HPLC-MS/MS method for determination of betamethasone in human plasma with application to a dichorionic twin pregnancy pharmacokinetic and placental transfers studies

Abstract Betamethasone (BET) is a synthetic glucocorticoid recommended for pregnant women at imminent risk of preterm birth before 34 weeks to reduce neonatal complications. There are different techniques to describe BET plasma quantification. However, none quantified the plasmatic concentration of BET in dichorionic (DC) twin pregnancies using LC-MS. Our objectives were to develop and validate a method for quantifying BET by LC-MS for pharmacokinetic (PK) and placental transfer studies in DC twin pregnancies. Blood samples were collected after intramuscular administration of a single BET dose containing 6 mg disodium phosphate + 6 mg acetate. BET was determined in plasma by liquid-liquid extraction. The method showed linearity in the range of 2-250 ng/mL, as well as precision and accuracy with a coefficient of variation and relative standard errors ≤ 15%. Additionally, the method presented selectivity and did not present matrix or carry-over effect. Stability tests also presented coefficient of variation and relative standard errors ≤ 15%. This is the first study which describe maternal and fetal plasma concentrations of BET in a DC twin pregnancy. The BET PK parameters were AUC0-∞, CL/F, Vd/F, Cmax, Tmax of 292.20 h*ng/mL, 39.08 L/h, 278.72 L, 25.55 ng/mL and 0.58 h, respectively. The placental transfer ratios of umbilical vein/maternal vein and intervillous space/maternal vein were 0.14 and 0.19 and 0.40 and 0.27 for both twins, respectively. However, a clinical study with more subjects is imperative to confirm this higher concentration of BET in the intervillous space

LC-MS analysis of 2-(2-phenylethyl) chromones in sodium chloride-treated suspension cells of Aquilaria sinensis / 中国中药杂志

Qualitative and quantitative analysis of 2-(2-phenylethyl) chromones in sodium chloride(NaCl)-treated suspension cells of Aquilaria sinensis was conducted by UPLC-Q-Exactive-MS and UPLC-QQQ-MS/MS. Both analyses were performed on a Waters T3 column(2.1 mm×50 mm, 1.8 μm) with 0.1% formic acid aqueous solution(A)-acetonitrile(B) as mobile phases at gradient elution. MS data were collected by electrospray ionization in positive ion mode. Forty-seven phenylethylchromones was identified from NaCl-treated suspension cell samples of A. sinensis using UPLC-Q-Exactive-MS, including 22 flindersia-type 2-(2-phenylethyl) chromones and their glycosides, 10 5,6,7,8-tetrahydro-2-(2-phenylethyl) chromones and 15 mono-epoxy or diepoxy-5,6,7,8-tetrahydro-2-(2-phenylethyl) chromones. Additionally, 25 phenylethylchromones were quantitated by UPLC-QQQ-MS/MS. Overall, the rapid and efficient qualitative and quantitative analysis of phenylethylchromones in NaCl-treated suspension cells of A. sinensis by two LC-MS techniques, provides an important reference for the yield of phenylethylchromones in Aquilariae Lignum Resinatum using in vitro culture and other biotechnologies.

Detection of Carbamazepine and Its Metabolites in Blood Samples by LC-MS/MS / 法医学杂志

OBJECTIVES@#To establish a method for the detection of carbamazepine and its metabolites 10,11-dihydro-10,11-epoxycarbamazepine and 10,11-dihydro-10-hydroxycarbamazepine in blood samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS).@*METHODS@#The blood samples were treated with 1-butyl-3-methylimidazolium hexafluorophosphate as an extraction solvent. The samples were extracted by ultrasound-assisted extraction and separated by ZORBAX Eclipse Plus C18, 95Å column. The mobile phase A aqueous solution containing 0.1% formic acid and 10 mmol/L ammonium acetate, and mobile phase B mixed organic solvent containing acetonitrile/methanol (Vacetonitrile∶Vmethanol=2∶3) were used for gradient elution at the flow rate of 1.00 mL/min. An electrospray ion source in positive mode was used for detection in the multiple reaction monitoring.@*RESULTS@#The linearities of carbamazepine and its metabolites 10,11-dihydro-10,11-epoxycarbamazepine and 10,11-dihydro-10-hydroxycarbamazepine in blood samples were good within the corresponding range, with correlation coefficients (r) greater than 0.995 6. The limits of detection were 3.00, 0.40 and 1.30 ng/mL, respectively. The limit of quantitation were 8.00, 1.00 and 5.00 ng/mL, respectively. The extraction recoveries ranged from 76.00% to 106.44%. The relative standard deviations of the intra-day and inter-day precisions were less than 16%. Carbamazepine and its main metabolite 10,11-dihydro-10,11-epoxycarbamazepine were detected in blood samples of death cases with a mass concentration of 2.71 μg/mL and 252.14 ng/mL, respectively.@*CONCLUSIONS@#This method has high sensitivity and good selectivity, which is suitable for the detection of carbamazepine and its metabolites in blood samples, and can be used for carbamazepine-related forensic identifications.

