A new HPLC MS method to determine loratadine in human plasma was established. The method involved extracting drug with organic solvent under basic conditions. The samples were seperated by ODS column and determined ...A new HPLC MS method to determine loratadine in human plasma was established. The method involved extracting drug with organic solvent under basic conditions. The samples were seperated by ODS column and determined by mass detector. The calibration curve of loratadine was linear within the range of 0.4～100 ng·mL -1 with r=0.9995 . The recovery of this method was within 95%～104%, within day and between day RSD were less than 12%. To study the pharmacokinetics and relative bioavailability of loratadine tablets, two formulations of loratadine tablets were given to 18 healthy male volunteers according to a randomized 2 way cross over design. The C max , AUC 0 t and T max values of the two formulations were 51.89±20.18 ng·mL -1 and 52.48±22.35 ng·mL -1 ; 140.75±88.42 ng·h·mL -1 and 147.24±92.33 ng·h·mL -1 ; 0.81±0.35 h and 0.81±0.27 h respectively. Results from statistic analysis showed that there were no significant difference between the C max , AUC 0-t and T max values of the two formulations. The relative bioavailability of tablets I with respect to tablets II was 97%±13% from the AUC 0 t measurement. Bioequivalance was observed between the two tablets.展开更多
Aim To develop and validate a sensitive and specific liquid chromatography electrospray ionization ion-trap mass spectrometry （LC-ESI-MS/MS） method for the identification and concentration of rupatadine in human pla...Aim To develop and validate a sensitive and specific liquid chromatography electrospray ionization ion-trap mass spectrometry （LC-ESI-MS/MS） method for the identification and concentration of rupatadine in human plasma. Methods After the addition of the internal standard （IS, loratadine） and 0.01 mol·L^-1 sodium hydroxide solution, plasma samples were extracted with methylene chloride： ethyl acetate mixture （20：80, V/V）. The organic layer was evaporated under vacuum drying at 37 ℃. The residue was reconstituted with 200 μL mobile phase. Chromatography was performed on an Agilent Eclipse XDB-C18 （4.6 mm × 150 mm, 5 μm） column with a mobile phase consisting of acetonitrile （1% formic acid） -20 mmol·L^-1 ammonium acetate （76：24, V/V） at a flow-rate of 0.6 mL·min^-1. Detection was performed on Agilent MSD Trap XCT ion-trap mass spectrometry connected to a Agilent 1100 high performance liquid chromatography （HPLC） by selected reaction monitoring （SRM） mode via electrospray ionization （ESI） source. Rupatadine （MRM m/z 416 → 309） and loratadine （MRM m/z 383 → 337） were detected by Agilent MSD Trap XCT ion-trap mass analyser. Results The method was proved to be sensitive and specific by testing 20 different plasma batches. Linearity was established for the range of concentrations 0.05 - 14.0 ng·mL^ -1 with a coefficient of determination （r） of 0.998. The intra-and inter-day precision （RSD %） were lower than 15% and accuracy ranged from 85.1% to 114.0%. The lower limit of quantitation （LLOQ） was identifiable and reproducible at 0.05 ng·mL^-1 with a precision of 9.22% （n =5）. Conclusion The proposed method is sensitive and reproducible enough to be used in pharmacokinetic, bioavailability or bioequivalence studies of rupatadine.展开更多
A new pre-column derivation HPLC method with solid-phase extraction to determine captopril in human plasma was established. Derivation products were extracted by a solid-phase extraction method after the reagent, p-a-...A new pre-column derivation HPLC method with solid-phase extraction to determine captopril in human plasma was established. Derivation products were extracted by a solid-phase extraction method after the reagent, p-a-dibromoacetophenone(p-BPB), was added in the plasma samples. The samples were analyzed in a VP-ODS column with UV-detector. The calibration curve of captopril was linear within the range of 5~1000 ngmL-1 with r=0.9987, the recovery of this method was 98.652.04%, within day and between day RSD were no more than 3.4% and 8.4% respectively. To study the pharmacokinetics and the relative bioavailability of captopril tablets, two formulations of captopril tablets were given to 18 healthy male volunteers according to a randomized 2-way cross-over design with a 1-week washout period. The respective AUC0~6 , Cmax and Tmax values of the two formulations were 424.5125.7 and 439.4113.3 mghL-1; 505.9244.6 and 504.8172.2 mgL-1; 0.6620.181 and 0.5280.176 h. Results from statistics analysis showed that there were no significant difference between the AUC0~6 , Cmax and Tmax values of the two formulations, The relative bioavailability of tablets I with respect to II was 96.114.6% from AUC0~6 measurement. Bioequivalance was observed between the two tablets.展开更多
