Simultaneous determination of six flavonoids in rat plasma by high-performance capillary electrophoresis and its application to a pharmacokinetic study

A high-performance capillary electrophoresis (HPCE) method was developed for the separation and quantification of six flavonoids in rat plasma, which provides the basis for further study and exploitation of the effective parts of Artemisia frigida. To the plasma sample, formic acid was added to precipitate protein first with kaempferol as the internal standard (IS). The organic layer was separated and evaporated to dryness and the supernatant was extracted with ethyl acetate. The residue was dissolved in 500 μL acetonitrile and filtrated through 0.45-μm filters, and then the samples were introduced into the capillary by electrokinetic injection. Separations were performed using 20 mM sodium borate with 10% acetonitrile as a buffer solution with UV detection at 283 nm. Applied voltage was 18 kV and temperature was 25°C. The calibration curves for the six flavonoids were linear (r > 0.9990) over the studied concentration range separately. The intra- and inter-day precision values were <5.2%, and the accuracy values were between ?4.4% and ?1.3% relative error. The extraction recoveries ranged from 90% to 97% across the calibration curve range. The validated method was successfully applied to a pharmacokinetic study of the six flavonoids in rats after oral administration of A. frigida extract.     

蒲黄中4个黄酮的对照品

目的建立蒲黄中对照品的研究方法。方法结合大孔吸附树脂、聚酰胺、Sephadex-LH20柱色谱方法对蒲黄中香蒲新苷(typhaneoside,1)、异鼠李素-3-O-新橙皮苷(isorhamnetin-3-O-neohes-peridoside,2)、柚皮素(naringenin,3)和异鼠李素(isorhamnetin,4)进行分离纯化,通过理化性质和光谱数据进行结构鉴定,TLC和HPLC进行纯度检查。结果制备得到的香蒲新苷、异鼠李素-3-O-新橙皮苷、柚皮素和异鼠李素的纯度分别为99.2%、99.7%、98.0%和96.2%。结论制备方法可作为蒲黄鉴别和含量测定用对照品。     

Quantitative analysis and chromatographic fingerprinting for the quality evaluation of Scutellaria baicalensis Georgi using capillary electrophoresis

Quantitative analysis and chromatographic fingerprinting for the quality evaluation of a Chinese herb Scutellaria baicalensis Georgi using capillary electrophoresis (CE) technique was developed. The separation was performed with a 50.0cm (42.0cm to the detector window)x75mum i.d. fused-silica capillary, and the CE fingerprint condition was optimized using the combination of central composite design and multivariate analysis. The optimized buffer system containing 15mM borate, 40mM phosphate, 15mM SDS, 15% (v/v) acetonitrile and 7.5% (v/v) 2-propanol was employed for the method development, and the baseline separation was achieved within 15min. The determination of the major active components (Baicalin, Baicalein and Wogonin) was carried out using the optimized CE condition. Good linear relationships were provided over the investigated concentration ranges (the values of R(2): 0.9997 for Baicalin, 0.9992 for Baicalein, and 0.9983 for Wogonin, respectively). The average recoveries of these target components ranged between 96.1-105.6%, 98.6-105.2%, and 96.3-105.0%, respectively. CE fingerprints combined with the quantitative analysis can be used for the quality evaluation of S. baicalensis.     

蒲黄总黄酮对麻醉犬心肌耗氧量的影响

目的：观察蒲黄总黄酮对麻醉犬心肌耗氧量的影响。方法：采用麻醉犬冠脉流量、心肌耗氧量和心肌氧摄取率等指标的变化，研究蒲黄总黄酮对缺血心肌的作用。结果：灌胃给药30min到120min的各时间点，蒲黄总黄酮可明显增加冠脉血流量，降低心肌摄氧率和心肌耗氧量，与生理盐水组比较有显著差异（P〈0．01）。结论：蒲黄总黄酮对缺血心肌具有一定的保护作用。     

Simultaneous determination of five flavonoids during the growth of Fructus Sophorae by capillary electrophoresis

A method of simultaneous determination of five flavonoids during the growth of Fructus Sophorae by β-cyclodextrin (β-CD-) modified capillary zone electrophoresis was developed. The effects of various parameters such as buffer concentration, pH, applied voltage, and β-CD concentrations were investigated. After a series of optimization processes, the determination of five flavonoids in Fructus Sophorae was successfully achieved in 20 mmol/L borax buffer (pH 9.5), 25 kV applied voltage, and 8 mmol/L β-CD. The linearity, detection limits, repeatability, and recovery were satisfactory. Thus, the proposed β-CD-modified capillary zone electrophoresis method was satisfactorily used to analyze Fructus Sophorae samples. The results can be useful for the quality control and medicinal resource development of Fructus Sophorae.     

