Species-dependent plasma metabolism of the ester compound daidzein 7,4'di-succinic acid mon-ester-O-ethoxy (DZ5)

Daidzein 7,4'di-succinic acid mon-ester-O-ethoxy (DZ5) is an ester-containing compound, which was recently synthesized. The objective of this study was to determine the hydrolysis rate of DZ5 in blood from the rat and the dog. The data showed that the hydrolysis rate of DZ5 in plasma was much more rapid in rats than in dogs following intravenous administration. Moreover, similar results were observed after in vitro incubation of DZ5 in the rat or dog plasma. The findings suggested that plasma esterases in the rat plasma have higher activity than in the dog and plasma metabolism of DZ5 is species-dependent.     

High-performance liquid chromatographic method for the determination and pharmacokinetic study of oxypeucedanin hydrate and byak-angelicin after oral administration of Angelica dahurica extracts in mongrel dog plasma

A high-performance liquid chromatographic method was developed and validated for the determination and pharmacokinetic study of oxypeucedanin hydrate and byak-angelicin after oral administration of Angelica dahurica extracts in mongrel dog plasma. The coumarin components and the internal standard isopsoralen were extracted from plasma samples with the mixture of tert-butyl methyl ether and n-hexane (4:1, v/v). Chromatographic separation was performed on a C(18) column (200 mm x 4.6mm, 5 microm) with the mobile phase acetonitrile-methanol-water-acetic acid (20:15:65:2, v/v/v/v) at a flow-rate of 1.0 ml/min. Only the peak of oxypeucedanin hydrate and byak-angelicin could be detected in dog plasma after oral administration of ethanol extracts of A. dahurica mainly containing xanthotoxol, osthenol, imperatorin, oxypeucedanin hydrate and byak-angelicin. The calibration curves of oxypeucedanin hydrate and byak-angelicin were linear over a range of 22.08-8830.00 and 6.08-2430.00 ng/ml in dog plasma, respectively. The quantification limit of oxypeucedanin hydrate and byak-angelicin in dog plasma was 22.08 and 6.08 ng/ml, respectively. The intra- and inter-day precision was less than 7.6% and 8.5% and the accuracy was from 91.9% to 106.1%. The lowest absolute recoveries of oxypeucedanin hydrate and byak-angelicin were 85.7% and 87.0%, respectively. The method was successfully applied to the pharmacokinetic studies of oxypeucedanin hydrate and byak-angelicin in dog plasma after oral administration of ethanol extracts from A. dahurica.     

HPLC法测定大鼠血浆中大豆苷元的浓度

目的:建立测定大鼠血浆中大豆苷元浓度的高效液相色谱法。方法:用乙酸乙酯提取血浆样品中大豆苷元,采用高效液相色谱法进行测定。色谱柱:Hypersil ODS C₁₈柱（250mm×4.6mm,5μm）,流动相:甲醇-0.05%磷酸溶液（60:40）,检测波长:260nm,柱温:30℃,流速:1ml·min^-1,进样量:20μl。结果:大豆苷元的线性范围为0.01～1.00μg·ml^-1（r=0.9998）;日内和日间精密度RSD均<4.1%;相对回收率97.11%～101.82%,绝对回收率>90.0%。结论:本法专属性强,灵敏度高,重复性好,适用于大豆苷元的药物动力学研究。     

葛根黄豆苷元衍生物DZ18的合成工艺评价

目的:为了提高葛根黄豆苷元溶解度和生物利用度,本文合成了葛根4'-氧代乙酸7羟乙氧基-黄豆苷元(DZ18).方法:本实验采用半合成的方法,以黄豆苷元为母体,在7位,4'位导入基团生成黄豆苷元双置换体.结果:DZ18经四大光谱分析符合设计要求.结论:新合成的化合物DZ18溶解度较黄豆苷元有较大提高.     

