Determination of a novel epothilone D analog (AV-EPO-106) in human plasma using ultra-performance liquid chromatography-tandem mass spectrometry

A novel ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method has been established for the determination of a newly synthesized epothilone D analog (AV-EPO-106) in human plasma. The plasma samples were prepared by liquid-liquid extraction with cold tert-butyl methyl ether. The chromatographic separation was achieved within 5 min on a C(18) column with water-methanol (10:90, v/v) as mobile phase at a flow-rate of 0.8 mL/min. Mass transition of m/z 568.2 to 386.1 was measured for AV-EPO-106 in positive atmospheric pressure chemical ionization mode. A detailed validation of the method was performed as per the USFDA guidelines. For AV-EPO-106 at the concentrations of 1.0, 5.0 and 10.0 microg/mL in human plasma, the absolute extraction recoveries were 86.17, 85.24 and 85.69%, respectively. The linear quantification range of the method was 0.10-20.0 microg/mL in human plasma with linear correlation coefficients greater than 0.999. The intra-day and inter-day accuracy for AV-EPO-106 at the levels of 1.0, 5.0 and 10.0 microg/mL in human plasma fell in the ranges of 98.25-100.47 and 94.19-97.25%, and the intra- and inter-day precision were in the ranges of 4.75-6.30% and 8.89-10.45%, respectively. The method was successfully applied to quantify AV-EPO-106 in human plasma to determine the half-life of this compound in human plasma.     

Determination and pharmacokinetic study of nodakenin in rat plasma by RP-HPLC method

A simple, sensitive and selective RP-HPLC method has been developed for quantification of nodakenin in rat plasma. Nodakenin in rat plasma was extracted with acetonitrile, which also acted as a deproteinization agent. Chromatographic separation of nodakenin was performed on an analytical Diamonsil ODS C18 column, with a mobile phase of MeOH-H2O (1:1, v/v) at a flow-rate of 1.0 mL/min, and UV detection was set at 330 nm. The calibration curve was linear over the range 0.2-12.0 microg/mL (R2 = 0.9995) in rat plasma. The lower limit of detection and quantification were 0.01 and 0.1 microg/mL, respectively, using the rat plasma sample. The extraction recoveries were 77.36 +/- 4.56, 82.89 +/- 1.84 and 81.66 +/- 2.49% at concentrations of 1.0, 5.0 and 10.0 microg/mL, respectively. The intra- and inter-day precision and accuracy were validated by relative standard deviation and relative error, which were in the ranges 5.07-5.83 and 3.95-6.29%, respectively. After i.v. administration to rats at a single dose of 40 mg/kg, the plasma concentration-time curve of nodakenin was best conformed to a two-compartment open model. This assay method has been successfully applied to the study of the pharmacokinetics of nodakenin in rats.     

Determination of calycosin-7-O-beta-D-glucopyranoside in rat plasma and urine by HPLC

A reversed-phase high-performance liquid chromatographic (HPLC) assay for calycosin-7-O-beta-D-glucopyranoside in rat plasma and urine with solid-phase extraction (SPE) was developed. Rutin was employed as an internal standard. The mobile phase consisted of acetonitrile-water (16:84, v/v) at a flow rate of 1.0 mL/min. Detection was set at 280 nm. The limit of quantitation of calycosin-7-O-beta-D-glucopyranoside was 0.2 microg/mL in both plasma and urine. The standard curve was linear from 0.2 to 10.0 microg/mL in plasma, and 0.2 to 5.0 microg/mL in urine. Both intra- and inter-day precision of the calycosin-7-O-beta-d-glucopyranoside were determined and their RSD did not exceed 10%. The method was successfully applied to the analysis of samples obtained from a basic pharmacokinetic study, in which calycosin-7-O-beta-d-glucopyranoside was administered orally to rats.     

