ABSTRACT
@#Cinnabaris(α-HgS) is a mineral traditional Chinese material medica, as a tranquilizer and sedative, which is widely used in combination with herbs for the treatment of children high fever and convulsion.However, a large amount of mercury in Cinnabaris poses a potential risk to the immature central nervous system of children and probably causes severe memory disorders.Inthisstudy,three groups of juvenile rats were given low, medium, and high doses of Cinnabaris by oral gavage once a day for 14 continuous weeks, respectively.The blood mercury concentrations of the rats at different growth phases were monitored by atomic fluorescence spectrometry.The brain structural and functional changes related to the memory functions were investigated through HE staining and Morris water-maze test. Correlation analysis was conducted to clarify the dose- mercury exposure-toxic effect relationship of Cinnabaris and memory disorders.It was found thatthe blood mercury levels increased in both time- and dose-dependent manner.After the 14-week continuous administration of Cinnabaris, the pathological lesions in hippocampal neurons of rats in the high dose group were observed including pyknosis and disordered cell arrangement.In the Morris water-maze test, compared with the control group, rats in the high dose group exhibited the significantly prolonged latency to find the platform and the target quadrant, and the time spent in the target quadrant was obviously shortened. Thus, the significant correlations were established between Cinnabaris dose and mercury exposure,mercury exposure and memory disorders, respectively. In conclusion, the long-term and overdose administration of Cinnabaris in juvenile rats can increase the in-vivo mercury level, destroy the normal hippocampal morphological structure, and lead to memory disorders. This study provided scientific references for the potential mercury poisoning risks pharmacovigilance of Cinnabaris-containing paediatric formulations.
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@#The UPLC fingerprint of colistimethate sodium was established for the study of quality consistency.The chromatographic column was Acquity UPLC? Peptide CSH C18 (2.1 mm × 150 mm, 1.7 μm).The mobile phase A was phosphate buffer-acetonitrile (19∶1), and the mobile phase B was phosphate buffer-acetonitrile (1∶1).The mobile phase was in gradient elution at a flow rate of 0.3 mL/min.The column temperature was set at 30 °C and the detection wavelength was 210 nm.The similarity of the fingerprints was analyzed with the Similarity Evaluation System for Chromatographic Fingerprint of Tradition Chinese Medicine (Version 2012) in combination with content determination of multiple index components to evaluate the quality consistency of imported and domestic bulk drugs.The result showed that both the original and generic bulk drugs met the specified limit requirements in the European Pharmacopoeia standards, and that their UPLC fingerprints were highly similar, indicating that the quality of the two substances was consistent.Establishing a fingerprint for similarity evaluation and combining it with the results of indicator component content determination as a comprehensive evaluation method for the study of drug quality consistency of complex components has the characteristics of fast, accurate, and comprehensive, which is helpful for drug quality evaluation and provides ideas for the evaluation of antibiotic quality consistency of complex components.
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@#The in vitro release is an important index to evaluate the quality of liposome formulation.Currently, there is no evaluation method for the in vitro release of liposome in pharmacopoeia of various countries, which leads to the lack of unified standard and safety guarantee for the quality evaluation of liposome formulation.Taking the self-made paclitaxel derivative liposomes as an example, the paddle membrane binding method established by optimizing external release conditions was used to simulate the complete release of paclitaxel derivative drugs in 12 hours under physiological conditions.The results showed that using 0.5% SDS-HEPES as the release medium and a dialysis bag with a molecular weight cutoff of 1 000 kD to release the liposome solution met the requirements and had discrimination ability, providing a reference for the development of drug-loaded liposomes release methods in vitro.
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@#At present , methamphetamine has become a major hidden danger in global public health safety. In order to judge methamphetamine addicts and methamphetamine abstainers more scientifically and reliably, this study analyzed the endogenous metabolites in plasma, serum and urine of methamphetamine addicts, methamphetamine abstainers and healthy volunteers by highly sensitive high-throughput liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) analytical instrument. The obtained metabolomic data were processed by univariate analysis (t-test) and multivariate analysis (PLS-DA and OPLS-DA) and eligible potential biomarkers were then screened.The identified biomarkers set enrichment analysis to find the connection between metabolites and metabolic pathways.Multivariate statistical results showed that methamphetamine acute group, recovery group and healthy group were clearly separated.3, 18 and 6 regulated metabolites were identified in serum, plasma and urine, respectively, suggesting that lipid metabolism was abnormal in methamphetamine acute group, and that fatty acid metabolism, sulfate/sulfite metabolism and sex hormone metabolism were abnormal in methamphetamine recovery group.The selected potential biomarkers in this study provide the possibility for scientific judgment of the clinical stage of methamphetamine detoxification.
