色谱技术在普萘洛尔对映体药动学研究中的应用进展

普萘洛尔(PPL)为非选择性β-肾上腺素受体阻滞剂,具有多方面药理作用,临床上使用的普萘洛尔是左旋和右旋异构体的等量混合物。目前已证实普萘洛尔S-型对映体的β受体阻断作用比R-型强约100倍,而R-型具有抗氧化活性,对其手性拆分研究在药理学研究方面有重要意义。该文综述了色谱方法在普萘洛尔对映体拆分方法学及其药动学研究方面的应用,为普萘洛尔质量控制、药动学研究及体内药理学研究提供方法学上的参考。     

Determination of bakkenolide A in rat plasma using liquid chromatography/tandem mass spectrometry and its application to a pharmacokinetic study

A sensitive rapid analytical method was established and validated to determine the bakkenolide A (BA) in rat plasma. This method was further applied to assess the pharmacokinetics of BA in rats receiving a single dose of BA. Liquid chromatography tandem mass spectrometry in multiple reaction monitoring mode was used in the method, and costundide was used as internal standard. A simple protein precipitation based on methanol was employed. The combination of a simple sample cleanup and short chromatographic running time (2.4 min) increased the throughput of the method substantially. The method was validated over the range of 1–1000 ng/mL with a correlation coefficient > 0.99. The lower limit of quantification was 1 ng/mL for BA in plasma. Intra‐ and inter‐day accuracies for BA were 93–112% and 103–104%, respectively, and the inter‐day precision was less than 15%. After a single oral dose of 20 mg/kg of BA, the mean peak plasma concentration (C_max) of BA was 234.7 ± 161 ng/mL at 0.25 h. The area under the plasma concentration–time curve (AUC_{0–24 h}) was 535.8 ± 223.7 h·ng/mL, and the elimination half‐life (T_1/2) was 5.0 ± 0.36 h. In case of intravenous administration of BA at a dosage of 2 mg/kg, the area under the plasma concentration–time curve (AUC_{0–24 h}) was 342 ± 98 h?ng/mL, and the elimination half‐life (T_1/2) was 5.8 ± 0.7 h. Based on the results, the oral bioavailability of BA in rats at 20 mg/kg is 15.7%. Copyright © 2012 John Wiley & Sons, Ltd.     

Degree of chemical functionalization of carbon nanotubes determines tissue distribution and excretion profile

Getting rid of the tubes: An assessment of the retention of functionalized multi-walled carbon nanotubes (MWNTs) in the organs of mice was carried out using single photon emission computed tomography and quantitative scintigraphy (see scheme). Increasing the degree of functionalization on MWNTs enhanced renal clearance, while lower functionalization promoted reticuloendethelial system accumulation.     

Development and validation of a high‐performance liquid chromatography–tandem mass spectrometry method for the determination of the novel proteasome inhibitor CEP‐18770 in human plasma and its application in a clinical pharmacokinetic study

CEP‐18770, [(1R)‐1‐{[(2S,3R)‐3‐hydroxy‐2‐{[(6‐phenyl‐2‐pyridinyl)carbonyl]amino}butanoyl]amino}‐3‐methylbutyl]boronic acid, is a novel proteasome inhibitor, now under early clinical evaluation as an anticancer agent. To investigate its clinical pharmacokinetics, a high‐performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method was developed and validated to measure the drug in human plasma, based on simple protein precipitation with acetonitrile after the addition of irbesartan as internal standard. The method requires a small volume of sample (100 µl) and is rapid and selective, allowing good resolution of peaks in 5 min. It is sensitive, precise and accurate, with overall precision, expressed as coefficient of variation (CV%), always < 10.0%, accuracy in the range 93.8–107.7% and high recovery, close to 100%. The limit of detection is 0.01 ng/ml and the lower limit of quantitation (LLOQ) is 0.20 ng/ml. The assay was validated in the range from the LLOQ up to 50.00 ng/ml. This is the first method developed and validated for analyzing a proteasome inhibitor with a boronic‐acid‐based structure in human plasma. The method was successfully applied to study the pharmacokinetics of CEP‐18770 in cancer patients with solid tumors or multiple myeloma who had received the drug as a short intravenous bolus during the initial Phase I trial. Copyright © 2010 John Wiley & Sons, Ltd.     

氟苯尼考在南美白对虾体内药物代谢及残留消除规律

研究了南美白对虾口服氟苯尼考药饵给药后,在血液、肌肉中的残留及消除规律,采用Agilengt 1100型液相色谱仪测定组织中药物含量.口服给药后血液中氟苯尼考浓度在1 h立即达到峰值,药物开始向肌肉组织中运转,血药浓度在1 h后下降,而肌肉中浓度达到峰值;此后无论血液还是肌肉中氟苯尼考浓度均缓慢下降,到10d后血液中的氟苯尼考不能检出.口服氟苯尼考后,在南美白对虾体内吸收快,血药浓度高;药物在肌肉中消除缓慢,维持时间长.     

Determination of piceid in rat plasma and tissues by high-performance liquid chromatographic method with UV detection

A rapid, sensitive and selective HPLC method was developed and validated for determination of piceid in rat plasma and tissues. The drug was isolated from plasma and tissues by a simple protein precipitation procedure. Chromatographic separation was performed on a C(18) column with acetonitrile-water (26:74, v/v) as mobile phase. The method was successfully applied to the pharmacokinetics and tissue distribution research after oral administration of a 50 mg/kg dose of piceid to healthy male Wistar rats. The pharmacokinetic parameters showed that piceid was quickly absorbed, distributed and eliminated within 4 h after oral administration. The tissue distribution results showed that, at 10 min, the concentrations of piceid in most tissues reached peak level except in heart and testis. The highest level of piceid was found in stomach, then in small intestine, spleen, lung, brain, testis, liver, kidney and heart. The amount of piceid in testis and heart reached the peak level at 30 min. At 120 min, the amount of piceid in all tissues decreased to a low percentage of the initial concentration. Piceid was absorbed throughout the gastrointestinal tract with considerable absorption taking place in the stomach and small intestine. There was no long-term accumulation of piceid in rat tissues.     