高效液相色谱法对新型大豆异黄酮磺酸酯的前药研究

目的:研究大豆异黄酮磺酸酯化学修饰物的理化性质,并预测其药代动力学性质。方法:建立高效液相色谱法进行药物的理化性质测试和体外水解动力学试验。结果:大豆苷元-7,4′-二苯磺酸酯(DBS1)和大豆苷元-7-苯磺酸酯(DBS2)的脂溶性与水溶性相对于原药大豆苷元(DZ)均有显著的提高,脂水分配系数分别为:3.57±0.75和1.97±0.45;水解反应半衰期分别为2.14 h和19.25 h。DBS1的水解反应中4′-的磺酸酯基更易断裂。结论:化合物DBS1和DBS2的脂溶性、水溶性、脂水分配系数、熔点、极性表面积等影响药物药代动力学的一些主要性质得以优化,预示这2个化合物可能有相对较好的过膜吸收性与转运分布特性,以及良好的口服生物利用度。     

三维HPLC法同步测定犬血浆中的葛根素及阿魏酸

以对 羟基苯甲酸为内标 ,甲醇 水 醋酸 (5 6 2 5mol/L ) (39∶5 8∶3 ,v/v)为流动相 ,InertsilODS 3色谱柱 (15 0mm× 4 6mm ,5 μm)为固定相 ,流速 0 9mL/min。以二极管阵列检测器同时获取 2 48nm和 32 1nm两个波长下的数据 ,并通过三维图观察其紫外吸收定性 ,以沸水浴法处理血浆样品。结果 :葛根素和内标及阿魏酸分离完全 ,葛根素在 0 2 35 4～ 1 883μmol/L范围内线性关系良好 (r =0 9943) ,变异系数 <10 % ,平均回收率为 10 1 0 2 % ,最低检测限为 0 33ng ,最低检测浓度为 0 0 396 μmol/L;阿魏酸则在 1 0 341～ 5 35 6 μmol/L范围内线性关系良好 (r =0 9942 ) ,变异系数 <10 % ,平均回收率为 10 0 88% ,最低检测限为 0 45ng ,最低检测浓度为1 115 9μmol/L。此法可用于不同波长下同步以内标法测定血浆中两种或多种成分     

Determination and pharmacokinetics of isoferulic acid in rat plasma by high-performance liquid chromatography after oral administration of isoferulic acid and Rhizoma Cimicifugae extract

A simple and specific high-performance liquid chromatographic (HPLC) method with ultraviolet (UV) absorbance detection has been developed for the determination of isoferulic acid in rat plasma. The plasma samples were deproteinized with methanol after the addition of internal standard (IS) tinidazole. The analysis was performed on a Kromasil C18 column (250 mm x 4.6 mm i.d., 5 microm particle size) with acetonitrile-0.05% phosphoric acid (25:75, v/v) as mobile phase. The linear range was 0.0206-5.15 microg ml(-1) and the lower limit of quantification (LLOQ) was 0.0206 microg ml(-1). The intra- and inter-day relative standard deviations (R.S.D.s%) were less than 11.4 and 12.3%, respectively, and accuracy as relative error (R.E.%) between -6.7 and -1.1%. Mean extraction recovery was above 80%. The validated method was successfully applied to the pharmacokinetic study of isoferulic acid in rat plasma after oral administration of isoferulic acid and Rhizoma Cimicifugae extract.     

Validated liquid chromatography-tandem mass spectrometric method for the quantitative determination of daidzein and its main metabolite daidzein glucuronide in rat plasma

A highly selective and sensitive liquid chromatographic-tandem mass spectrometric (LC-MS-MS) method was developed and validated to determine daidzein and its main metabolite daidzein glucuronide in rat plasma. The analytes and internal standard genistein were extracted from plasma samples by n-hexane-diethyl ether (1:4, v/v), and separated on a C18 column. The mobile phase consisted of acetonitrile-water-formic acid (80 : 20: 1, v/v/v). Detection was performed on a triple quadrupole tandem mass spectrometer by selected reaction monitoring (SRM) mode via atmospheric pressure chemical ionization (APCI) source. The method has a limit of quantification of 0.24 ng/ml. The linear calibration curves were obtained in the concentration range of 0.24-1000 ng/ml. The intra- and inter-day precisions were lower than 13.2% in terms of % RSD. The accuracy ranged from -0.5% to 2.4% in terms of % RE (relative error). This method was successfully applied to the determination of plasma concentration of daidzein and its main metabolite daidzein glucuronide in rats after an oral administration of 20 mg/kg daidzein.     