A simple and sensitive high-performance liquid chromatography mass spectrometry（LC-MS）method for the simultaneous determination of irbesartan and hydrochlorothiazide in human plasma was developed and applied to a ph...A simple and sensitive high-performance liquid chromatography mass spectrometry（LC-MS）method for the simultaneous determination of irbesartan and hydrochlorothiazide in human plasma was developed and applied to a pharmacokinetic study. Acetaminophen was used as the internal standard（IS）.Sample pretreatment using liquid-liquid extraction with ethyl acetate was used.The analysis was carried out on an Elite SinoChrom ODS-BP C_（18）column with a mobile phase composed of acetonitrile-water （35：65,v/v）.Target ions were [M-H]^-m/z 427.25 for irbesartan,[M-H]^-m/z 295.95 for hydrochlorothiazide and [M-H]^- m/z 150.05 for the IS via an electrospray ionization（ESI）source.The intra-and inter-day precision（RSD%）was below 14.5% for irbesartan and hydrochlorothiazide,and the accuracy（RE%）was less than 1.9% and-2.0% for irbesartan and hydrochlorothiazide,respectively.The linear calibration curves were obtained in the concentration range of 10-5000 ng/mL （r0.99）for irbesartan and 1-200 ng/mL（r0.99）for hydrochlorothiazide with the lower limit of quantification（LLOQ）of 10 ng/mL and 1 ng/mL,respectively.The method was applied to a clinical pharmacokinetic study of a tablet containing irbesartan and hydrochlorothiazide in healthy Chinese volunteers after oral administration.展开更多
Geniposide is a major bioactive constituent isolated from Gardeniajasminoides Ellis. To evaluate the pharmacokinetics of geniposide in pre-clinical studies, a rapid and specific liquid chromatography-tandem mass spect...Geniposide is a major bioactive constituent isolated from Gardeniajasminoides Ellis. To evaluate the pharmacokinetics of geniposide in pre-clinical studies, a rapid and specific liquid chromatography-tandem mass spectrometry （LC-MS/MS） method was developed and validated. After simple protein precipitation, geniposide was analyzed on a DiamonsilR C18 column with a mobile phase of 10 mM ammonium acetate and methanol （20：80, v/v） at a flow rate of 0.6 mL/min. Detection was performed in ＂Truncated＂ multiple-reaction monitoring （MRM） mode with positive electrospray ionization （ESI） at m/z 411→411 for geniposide, and MRM mode with negative ESI ionization at m/z 415→295 for puerarin （internal standard, IS）. Linearity was established in the concentration range from 10.0 to 5000 ng/mL. The extraction recoveries ranged from 84.8% to 90.5% at concentrations of 10.0, 500 and 4.5x 103 ng/mL. The lower limit of quantification （LLOQ） was 10.0 ng/mL with 50 ~tL plasma. The validated method was successfully applied to the pharmacokinetic study of geniposide in rats at a dose of 200 mg/kg by oral administration.展开更多
A new high-performance liquid chromatography （HPLC） method for the quantitative determination of sitagliptin in rat plasma was developed and validated for pharmacokinetics study. The plasma was spiked with the inter...A new high-performance liquid chromatography （HPLC） method for the quantitative determination of sitagliptin in rat plasma was developed and validated for pharmacokinetics study. The plasma was spiked with the internal standard （hydrocortisone, IS）, treated with sodium hydroxide, and extracted with ethyl acetate. The extracted analyte was injected into an Agilent Zorbax Extend-C18 column （250 mm×4.6 mm, 4 μm） maintained at 30℃ and monitored at 267 nm. The mobile phase consisting of methanol-water （60：40, v/v, containing 10 mM Tris and 10 mM triethylamine） was titrated to pH 9.0 using 1 mol/L hydrochloric acid. The flow rate was 1.0 mL/min. The method showed high specificity. Calibration curves of the