ABSTRACT
@#The waste water-based epidemiology is an important technique to fight against drug abuse by analyzing the concentration of illicit drugs in urban sewage, which can monitor the abuse of drugs.An SPE-UPLC-MS/MS method was developed for the analysis of 12 common drugs and their metabolites involving amphetamine and morphine.It was shown that the best result was achieved when hydrochloric acid/ acetonitrile (5∶95) was added to acidify the sample during the concentration process, guaranteeing the anti-across contamination of the analysis of organic nitrogen basic trace components, and improve the stability, specificity, and accuracy of the method.The optimized method meets the analytical requirements of complex sewage samples, and has been successfully applied to the assessment of urban drug abuse through sewage analysis.
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@#This study aimed to identify the related substances of lorazepam tablets by liquid chromatography mass spectrometry (LC-MS). To separate the related substances of lorazepam tablets, gradient elution was performed using acetonitrile and 0.1% acetic acid -20 mmol/L of ammonium acetate as mobile phase on Inert Sustain C18 (250 mm × 4.6 mm, 5 μm).The accurate mass and elemental composition of the parent ions and their product ions of related substances were determined by electrospray-ionization quadrupole time-of-flight high resolution mass spectrometry (ESI-Q-TOF/MS).The structures of the related substances were identified by spectral analysis. Under the established analytical condition, lorazepam and its related substances were adequately separated, and 22 major related substances with content greater than 0.1% were detected and identified by hyphenated techniques in lorazepam tablets and their stressed samples.Among them, 5 were the impurities listed in the USP or EP, and the others were unknown related substances identified for the first time in this paper.The LC-MS technique can effectively separate and identify the related substances of lorazepam tablets, which provides some reference for quality control.
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@#To establish a method for the determination of formaldehyde and glyoxal simultaneously in varenicline tartrate active pharmaceutical ingredient (API) and its intermediate, formaldehyde and glyoxal were derivatized by 2, 4-dinitrophenylhydrazine (2,4-DNPH) to improve the HPLC retention and UV detection sensitivity. Separation was performed on a C8 (150 mm × 4.6 mm, 5 μm) column by linear gradient elution using acetonitrile and water as the mobile phase; the detective wavelength was set at 380 nm.Formaldehyde and glyoxal were quantitatively determined by an external reference method.Linear calibration was established for both formaldehyde and glyoxal in the range from 0.094 to 1.88 μg/mL.The detection and the quantification limits were 0.047 μg/mL (19 μg/g) and 0.094 μg/mL (38 μg/g), respectively.The recoveries were (95.0±1.1)% and (99.4 ± 2.6)% for formaldehyde and glyoxal, respectively.This method has been fully validated to be applicable to quantitative analysis of trace amount of formaldehyde and glyoxal in varenicline tartrate API and its intermediate.Test results demonstrated that the contents of both formaldehyde and glyoxal met the permitted daily exposure (PDE) limits for the finished products of varenicline tartrate API as well as its intermediate, though the glyoxal contents in the crude intermediates were likely to exceed the limit.The established method is valuable for the manufacturing process and quality control of varenicline tartrate.