HPLC法测定大鼠血浆中色胺酮的浓度及药代动力学参数

目的建立测定血浆中色胺酮含量的HPLC法,并用于色胺酮在大鼠体内的药代动力学研究。方法采用ODSC18色谱柱(4.6 mm×250 mm),流动相为乙腈∶水(47∶53),流速为1.0 ml.min-1,检测波长为251 nm,柱温30℃,进样量20μl,内标物为桂皮醛。按56 mg.kg-1剂量给大鼠灌胃后,用HPLC法测定给药后不同时刻大鼠血浆中色胺酮的浓度。采用DAS 2.1.1软件分析,计算药动学参数。结果色胺酮在0.0183～1.1712 mg.L-1范围内线性关系良好(r2=0.999),最低定量限为0.02 mg.L-1。回收率大于95.0%,其日内、日间RSD均小于8%。大鼠灌胃色胺酮56mg.kg-1后,♀和♂T12分别为4.314和5.597 h,Tmax分别为5.2和4.6 h,Cmax分别为1.887和2.620 mg.L-1,AUC0→t分别为12.1和14.70 mg.h.L-1。结论本方法操作简便,准确,灵敏度高、重复性好,可用于色胺酮血药浓度检测及药代动力学研究。     

大鼠血浆中的新藤黄酸HPLC测定及其药代动力学研究

目的建立测定大鼠血浆中新藤黄酸浓度的HPLC方法,并用于新藤黄酸在大鼠体内的药代动力学研究。方法以藤黄酸为内标,建立大鼠血浆中新藤黄酸的HPLC测定方法。采用该方法测定大鼠单剂量静脉注射1、2、4 mg.kg-1新藤黄酸后不同时间点大鼠血浆中的新藤黄酸的浓度,对其血药浓度-时间采用BABP 3.0软件拟合,计算药动学参数。结果血浆中新藤黄酸在0.07～18.0 mg.L-1浓度范围,其线性关系良好(r=0.999),定量下限为0.07 mg.L-1,提取回收率分别为大于70%,其日内、日间RSD均小于10%。新藤黄酸以1、2和4 mg.kg-1静脉给药后,在大鼠体内的T12分别为(43.61±0.61)、(46.07±2.11)和(46.73±1.14)min,AUC0-t分别为(158.52±6.27)、(211.13±9.33)和(361.37±14.97)min.mg.L-1。结论所建立的HPLC法样品前处理简便、操作简便、能满足新藤黄酸在大鼠体内的药代动力学研究。     

UPLC法测定大鼠血浆中大豆苷元浓度及药动学研究

目的建立测定大鼠血浆中大豆苷元浓度的UPLC法,探讨大豆苷元在大鼠体内的药代动力学过程。方法 SD大鼠6只,ig给予30mg·kg-1大豆苷元混悬液,血浆样品经β-葡萄糖醛酸苷酶水解后,采用UPLC法测定大豆苷元浓度,并用DAS软件拟合并计算其药代动力学参数。结果大豆苷元的血药浓度在20μg·L-1～800μg·L-1范围内线性良好,提取回收率均大于85%,日间和日内RSD小于10%,符合生物样品分析要求。大鼠灌胃给药后,血浆中大豆苷元的药时曲线呈二室开放模型,主要药动学参数Tmax,Cmax,T12β,AUC(0-t),AUC(0-∞),CL,Vd分别为33.3min,355.4μg·L-1,915.7min,213.2mg·min·L-1,218.2mg·min·L-1,0.1467L·min-1·kg-1,74.4L·kg-1。结论该方法操作简便、快速、专属性强,可用于大豆苷元体内大批量样品定量分析及药代动力学研究。     

