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1.
A high‐performance liquid chromatography/positive ion electrospray tandem mass spectrometry method for the simultaneous quantification of lamivudine, stavudine and nevirapine was developed and validated in dried blood spot (DBS) cards. The analytes were separated using an isocratic mobile phase on a reverse phase column and analyzed by MS/MS in the MRM mode using the respective [M + H]+ ions, m/z 230–112 for lamivudine, m/z 225–127 for stavudine, m/z 267–226 for nevirapine, m/z 383–337 for zidovudine (IS). The lower limit of quantification was 1 ng/mL for both lamivudine and stavudine and 10 ng/mL for nevirapine. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The method was successfully applied to quantify them in a rat pharmacokinetic study in whole blood, plasma and DBS cards after a single oral co‐administration at the dose of 10, 2 and 13 mg/kg for lamivudine, stavudine and nevirapine, respectively, to male Wistar rats. Following oral administration the pharmacokinetic results in all the matrices are in close agreement. Thus accomplishment of this method would facilitate the ease of collection of clinical samples on DBS cards for lamivudine, stavudine and nevirapine during human clinical trials and therapeutic drug monitoring. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

2.
Dried blood spots (DBS), collected as part of the newborn screening program (NSP) in the USA, is a valuable resource for studies on environmental chemical exposures and associated health outcomes in newborns. Nevertheless, determination of concentrations of environmental chemicals in DBS requires assays with great sensitivity, as the typical volume of blood available on a DBS with 16-mm diameter disc is approximately 50 μL. In this study, we developed a liquid–liquid extraction and high-performance liquid chromatography/tandem mass spectrometry method for the detection of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and bisphenol A (BPA) in DBS. The method was validated for accuracy, precision, and sensitivity, by spiking of target chemicals at different levels on Whatman 903 filter cards, which is used in the collection of DBS by the NSP. Contamination arising from collection, storage, and handling of DBS is an important issue to be considered in the analysis of trace levels of environmental chemicals in DBS. For the evaluation of the magnitude of background contamination, field blanks were prepared from unspotted portions of DBS filter cards collected by the NSP. The method was applied for the measurement of PFOS, PFOA, and BPA in 192 DBS specimens provided by NSP of New York State. PFOS and PFOA were detected in 100 % of the specimens analyzed. The concentrations of PFOS and PFOA measured in DBS were similar to those reported earlier in the whole blood samples of newborns. BPA was also found in 86 % of the specimens at concentrations ranging from 0.2 to 36 ng/mL (excluding two outliers). Further studies are needed to evaluate the sources of BPA exposures and health outcomes in newborns.  相似文献   

3.
Larotrectinib is a first-generation tropomyosin kinase inhibitor, approved for the treatment of solid tumors. In this paper, we present a validated dried blood spot (DBS) method for the quantitation of larotrectinib from mouse blood using HPLC–MS/MS, which was operated under multiple reaction monitoring mode. To the DBS disc cards, acidified methanol enriched with internal standard (IS; enasidenib) was added and extracted using tert-butyl methyl ether as an extraction solvent with sonication. Chromatographic separation of larotrectinib and the IS was achieved on an Atlantis dC18 column using 10 mm ammonium formate–acetonitrile (30:70, v/v) delivered at a flow-rate of 0.80 ml/min. Under these optimized conditions, the retention times of larotrectinib and the IS were ~0.93 and 1.37 min, respectively. The total run time was 2.50 min. Larotrectinib and the IS were analyzed using positive ion scan mode and parent–daughter mass to charge ion (m/z) transitions of 429.1 → 342.1 and 474.1 → 267.1, respectively, were used for the quantitation. The calibration range was 1.06–5,080 ng/ml. No matrix effect or carryover was observed. Hematocrit did not influence DBS larotrectinib concentrations. All of the validation parameters met the acceptance criteria. The applicability of the validated method was shown in a mouse pharmacokinetic study.  相似文献   