Fragmentation stability and retention time-shift obtained by LC-MS/MS to distinguish sialylated N-glycan linkage isomers in therapeutic glycoproteins / 药物分析学报

Sialylated N-glycan isomers with α2-3 or 42-6 linkage(s)have distinctive roles in glycoproteins,but are difficult to distinguish.Wild-type(WT)and glycoengineered(mutant)therapeutic glycoproteins,cyto-toxic T lymphocyte-associated antigen-4-immunoglobulin(CTLA4-Ig),were produced in Chinese ham-ster ovary cell lines:however,their linkage isomers have not been reported.In this study,N-glycans of CTLA4-Igs were released,labeled with procainamide,and analyzed by liquid chromatography-tandem mass spectrometry(MS/MS)to identify and quantify sialylated N-glycan linkage isomers.The linkage isomers were distinguished by comparison of 1)intensity of the N-acetylglucosamine ion to the sialic acid ion(Ln/Nn)using different fragmentation stability in MS/MS spectra and 2)retention time-shift for a selective m/z value in the extracted ion chromatogram.Each isomer was distinctively identified,and each quantity(＞0.1％)was obtained relative to the total N-glycans(100％)for all observed ionization states.Twenty sialylated N-glycan isomers with only α2-3 linkage(s)in WT were identified,and each isomer's sum of quantities was 50.4％.Furthermore,39 sialylated N-glycan isomers(58.8％)in mono-(3 N-glycans;0.9％),bi-(18;48.3％),tri-(14;8.9％),and tetra-(4;0.7％)antennary structures of mutant were obtained,which comprised mono-(15 N-glycans;25.4％),di-(15;28.4％),tri-(8;4.8％),and tetra-(1;0.2％)sialy-lation,respectively,with only α2-3(10 N-glycans;4.8％),both α2-3 and α2-6(14;18.4％),and only α2-6(15;35.6％)linkage(s).These results are consistent with those for α2-3 neuraminidase-treated N-glycans.This study generated a novel plot of Ln/Nn versus retention time to distinguish sialylated N-glycan linkage isomers in glycoprotein.

An emerging analytical tool for highly sensitive quantitative analysis based on liquid chromatography-multiple-reaction monitoring cubed (MRM3) / 中国药科大学学报

@#Liquid chromatography-multiple-reaction monitoring (LC-MRM) has been widely recognized as the golden standard for multiple components-targeted quantitative analysis of complicated matrices,with extensive applications for analysis in such fields as chemical drugs, traditional Chinese medicines and foods.Unfortunately, when facing the task of quantitatively analyzing trace chemical components in complex matrices, MRM suffers dramatically from the background noise or matrix interference, leading to undesirable sensitivity and selectivity in terms of the lower limits of quantification (LOQ) and detection (LOD).In recent years, MRM cubed (MRM3), also known as MS3 scan, has received much attention because of its unique ability to significantly improve detection selectivity and sensitivity attributing to the successive ion filtering function, enabling LC-MRM3 as an emerging analytical tool.In this review,our attention is devoted to: 1) the illustration of the principle for MRM3; 2) parameter settings; and 3) the application progress of LC-MRM3 in such fields as the pursuit of biomarkers, pharmaceutical analysis, forensic analysis, toxicological analysis, food chemistry, and environmental analysis, aiming to provide a promising analytical tool of LC-MRM3 advantageous in the quantification analysis of trace chemical components in complex matrices.

