain tumors.

Introduction: Primary central nervous system lymphoma (PCNSL) is a rare type of non-Hodgkin's lymphoma that affects brain parenchyma, eyes, cerebrospinal fluid, and spinal cord. Diagnosing PCNSL can be challenging because imaging studies often show similar patterns as other brain tumors, and stereotactic brain lesion biopsy conformation is invasive and not always possible. This study aimed to validate a previous proteomic profiling (PMID: 32610669) of cerebrospinal fluid (CSF) and develop a CSF-based proteomic panel for accurate PCNSL diagnosis and differentiation. Methods: CSF samples were collected from patients of 30 PCNSL, 30 other brain tumors, and 31 tumor-free/benign controls. Liquid chromatography tandem-mass spectrometry targeted proteomics analysis was used to establish CSF-based proteomic panels. Results: Final proteomic panels were selected and optimized to diagnose PCNSL from tumor-free controls or other brain tumor lesions with an area under the curve (AUC) of 0.873 (95%CI: 0.723-0.948) and 0.937 (95%CI: 0.807- 0.985), respectively. Pathways analysis showed diagnosis panel features were significantly enriched in pathways related to extracellular matrices-receptor interaction, focal adhesion, and PI3K-Akt signaling, while prion disease, mineral absorption and HIF-1 signaling were significantly enriched with differentiation panel features. Discussion: This study suggests an accurate clinical test panel for PCNSL diagnosis and differentiation with CSF-based proteomic signatures, which may help overcome the challenges of current diagnostic methods and improve patient outcomes.

Acrylamide formation in air-fryer roasted legumes as affected by legume species and roasting degree: the correlation of acrylamide with asparagine and free sugars.

Acrylamide is a well-recognized hazardous compound with known carcinogenic, genotoxic, neurotoxic, and reproductive toxic effects. This research aimed to investigate how different legume species and roasting durations influence acrylamide formation during air-fryer roasting. The study also examined the relationship between acrylamide formation and the levels of free asparagine and free sugars in different bean species. Asparagine content varies substantially across different bean species. Sucrose was the predominant sugar across all bean species, with smaller amounts of galactose and glucose. Air-fryer-roasted Wandu kong (garden pea) showed the highest acrylamide formation, followed by Ultari kong (kidney bean) and Heoktae (black soybean), in that order. Beans roasted for longer periods in an air fryer contained significantly higher levels of acrylamide. This study revealed a strong positive correlation between acrylamide formation and the level of free asparagine in the beans, highlighting the risks associated with certain legume species and air-fryer roasting durations.

Use of Proteomics for Dietary Reconstruction: A Case Study Using Animal Teeth from Ancient Mesopotamia.

This research examines animal teeth from Early Dynastic (2900-2350 BCE) Mesopotamia (Southern Iraq) to assess animal management practices and identify consumption patterns in animal diets. The objective to answer larger questions about food management and environmental resilience in ancient early complex societies in the Near East was achieved by the use of mass spectrometry-based proteomics for dietary reconstruction. Dietary MS, a revolutionary new methodology applying proteomics techniques to archeological sample sets to reconstruct ancient animal diet. A developed protein extraction technique followed by liquid chromatography tandem mass spectrometry allowed for the identification of the specific plant species consumed in order to highlight variable herd management strategies, resource optimization, for each taxon over time. It also provided information about overall health and indications of disease. This is the first study to apply a full suite of analyses to the region and provides the foundations of a necessary long-term view of human interaction within an environment, through both time and space.

A quantitative LC-MS/MS method for investigation of polysubstance use involving heroin and cocaine.