4.
Thiorphan, the active metabolite of racecadotril, can undergo oxidation in biological matrices such as blood and plasma. In bioanalysis, a general approach for the stabilization of such a molecule is to derivatize the thiol group to a more stable thioether, often requiring complex handling procedures at the clinical site. In this research, the concept of dried blood spot (DBS) on‐card derivatization was evaluated to stabilize thiorphan. DBS cards were in‐house pre‐treated with 2‐bromo‐3′‐methoxyacetophenone and left to dry prior to blood spotting. Thiorphan was shown to be effectively derivatized to thiorphan–methoxyacetophenone once applied on the in‐house pre‐treated cards. Thiorphan–methoxyacetophenone was extracted by soaking a 6 mm DBS punch in methanol containing the internal standard (thiorphan–methoxyacetophenone‐D5). Chromatographic separation was achieved on a Waters XBridge C18 column with a gradient elution of 5 m m NH4HCO3 and methanol in 2.5 min and detection by ESI(+)/MS/MS. A linear (weighted 1/x2) relationship was obtained over a concentration range of 5.00–600.00 ng/mL. The assay met regulatory guidelines acceptance criteria for sensitivity, selectivity, precision and accuracy, matrix effect, recovery, dilution integrity and multiple stability evaluations. The DBS on‐card derivatization has shown to be an easy and reliable alternative form of sample collection for the quantification of thiorphan. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

5.
Kaletra® (Abott Laboratories) is a co-formulated medication used in the treatment of HIV-1-infected children, and it contains the two antiretroviral protease inhibitor drugs lopinavir and ritonavir. We validated two new ultrafast and high-throughput mass spectrometric assays to be used for therapeutic drug monitoring of lopinavir and ritonavir concentrations in whole blood and in plasma from HIV-1-infected children. Whole blood was blotted onto dried blood spot (DBS) collecting cards, and plasma was collected simultaneously. DBS collecting cards were extracted by an acetonitrile/water mixture while plasma samples were deproteinized with acetone. Drug concentrations were determined by matrix-assisted laser desorption/ionization-triple quadrupole tandem mass spectrometry (MALDI-QqQ-MS/MS). The application of DBS made it possible to measure lopinavir and ritonavir in whole blood in therapeutically relevant concentrations. The MALDI-QqQ-MS/MS plasma assay was successfully cross-validated with a commonly used high-performance liquid chromatography (HPLC)–ultraviolet (UV) assay for the therapeutic drug monitoring (TDM) of HIV-1-infected patients, and it showed comparable performance characteristics. Observed DBS concentrations showed as well, a good correlation between plasma concentrations obtained by MALDI-QqQ-MS/MS and those obtained by the HPLC-UV assay. Application of DBS for TDM proved to be a good alternative to the normally used plasma screening. Moreover, collection of DBS requires small amounts of whole blood which can be easily performed especially in (very) young children where collection of large whole blood amounts is often not possible. DBS is perfectly suited for TDM of HIV-1-infected children; but nevertheless, DBS can also easily be applied for TDM of patients in areas with limited or no laboratory facilities.  相似文献   

6.
There is significant evidence that athletes are using recombinant human growth hormone (rhGH) to enhance performance, and its use is banned by the World Anti-Doping Agency and professional sports leagues. Insulin-like growth factor-1 (IGF-1) is the primary mediator of growth hormone action and is used as a biomarker for the detection of rhGH abuse. The current biomarker-based method requires collection and expedited shipment of venous blood which is costly and may decrease the number of tests performed. Measurement of GH biomarkers in dried blood spots (DBS) would considerably simplify sample collection and shipping methods to allow testing of a greater number of samples regardless of location. A method was developed to quantify intact IGF-1 protein in DBS by liquid chromatography–tandem mass spectrometry. A step-wise acid–acetonitrile extraction was optimized to achieve a sensitive assay with a lower limit of quantification of 50 ng/mL. IGF-1 remained stable at room temperature for up to 8 days, which would allow shipment of DBS cards at ambient temperature. In a comparison between plasma concentrations of IGF-1 and concentrations measured from venous and finger prick DBS, there was good correlation and agreement, r 2 of 0.8551 and accuracy of 86–113 % for venous DBS and r 2 of 0.9586 and accuracy of 89–122 % for finger prick DBS. The method is intended for use as a rapid screening method for IGF-1 to be used in the biomarker method of rhGH abuse detection.  相似文献   