LC-MS/MS method for the determination of an anti-tumor compound C17 in nude mice plasma and its application to a pharmacokinetic study / 药学学报

C17 is an orally available anti-tumor compound inhibiting cancer stem cell (CSC). In this study, a stable, sensitive and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established and validated, and was further applied to a pharmacokinetic study in nude mice receiving C17 by gavage. Using propranolol as the internal standard, the plasma samples were pre-treated by precipitation with methanol and analyzed on an Intersil C8-3 column (100 mm × 2.1 mm, 3 μm), and gradient elution was performed with a mobile phase consisting of 0.1% formic acid aqueous and solution mixed up by 90% isopropanol and 10% acetonitrile. The analyte was detected by a triple quadrupole tandem mass spectrometer, and multiple reaction monitoring was employed to select C17 at m/z 439.3/247.1 and propranolol at m/z 260.2/116.2 in the positive ion mode. The calibration curves were linear (r > 0.995) over the range of 5-800 ng·mL-1. The intra- and inter-day precisions and accuracies were 7.42%-13.22% and -8.99%-8.81% respectively. The method was successfully applied to a PK study in nude mice administered with a single oral dose of 50 mg·kg-1 C17, and the PK data were analyzed with non-linear mixed effect model (NONMEM). Two separated absorption peaks were found in the PK curve of C17, and a two-compartment model with two sequential first-order absorption rate was utilized to describe the PK properties of C17, and the model could provide insights into the physiological process and exposure of C17 in nude mice. All animal experiments were in strict accordance with the regulations of the Biomedical Ethics Committee of Peking University.

Development of national secondary reference materials of urea and creatinine in frozen human serum / 中华检验医学杂志

Objective:To develop a national secondary reference material of Urea and Creatinine in frozen human serum as a standard for metrological traceability.Methods:According to JJF1343-2012 "General and Statistical Principles for Characterization of Reference Materials" and JJF 1006-1994 " Technical Norm of Primary Reference Material ", the homogeneity, stability, and commutability were evaluated;Using the JCTLM recommended methods, the value of the reference materials was assigned through collaboration with 6 accredited reference laboratories from Guangdong Provincial Hospital of Chinese Medicine, Beijing Aerospace General Hospital, Shenzhen Mindray Bio-Medical Electronics, Maccura Biotechnology, Beijing Leadman Biochemistry, and Zhejiang MedicalSystem Biotechnology. Uncertainty components including inhomogeneity, stability and value assignment were evaluated.Results:The results of one-way analysis of variance of homogeneity for the reference materials showed P>0.05, and the stability evaluation was less than the critical value of the t-test. The measured values were in the 95% confidence interval in the four conventional detection systems for commutability, and the certified values and expanded uncertainties were urea:(14.7±0.3) mmol/L ( k=2),Cr:(313.9±14.5) μmol/L ( k=2). Conclusion:The prepared secondary reference materials of urea and creatinine had promising homogeneity, stability, and commutable, the values of urea and creatinine concentration in reference materials were accurate and reliable.

Pharmacokinetic study of five ingredients from Chitong xiaoyanling granules in rats / 中国药房

OBJECTIVE To study the pharmacokinetics of paeoniflorin， hesperidin， naringenin， formononetin and enoxolone from Chitong xiaoyanling granules in rats. METHODS Six male SD rats fasted but not deprived of water for 12 h were given Chitong xiaoyanling granules （5.0 g/kg） intragastrically at one time. Blood was collected from inner canthus of rats at different time points after administration. Plasma samples were pretreated with acetonitrile precipitated protein （sulfamethoxazole as internal standard）， and the concentrations of 5 ingredients in plasma were determined by liquid chromatography-tandem mass spectrometry （LC-MS/MS）. The pharmacokinetic parameters of each ingredient were calculated using DAS 3.0 software. RESULTS After intragastric administration of Chitong xiaoyanling granules， tmax and t1/2 of formononetin were the shortest among 5 ingredients （0.25 h and 0.39 h， respectively）. For naringenin and enoxolone， the tmax was shorter， but t1/2 was longer， and there was an obvious double-peak phenomenon in the drug-time curve of naringenin. Compared with the other three components， cmax and AUC of paeoniflorin and hesperidin were not directly proportional to the content of in vitro components. CONCLUSIONS Formononetin， naringin and enoxolone in Chitong xiaoyanling granules were absorbed rapidly in rats， while paeoniflorin and hesperidin were absorbed slowly.