Determination and pharmacokinetic study of bergenin in rat plasma by RP-HPLC method

A validated reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed for the determination of bergenin in rat plasma. Bergenin in rat plasma was extracted with methanol, which also acted as a deproteinization agent. Chromatographic separation of bergenin was performed on a C(18) column, with a mobile phase of methanol-water (22:78, v/v) at a flow-rate of 0.8 mL/min and an operating temperature of 40 degrees C, and UV detection was set at 220 nm. The calibration curve was linear over the range 0.25-50 microg/mL (r = 0.9990) in rat plasma. The limit of quantification was 0.25 microg/mL using a plasma sample of 100 microL. The extraction recoveries were 83.40 +/- 6.02, 81.49 +/- 2.40 and 72.51 +/- 2.64% at concentrations of 0.5, 5 and 50 microg/mL, respectively. The intra-day and inter-day precision and accuracy were validated by relative standard deviation (RSD%) and relative error (RE%), which were in the ranges 3.74-9.91 and -1.6-8.0%. After intravenous administration to rats at the dose of 11.25 mg/kg, the plasma concentration-time curve of bergenin was best conformed to a two-compartment open model. The main pharmacokinetic parameters indicated that bergenin exhibited a wide distribution and moderate elimination velocity in rat.     

Determination of puerarin in rat cortex by high-performance liquid chromatography after intravenous administration of Puerariae flavonoids

In the present study, a rapid and simple high-performance liquid chromatographic (HPLC) assay for determination of puerarin in rat cortex was developed. The analysis was carried out on a Zorbax SB-C18 column with mobile phase acetonitrile-0.5% aqueous phosphoric acid (11:89, v/v). The detection was by UV at 252 nm. The calibration curve for puerarin was linear (r=0.9999) over the concentration range 0.516-206.250 microg/mL. The limit of detection was 0.206 microg/mL (signal-to-noise ratio 3) and the limit of quantification (signal-to-noise ratio 10) was 0.516 microg/mL. Stability studies showed that puerarin was stable at temperatures of 4 degrees C in methanol for at least 30 days. The intra- and inter-day assays of puerarin from rat cortex were less than 2.5% at concentration range 0.516-206.250 microg/mL and good overall recoveries (97.4-101.7%) were found at same concentrations. The method was applied to determine the pharmacokinetic parameters and the time course of puerarin in rat cortex, following a single dosage of intravenous administration of flavonoids from Puerariae radix at 32 mg/kg of puerarin to male Wistar rats.     

High performance liquid chromatographic method for the determination and pharmacokinetic studies of oxyresveratrol and resveratrol in rat plasma after oral administration of Smilax china extract

A sensitive and simple HPLC method has been developed and validated for the determination of oxyresveratrol (trans-2,4,3',5'-tetrahydroxystilbene, OXY) and resveratrol (trans-3,5,4'-trihydroxystilbene, RES) in rat plasma. The plasma samples were extracted with ethyl acetate and analyzed using HPLC on an Aglient Zorbax SB-C(18) column (250 x 4.6 mm, 5 microm) at a wavelength 320 nm, with a linear gradient of (A) acetonitrile and (B) 0.5% aqueous acetic acid (v/v), at a flow rate of 1.0 mL/min. The method was linear over the range of 0.1265-25.3 microg/mL for OXY and 0.117-23.4 microg/mL for RES. The extraction recovery for OXY, RES and internal standard ranged from 71.1 to 88.3%. The intra- and inter-day precisions were better than 10%, and the accuracy ranged from 89 to 108%. The validated method was used to study the pharmacokinetic profiles of OXY and RES in rat plasma after oral administration of Smilax china root extract.     