Concurrent use of heroin and cocaine (known as the "speedball") prevails among substance use disorder populations, especially in opioid-dependent individuals, with severe consequences and a high fatality rate. Little is known about the patterns and correlations of the concurrent use of heroin and cocaine. It is vital to investigate such a polydrug use in both humans and animals to uncover concomitant toxicity and the cause of fatal overdose (death). In this study, we aimed to shed some light on the role of cocaine in the etiology of heroin-related deaths in the context of molecular pharmacokinetics (PK). For the purpose, a high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of heroin, cocaine, and their metabolites in whole blood was developed and fully validated in accordance with the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. Then, this method was used to analyze heroin, cocaine, and their metabolites in blood from the rats intraperitoneally administered non-lethal 10 mg/kg heroin or 20 mg/kg cocaine alone, or their combination that is lethal with a proximal mortality of 33 %. The obtained results from the rats that experienced the lethal toxicity revealed that the concurrent use of heroin and cocaine significantly increased the risk of fatality from overdose. Heroin significantly slowed down the elimination of cocaine and its main metabolites in blood, while cocaine significantly enhanced heroin metabolism from 6-monoacetylmorphine (6-MAM) to morphine. Similar elimination half-lives for other heroin metabolites were observed. These findings are reported for the first time in this study, facilitating our understanding of the polysubstance metabolism and severe consequences produced by the polydrug use.

Quantitative determination of liposomal irinotecan and SN-38 concentrations in plasma samples from children with solid tumors: Use of a cryoprotectant solution to enhance liposome stability.

Preclinical studies have demonstrated that liposomal irinotecan (CPT-11), a topoisomerase I inhibitor, has broad activity against adult cancers, including pancreatic, gastric, colon, lung, glioma, ovarian, and breast cancer. Encapsulation of irinotecan into liposomes can modify its pharmacokinetic properties dramatically. Also, the pharmacokinetic profiles of liposomal drug formulations are not fully understood; thus, bioanalytical methods are needed to separate and quantify nonencapsulated vs. encapsulated concentrations. In this study, two robust, specific, and sensitive LC-MS/MS methods were developed and validated to separate and quantify the nonencapsulated CPT-11 (NE-CPT-11) from the sum-total CPT-11 (T-CPT-11) and its major metabolite, SN-38, in human plasma after intravenous administration of liposomal irinotecan. NE-CPT-11 and SN-38 were separated from plasma samples by using solid-phase extraction, and T-CPT-11 was measured by protein precipitation. The liposomal CPT-11 formulation was unstable during sample storage and handling, resulting in elevated NE-CPT-11 concentration. To improve the stability of liposomal CPT-11, a cryoprotectant solution was added to human plasma samples prior to storage and processing. CPT-11, SN-38, and their respective internal standards, CPT-11-d10 and SN-38-d3, were chromatographically separated on a reversed-phase C18 analytical column. The drugs were detected on a triple quadrupole mass spectrometer in the positive MRM ion mode by monitoring the transitions 587.3 > 124.1 (CPT-11) and 393.0 > 349.1 (SN-38). The calibration curves demonstrated a good fit across the concentration ranges of 10-5000 ng/mL for T-CPT-11, 2.5-250 ng/mL for NE-CPT-11, and 1-500 ng/mL for SN-38. The accuracy and precision were within the acceptable limits, matrix effects were nonsignificant, recoveries were consistent and reproducible, and the analytes were stable under all tested storage conditions. Finally, the LC-MS/MS methods were successfully applied in a phase I clinical pharmacokinetic study of nanoliposomal irinotecan (Onivyde®) in pediatric patients with recurrent solid malignancies or Ewing sarcoma.

Effect of ozone oxidation on gastrointestinal digestion and absorption characteristics of silver carp (Hypophthalmichthys molitrix) surimi gels in vitro.

To investigate the quality of different ozone-oxidized surimi gels and their in vitro digestion and absorption characteristics, surimi rinsed with different concentrations of ozonated water (0, 8, 26 mg/L) were prepared. Then, the degree of oxidation and gel structure of surimi were determined, the in vitro digestion and absorption of the gels were simulated, and the digestion and absorption products were analyzed by LC-MS/MS. The results showed that the quality of surimi gels was improved after proper ozone oxidation. After ozone water rinsing, the dry matter digestibility, peptide, and amino acid content increased, and the changes of all three were in line with the Logistic kinetic model (R2 = 0.95-0.99). Caco-2 cell absorption experiments showed that the absorption rate of peptides and amino acids decreased after ozone water rinsing. In summary, ozone oxidation can promote the digestion of surimi gels, but it also reduces the absorption of peptides and amino acids by Caco-2 cells. This study provides a reference for the application of ozone in the food field.