Development and validation of a sensitive quantification method for hematoporphyrin monomethyl ether in plasma using high-performance liquid chromatography with fluorescence detection

A rapid, sensitive, precise and specific method for determination of hematoporphyrin monomethyl ether (HMME), a novel photodynamic therapy (PDT) drug, was developed and validated using high-performance liquid chromatography (HPLC) with fluorescence detection. HMME was isolated from the plasma by a single-step liquid-liquid extraction with ethyl acetate. The analyte and internal standard fluorescein were baseline separated on a Diamonsil C(18) analytical column (4.6 x 150 mm, 5 microm) and analyzed using a fluorescence detector with the excitation and emission wavelengths set at 395 and 613 nm, respectively. The method was linear in the concentration range 0.025-5 microg/mL with a lower limit of quantitation (LLOQ) of 10 ng/mL. The inter- and intra-day accuracies and precisions were all within 10% and the mean recoveries of HMME and fluorescein were 95 +/- 3.7 and 90 +/- 2.3%, respectively. The analyte was stable during all sample storage, preparation and analysis periods. This method was successfully applied to a pharmacokinetic study after a single-dose intravenous administration of HMME (5 mg/kg) to beagle dogs. This method was reproducible and sensitive enough for the pharmacokinetic study of HMME. Based on the results of the pharmacokinetic study, we suggest that a rather long light-avoiding time is essential for patients under HMME therapy.     

Quantification of fudosteine in human plasma by high-performance liquid chromatography-electrospray ionization mass spectrometry employing precolumn derivatization with 9-fluorenylmethyl chloroformate

This paper describes a novel method for the sensitive and selective determination of fudosteine in human plasma. The method involves a derivatization step with 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer and detection based on high-performance liquid chromatography-electrospray ionization mass spectrometry (LC/ESI/MS). After acetonitrile-induced protein precipitation of plasma samples, fudosteine was derivatized with FMOC-Cl, then extracted by ethyl acetate, evaporated, reconstituted and injected using an LC/ESI/MS instrument. Separation was achieved using an ODS column and isocratic elution. Excellent linearity was obtained for the entire calibration range from 0.05 to 20 microg/ml. Validation assays of the lower limit of quantification (LLOQ) as well as for the intra- and inter-batch precision and accuracy met the international acceptance criteria for bioanalytical method validation. Using the developed analytical method, fudosteine could be detected for the first time in human plasma with a low limit of detection (LLOD) of 0.03 microg/ml. The proposed method has been successfully applied to study the pharmacokinetics of fudosteine in healthy Chinese volunteers after single and multiple oral administration.     

Simple,Sensitive, and Rapid LC–MS Method for the Quantitation of Indapamide in Human Plasma—Application to Pharmacokinetic Studies

Abstract

A sensitive and specific liquid chromatography electrospray ionization mass spectrometry (LC–ESI–MS) method was developed and validated for the identification and quantification of indapamide in human plasma. After the addition of the internal standard (IS) and 0.1 M sodium hydroxide solution, plasma samples were extracted with diethyl ether. The organic layer was evaporated under a stream of nitrogen at 40°C. The residue was reconstituted with 200 µL methanol. The compounds were separated on a stainless‐steel column (C₁₈ Shim‐pack 5 µm 150 mm×2.0 mm I.D., Shimadzu) at a flow rate of 0.2 mL/min by a gradient elution. Detection was performed on a single quadrupole mass spectrometer by selected ion monitoring (SIM) mode via an electrospray ionization (ESI) source. The method was proved to be sensitive and specific by testing six different plasma batches. Linearity was established for the range of concentrations 0.5–100.0 ng/mL with a coefficient of determination (r) of 0.9998 and good back‐calculated accuracy and precision. The intra‐ and inter‐day precision (RSD%) was lower than 10% and accuracy ranged from 85% to 115%. The lower limit of quantification was identifiable and reproducible at 0.2 ng/mL with 0.2 mL plasma. The proposed method enables the unambiguous identification and quantification of indapamide for pharmacokinetic, bioavailability, or bioequivalence studies.     

Liquid Chromatography‐Electrospray Ionization Mass Spectrometric Method for Determination of Gliclazide in Human Plasma

Abstract

A rapid, sensitive, and specific liquid chromatography‐electrospray ionization mass spectrometric (LC‐ESI‐MS) method has been developed for quantification of gliclazide in human plasma. The analyte and tolbutamide (internal standard, I.S.) were extracted from plasma samples with n‐hexane–dichloromethane (1:1, v/v) and analyzed on a C₁₈ column. The chromatographic separation was achieved within 4.0 min by using methanol–0.5% formic acid (80:20, v/v) as mobile phase and the flow rate was 1.0 mL/min. Ion signals m/z 324.0 and 271.0 for gliclazide and internal standard were measured in the positive mode, respectively. The method was linear within the range of 2.5–2000 ng/mL. The lower limit of quantification (LLOQ) was 2.5 ng/mL. The intra‐ and inter‐day precisions were lower than 2.8% in terms of relative standard deviation (RSD). The inter‐day relative error (RE) as determined from quality control samples (QCs) ranged from ?1.93% to 1.85%. This validated method was successfully applied for the evaluation of pharmacokinetic profiles of gliclazide modified‐release tablets in 20 healthy volunteers.