High-performance liquid chromatographic method for the determination of mangiferin in rat plasma and urine

A reversed-phase high-performance liquid chromatography assay for mangiferin in rat plasma and urine was developed. Rutin was employed as an internal standard. The mobile phase consisted of acetonitrile-water (16:84, v/v) containing 3% acetic acid at a flow rate of 1 mL/min. Detection was at 257 and 365 nm for mangiferin in plasma and urine, respectively. The limit of quantitation (LOQ) of mangiferin was 0.6 microg/mL in plasma, and 0.48 microg/mL in urine. The standard curve was linear from 0.6 to 24 microg/mL in plasma, and 0.48 to 24 microg/mL in urine, both intra- and inter-day precision of the mangiferin were determined and their RSD did not exceed 10%. The method provides a technique for rapid analysis of mangiferin in rat plasma and urine, which can be used in pharmacokinetic studies.     

A chromatographic method for baicalin quantification in rat thalamus

A rapid reversed-phase high-performance liquid chromatographic (rp-HPLC) assay for the determination of baicalin in rat thalamus was developed. This was carried out on a Hypersil -C(18) column using 4-nitro-benzoic acid as the internal standard with a mobile phase of methanol-water-H(3)PO(4) (45:55:0.2, v/v/v). Detection was by UV at 277 nm. The calibration curve for baicalin was linear (r=0.9992) over the concentration range of 0.05--4.0 microg/mL and the limit of detection was 10 ng/mL. The coefficients of variation of intra- and inter-day assays were 2.64, 5.19 and 3.19% and 3.46, 6.21 and 5.58% at concentrations of 0.5, 1.0 and 3.0 microg/mL, respectively. The recoveries of baicalin from rat thalamus were 85.4+/- 5.62, 90.7+/- 2.43 and 89.1+/- 4.75% at concentrations of 0.5, 1.0 and 3.0 microg/mL, respectively. The method was applied to determine the time course of baicalin in rat thalamus, following a single dosage of intravenous administration of Scutellariae radix extract at 90 mg/kg of baicalin to male Wistar rats.     

Quantification of myrislignan in rat plasma by solid-phase extraction and reversed-phase high-performance liquid chromatography

A rapid and simple reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed for determination of myrislignan in rat plasma after intravenous administration. The analytes extracted from plasma samples by solid-phase extraction were successfully carried out on a Diamonsiltrade mark ODS C(18) column (250 x 4.6 mm i.d., 5 microm) with an RP(18) guard column (8 x 4.6 mm i.d., 5 microm) and a mobile phase of MeOH-H(2)O (4:1, v/v). The UV detector was set at a single wavelength of 270 nm. The linear ranges of the standard curves were 0.5-30.0 microg/mL with the correlation coefficients greater than 0.9992. The lower limits of detection and quantification were 0.1 and 0.3 microg/mL for myrislignan. Intra- and inter-day precisions were 2.4-7.5 and 1.3-5.7%, respectively. The extraction recovery from plasma was more than 90%. This assay method has been successfully used to study the pharmacokinetics of myrislignan in rats.     

Determination of atractylenolide II in rat plasma by reversed-phase high-performance liquid chromatography

A method for quantitative determination of atractylenolide II in rat plasma using reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with UV spectrometry was established. From a variety of compounds and solvents tested, atractylenolide III was selected as the internal standard (IS) and ethyl acetate was found to be the best solvent for extracting atractylenolide II from plasma samples. RP-HPLC analysis of the extracts was performed on an analytical column (DIKMA ODS, 150 x 4.6 mm; i.d., 5 microm) equipped with a security guard pre-column system. There was good linearity over the range 0.05-5.0 microg/mL (r > 0.99). The recoveries were more than 90.0% in plasma, and the intra- and inter-day coefficients of variation were less than 10.0% in all cases. The limit of detection (LOD) was 0.025 microg/mL and the lower limit of quantification (LLOQ) was 0.05 microg/mL. The RP-HPLC method was applied to quantitate atractylenolide II in rat plasma within 24 h in a pharmacokinetics study where experimental rats received a single dose of atractylenolide II (60 mg/kg).     