Determining nine fasciolicides and three metabolite residues in milk and infant formula using solid-phase extraction and liquid chromatography-tandem mass spectrometry.

A new sensitive method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for nine fasciolicides (closantel, rafoxanide, oxyclozanide, niclosamide, nitroxinil, ioxynil, 4-nitro-3-(trifluoromethyl)phenol, salicylanilide, and triclabendazole) and three metabolite residues (ketotriclabnedazole, triclabendazole sulfone, and triclabendazole sulfoxide) in milk and infant formula was established. The samples were extracted and purified through solid-phase extraction and analyzed using LC-MS/MS. The proposed method demonstrated high accuracy (the average recoveries ranged from 70.5 % to 107.4 %) and high sensitivity (the limits of quantification ranged from 1.0 to 25.0 µg/kg). This method was successfully applied to determine nine fasciolicides and three metabolite residues in 45 milk and infant formula, providing technical support for the safety and quality evaluation of dairy products.

Basal release and relaxation responses to 6-nitrodopamine in swine carotid, coronary, femoral, and renal arteries.

Mammalian and reptilian vascular tissues present basal release of 6-nitrodopamine, which is reduced when the tissues are pre-incubated with the NO synthase inhibitor L-NG-Nitro arginine methyl ester (L-NAME), or when the endothelium is mechanically removed. 6-Nitrodopamine induces vasorelaxation in pre-contracted vascular rings by antagonizing the dopaminergic D2-like receptor. Here it was investigated whether male swine vessels (including carotid, left descendent coronary, renal, and femoral arteries) release 6-nitrodopamine, dopamine, noradrenaline, and adrenaline, as measured by liquid chromatography coupled to tandem mass spectrometry. The in vitro vasorelaxant action of 6-nitrodopamine was evaluated in carotid, coronary, renal, and femoral arteries precontracted by U-46619 (3 nM), and compared to that induced by the dopamine D2-receptor antagonist L-741,626. Expression of tyrosine hydroxylase and the neuromaker calretinin was investigated by immunohistochemistry. All vascular tissues presented basal release of endothelium-derived catecholamines. The relaxation induced by 6-nitrodopamine was not affected by preincubation of the tissues with either L-NAME (100 µM, 30-min preincubation) or the heme-site inhibitor of soluble guanylyl cyclase ODQ (100 µM, 30-min preincubation). Electrical field stimulation (EFS)-induced contractions were significantly potentiated by previous incubation with L-NAME, but unaffected by ODQ preincubation. The contractions induced by EFS were reduced by preincubation with either 6-nitrodopamine or L-741,626. Immunohistochemistry in all arteries revealed the presence of tyrosine hydroxylase in the endothelium, whereas immunoreactivity for calretinin was negative. Swine vessels present basal release of endothelium-derived catecholamines and expression of tyrosine hydroxylase in the endothelium. The vasodilation induced by 6-nitrodopamine is due to blockade of dopaminergic D2-like receptors.

P-glycoprotein-mediated herb-drug interaction evaluation between Tenacissoside G and paclitaxel.

P-glycoprotein (P-gp)-mediated herb-drug interactions (HDIs) may impact drug efficacy and safety. Tenacissoside G (Tsd-G), a major active component of Marsdenia tenacissima, exhibits anticancer activity. To analyze the effect of Tsd-G on the pharmacokinetics of paclitaxel (PTX), researchers selected 30 Sprague-Dawley (SD) rats, randomized into a solvent control group, a verapamil positive control group, and 20, 40, and 60 mg/kg Tsd-G groups. After seven consecutive days of intraperitoneal injection of verapamil or Tsd-G, a single dose of 6 mg/kg PTX was injected intravenously. Plasma samples were collected at different time points, and proteins were precipitated using a methanol-acetonitrile solution. An ultrahigh-performance liquid chromatography-tandem mass spectrometry method was developed, with docetaxel as an internal standard, and quantified using positive ion multiple reaction monitoring (MRM) mode. This analytical method's specificity, accuracy, precision, recovery, matrix effect, and sample stability meet the requirements for biological sample determination. After Tsd-G administration in rats, the mean residence time of PTX was significantly prolonged. And Tsd-G can stably bind to P-gp by forming hydrogen bonds and inhibiting the expression of P-gp in rat liver. Although the metabolites of PTX were not detected in this study, the above results still indicate the existence of HDIs between Tsd-G and PTX, and P-gp may be the main target to mediate HDIs.