蒲黄与草蒲黄的质量分析

目的考察蒲黄与草蒲黄之间的质量差异。方法从药材性状、显微鉴别、总灰分检查、醇浸出物测定和含量测定等方面,比较蒲黄与草蒲黄之间的质量差异。结果蒲黄与草蒲黄之间的质量差异较大。结论蒲黄的质量明显优于草蒲黄,商品蒲黄需要综合从多方面对其进行质量控制。     

蒲黄近红外光谱法鉴别初探

目的建立蒲黄的近红外光谱快速鉴别方法。方法收集不同来源的蒲黄样品,采集其近红外光谱,用矢量归一加二阶导数法和因子化法建立鉴别模型。结果经验证,该方法能准确无误地鉴别蒲黄及掺伪品。结论近红外光谱法可快速、准确地鉴别蒲黄的真伪,可在药品检测车上推广应用。     

近红外光谱法应用于蒲黄总灰分的定量预测研究

目的:利用近红外光谱分析技术,建立中药蒲黄总灰分的快速、无损测定方法。方法:采用偏最小二乘回归方法(PLSR)对不同的光谱预处理方法、建模波段和因子数选择等进行比较,建立定量预测模型,并考察模型预测准确度。结果:以一阶导数结合多元散射校正法建立模型,校正模型的相关系数为0.9994,内部交叉验证均方根差(RMSECV)为0.293;交叉检验决定系数(RPD)为29.4,偏移小于0.013。结论:结果表明,总灰分为6.0%～27.3%的10批蒲黄样品的预测值与实测值的相对偏差均小于7.5%。该方法与常规总灰分测定方法比较快速、无损,预测结果准确、可靠,有望推广应用于中药蒲黄的快速检验。     

高效毛细管电泳法测定注射用头孢地嗪的含量

目的 :探讨注射用头孢地嗪含量的测定方法。方法 :用高效毛细管电泳法 (HPCE)。毛细管6 0cm× 75 μm ;运行缓冲液硼砂 30mmol·L- 1(pH9.2 ) ,压力进样 5s ,分离电压 12kV ,温度为 2 5°C ,检测波长为 2 5 4nm ,头孢噻肟为内标。结果 :头孢地嗪在 4～ 2 0mg·L- 1浓度范围内线性关系良好 (r=0 .9998) ,平均回收率为 99.2 %。结论 :HPCE法测定头孢地嗪的含量简单、快捷、灵敏。     

用高效毛细管电泳法鉴别冬虫夏草及其伪品

目的:应用高效毛细管电泳法鉴别冬虫夏草及其伪品。方法:石英毛细管70μm×60 cm,电解缓冲液30mmol/L硼酸盐溶液(pH 8.5)、电压20 kV,检测波长200 nm。结果:在该分离条件下,15 min可获得冬虫夏草及其伪品的特征性电泳图谱,经电泳图谱解析可鉴别两者。结论:该法简便、快速、准确,可作为中药冬虫夏草及其伪品的有效鉴别方法。     

Role of phospholipids in drug-LDL bindings as studied by high-performance frontal analysis/capillary electrophoresis