7.
The use of blood spot collection cards is a simple way to obtain specimens for therapeutic drug monitoring, assessing adherence to medications and preventing toxicity in a clinical setting. A high‐throughput liquid chromatography–electrospray ionization mass spectrometric (LC‐ESI‐MS) method for determination of rifaximin on dried blood spots (DBS) was developed and validated. It involves solvent extraction of a punch of DBS followed by reversed‐phase LC on a monolithic column consisting of a silica rod with bimodal pore structure and detection by ESI‐MS. Rifampicin was used as an internal standard (IS). The run time was within 5.0 min with a very low back‐pressure at a flow rate of 0.5 mL/min. The assay was linear from 0.1 to 10 ng/mL. The mean recovery was 98.42%. The developed method is very simple, rapid and useful for clinical applications. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

8.
Dried blood spot (DBS) sampling has gained considerable interest as a microsampling technique to support drug discovery and development owing to its enormous ethical and practical benefits. Quantitative determinations of drugs and/or their metabolites collected in DBS matrix in its current format, however, have encountered technical challenges and regulatory uncertainty. The challenges of DBS bioanalysis are largely ascribed to the way how samples are collected and analyzed. Currently, an uncontrolled amount of a blood sample, e.g. 20 µl, is collected per time point per sample and spotted onto cellulose paper. Quantitation is based on removal of a fixed area of the DBS sample, resulting in sample waste, a need for mechanical punching and concomitant potential punching carryover, uncertainty in recovery assessment and the adverse impact of hematocrit on accurate quantitation. Here, we describe the concept and applications of a novel concept, namely perforated dried blood spot (PDBS), for accurate microsampling that addresses previous challenges. Advantages of PDBS are enumerated and compared with conventional DBS in the context of microsampling and liquid chromatography tandem mass spectrometry bioanalysis. Two approaches for accurate microsampling of a small volume of blood (5 µl) are proposed and demonstrated, i.e. Microsafe® pipettes and the Drummond incremental pipette. Two online sample enrichment techniques to enhance liquid chromatography tandem mass spectrometry sensitivity for microsampling bioanalysis are discussed. The PDBS concept was successfully applied for accurate sample collection (5 µl) in a toxicokinetic study in rats given a single oral gavage dose of acetaminophen. Perspectives on bioanalytical method validation for regulated DBS/PDBS microsampling are also presented. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

9.
A rapid and highly sensitive assay method has been developed and validated for the estimation of bicalutamide (BCL) on mouse dried blood spots (DBS) using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the negative‐ion mode. The assay procedure involves a simple liquid extraction of BCL and tolbutamide (internal standard, IS) from mouse blood DBS cards using tert‐butyl methyl ether. Chromatographic separation was achieved with 5 mm ammonium acetate (pH 6.5)–acetonitrile (35:65, v/v) at a flow rate of 0.60 mL/min on an Atlantis dC18 column with a total run time 3.0 min. The MS/MS ion transitions monitored were 428.80 → 254.70 for BCL and 269.00 → 169.60 for IS. Method validation was performed as per regulatory guidelines. A linear response function was observed from 0.92 to 1911 ng/mL for BCL in mouse blood. The intra‐ and inter‐day precisions were in the ranges of 1.86–12.5 and 3.19–10.8%, respectively. This novel DBS method has been applied to a pharmacokinetic study in mice. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