A high-performance liquid chromatographic method for determination of scopolin in rat plasma: application to pharmacokinetic studies

An analytical method based on high-performance liquid chromatographic (HPLC) with ultraviolet (UV) detection was developed for determination of scopolin in rat plasma using aesculin as internal standard (IS). After protein precipitation of plasma sample with methanol, the supernatant was directly injected and analyzed. Chromatographic separation was achieved on a C18 column using methanol and distilled water (22:78, v/v) containing 0.2% (v/v) glacial acetic acid as mobile phase with a column temperature of 30 degrees C. The UV detector was set at 338 nm. The calibration curve was linear over the range of 0.105-13.125 microg/mL with a correlation coefficient of 0.9998. The retention times of aesculin and scopolin were 10.4 and 12.8 min, respectively. The recoveries for plasma samples of 0.105, 4.725 and 13.125 microg/mL were 91.08, 95.30 and 96.10%, respectively. The RSD of intra- and inter-day assay variations was less than 7.35%. The lower limit of detection was 0.03 microg/mL .This HPLC assay is a simple, sensitive and accurate and was successfully applied to the pharmacokinetic study of scopolin in rats.     

Improved HPLC method for doxorubicin quantification in rat plasma to study the pharmacokinetics of micelle-encapsulated and liposome-encapsulated doxorubicin formulations

An improved simple, rapid and accurate HPLC method for quantification of doxorubicin derived from micelle-encapsulated or liposome-encapsulated doxorubicin formulation in rat plasma was described. The mobile phase consisting of a mixture of methanol-water [containing 0.1% formic acid anhydrous and 0.1% ammonia solution (25%), pH 3.0], 60:40, was delivered at a flow rate of 1.0 mL/min. Sample preparation for micelle- or liposome-encapsulated doxorubicin in rat plasma were achieved directly by protein precipitation with acetonitrile. Doxorubicin and daunorubicin (internal standard, IS) were separated on a C(18) reversed-phase HPLC column and quantified by a fluoresence detection with an excitation wavelength of 475 nm and an emission wavelength of 580 nm. The linearity was obtained over the range of 5.0-1000.0 ng/mL and 1.0-200.0 microg/mL for doxorubicin and the lower limit of quantitation was 5.0 ng/mL. For each level of quality control samples, inter- and intra-assay precision was less than 9.6 and 5.1% (relative standard deviation), respectively, and percentage error was within +/-2.6%. The extraction recoveries of doxorubicin in the range of 10 ng/mL to 100 microg/mL in rat plasma were between 94.1 and 105.6%. This method was successfully applied to the pharmacokinetic study of doxorubicin formulations after i.v. administration to rats.     

高效液相色谱法测定大鼠血浆中的原儿茶酸

建立了大鼠血浆中原儿茶酸含量测定的高效液相色谱方法。采用的色谱柱为DiamondsilTM C18 柱(150 mm×4.6 mm,5 μm);流动相为乙腈-水(体积比为9∶91,用H3PO4 调pH至2.5);流速1.2 mL/min;检测波长260 nm;内标为对羟基苯甲酸。原儿茶酸的线性范围为0.050~3.20 mg/L,线性相关系数为0.9978，最低定量限为0.050 mg/L,日内和日间测定的精密度（以相对标准偏差表示）均低于7.0%,准确度（以相对误差表示）为-1.4%～2.6%；在0.050,0.40,3.20 mg/L低、中、高3个添加浓度水平下，血浆样品的提取回收率分别为83.4%,87.3%,91.1%。该方法简便,灵敏,准确,适用于大鼠体内原儿茶酸的药物动力学研究。     

Pharmacokinetic study of p-coumaric acid in mouse after oral administration of extract of Ananas comosus L. leaves

Quantification of p-coumaric acid in mouse plasma following oral administration of Ananas comosus L. leaves was achieved by reversed-phase high-performance liquid chromatography using a mobile phase of water-acetonitrile (82:18, v/v) and UV detection at 310 nm. The method was linear (determination coefficient, r2 = 0.9997) within the tested range (0.04-1.28 microg/mL). Intra- and inter-day precision coefficients of variation and accuracy bias were acceptable (maximal CV value was 4.06% for intra-day and 4.19% for inter-day) over the entire range. The recoveries were 90.63, 97.98 and 100.01% for concentrations of 0.04, 0.32 and 1.28 microg/mL, respectively. This is a very rapid, sensitive and economical way to determine p-coumaric acid concentration in mouse plasma after oral administration of A. comosus leaves. The concentration-time curve was fitted to the one-compartment model. This is the first time that p-coumaric acid extracted from A. comosus leaves was detected by HPLC-UV method and its pharmacokinetic characteristic was comprehensively studied.     