The binding study between basic drugs ((S)-verapamil (VER) and (S)-propranolol (PRO)) and phospholipid liposomes was performed by using high-performance frontal analysis/capillary electrophoresis (HPFA/CE) in order to investigate the effect of oxidative modification of low-density lipoprotein (LDL) upon drug-binding affinity from molecule-based viewpoint. 1-Palmitoyl-2-oleoyl-phosphatidylcholine (POPC, 16:0, 18:1), 1-palmitoyl-2-linoleoyl-phosphatidylcholine (PLPC, 16:0, 18:2), dilauloyl-phosphatidylcholine (DLaPC, 12:0, 12:0), 1-palmitoyl-2-oleoyl-phosphatidyl-glycerol (POPG, 16:0, 18:1), and 1-palmitoyl-sn-glycero-3-phosphocholine (monoPPC, 16:0) were used to prepare the model liposomes. At physiological pH (pH 7.4), the model liposome prepared from POPG+POPC had negative net charges, while the total net charge of the other model liposomes (POPC liposome, PLPC liposome, DLaPC liposome, and monoPPC+POPC liposome) was zero. The drug and the model liposome mixed solutions were subjected to HPFA/CE, and the total binding affinities (nK) were calculated. The nK values of VER and PRO to POPG+POPC liposome were more than six and 10 times higher than those of other liposomes, respectively. On the other hand, the nK values of the model drugs to POPC liposome, PLPC liposome, DLaPC liposome and monoPPC+POPC liposome showed small differences less than twice. These results indicate that the electrostatic interaction plays an important effect on drug–liposome binding, and suggest that the increase in the negative charge of LDL phospholipids gives more significant effect on the drug-binding affinity of the basic drugs than the acyl-chain structure.     

高效毛细管电泳法测定绞股蓝中芦丁和槲皮素的含量

目的采用高效毛细管电泳法对绞股蓝中的有效成分芦丁和槲皮素同时进行含量测定。方法采用未涂层熔融石英毛细管柱（57 cm×75μm,有效长度50 cm）为分离通道,以12 mmol.L-1硼砂-甲醇（80∶20）为电泳介质,分离电压30 kV,毛细管温度30℃,检测波长360 nm。结果芦丁和槲皮素在20 min内得到很好的分离,分别在0.054~1.070、0.009~0.180 mg.mL-1与峰面积线性关系良好,平均回收率分别为99.0%、98.8%。结论方法简便快速、结果准确、重现性好,可用于绞股蓝及其制剂的质量控制。     

他唑巴坦的高效毛细管电泳分析

用毛细管区带电泳法快速测定他唑巴坦的含量。选择 ５０ｍｍｏｌ／Ｌ硼砂溶液（ｐＨ ８． ８）为运行缓冲液,以阿昔洛韦为内标,在电泳电压 ２０ｋＶ,紫外检测波长 ２２０ｎｍ处测定;结果在 １～８ｍｇ／ｍｌ浓度范围内线性良好,平均回收率达 ９９．８１％, ＲＳＤ为１． ３６％（ｎ＝８）。应用 ＣＺＥ与 ＨＰＬＣ测定他唑巴坦含量所得结果一致。     

方差分析法优选生蒲黄包煎袋及其提取液热稳定性考察

目的：优选生蒲黄包煎提取工艺中包煎袋的材料、层数和装量容积比,并对生蒲黄提取液进行热稳定性考察。方法：采用HPLC法同时测定香蒲新苷、异鼠李素-3-O-新橙皮苷含量。以香蒲新苷、异鼠李素-3-O-新橙皮苷和溢出率为评价指标并进行综合评分。在SPSS 22.0软件上,以综合评分为数据资料,采用方差分析法对包煎袋的材料、层数和装量容积比进行单因素方差分析并多重比较。通过测定不同受热温度和时间下香蒲新苷、异鼠李素-3-O-新橙皮苷含量的变化,考察蒲黄提取液的热稳定性。结果：蒲黄应置于装量容积比为1∶4的两层无纺布袋中,按已优选的醇提工艺提取。回收乙醇后的提取液在高温或长时间受热下易降解,提取液应采用减压浓缩。结论：蒲黄提取工艺应避免高温或长时间受热,浓缩工艺应采用减压浓缩,以降低成分的降解。优选的蒲黄包煎袋材料、层数、装量容积比合理可行、稳定科学,适合于该制剂的工业化生产。     

Simultaneous enantioseparation of cis-diltiazem hydrochloride and its metabolite cis-desacetyldiltiazem using high-performance liquid chromatography and capillary electrophoresis.

Two alternative methods were developed using high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) for a simultaneous enantioselective determination of Ca(2+) blocking chiral drug cis-diltiazem hydrochloride (DLT) and its degradation product and metabolite cis-desacetyldiltiazem (Desac-DLT). The methods were compared from the viewpoint of analytical performance. The identification of HPLC peaks were performed using off-line electrospray ionization mass spectrometry. In addition, CE method was evaluated for quantitative determination of minor enantiomeric impurities in pharmacologically active (+)-cis-DLT.     