Searching for potential biomarkers reflecting early injury and progressive of podocytes in nephropathy based on cellular metabolomics combined with ROC analysis / 药学学报

The pathogenesis of the nephrotic syndrome is complex and the pathological types are diverse, so the minor symptoms in its early phases are difficult to detect. Renal biopsy is the gold indicator for the diagnosis of renal pathology and progression, but poor patient compliance shows, and the optimal treatment time is often delayed. Therefore, the discovery of biomarkers for early diagnosis and disease progression monitoring is of great clinical significance. In this study, doxorubicin-injured podocyte models were used to simulate human kidney disease at different stages of progression. LC-MS-based metabolomic technology combined with statistical methods was used to screen and identify the potential biomarkers associated with early injury or progression of podocytes. The results of cell viability, apoptosis tests and podocyte structural protein analysis showed that the model was successfully constructed, and the degree of podocyte injury was significantly different between the two modeling methods. According to VIP > 1 and P < 0.05 based on the orthogonal partial least squares discriminant analysis (OPLS-DA) model, nine differential metabolites reflecting early podocyte injury and twelve differential metabolites reflecting the injury progression were screened, respectively. ROC analysis was adopted to focus on the potential biomarkers that can reflecting the early podocyte injury including L-tryptophan, guanosine triphosphate (GTP), 5′-thymidylic acid (dTMP) and thymidine, and the biomarkers reflecting the injury progression of podocytes composed of L-phenylalanine, L-tyrosine acid, uridine 5′-diphosphate (UDP) and guanosine 5′-diphosphate (GDP) AUC > 0.85. It indicated that these eight metabolites may have high sensitivity and diagnostic ability. This study provides a reference for the research on biomarkers of progressive diseases.

In vivo pharmacokinetic study on determination of effective components in Xiakucao Xiaoliu mixture in Normal Rat Plasma By LC-MS/MS / 药学实践杂志

Objective To establish a method and study the pharmacokinetics for concentration determination of effective components in Xiakucao Xiaoliu mixture in Normal Rat Plasma By LC-MS/MS. Methods The mobile phase was methanol-water (0.1% formic acid) system under the positive ion mode of C18 chromatographic column, gradient elution was adopted, and the flow rate was 0.3 ml/min. In the negative ion mode, the mobile phase was acetonitrile-water (0.1% formic acid) system, gradient elution, with a flow rate of 0.4 ml/min. Caffeic acid, rosmarinic acid, syringic acid, rutin in positive ion mode and Atractylodes lactone II and Atractylodes lactone III in negative ion mode were respectively determined. Normal rats were intragastrically given Xiakucao Xiaoliu Mixture 7.8 ml/kg, and blood was taken from the orbit at different time points after the administration. The blood concentration was determined by the validated LC-MS/MS method and the non-standard DAS2.0 software was used. The pharmacokinetic parameters of rats after administration were calculated by the compartment model. Results The pharmacokinetic parameters belonged to non atrioventricular model. The pharmacokinetic characteristics of the four main anti-cancer active ingredients of Caffeic acid, Rosmarinic acid, Syringic acid and Atractylodes Ⅲ in rats after administration of Xiakucao Xiaoliu Mixture were significantly different from those reported in the literature after the administration of monomers. Conclusion The established method was simple, accurate and sensitive, which could be suitable for the content determination of effective components in Xiakucao Xiaoliu mixture in Normal Rat Plasma, which would be a valuable information for the study on main anticancer active substances.