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@#This study aimed to identify the related substances of midazolam hydrochloride by liquid chromatography-mass spectrometry (LC-MS). To separate the related substances of midazolam hydrochloride, gradient elution was performed using acetonitrile and 25 mmol/L of ammonium acetate (pH was adjusted to 5.5 with acetic acid) as mobile phase on Thermo BDS Hypersil C18 column (100 mm × 4.6 mm, 2.4 μm). The accurate mass and elemental composition of the parent ions and their product ions of related substances were determined by electrospray-ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF/MS). The structures of the related substances were identified by spectral analysis and process synthesis, and some of them were further confirmed by reference substances. Under the established HPLC condition, midazolam hydrochloride and its related substances were adequately separated, and 22 major related substances were detected and identified by hyphenated techniques in midazolam hydrochloride and its stressed samples, of which 8 were recorded as impurities in the United States Pharmacopeia. The LC-MS techniques can effectively separate and identify the related substances of midazolam hydrochloride and provide reference for the establishment of storage condition, optimization of synthetic processes and quality control.
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@#To identify the amino alcohols related substances in atenolol. The related substances in atenolol and its stressed samples were pre-column derivatized with 9-fluorenylmethyl chloroformate. The separation was carried out on an Inertsil ODS-SP column (250 mm×4.6 mm, 5 μm) with linear gradient elution by methanol-ammonium acetate solution as the mobile phases. Electrospray positive ionization high-resolution Q-TOF/MS was used for the determination of the accurate masses and elemental compositions of the parent and fragment ions of these related substance derivatives. The structures of all the detected substances were identified by spectral analysis and synthetic analysis. Under the established conditions, atenolol and its amino alcohols related substances were well separated, and a total of 14 impurity peaks were detected and identified, of which 12 were related substances and 2 were derivatization reaction by-products. The established LC-MS method provides a reference for the examination and quality control of atenolol related substances.
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@#To identify the related substances of cyclosporin A by LC-MS techniques, the separation of cyclosporin A and its related substances was carried out on a Hypersil BDS C18(100 mm×4. 6 mm, 2. 4 μm)column with isocratic elution by a mixture of acetonitrile-water-MTBE and formic acid(430 ∶520 ∶50 ∶1)as the mobile phase. Cyclosporin A and its 29 related substances(9 process related and 20 degradants)were well separated under the established conditions. Among them, 13 were listed in EP and the rest 16 were unknown products having not been reported before. Electrospray positive ionization high resolution TOF/MS was used for the determination of the accurate mass and elemental composition of parent ions of all the components, and triple quadrupoles tandem mass was employed for the product mass spectra determination. Thence, the structures of all the 29 detected substances were successfully characterized through spectra elucidation and the fragmentation pathways analysis. The established LC-MS method was successfully employed for the separation and identification of the related substances of cyclosporin A and it is useful for its fermentation processes and quality control.
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@#A novel method was developed for the content assay and related substances determination of neomycin sulfate by high performance liquid chromatography combined with pulsed amperometric detection(HPLC-PAD). The HPLC was performed on Thermo AcclaimTMAmG C18(4. 6 mm×150 mm, 3 μm). The mobile phase consisted of aqueous solution with 2% trifluoroacetic acid containing 0. 01% pentafluoropropionic acid and 0. 6%NaOH. The pulsed amperometric detector was operated with aquadruple-potential waveform for the detection. Neomycin B, Neomycin C and thirteen related substances were adequately separated by the established HPLC conditions. The limits of detection(LOD)and quantification(LOQ)of neomycin B and neomycin C were both 1. 75 ng and 3. 5 ng, respectively. Good linearities of neomycin B and neomycin C were found in their respective ranges which their correlation coefficients were greater than 0. 998 5. The established method is characterized by high specificity, sensitivity and wide range of linearity which has a good application prospect and provides the basis for improving the standard and quality control of neomycin sulfate.
ABSTRACT
To identify the related substances of fusidic acid by LC-MS,separation was performed on an Agilent Extend-C18column(150 mm ×4. 6 mm,3. 5 μm)by linear gradient elution with a mobile phase consisting of methanol,acetonitrile and formic acid. Electrospray positive ionization high resolution TOF/MS was used for the determination of the accurate mass and elemental composition of parent ions of the related substances;triple qua-drupole tandem mass was employed for the mass spectra determination of the product. The structures of the related substances were then figured out through the elucidation of the fragment ions. Fusidic acid and its related sub-stances were adequately separated under the established HPLC conditions. Nineteen major related substances of fusidic acid were detected and speculated by hyphenated techniques. Eleven of them were recorded in European Pharmacopoeia,while the others have not been previously reported. The established LC-MS method is effective for the separation and identification of the related substances of fusidic acid and the results are useful for its storage conditions and quality assurance.