Simultaneous determination of hydrochlorothiazide and several angiotensin-II-receptor antagonists by capillary electrophoresis

We have investigated the capability of the capillary zone electrophoretic (CZE) and micellar electrokinetic capillary chromatographic (MEKC) methods to simultaneously separate hydrochlorothiazide and six angiotensin-II-receptor antagonists (ARA-IIs): candesartan, eprosartan mesylate, irbesartan, losartan potassium, telmisartan, and valsartan. The CZE and MEKC methods are suitable for the qualitative and quantitative determination of combined HCT/ARA-IIs in pharmaceutical formulations. Depending on the ARA-II, at least one of the two methods can be used for each combination. The two methods have been validated in terms of their linearity of response, reproducibility, and accuracy.     

Simultaneous stereoselective analysis of venlafaxine and O-desmethylvenlafaxine enantiomers in clinical samples by capillary electrophoresis using charged cyclodextrins

Capillary electrophoresis (CE) was used for the simultaneous chiral determination of venlafaxine (Vx), a new antidepressant drug and its main active metabolite. O-desmethyl venlafaxine (ODV). Among the charged cyclodextrins (CD) tested, phosphated gamma-CD was the most appropriate. Resolution of Vx and ODV was obtained with 50 mM phosphate buffer (pH 2.5) containing 20 mg/ml of phosphated gamma-CD. After optimisation of the method (including robustness), validation was carried out. Vx and ODV concentrations, as well as the enantiomeric ratio, were investigated in clinical samples. Chiral determination of Vx and ODV was performed after a simple liquid-liquid extraction (LLE). In the tested concentration range (25-500 ng/ml), coefficients of correlation were superior to 0.996. Within-day and between-day accuracy and precision were determined at three different concentrations for each enantiomer. Analyses of clinical samples (n = 16) exhibited non-racemic ratios for Vx and ODV, which suggests a stereoselective metabolism in humans.     

Qualitative and quantitative chromatographic investigation of flavonoids in Bellis perennis L

The qualitative and quantitative analysis of flavonoids in the flowers and leaves of naturally growing B. perennis and in the flowers of cultivated variations 'rosea' and 'rubra' were carried out. The qualitative analysis was carried out by TLC and compared with flavonoid compounds isolated from flowers of common daisy. The quantitative determinations were carried out by Christ-Müller's method and by HPLC after acid hydrolysis. Similar flavonoids were found in all the flowers, while differences were noted in the flavonoid composition of the leaves. The flavonoid contents were higher in the flowers than in the leaves.     

毛细管区带电泳法测定司巴沙星和茶碱的血药浓度

目的：建立用毛细管区带电泳法同时测定司巴沙星和茶碱血药浓度方法。方法血 离心后，分离血清，直接进样测定，用２０ｍｍｏｌ／Ｌ硼砂缓冲液分离，２９８ｎｍ为测定波长，外标峰面积法定量。结果：血清中司巴沙星和茶碱分离良好，分别在１．２～１２．５μｇ／ｍｌ、３．８～３７．６μｇ／ｍｌ的浓度范围内线性关系良好。其血清最低检测浓度分别为０．８和２．５μｇ／ｍｌ。结论本法可作为同巴沙得和茶碱药物动力学研究时的血药     

Enantiomeric separation of denopamine by capillary electrophoresis and high-performance liquid chromatography using cyclodextrins

Direct separation of enantiomers of denopamine was investigated by two separation methods. One is capillary zone electrophoresis (CZE) using cyclodextrins (CDs) (CD-CZE) and the other is high-performance liquid chromatography (HPLC) using CD immobilized chiral stationary phases (CD-CSPs). Enantiomers of denopamine were successfully resolved by employing heptakis (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) and acetyl-β-cyclodextrin (AC-β-CD), and partially resolved with heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) and β-CD polymer under acidic conditions. Separation of enantiomers of denopamine by HPLC was also successful with one of the CD-CSPs, where perphenylated β-CD (Phβ-CD) was immobilized. In CD-CZE, some polymeric additives, such as hydroxypropylmethylcellulose (HPMC) and polyvinylalcohol (PVA), and a coated capillary were used to improve the enantioseparation of denopamine. Method validations such as linearity, recovery and repeatability, etc., were investigated for HPLC, and the method was applied to the optical purity testing of the drug substances and in tablet form.