Establishment and application for simultaneous determination method of atorvastatin and its active/toxic metabolites in rat plasma / 中国药房

OBJECTIVE To establish a method for simultaneous determination of atorvastatin （ATV） and its active metabolites 2-hydroxy atorvastatin acid （2-HAT）， 4-hydroxy atorvastatin acid （4-HAT） and toxic metabolite atorvastatin lactone （ALT） in rat plasma and apply it for pharmacokinetic study. METHODS LC-MS/MS method was adopted for analysis. The one-step precipitation method was used for processing plasma samples （plasma samples were pretreated by acidification to adjust pH value so as to prevent inversion of configuration）， gradient elution was used to analyze the samples， and the analysis time was 5 min. Electrospray positive ionization was adopted， and positive ion scanning was performed in multi-reaction monitoring. The m/z of quantified ion pairs of ATV and its metabolites such as 2-HAT， 4-HAT and ATL， and internal standard pitavastatin were 559.3→ 440.2， 575.2→440.3， 575.0→440.2， 540.9→448.2 and 422.2→290.0， respectively. After conducting a comprehensive methodological investigation of the analytical method， the concentrations of ATV and its metabolites 2-HAT， 4-HAT，and ATL were determined， and the pharmacokinetic parameters of ATV and its metabolites were calculated using the non- compartment model of WinNonlin 6.1. RESULTS The results of methodological validation showed that endogenous substances in blank plasma did not interfere with the determination of the components to be tested， and the standard curve had a good linear relationship； the lower limits of quantification for ATV， 2-HAT， 4-HAT and ATL were 0.5， 0.5， 0.25 and 0.063 nmol/L， respectively. The precision， accuracy， recovery， matrix effect and stability investigation were all in line with the requirements of biological analysis. Pharmacokinetic analysis showed that after intragastric administration in rats， ATV calcium metabolized rapidly， and was mainly exposed to blood circulation in the form of ATV and 2-HAT， with the lowest concentration of lactone-type metabolites. CONCLUSIONS The established method is precise， rapid and accurate for plasma concentration analysis of ATV and its active/toxic metabolites. The application of the method could help to fully elucidate the pharmacokinetic characteristics of atorvastatin calcium in rats.

Analysis of Intervention of Erxiantang in Ovariectomized Rats by LC-MS Serum Metabolomics / 中国实验方剂学杂志

ObjectiveTo investigate the changes of endogenous metabolites in serum of ovariectomized rats and the effect of Erxiantang on them based on liquid chromatography-mass spectrometry（LC-MS）. MethodTwenty-four healthy female SD rats were randomly divided into sham-operated group， model group and Erxiantang group（7.5 g·kg-1）， with 8 rats in each group. Bilateral ovarian tissues were excised in the model and Erxiantang groups， and small pieces of adipose tissues were excised in the abdominal cavity of the sham-operated group bilaterally， and gastric administration was started 2 weeks after surgery， and equal volumes of distilled water were gavaged in the sham-operated and model groups. After 12 weeks of administration， blood was collected from abdominal aorta， and non-targeted metabonomics was performed on rat serum by LC-MS， and orthogonal partial least squares-discriminant analysis（OPLS-DA） was used to screen differential metabolites. Metabolic pathway analysis was performed based on Kyoto Encyclopedia of Genes and Genomes（KEGG）， and the levels of key enzymes of metabolic pathways were verified by enzyme-linked immunosorbent assay（ELISA）. ResultThe results of metabonomics showed that 82 differential metabolites between the model group and the sham-operated group were glycerophospholipids， fatty acyls， steroids and steroid derivatives， of which the most significant difference was glycerophospholipids. At the same time， Erxiantang could call back 65 out of 82 differential metabolites， of which 11 were statistically significant， mainly phosphatidylcholine（PC） and lysophosphatidylcholine（LysoPC） in glycerophospholipids， followed by corticosterone and 11-deoxycortisol in steroids and steroid derivatives. Metabolic pathway analysis showed that the pathways of glycerophospholipid metabolism and steroid hormone biosynthesis in model group were changed， and were recovered after the administration of Erxiantang. ELISA results showed that compared with the sham-operated group， serum levels of cholinephosphate cytidylytransferase（CCT）， secretory phospholipase A2（sPLA2） and lysophosphatidylcholine acyltransferase（LPCAT）， which were the key metabolic enzymes of glycerophospholipid metabolite PC and LysoPC， were significantly decreased in the model group（P<0.05， P<0.01）， and choline phosphotransferase 1（CPT1） levels decreased but the difference was not statistically significant， compared with the model group， the levels of CCT， sPLA2 and CPT1 were significantly increased in Erxiantang group（P<0.01）. In addition， compared with the sham-operated group， the levels of cholesterol（TC）， triglyceride（TG） and low density lipoprotein cholesterol（LDL-C） were significantly increased in the model group（P<0.01）， the high density lipoprotein cholesterol（HDL-C） level was decreased（P<0.05）， compared with the model group， the levels of TC， TG and LDL-C were significantly decreased and the level of HDL-C was significantly increased in Erxiantang group（P<0.01）. ConclusionEndogenous metabolites and related metabolic pathways in ovariectomized rats were altered， and Erxiantang can reverse some of the different metabolites and related pathways， such as regulating glycerophospholipid metabolism by regulating metabolic enzymes CCT， sPLA2 and CPT1 to increase the levels of PC and LysoPC， and then improve the pathological changes such as lipid metabolism disorder in ovariectomized rats.