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Simple and sensitive methods were developed for the determination of indapamide, perindopril and its active metabolite perindoprilat in human plasma or whole blood by hyphenated ultra-performance li-quid chromatography-mass spectrometry (UPLC-MS/MS). Indapamide-d3, perindopril-d4 and perindo-prilat-d4 were used as the internal standards. The separation was performed on a Thermo BDS Hypersil C18column (4.6 mm × 100 mm, 2.4 μm) for indapamide and perindopril simultaneously following a protein precipitation pretreatment of the biosamples. The separation of perindoprilat was achieved in-dependently on a phenomenex PFP column (4.6 mm × 150 mm, 5 μm). All the analytes were quantitated with positive electrospray ionization and multiple reactions monitoring mode. The assay exhibited a linear range of 1–250 ng/mL for indapamide, 0.4–100 ng/mL for perindopril and 0.2–20 ng/mL for peri-ndoprilat. The methods were fully validated to meet the requirements for bioassay in accuracy, precision, recovery, reproducibility, stabilities and matrix effects, and successfully applied to the pharmacokinetic study of perindopril tert-butylamine/indapamide compound tablets in Chinese healthy volunteers and the comparative pharmacokinetic study between plasma and whole blood.
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@#The study aims to investigate different pharmacokinetic profilesof anthraquinones after oral administration of Rhei Radix et Rhizoma and Niuhuang Jiedu Tablets(NHJDT)in rats, respectively. Rats were administrated with 96 mg/kg of Rhei Radix et Rhizoma(1. 83 mg/kg of total anthraquinone, equivalent to 0. 28 mg/kg of rhein, 0. 30 mg/kg of emodin, 0. 81 mg/kg of chrysophanol, 0. 23 mg/kg of aloe-emodin and 0. 20 mg/kg of physcion)or 250 mg/kg of NHJDT(equal dose of total anthraquinone as Rhei Radix et Rhizoma, equivalent to 0. 33 mg/kg of rhein, 0. 38 mg/kg of emodin, 0. 71 mg/kg of chrysophanol, 0. 24 mg/kg of aloe-emodin and 0. 17 mg/kg of physcion), respectively. Followed by protein precipitation with methanol, the anthraquinones in plasma samples were determined by LC-MS/MS. The pharmacokinetic parameters were calculated by WinNonlin 7. 0. The cmaxof rhein were(121±103)and(474±251)μg/L, and the AUC0-twere(275±176)and(406±194)μg ·h/L for Rhei Radix et Rhizoma and NHJDT, respectively. The cmaxof chrysophanol isomer were(2 325±1 390)and(3 580±2 169)μg/L, and the AUC0-twere(8 170±2 661)and(8 856±4 023)μg ·h/L, respectively. Emodin in very low levels was only detected in rat plasma samples after oral gavage of NHJDT. The cmax, AUC and t1/2 of rhein, as well as Vd and CL of chrysophanol isomer were observed with a much increased degree in comparison with Rhei Radix et Rhizoma counterparts. However, much shorter tmaxwas found in NHJDT group. Therefore, NHJDT with co-existing components enhanced the absorption and influenced the pharmacokinetic behaviors of active ingredients in Rhei Radix et Rhizoma.
ABSTRACT
To identify the related substances in pioglitazone hydrochloride by hyphenated LC-MS techniques,an Ultimate XB-C18 (250 mm × 4.6 mm,5 μm) column was used for separation of the related substances with methanol and 0.1％ ammonium acetate buffer as the mobile phases in gradient elution.Electrospray positive ionization high resolution TOF/MS was used for the determination of the accurate mass and elemental composition of parent [M + H] + ions of the related substances,and triple quadrupole tandem mass spectrometry was employed for the product mass spectra determination.Eleven major related substances were detected and identified to be one synthesis intermediate,six by-products and four degradation products,by using LC-MS determination,spectra elucidation,and further synthetic process and stress degradation mechanisms analysis.The results are useful for pioglitazone hydrochloride manufacturing processes optimization and quality control.