10.
A simple, sensitive and rapid assay method has been developed and validated as per regulatory guidelines for the estimation of enasidenib on mouse dried blood spots (DBS) using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive‐ion mode. The method employs liquid extraction of enasidenib from DBS disks of mouse whole blood followed by chromatographic separation using 0.2% formic acid–acetonitrile (25:75, v/v) at a flow rate of 1.0 mL/min on an Atlantis dC18 column with a total run time of 2.0 min. The MS/MS ion transitions monitored were m/z 474.0 → 267.1 for enasidenib and m/z 309.2 → 251.3 for the internal standard (warfarin). The assay was linear in the range of 1.01 – 3044 ng/mL. The within‐run and between‐run precisions were in the range of 3.18 – 9.06 and 4.66 – 8.69%, respectively. Stability studies showed that enasidenib was stable on DBS cards for 1 month. This novel method has been applied to analyze the DBS samples of enasidenib obtained from a pharmacokinetic study in mice.  相似文献   

11.
A method for pharmacokinetic studies using cassette dosing associated with serial bleeding in mice is described. PK profiles of four soluble epoxide hydrolase inhibitors were determined following oral, subcutaneous or intraperitoneal administration individually or in cassette dosing. Parent analyses were performed on only 5 μL of whole blood from serial bleeds (up to 10 per animal), by LC/MS/MS. An accuracy (88-100%) and precision (<10% RSD) were observed, leading to reliable datum points for PK calculation. PK profiles, Tmax, Cmax and half-life values after cassette dosing were similar to the individual PK results. This method dramatically increases speed of data collection while dramatically reducing cost and animal usage. The results presented here clearly indicate that this proposed method could be applicable to high-throughput PK studies.  相似文献   

12.
The present study was undertaken to investigate the pharmacokinetics of isoliquiritigenin (isoLQ) as determined by the automated dosing/blood sampling (ABS) and traditional manual blood sampling techniques in awake and freely moving mice using combined liquid chromatography tandem mass spectrometry. Pharmacokinetic comparison was conducted by allocating mice into two groups; an ABS group (intravenous study and oral studies, n = 5 each) and a manual group (intravenous and oral studies; n = 5 each). Significant differences in pharmacokinetic parameters (area under the curve and clearances) were observed between ABS and manual groups. This could be mainly due to the blood sampling site difference (via heart puncture in traditional manual group and via carotid artery in ABS groups). The low F of isoLQ could be mainly due to a considerable gastrointestinal and/or hepatic first‐pass effect and not to incomplete absorption. The driving force for distribution and elimination of drugs is its concentration in the arterial blood. Therefore, the ABS method was found to be a useful drug development tool for accelerating the process of preclinical in vivo studies and for obtaining reliable and accurate pharmacokinetic parameters in mice. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

13.
A simple, selective and reliable LC‐MS/MS method was validated for simultaneous quantitation of darolutamide diastereomers in 50 μL mouse plasma using warfarin as an internal standard (IS) as per regulatory guidelines. Plasma samples were extracted by liquid–liquid extraction and the chromatographic separation was achieved on a Chiralpak IA column with an isocratic mobile phase 5 mm ammonium acetate–absolute alcohol (20:80, v/v) at a flow rate of 1.0 mL/min. Detection and quantitation was done in multiple reaction monitoring mode following the transitions m/z 397 → 202 and 307 → 250 for darolutamide diastereomers and the IS, respectively, in the negative ionization mode. The linearity range was 100–2400 ng/mL for each diastereomer. The intra‐ and inter‐day precisions were in the ranges of 1.78–4.20 and 4.34–14.6, and 3.63–4.74 and 4.78–5.15 for diastereomer‐1 and diastereomer‐2, respectively. Both diastereomers were found to be stable under different stability conditions. The validated method was applied to a pharmacokinetic study in mice. Following oral administration of darolutamide at 10 mg/kg, maximum concentration in plasma was 4189 and 726 ng/mL for diastereomer‐1 and diastereomer‐2, respectively. The terminal half‐life was found to be ~0.50 h for both the diastereomers. The AUC(0–t) was found to be 18,961 ng*h/mL for diastereomer‐1 and 1340 ng*h/mL diastereomer‐2.  相似文献   