甘草次酸差向异构体单独和联合给药后在大鼠体内的药动学研究

本文建立了大鼠血浆中甘草次酸差向异构体的高效液相测定方法, 用于研究甘草次酸差向异构体在单独与混合灌胃给药后大鼠的药物代谢动力学过程。本研究分别对大鼠灌胃给予甘草次酸α异构体、β异构体和两者的混合物, 于给药后不同时间点采集血样, 样品经液液萃取后, 用高效液相色谱法测定甘草次酸差向异构体的血药浓度。色谱柱为Kromasil C₁₈ (150 mm × 4.6 mm, 5 µm); 流动相为乙腈–4 mmol·L⁻¹醋酸铵水溶液 (46∶54, v/v); 流速为1.0 mL·min⁻¹; 检测波长为250 nm; 采用DAS 2.0软件计算药动学参数。结果显示, 大鼠单独给予单体后, α-甘草次酸的AUC_0−t为 (11.30 ± 1.53) μg·h·mL⁻¹, C_max为 (2.36 ± 0.58) μg·mL⁻¹; β-甘草次酸的AUC_0−t为 (9.79 ± 0.98) μg·h·mL⁻¹, C_max为 (2.09 ± 0.41) μg·mL⁻¹。两单体混合给药后, α-甘草次酸的AUC_0−t为 (13.04 ± 2.63) μg·h·mL⁻¹, C_max为 (2.72 ± 0.50) μg·mL⁻¹; β-甘草次酸的AUC_0−t为 (7.46 ± 1.77) μg·h·mL⁻¹, C_max为 (1.90 ± 0.31) μg·mL⁻¹。本研究所建立的高效液相色谱法专属性强、灵敏度高, 可用于甘草次酸差向异构体的体内药动学研究。α-甘草次酸与β-甘草次酸混合给药时, 主要药动学参数存在显著性差异 (P < 0.05); 单独给药时, α-甘草次酸与β-甘草次酸的主要药动学参数无显著性差异。对各差向异构体单独给药与混合给药时的主要药动学参数进一步进行统计分析, α-甘草次酸在两种给药方式时无显著性差异, 而β-甘草次酸的AUC_0−t与AUC_0−∞存在显著性差异。     

RP-HPLC法测定人血浆中黄豆苷元的浓度

目的:建立以反相高效液相色谱法测定人血浆中黄豆苷元浓度的方法。方法:采用甲醇沉淀蛋白法提取血浆中黄豆苷元,色谱柱为Hypersil ODS C18(250mm×4.6mm,5μm),流动相为5%乙酸溶液(用三乙胺调pH值为4)-甲醇(55∶45),检测波长为254nm,流速为1.0mL·min-1,柱温25℃。结果:黄豆苷元血药浓度在1.5～700.0ng·mL-1范围内线性关系良好(r=0.9995),低、中、高浓度(5.0、16.5、231.0ng·mL-1)的平均回收率分别为(96.95±4.36)%、(101.30±3.32)%和(98.73±2.54)%。结论:本法简单、快速、准确,可用于黄豆苷元的血药浓度测定和人体药动学研究。     

HPLC method for analysis of a new 1,4-dihydropyridine: application to pharmacokinetic study in rabbit

A high sensitive HPLC assay for plasma analysis of a new 1,4-dihydropyridine (nitrimidodipine) was developed to support the subsequent preclinical development of the compound. To 1 ml of rabbit plasma was added internal standard (3-(4-nitrooxy butyl)-5-ethyl-1,4-dihydro-2,6-dimethyl-4-(1-methyl-5-nitro-2-imidazolyl)-3,5-pyridine dicarboxylate) and 0.5 ml of 1M HCl. The plasma was extracted using 5 ml ethyl acetate which evaporated under gentle stream of nitrogen. The residue was reconstituted in 200 microl mobile phase and 100 microl of aliquots were injected to HPLC system. Chromatographic separation was accomplished on octadecyl column (250 mm x 4.6mm) using a mobile phase consisting of acetonitrile-water (45:55, v/v). The method was sensitive to 2.5 ng/ml in plasma (LOD), acceptable within- and between day reproducibility and a linearity (r2>0.9957) over a concentration range from 5 to 400 ng/ml. The mean extraction efficacy was 90.6% and no interfering peaks of the blank plasma chromatograms were observed. By using the above procedure, a simple, sensitive and convenient HPLC assay for determination, stability evaluation and pharmacokinetic study of nitrimidodipine was developed.     