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A sensitive and selective method was developed for the separation and characterization of related substances (RSs) in EVT-401 by hyphenated LC–MS techniques. Complete separation of the RSs was achieved with an Inertsil ODS-SP column (250 mm×4.6 mm, 5 μm) by linear gradient elution using a mobile phase consisting of 0.2% formic acid solution, methanol and acetonitrile. EVT-401 was found to be susceptible to acid, alkaline and oxidative stresses, while relatively stable under photolytic and thermal dry stress conditions. Fourteen RSs including six process-related substances and eight degradation products were detected and identified in EVT-401 with positive ESI high-resolution TOF-MS analysis of their parent ions and the corresponding product mass spectra elucidation, and some of them were further verified by chemical synthesis and NMR spectroscopy. The specific LC–MS method developed for separation, identification and characterization of RSs is valuable for EVT-401 manufacturing process optimization and quality control.
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An LC-TOF /MS and LC-MS /MS method was established for the identification the related substances in ambrisentan.HPLC separation was carried out on an XBridge C18 column(4.6 mm ×150 mm,3.5 μm)with linear gradient elution using a mobile phase consists of acetonitrile,water and 0.15% formic acid.The structures of the related substances were identified by electrospray positive ESI high resolution TOF /MS and MS /MS spec-tra,and verified further through reference substances.Ambrisentan and its related substances can be separated under the established HPLC conditions.Ten related substances were detected and identified.The established method is useful for the identification of related substances in ambrisentan.The results obtained are valuable for its manufacturing process optimization and quality control.
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@#The purpose of this research was to explore the differences of the components of Radix Polygalae in herbal pair of Radix Polygalae and Rhizoma Acori Tatarinowii. An HPLC-Q-TOF-MS/MS method and an HPLC-UV method were established for the identification and determination of the components of Radix Polygalae, respectively. HPLC separation was carried out on a C18 column(250 mm×4. 6 mm, 5 μm)with linear gradient elution using a mobile phase consisting of acetonitrile and 0. 1% formic acid aqueous solution. Mass spectrometry with ESI source was performed in the positive ion mode to scan MS data including total ion chromatograms and ion peaks of Radix Polygalae. Eight components including 3, 4, 5-trimethoxycinnamic acid, p-methoxycinnamic acid, tenuifolin, sibiricose A5, polygalaxanthone III, tenuifoliside B, 3, 6′-disinapoly sucrose, and tenuifoliside A were identified according to the reference substance retention time, MS data and literatures. There was no significant variation found in the contents of eight chemical constituents of Radix Polygalae. The qualification and quantitation study of the components in herbal pair of Radix Polygalae and Rhizoma Acori Tatarinowii provide the methodological basis for compatibility mechanism exploration in vivo.
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A sensitive and selective liquid chromatography–tandem mass spectrometric (LC ? MS/MS) method was established to determine 2-oxo-clopidogrel, a crucial intermediate metabolite in human plasma. A chromatographic separation was performed on a Sapphire C18 column following a liquid–liquid extraction sample preparation with methyl t-butyl ether. Detection was carried out on a triple quadrupole mass spectrometer operated in multiple reaction monitoring (MRM) with an electrospray ionization (ESI) mode. The method was validated in terms of specificity, accuracy, precision and limit of quantification. The calibration curves ranged from 0.50 to 50.0 ng/mL with good linearity. The stability was fully validated with addition of 1,4-dithio-DL-threitol (DTT) into the plasma sample prior to and in the preparation procedure. The validated method was proved to be suitable for use in pharmacokinetic study after single oral administration of 75 mg clopidogrel tablets in human subjects, which could make contribution to intensive study of the clinical drug–drug interactions of clopidogrel and individual treatment.
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To study the related substances in nicergoline, electrospray positive ionization high resolution TOF/MS was used for the determination of the accurate mass and elemental composition of the related substances. Triple quadrupoles tandem MS/MS was employed for the determination of the fragmentations of the parent ions. 16 related substances were detected and identified to be eight synthetic by-products and eight degradation products, by using impurity references matching, product mass spectra fragmentations elucidation, and verified further according to synthetic processes and stress testing results. The results obtained are valuable for nicergoline manufacturing process control and quality assurance.