14.
An approach has been developed for the quantitative determination of concentrations of centchroman ( I), a nonsteroidal once‐a‐week oral contraceptive, and its major metabolite (7‐desmethyl centchroman, II) using dried blood spots (DBS) on paper, rather than conventional plasma samples. The assay employed simple solvent extraction of the DBS sample circle (6 mm) requiring small blood volumes (30 μL) followed by reversed‐phase HPLC separation, combined with multiple reaction monitoring mass spectrometric detection. The calibration plot in matrix using d ‐trans‐hydroxy chroman as internal standard (IS) was linear (r2 = 0.998) over ranges of 1.5–240 and 4.5–720 ng/mL for I and II, respectively. The recoveries of both I and II were always >60% with quantification limits (signal‐to‐noise ratio = 10) of 1.5 and 4.5 ng/mL for I and II, respectively. The intra‐day and inter‐day precision (%RSD) and accuracy (%bias) variations in blood spots for both I and II were better than 13%. Moreover, both I and II were stable in DBS for at least 3 months when stored at room temperature. The developed method was successfully applied to the pharmacokinetic interaction study after oral administration of centchroman with and without co‐administration of carbamazepine in female Sprague–Dawley rats using serial sampling and results were comparable with the plasma concentrations reported earlier. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

15.
Two different internal standard dried blood spot (DBS) pre-impregnation procedures (prior to blood spotting) were investigated. In the first procedure DBS pre-impregnation is performed by immersing the DBS card fully into an internal standard solution. In the second procedure pre-impregnation is performed by pipetting a certain volume of an internal standard solution onto the DBS card. Morphine-d3 was used as the model compound for all experiments. The pre-impregnation procedure by immersing was further investigated with respect to homogeneity of impregnation, influence of different blood spotting techniques and the influence of spotting different blood volumes on the internal standard distribution, calibration and stability of pre-impregnated cards. Finally, the immersing procedure was used for the analysis of morphine in dried blood spots and the results were compared to the conventional procedure in which the internal standard morphine-d3 was added to the extraction solvent. The new pre-impregnated cards couple simplicity of operation and convenient use in the field to results equivalent to the conventional procedure.  相似文献   

16.
Antibiotic susceptibility test (AST) discs are used as an in-vitro diagnostic tool to select the appropriate antibiotic to treat an infection. Generally, the concentration of the drug loaded on to the AST discs is measured by studying its activity against quality control organisms. This methodology has several limitations—it is time consuming, requires trained manpower, has a wider acceptance criteria of zone of inhibitions—causing ambiguity in judging smaller variations in drug concentration. To overcome these issues, we have developed and validated high-performance liquid chromatographic (HPLC) methods for the determination of strength of AST discs for in-house researched antibiotics, namely Levonadifloxacin/WCK 771, Nafithromycin/WCK 4873, Cefepime-Tazobactam/WCK 4282, and Cefepime-Zidebactam/WCK 5222. The drugs were extracted from the AST discs using an appropriate solvent. The developed methods are simple, accurate, precise, reproducible, rugged, and robust. They are efficient in terms of time, and can be easily conducted in a quality control laboratory during release as well as stability evaluation of AST disc. Application of HPLC methods for the determination of strength of AST discs ensures flawless quality and, consequently, a better selection of drugs to treat bacterial infections in clinics.  相似文献   