Influence of dosage forms on pharmacokinetics of daidzein and its main metabolite daidzein-7-O-glucuronide in rats

AIM: To investigate the influence of dosage forms on the pharmacokinetics of daidzein and its main metabolite daidzein-7-O-glucuronide in Wistar rats. METHODS: After administration of two typical dosage forms (daidzein solution and suspension), the concentrations of daidzein and daidzein-7-O-glucuronide were determined by an LC-MS-MS method. The pharmacokinetic parameters were calculated and analyzed statistically using the Student's t-test. RESULTS: Absorption of daidzein after administration of daidzein solution (tmax=0.46 h) was more rapid than that of the suspension (tmax=5.00 h). The peak plasma concentrations of daidzein after administration of daidzein solution and suspension were 601.1 microg/L and 127.3 microg/L, respectively, and those of daidzein-7-O-glucuronide were 3000 microg/L and 192.6 microg/L, respectively. The absolute bioavailabilities of free daidzein in rats after administration of daidzein solution and suspension were 12.8% and 6.1%, respectively, which were calculated to be 47.0% and 12.2%, respectively, in the form of total daidzein (free plus conjugated daidzein). CONCLUSION: Absorption of daidzein solution was better than absorption of suspension (P<0.05).     

LC-MS/MS method for the simultaneous determination of icariin and its major metabolites in rat plasma

A rapid and sensitive method using liquid chromatography-tandem mass spectroscopy (LC-MS/MS) was developed and validated for the simultaneous quantitative determination of icariin and its two major metabolites, icariside I and icariside II in rat plasma. The analytes were extracted by liquid-liquid extraction with ethyl acetate after internal standard (daidzein) spiked. The separation was performed by a ZORBAX SB-C(18) column (3.5 microm, 2.1 mm x 100 mm) and a C(18) guard column (5 microm, 4.0 mm x 2.0mm) with an isocratic mobile phase consisting of acetonitrile-water-formic acid (50:50:0.05, v/v/v) at a flow rate of 0.25 mL/min. The Agilent G6410A triple quadrupole LC-MS system was operated under the multiple reaction monitoring (MRM) mode using the electrospray ionization technique in positive mode. The nominal retention times for icariin, icariside I, icariside II and daidzein were 1.21, 1.88, 2.34 and 1.35 min, respectively. The lower limits of quantification (LLOQ) of icariin, icariside I and icariside II of the method were 1.0, 0.5 and 0.5 ng/mL, respectively. The method was linear for icariin and its metabolites with correlation coefficients >0.995 for all analytes. The intra-day and inter-day accuracy and precision of the assay were less than 12.5%. This method has been applied successfully to a pharmacokinetic study involving the intragastric administration of icariin to rats.     

Simultaneous determination of Gastrodin and Ligustrazine hydrochloride in dog plasma by gradient high-performance liquid chromatography

A novel reversed-phase HPLC method was developed for the simultaneous determination of Gastrodin (Gas) and Ligustrazine hydrochloride (LZH) in dog plasma after oral administration of the preparation 'Tianxiong Capsule'. The assay involves deproteinization, extraction and subsequent detection with a gradient solvent system at two different wavelengths. Retention times were 10.6 and 18.9 min for Gas and LZH, respectively. Linear responses were observed over a wide range (0.40-200.0 microg/ml for Gas and 0.0999-39.96 microg/ml for LZH) in plasma. The mean intra- and inter-assay variation coefficients were 2.7 and 3.4% for Gas and 3.4 and 4.2% for LZH, respectively. The average extract recoveries were 76.77% for Gas and 75.8% for LZH. This assay has been successfully used to provide pharmacokinetic data for Gastrodin with oral administration of Tianxiong capsules.     