Structural elucidation and mechanism study for Hofmann-Martius-like rearrangement products in duloxetine hydrochloride under the process condition / 中国药科大学学报

@#Two Hofmann-Martius-like rearrangement products generated in the production of duloxetine hydrochloride were studied. The structures and generation mechanism of the two Hofmann-Martius rearrangement products were analyzed by LC-MS and NMR. The results showed that under the acidic conditions, the naphthol ether bond of duloxetine would break down and the intermediates of naphthol and the alkyl thiophene cation was generated; the two Hofmann-Martius-like rearrangement products were proven to be a pair of isomers produced by nucleophilic substitution between the naphthol intermediate state and the alkyl thiophene cation intermediate state at the ortho or the para position, respectively. The production of two isomers was related to the strong acidic and protic solvent environment. Therefore, in the salting process of duloxetine hydrochloride, the pH value should be controlled in the range of 3-7 and temperature should be maintained below 50 °C, as well as the nonprotic solvent acetone is chosen to avoid generation of the two isomers.

Pharmacokinetic study of small molecule inhibitor SYHA1809 in Beagle dogs / 中国药房

OBJECTIVE To study the pharmacokinetics of small molecule inhibitor SYHA1809 in Beagle dogs. METHODS LC-MS/MS method was adopted. Beagle dogs were randomly divided into single intravenous administration group （3.75 mg/kg）， single low-dose intragastric administration group （3.75 mg/kg）， single medium-dose intragastric administration group （7.5 mg/kg）， single high-dose intragastric administration group （15 mg/kg） and multiple intragastric administration group （7.5 mg/kg， once a day， for 7 consecutive days）， with 6 dogs in each group， half male and half female. The plasma samples of Beagle dogs were collected in each group according to the set time point， and underwent LC-MS/MS quantitative analysis after preprocessing. The pharmacokinetic parameters were calculated by using Phoenix WinNonlin 8.0 software using obtained data. RESULTS After intravenous injection， CL of SYHA1809 in Beagle dogs was （2.70±0.48） mL/（min·kg）， steady-state distribution volume was 0.757 L/kg， and t1/2 was （3.35±1.36） h； after single intragastric administration of low-dose， medium-dose and high-dose of SYHA1809， average tmax was （0.53±0.02） h， and the blood drug concentration increased with the increase of dose； after single intragastric administration of 3.75 mg/kg SYHA1809， the absolute bioavailability was 83.5%； within the dose range of 3.75-15 mg/kg， the increase in cmax and AUC of SYHA1809 was positively correlated with the dose； after intragastric administration of 7.5 mg/kg SYHA1809 for 7 consecutive days， the pharmacokinetic parameters of SYHA1809 were comparable to those of a single intragastric administration of the same dose， with no statistically significant difference （P＞0.05）. CONCLUSIONS SYHA1809 is absorbed rapidly in Beagle dogs， shows the dose-dependent blood concentration， high bioavailability， no obvious accumulation after multiple intragastric administration， and good pharmacokinetic behavior.