Ontogeny and organ-specific steroidal glycoside diversity is associated with differential expression of steroidal glycoside pathway genes in two Solanum dulcamara leaf chemotypes.

Solanaceous plants, such as Solanum dulcamara, produce steroidal glycosides (SGs). Leaf SG profiles vary among S. dulcamara individuals, leading to distinct phytochemical phenotypes ('chemotypes') and intraspecific phytochemical diversity ('chemodiversity'). However, if and how SG chemodiversity varies among organs and across ontogeny, and how this relates to SG metabolism gene expression is unknown. Among organs and across ontogeny, S. dulcamara plants with saturated (S) and unsaturated (U) SG leaf chemotypes were selected and clonally propagated. Roots, stems and leaves were harvested from vegetative and flowering plants. Extracts were analysed using untargeted LC-MS. Expression of candidate genes in SG metabolism (SdGAME9, SdGAME4, SdGAME25, SdS5αR2 and SdDPS) was analysed using RT-qPCRs. Our analyses showed that SG chemodiversity varies among organs and across ontogeny in S. dulcamara; SG richness (Dmg) was higher in flowering than vegetative plants. In vegetative plants, Dmg was higher for leaves than for roots. Lack of SdGAME25 expression in U-chemotype leaves, while readily expressed in roots and stems, suggests a pivotal role for SdGAME25 in differentiation of leaf chemotypes in vegetative and flowering plants. By acting as an ontogeny-dependent chemotypic switch, differential regulation of SdGAME25 enables adaptive allocation of SGs, thereby increasing SG chemodiversity in leaves. This indicates that differential expression and/or regulation of glycoalkaloid metabolism genes, rather than their presence or absence, explains observed chemotypic variation in SG chemodiversity among organs and across ontogeny.

Application of ATR-FTIR and FT-NIR spectroscopy coupled with chemometrics for species identification and quality prediction of boletes.

The taste and aroma of edible mushrooms, which is a criterion of judgment for consumer purchases, are influenced by amino acids and their metabolites. Sixty-eight amino acids and their metabolites were identified using liquid chromatography mass spectrometry (LC-MS), and 16 critical marker components were screened. The chemical composition of different species of boletes was characterized by two-dimensional correlation spectroscopy (2DCOS) to determine the sequence of molecular vibrations or group changes. Identification of boletes species based on partial least squares discrimination (PLS-DA) combined with Fourier transform near-infrared spectroscopy (FT-NIR) and Fourier transform infrared spectroscopy (ATR-FTIR), residual convolutional neural network (ResNet) combined with three-dimensional correlation spectroscopy (3DCOS) was performed with 100% accuracy. Partial least squares regression (PLSR) analysis showed that FT-NIR and ATR-FTIR spectra were highly correlated with the amino acids and their metabolites detected by LC-MS. All models had achieved an R2p of 0.911 and an RPD >3.0. The results show that FT-NIR and ATR-FTIR spectroscopy in combination with chemometrics methods can be used for rapid species identification and estimation of amino acids and their metabolites content in boletes. This study provides new techniques and ideas for the authenticity of species information and the quality assessment of boletes.

Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of polymixin B1, B2, ile-B1, E1, and E2 in human plasma and its clinical pharmacokinetic application.

Polymyxin B (PB) and Polymyxin E (PE, also called colistin) are used as the last treatment resort for multidrug-resistant Gram-negative bacterial infections. The nephrotoxicity and neurotoxicity of polymyxins limit their clinical use, and guidelines recommend therapeutic drug monitoring (TDM) to optimize efficacy and reduce toxicity. However, there are limited analytical methods available for the determination of PB and PE. This study aimed to develop a simple and robust liquid chromatography with tandem mass spectrometry (LC-MS/MS) analytical method for determining the main compounds of PB and PE, namely PB1, PB2, ile-PB1, PE1, and PE2, in human plasma and to investigate of their pharmacokinetics in critically ill patients with the use of PB and PE, respectively. Plasma PB1, PB2, ile-PB1, PE1, and PE2 were chromatographically separated on a Welch LP-C18 column and detected using electrospray ionization mode coupled with multiple reaction monitoring. The calibration curve showed acceptable linearity over 20-10,000 ng/mL for PB1, PE1, and PE2 and 10-5000 ng/mL for PB2 and ile-PB1 in the plasma, respectively. After validation following approved guidelines, this method was successfully applied for PB and PE pharmacokinetic analysis and TDM in critically ill patients. Additionally, the composition of PB1, PB2, ile-PB1, PE1, and PE2 remains unchanged from 0 to 12 h after entering the patient's body.