17.
A bioanalytical method for the quantification of tacrolimus (TAC) on dried blood spots (DBS) using liquid chromatography, electrospray ionization coupled with tandem mass spectrometry (LC‐ESI‐MS/MS) was developed and validated. It involves solvent extraction of a punch disk of DBS followed by liquid–liquid extraction. The analyte and the internal standard (IS, ascomycin) were separated on a phenyl column using an isocratic mobile phase elution at a flow rate of 0.3 mL/min. The assay was linear from 1 to 80 ng/mL. The mean recovery of TAC was 76.6%. Intra‐assay, inter‐assay imprecision and biases were all less than 15%. TAC on DBS was stable for at least 10 days at room temperature, and at least 24 h at 50°C. A chromatographic effect of the filter paper (Whatman 903) was not detected. The volume of blood (15–50 μL) and hematocrit of blood (ranging from 23.2 to 48.6%) did not show a significant influence on detection of TAC concentration by DBS‐LC‐MS/MS. Fifty samples from patients were detected by both DBS‐LC‐MS/MS and microparticle enzyme‐linked immunoassay (MEIA). TAC concentrations measured by DBS‐LC‐MS/MS method tended to be lower than those by MEIA. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

18.
An LC–MS/MS method was developed and validated for bioanalysis of clofazimine in human dried blood spot (DBS) samples in support of a clinical study on multidrug‐resistant tuberculosis in developing countries. The validated assay dynamic range was from 10.0 to 2000 ng/mL using a 1/8 inch DBS punch. The accuracy and precision of the assay were ±11.0% (bias) and ≤13.5% (CV) for the LLOQs (10.0 ng/mL) and ±15% (bias) and ≤15% (CV) for all other QC levels. The assay was proved to be free from the possible impact owing to spot size and storage temperature (e.g. at 60°C, ≤ − 60°C). The validated assay is well suited for the intended clinical study where conventional pharmacokinetic sample collection is not feasible.  相似文献   

19.
Pidotimod is widely used in children as an immune promoter but it has not been fully evaluated in animals. The pharmacokinetics of pidotimod and its oral bioavailability have not been described in broiler chickens. We developed a simple and sensitive UHPLC–MS/MS assay for rapid determination of pidotimod levels in chicken blood. Recoveries were nearly 100% and the coefficients of accuracy and precision were minimal. Healthy broiler chickens were given 10 mg/kg pidotimod either orally or intravenously. The oral pidotimod was rapidly absorbed (time to reach maximum concentration, 1.25 h) and rapidly eliminated (the mean residence time was 3.2 h). A noncompartmental analysis of the intravenous route indicated a mean plasma clearance of 2.2 L (h kg)−1 with an estimated mean volume of distribution at steady state of 12.69 L/kg. The bioavailability of pidotimod after oral dosing was 27%.  相似文献   

20.
Oxypeucedanin, a furanocoumarin extracted from many traditional Chinese herbal medicines, has a variety of pharmacological effects. However, the independent pharmacokinetic characteristics and bioavailability of this compound remains elusive. In this study, a rapid, sensitive, and selective method using ultra-high performance liquid chromatography–tandem mass spectrometry (UPLC/MS/MS) was developed for evaluating the intravenous and oral pharmacokinetics of oxypeucedanin. After intravenous administration of oxypeucedanin (2.5, 5, and 10 mg/kg), and intragastric administration of oxypeucedanin (20 mg/kg), blood samples were collected periodically from the tail vein. The plasma concentration-time curves were plotted, and the pharmacokinetic parameters were calculated using a non-compartmental model analysis. After intravenous administration of oxypeucedanin (single dosing at 2.5, 5, and 10 mg/kg) to rats, the pharmacokinetics fit the linear kinetics characteristics, which showed that some parameters including average elimination half-life (T1/2Z of 0.61~0.66 h), mean residence time (MRT of 0.62~0.80 h), apparent volume of distribution (VZ of 4.98~7.50 L/kg), and systemic clearance (CLZ of 5.64~8.55 L/kg/h) are dose-independent and the area under concentration-time curve (AUC) increased in a dose-proportional manner. Single oral administration of oxypeucedanin (20 mg/kg) showed poor and slow absorption with the mean time to reach the peak concentration (Tmax) of 3.38 h, MRT of 5.86 h, T1/2Z of 2.94 h, and a mean absolute bioavailability of 10.26% in rats. These results provide critical information for a better understanding of the pharmacological effect of oxypeucedanin, which will facilitate its research and development.  相似文献   

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