Determination of 22 phospholipids in serum by ultra performance liquid chromatography-tandem mass spectrometry / 中华劳动卫生职业病杂志

Objective: To establish ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of 22 phospholipids in serum. Methods: In September 2022, Using synthetic non endogenous phospholipids as internal standard, phospholipids in serum were extracted by methanol-dichloromethane (2∶1, V/V) protein precipitation method. Chromatographic separation was achieved on an ACQUITY UPLC BEH shield RP18 column, and the mobile phase was methanol/water (5∶95, V/V) containing 10 mM ammonium formate and methanol. Detection was performed in multiple reaction monitoring mode with ion mode switching. And the method was applied by analyzing phospholipids in the serum of coal workers' pneumoconiosis patients. Results: The 22 phospholipids showed good linear relationships in their respective concentration ranges and the correlation coefficients were higher than 0.990. The spiked recoveries of the 22 phospholipids were 81.03%-121.63% at the three spiked levels. The intra-assay were less than 14.52%, and the inter-assay were less than 15.00%. Conclusion: The method with the advantages of simplicity, stability and high sensitivity, and it can be used for the analysis of phospholipids in serum.

Rapid determination of acetaminophen in plasma by LC-MS/MS / 中华劳动卫生职业病杂志

Objective: To establish a method for the rapid determination of acetaminophen (APAP) in human plasma by LC-MS/MS. Methods: The plasma samples were extracted by methanol and acetonitrile (1: 1) and purified directly. C(18) column was used for sample separation. The mobile phase were methanol (5 mmol/L ammonium acetate) and water (5 mmol/L ammonium acetate). Samples were analyzed by LC MS/MS with the electrospray ionization multi reaction monitoring (MRM) mode. Results: The calibration curves of APAP was linear in the concentration range of 0~10 mg/L, the correlation coefficient (r) was greater than 0.999 0. The relative standard deviation within and between batches was less than 10%. The recovery rate were 96.81%~101.7%. The detection limit of the method was 0.1 μg/L and the lower limit of quantification was 0.3 μg/L. Conclusion: This method has strong specificity, high sensitivity and reliable determination results. It is suitable for the rapid analysis of clinical plasma samples.

Pharmacokinetic study of HMS-01 in mice / 药学实践杂志

Objective To study the pharmacokinetics of HMS-01 in mice and provide support for subsequent studies. Methods Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to establish a sensitive and specific method for the determination of the concentration of HMS-01 in plasma and other biological samples. The pharmacokinetics of HMS-01 in C57BL/6J mice were studied by the established method. To obtain the basic pharmacokinetic parameters, three doses of HMS-01 were given orally and one dose of HMS-01 was given intravenously. Results The pharmacokinetic results of mice showed that the intestinal absorption of HMS-01 was fast, the oral bioavailability of HMS-01 in mice was moderate (50% to 70%). The exposure levels (AUC and cmax) of HMS-01 in mice increased with the increase of dosage, while the AUC was linearly correlated with the increase of dosage. After intravenous administration of HMS-01, the half-life period in mice was about 1 h which was not long. The plasma clearance rate (CLtotal.p) was 2.8 L/h·kg, which was similar to the hepatic blood flow of mice. The apparent volume of distribution (VSS) was 5 L/kg, which was much larger than the total mouse fluid. There were significant differences in AUC and F (P<0.05), but no significant differences in parameters such as cmax,AUC0−∞,t1/2,CLtot,p,MRT,Vss in male and female mice which were given 30 and 60mg/kg HWS-01 orally. Conclusion The pharmacokinetic process of HMS-01 in mice showed gender differences, and the area under the curve of blood concentration time and bioavailability of female mice were higher than that of male mice. As oral bioavailability was reasonable, further in vivo studies on HMS-01 in mice with heart failure by oral administration could be considered to provide evidence.