Optimized extraction methodology for phenolic compounds in soil and plant tissues: Their implications in plant growth and gall formation.

Phenolic compounds, abundant secondary metabolites in plants, profoundly influence soil ecosystems, plant growth, and interactions with herbivores. Phenolic in soil microorganisms have the potential to impact a wide range of activities in plant-soil interactions. However, the existing methods for measuring microbial activity are typically time-consuming, intricate, and expensive. In this study, we propose modifications to the method used for the extraction and quantification of various types of phenolics in soil and plant tissues. There have been substantial advancements in research aimed at extracting, identifying, and quantifying phenolic compounds in the plant and soil samples. This study discusses the use of different methodologies in the analysis of phenolic compounds. In addition, we investigated the effect of phenolics on plant growth and cues in gall-forming under environmental disturbances.•This method is the optimum way to extract phenolic from soil and microbial activity in bulk and rhizosphere soil.•It can be used on any soil type and plant tissue, metabolites extracted from living organisms.

Determination of warfarin in volumetric absorptive microsampling by liquid chromatography-tandem mass spectrometry.

Objective: This study aims to develop and validate bioanalytical method for quantifying warfarin in VAMS samples using liquid chromatography tandem mass spectrometry (LC-MS/MS), directly implementing the method to patients receiving warfarin therapy. Methods: The UPLC-MS/MS method was developed and optimized, with quercetin as the internal standard. Sample preparation was carried out using protein precipitation with methanol-acetonitrile (1:3 v/v). Results: Chromatographic separation was achieved using Acquity® UPLC BEH C18 column with 0.1 % formic acid-acetonitrile-methanol (30:69:1 v/v) as mobile phase, in isocratic elution. Multiple Reaction Monitoring (MRM) detection was done using m/z values of 307.10 â†’ 161.06 for warfarin and 301.03 â†’ 150.98 for quercetin as internal standard, using Electrospray Ionization (ESI) negative ion source. The clinical application of the bioanalytical method was carried out on 25 patients receiving warfarin therapy at Universitas Indonesia Hospital and warfarin levels were well within the calibration range from 6.05 to 431.39 ng/mL. Conclusion: A novel method has been developed to analyze warfarin in VAMS samples. This method has been fully validated according to guideline from FDA 2022 and is linear in the range of 5-500 ng/mL and the value of r ≥ 0.9977, and successfully applied for the analysis of warfarin in VAMS samples of clinical patients.

Determination of Normal Range of Acylcarnitine in Neonatal Dried Blood Spots using LC-MS/MS.

Background: Acylcarnitine is one of the crucial markers of fatty acid metabolism, and examination of their level in infants can reveal several Inherited Metabolic Disorders (IDM) or Inborn errors of Metabolism (IEM). Because of the great importance of hereditary, metabolic, and other inherited disorders early diagnosis before the appearance of clinical symptoms, this study was carried out to establish a reference range for carnitine analytes and to identify acylcarnitine profiles in normal weight neonatal dried blood spots (DBS) specimens. Methods: By using liquid chromatography tandem mass spectrometry (LC-MS/MS) for neonatal screening and eventually the examination and analysis of LC-MS/MS results, 34 acylcarnitine derivatives were identified. Results: The normal range for acylcarnitine analytes with carbon numbers ranging from zero to 18, both main and the branched ones, were ultimately measured. Afterward, they were compared with the results of some other diagnostic laboratories to be verified. Conclusions: This study differed from the other findings, which could be due to diversity in population and work methods. However, the reference range of most acylcarnitine derivatives in Tehran closely aligned with this study's findings.