High-performance liquid chromatographic method for the determination and pharmacokinetic study of wogonoside in rat serum after oral administration of traditional Chinese medicinal preparation Huang-Lian-Jie-Du decoction

A high-performance liquid chromatographic method for the determination of wogonoside in plasma of rats administrated orally with the traditional Chinese medicinal preparation Huang-Lian-Jie-Du decoction was developed. Sample preparation was carried out by protein precipitation with a mixture of acetonitrile and methanol (1:1, v/v). The extracted sample was separated on a Hypersil C(18) (150 x 5 mm i.d., 5 microm) analytical column by linear gradient elution using 0.05% (v/v) phosphoric acid (containing 5 mm sodium dihydrogen phosphate) and acetonitrile as mobile phase at a flow rate of 1.5 mL/min. The eluate was detected using a UV detector at 276 nm. The assay was linear over the range 0.109-7.0 microg/mL (R(2) = 0.9999, n = 5). Mean recovery was determined as 98.39%. Intra- and inter-day precisions (RSD) were < or =7.59%. The limit of quantitation was 0.109 microg/mL. After validation, the HPLC method developed was applied to investigate the preliminary pharmacokinetics of wogonoside in rat after oral administration of Huang-Lian-Jie-Du decoction.     

Determination of iguratimod in rat plasma by high performance liquid chromatography: method and application

A high-performance liquid chromatographic method with UV detection has been developed for the determination of iguratimod (T-614) in rat plasma. Plasma was precipitated with acetonitrile after the addition of the internal standard (IS), N-[4-(2-formylaminoacetyl)-5-methoxy-2-phenoxyphenyl]-methanesulfonamide. The chromatographic separation was achieved on a reversed-phase C(18) column with the mobile phase acetonitrile-acetic acid aqueous solution, pH 4.5 (40:60, v/v), at a flow rate of 1 mL/min, and the UV detection wavelength was set at 257 nm. The calibration curve was linear over the range 0.10-50.0 microg/mL, and the lower limit of quantification was 0.10 microg/mL. The intra- and inter-day relative standard deviations were all less than 11.5%. The method has been successfully applied to study the pharmacokinetics of iguratimod in rats. A single 10 mg/kg dose of iguratimod was given to the rats by intragastric administration. The mean maximum plasma concentration of iguratimod for the six rats was 14.5 microg/mL, and the mean elimination half-life of iguratimod was 4.0 h.     

LC determination of luteolin-7-O-β-D-glucoside and apigenin-7-O-β-D-glucoside in rat plasma after administration of Humulus scandens extract and its application to pharmacokinetic studies

The present study was to investigate the pharmacokinetics of luteolin-7-O-β-D-glucoside (LGL) and apigenin-7-O-β-D-glucoside (AGL) in rat plasma after intravenous administration of the Humulus scandens extract (HSE). A simple and accurate high-performance liquid chromatographic (HPLC) method was successfully developed for simultaneous determination of LGL and AGL in rat plasma after the plasma protein was precipitated with methanol. HPLC analysis was performed on a C?? column with UV detection at 350?nm and a mobile phase of methanol-0.2% phosphoric acid (1?:?1, v/v). Calibration curves of LGL and AGL were linear over the concentration range of 0.16-20.0 and 0.06-7.20?μg?mL?1, respectively. The accuracy and precision of the two analytes at low, medium and high concentrations were within the range of -3.4% to 8.1%. The relative standard deviations (RSDs) of the intra- and inter-day precisions were less than 11.7% and 10.0%, respectively. The extraction recoveries (n?=?5) varied from 91.9% to 104.1% for LGL and from 92.6% to 109.3% for AGL. The method was fully validated and successfully applied to a pharmacokinetic study of LGL and AGL in rat plasma after the intravenous administration of HSE.     