A validated HPLC-ESI-MS method for the determination of loratadine in human plasma and its application to pharmacokinetic studies

A liquid chromatographic-mass spectrometric (LC-MS) assay was developed and validated for the determination of loratadine in human plasma using reversed-phase HPLC combined with electrospray ionization (ESI) mass spectrometry. The analysis involved a simple liquid-liquid extraction. The organic extract was then evaporated and the residue was reconstituted in mobile phase. The reconstituted solution was injected into an HPLC system and was subjected to reverse-phase HPLC on a 5-microm ODS-3 column at a flow-rate of 0.2 ml/min. The mobile phase comprised of acetonitrile-ammonium acetate (pH 4.0; 0.02 M, using formic acid to adjust) using gradient elution. Loratadine was detected in the single ion monitoring (SIM) mode. Standard curves were linear over the concentration range of 0.2-100 ng/ml. The mean predicted concentrations of the quality control (QC) samples deviated by less than 10% from the corresponding nominal values; the intra-assay and inter-assay precision of the assay were within 12% relative standard deviation. The extraction recovery of loratadine was more than 80%. The validated assay was applied to a pharmacokinetic study of loratadine in human plasma following the administration of a single loratadine tablet (40 mg).     

Simultaneous determination of liensinine, isoliensinine and neferine from seed embryo of Nelumbo nucifera Gaertn. in rat plasma by a rapid HPLC method and its application to a pharmacokinetic study

A rapid and specific HPLC method has been developed and validated for the simultaneous determination of liensinine (CAS 2586-96-1), isoliensinine (CAS 6817-41-0) and neferine (CAS 2292-16-2) in rat plasma. The sample was prepared by a liquid-liquid extraction with diethyl ether and the recovery was above 80% from the plasma for the three compounds. Chromatographic separation was achieved with a Hypersil BDS C18 column (4.0 mm x 250 mm, particle size 5 microm). A mobile phase consisting of methanol: 0.2 M KH2PO4:0.2 M NaOH:triethylamine (71:17:12:0.002, v/v/v/v, pH 9.2-9.3) was slowly delivered at 0.8 ml/min in isocratic mode with a detection wavelength of 282 nm. The linearity of calibration curves were good (r > 0.999) in the concentration range of 0.031-2.00 microg/ ml. The lower limit of quantification can reach 0.03 microg/ml for the three compounds. The intra-day and inter-day variations estimated with QC samples were less than 8% for the three tested concentration levels. This developed method was applied in the plasma pharmacokinetic study of total bisbenzylisoquinoline alkaloids (TAL) of the lotus flower (Lian Zi Xin) following a single oral and intravenous administration of TAL in rats.     

HPLC method for the determination of fluvoxamine in human plasma and urine for application to pharmacokinetic studies

A simple, specific and sensitive high-performance liquid chromatographic (HPLC) method has been developed for the assay of fluvoxamine in human plasma and urine. The method was based on reaction of fluvoxamine with 1,2-naphthoquinone-4-sulphonic acid sodium salt (NQS) forming orange colored product. The fluvoxamine-NQ derivative was separated by isocratic reversed-phase HPLC and detected at 450 nm. The chromatographic conditions were as follows: Phenomenex C(18) (250 mm x 4.6 mm i.d., 5 microm) column, mobile phase consisting of acetonitrile/water (80:20 v/v) at a flow rate of 1 ml/min. Tryptamine was selected as an internal standard. The assay was linear over the concentration range of 5-145 and 2-100 ng/ml for plasma and urine, respectively. The limits of detection (LOD) were 1.4 and 1 ng/ml for plasma and urine estimation at a signal-to-noise (S/N) ratio of 3. The limits of quantification (LOQ) were 5 and 2 ng/ml for plasma and urine, respectively. The extraction recoveries were found to be 96.66+/-0.69 and 96.73+/-2.17% for plasma and urine, respectively. The intra-day and inter-day standard deviations (S.D.) were less than 1. The method indicated good performance in terms of specificity, linearity, detection and quantification limits, precision and accuracy. This assay was demonstrated to be applicable for clinical pharmacokinetic studies.