Structure identification and content analysis of active components in Xiaoyao pills / 药学学报

Xiaoyao pills are a famous traditional Chinese medicine collected in Welfare Pharmacy, which is a classic prescription for treating liver depression and spleen deficiency. However, its composition is complex. In order to better control the quality of Xiaoyao pills, in this study, HPLC-ion-trap time-of-flight mass spectrometry (LC-IT-TOF/MS) was used to identify the main ingredients of Xiaoyao pills, paeoniflorin, albiflorin, glycyrrhizic acid, saikosaponin A and saikosaponin B2. Then a liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for simultaneous determination and quantification of the main compounds. Fragmentation pathways of five active components were obtained. The method was validated. Five active ingredients in Xiaoyao pills had a good linear relationship, and the values of RSD (%) of repeatability were all less than 5%, the recovery ranges were between 90% and 115%, and the values of RSD (%) of each substance were less than 10% after the sample solution is placed for 24 hours. Three batches of Xiaoyao pills (concentrated pellets) and two batches of Xiaoyao pills (water pellets) were determined, the contents of paeoniflorin in concentrated pills were more than 4.0 mg·g-1, and those in water pills were more than 2.5 mg·g-1, which was accordance with Chinese Pharmacopoeia. However, other compounds behave differently. This method has high sensitivity and reliable measurement results, which provides basis for quality control of Xiaoyao pills and material basis for pharmacology research.

Pharmacokinetic study about compatibility of Eucommia ulmoides and Psoralea corylifolia / 中草药·英文版

OBJECTIVE@#The compatibility of Eucommia ulmoides (Eu) and Psoralea corylifolia (Pc) on the pharmacokinetic (PK) properties in the rat was explored in this study.@*METHODS@#Eu extract, Pc extract and the combined extracts (crude drug ratio was 2:1) was administered by gavage, respectively. Two PK experiments were conducted. In first one, the blood samples were collected via the occuli chorioideae vein to get the PK properties of the components. In second one, the blood samples were simultaneously collected via the internal jugular vein or portal vein at different time points and the concentrations of target ingredients were detected by LC/MS/MS to clear the location where the interaction of Eu and Pc took place in vivo.@*RESULTS@#Eight of 11 ingredients in Eu and Pc extract were determined in rat plasma. The exposure levels of geniposidic acid (GPA), aucubin (AU), geniposide (GP), pinoresinol diglucoside (PDG), psoralen glycosides (PLG) and isopsoralen glycosides (IPLG) were decreased 1/5-2/3 after administration of combined extracts. Comparing to the combined administration, the exposure of GPA and AU in plasma of single Eu administration collected via the portal vein were decreased 1/3-2/3, and the values of AUC0-24h and AUC0-∞ of GP collected from the portal vein or internal jugular vein were double increased. The other components' parameters were not significantly changed.@*CONCLUSION@#In summary, the Pc and Eu combined administration could affect the exposure of the main components of Eu extract in rats due to the changed intestinal absorption. The research on the compatibility of Pc and Eu was helpful to guide the clinical administration of Eu and Pc simultaneously.

Analysis of Forty-Two Psychoactive Substances in a Single Hair by Micro-Segmental Technique / 法医学杂志

OBJECTIVES@#To establish an LC-MS/MS method based on single hair micro-segmental technique, and verify the detection of 42 psychoactive substances in 0.4 mm hair segments.@*METHODS@#Each piece of single hair was cut into 0.4 mm segments and extracted by sonication and the segments were immersed in dithiothreitol-containing extraction medium. Mobile phase A was the aqueous solution containing 20 mmol/L ammonium acetate, 0.1% formic acid, and 5% acetonitrile. Mobile phase B was acetonitrile. An electrospray ionization source in positive ion mode was used for data acquisition in multiple reaction monitoring (MRM) mode.@*RESULTS@#The 42 psychoactive substances in hair had a good linear relationship within their respective linear ranges (r>0.99), the limits of detection were 0.2-10 pg/mm, the limits of quantification were 0.5-20 pg/mm, the intra-day and inter-day precisions were 1.5%-12.7%, the intra-day and inter-day accuracies were 86.5%-109.2%, the recovery rates were 68.1%-98.2%, and the matrix effects were 71.3%-111.7%. The method was applied to hair samples collected from one volunteer at 28 d after a single dose of zolpidem, with zolpidem detected in 5 hairs was 1.08-1.60 cm near the root tip, and the concentration range was 0.62-20.5 pg/mm.@*CONCLUSIONS@#The micro-segmental technique of single hair analysis can be applied to the investigation of drug-facilitated sexual assault cases.