Determination of human plasma protein binding of baicalin by ultrafiltration and high-performance liquid chromatography

A simple and selective HPLC assay was developed and utilized for determination of human plasma protein binding of baicalin. The method involved solid-phase extraction and reversed-phase chromatographic separation with a mobile phase of acetonitrile-0.02 mol/L phosphate buffer (pH 2.5; 25:75, v/v) and UV detection at 276 nm. The standard curve for baicalin was linear over the concentration range 0.1-20 microg/mL and the limit of detection was 0.02 microg/mL. The absolute recovery was greater than 76%. The intra-day and inter-day variations were less than 10%. Ultrafiltration technique was applied to determining the plasma protein binding of baicalin in human plasma. Results show the plasma protein binding of baicalin was in the range 86-92% over all the concentrations studied and the protein binding association constant was determined to be 1.21 x 10(5) L/mol at 4 degrees C.     

Simultaneous determination of hydroxysafflor yellow A and ferulic acid in rat plasma after oral administration of the co-extractum of Rhizoma chuanxiong and Flos Carthami by HPLC-diode array detector

A simple, rapid and accurate HPLC method has been developed for simultaneous determination of hydroxysafflor yellow A and ferulic acid in rat plasma after oral administration of the co-extractum of Rhizoma chuanxiong and Flos Carthami. Plasma samples were deproteinized with 6% perchloric acid, and riboflavin was used as internal standard. The supernatant after centrifuge was injected into a Shimadzu C(18) (150 x 4.6 mm, i.d. 5 microm) column. Gradient elution for A:B (0 min, 90:10; 25 min, 70:30; 27 min, stop) was applied. The mobile phase was composed of 0.022 mol/L potassium dihydrogen phosphate solutions, adjusted to pH 3.0 with phosphoric acid for pump A, and 90% (v/v) acetonitrile for pump B. The assay was shown to be linear over the range 0.046-4.6 microg/mL (r(2) = 0.9995) for hydroxysafflor yellow A and 0.037-3.7 microg/mL (r(2) = 0.9998) for ferulic acid. Mean recovery was 97.5% for hydroxysafflor yellow A and 83.6% for ferulic acid. Both of the intra-day and inter-day precisions were 相似文献   

Determination of Paclitaxel in Human Plasma by UPLC-MS-MS

A sensitive and specific ultra-performance liquid chromatography-tandam mass spectrometry method for the quantitation of paclitaxel is established. A 200 microL human plasma sample is spiked with 13C6-labeled paclitaxel as an internal standard and extracted with 1.3 mL of tert-butyl methyl ether. The chromatographic separation is achieved within 2 min on a C18 column with methanol-0.1% aqueous formic acid (75:25, v/v) as a mobile phase at a flow rate of 0.4 mL/min. Multiple reaction monitoring mass transitions of m/z 876.2 to 307.9 and 882.2 to 313.9 are measured for paclitaxel and the internal standard, respectively. For paclitaxel at the concentrations of 1.021, 5.105, and 10.21 microg/mL in human plasma, the extraction recoveries are 105.87%, 103.91%, and 100.39%, respectively. The linear quantitation range of the method is 0.1021-20.42 microg/mL in human plasma with a correlation coefficient greater than 0.999. The intra- and inter-day accuracy for paclitaxel at 1.021, 5.105, and 10.21 microg/mL levels in human plasma fell in the ranges of 95.01-99.23% and 95.29-101.28%, and the intra- and inter-day precision were in the ranges of 6.37-10.88% and 7.21-9.05%, respectively. This method is successfully applied to the determination of the half-life of paclitaxel in human plasma.