A multianalyte LC-MS/MS method for accurate quantification of Nitrosamines in Olmesartan tablets.

This research summaries the development, optimization and validation of liquid chromatography tandem mass spectrometric (LC-MS/MS) method for concurrent measurement of seven nitrosamines viz; NDMA, NDEA, NDIPA, NDPA, NEIPA, NMPA & NMBA in Olmesartan tablet. Controlling these nitrosamines at trace levels is imperative for ensuring the safety of drug substances and products for consumption. Various regulatory authorities stress the significance of utilizing highly sensitive analytical methods to precisely measure nitrosamines at trace levels. The method applied effective chromatographic separation and optimized parameters for mass spectrometric detection. Detection was carried out using APCI positive ion mode. Chromatographic separation was achieved using a Thermo Accucore PFP column (150 mm x 4.6 mm, 2.6 µ), with a simple gradient elution of mobile phase consisting of 0.1 % formic acid in water (mobile phase A) and methanol (mobile phase B). The total run time was 20 min, with a flow rate of 0.800 mL/min. The method was validated according to the International Council on Harmonisation (ICH Q2 (R2)) guidelines. The established method demonstrated excellent linearity (R2> 0.99) and sensitivity for all the nitrosamines. Detection and quantification limits were sufficiently low for trace nitrosamine levels having good S/N ratio. The method showed good accuracy in Olmesartan tablet samples, with recoveries ranges between 80 % to 120 %. The new analytical approach has exceptional repeatability and reliability, making it possible to precisely quantify the levels of seven nitrosamines in Olmesartan medoxomil tablets in a single analytical run.

Forensic toxicological studies of acute glufosinate poisoning: A case series.

Glufosinate is a widely and increasingly used non-selective, broad-spectrum herbicide. Although cases of glufosinate poisoning are frequently reported, they are rarely documented in forensic case reports, particularly in fatal instances. The present study examined six cases of glufosinate poisoning, including a fatal case involving a 25-year-old female found deceased by the roadside, with an empty 1000 mL bottle labeled "glufosinate" by her side. Biological specimens such as plasma or cardiac blood, gastric contents, and liver tissues were collected for quantitative analysis of glufosinate levels using LC-MS/MS. In five cases of acute glufosinate poisoning, glufosinate plasma concentrations ranged from 0.62 to 3.92 µg/mL. In the fatal case, the concentrations of glufosinate in cardiac blood, gastric contents, and liver tissues were 8.41 µg/mL, 31.25 µg/mL, and 66.1 µg/g, respectively. The pathological autopsy concluded that the cause of death was acute cardio-respiratory failure due to glufosinate poisoning, characterized by multi-organ congestion without specific pathological findings. The toxicological data provided in this study aim to serve as a critical reference for future clinical treatment and forensic validation of glufosinate poisoning-related deaths.

Electromembrane extraction of peptides based on charge, hydrophobicity, and size - A large-scale fundamental study of the extraction window.

This study investigated the capability of electromembrane extraction (EME) as a general technique for peptides, by extracting complex pools of peptides comprising in total of 5953 different substances, varying in size from seven to 16 amino acids. Electromembrane extraction was conducted from a sample adjusted to pH 3.0 and utilized a liquid membrane consisting of 2-nitrophenyl octyl ether and carvacrol (1:1 w/w), containing 2% (w/w) di(2-ethylhexyl) phosphate. The acceptor phase was 50 mM phosphoric acid (pH 1.8), the extraction time was 45 min, and 10 V was used. High extraction efficiency, defined as a higher peptide signal in the acceptor than the sample after extraction, was achieved for 3706 different peptides. Extraction efficiencies were predominantly influenced by the hydrophobicity of the peptides and their net charge in the sample. Hydrophobic peptides were extracted with a net charge of +1, while hydrophilic peptides were extracted when the net charge was +2 or higher. A computational model based on machine learning was developed to predict the extractability of peptides based on peptide descriptors, including the grand average of hydropathy index and net charge at pH 3.0 (sample pH). This research shows that EME has general applicability for peptides and represents the first steps toward in silico prediction of extraction efficiency.