peak area ratio of each analyte/IS versus sitagliptin concentration were linear in the range of 0.75-100.0μg/mL （r〉0.9957）. The lower limit of quantification （LLOQ） was 0.75 μg/mL. The intra-day and inter-day coefficient of variation was lower than 10%. The accuracy （relative recovery） at three levels was 105.3% （0.75 μg/mL）, 99.8% （10.0 μg/mL） and 99.0% （100.0 μg/mL）. The extraction recovery was 81.5%, 82.4% and 84.5% at the concentrations of 0.75, 10.0 and 100.0 μg/mL, respectively. The short-term, long-term, freeze-thaw storage stability of plasma samples and the stability of standard solutions were satisfactory. This HPLC method is suitable for determining the concentration of sitagliptin in rat plasma and it was applied to determine the concentration-time profiles of sitagliptin in rat plasma following oral administration of sitagliptin.展开更多
An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deprotei...An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deproteinated with 10% （v/v） perchloric acid. Separation was achieved on a UltimateTM AQ-C18 column （250 mm×4.6 mm, 5 μm） with a mobile phase （pH 5.05） composed of acetonitrile-water （31：69, v/v, containing 0.002 M sodium dodecyl sulfate, 0.0125 M potassium dihydrogen phosphate, 0.015 M triethylamine） at a flow rate of 1.0 mL/min. The calibration curve was linear （r〉0.994） between 7.5 and 4000 ng/mL. The lower limit of quantification （LLOQ） was 7.5 ng/mL. The precision was validated and the relative standard deviation was in the range of 1.87% to 15.70%; the accuracy was between 93.98%-106.89%. The mean recoveries were 95.40% and 95.31% for metformin and IS, respectively. The relative error （RE） of stability at different storage conditions was within ±9.00%. This method was used to determine the concentration-time profile of metformin in diabetic rat plasma following an oral administration of metformin at the dose of 10 mg/kg. Our results indicated that ion-pair HPLC-UV method using UltimateTM AQ-C18 column was effective for the pharmacokinetic studies of high polarity compounds like metformin.展开更多
A selective and sensitive HPLC method has been developed and validated for the quantification of ganoderic acid T in rat plasma. A reverse-phase column was used with UV detection at 245 nm. The mobile phase consisted ...A selective and sensitive HPLC method has been developed and validated for the quantification of ganoderic acid T in rat plasma. A reverse-phase column was used with UV detection at 245 nm. The mobile phase consisted of methanol-water-acetic acid （95.5：4.5：0.5, v/v/v） run at a flow rate of 1 mL/min. Testosterone propionate was used as the internal standard. The standard curve was linear over the range of 0.05-50 ~tg/mL in rat plasma with a linear correlation coefficient greater than 0.999. The lower limit of quantification of this assay was 20 ng/mL. The recoveries of samples at 0.05, 2 and 40 μg/mL were 97.6%, 98.4% and 103.2%, respectively. The relative standard deviations of intra- and inter-day assay variations were less than 8.2%. The usefulness of the assay was confirmed by the successful analysis of plasma samples from a pharmacokinetics study in rats. Following a single dose of ganoderic acid T （5 mg/kg for i.v. or 14 mg/kg for p.o.）, the main pharmacokinetic parameters by intravenous injection were： t1/2α （5.46±1.25） min; t1/2β：（227.18±11.40） min; CL： （1.09±0.16） mL/（kg·min）; A UC0-12 h： （3939.13±311.14） μg.min/mL; AUC0-12h （4681.96±710.70）μg.min/mL and the absolute bioavailability was 41.98%±2.40%. This method is simple, sensitive, and accurate. It is suitable for pharmacokinetic studies of ganoderic acid in rats.展开更多
In the present study, we developed and validated a selective, specific and sensitive liquid chromatography-electrospray ionization mass spectrometry （LC-ESI-MS/MS） method for the determination of tenofovir in human ...In the present study, we developed and validated a selective, specific and sensitive liquid chromatography-electrospray ionization mass spectrometry （LC-ESI-MS/MS） method for the determination of tenofovir in human plasma. Entecavir was used as an internal standard, and plasma samples were prepared by solid-phase extraction performed on Phenomenex Strata cartridges （30 mg）. The mobile phase consisted of 10 mM ammonium acetate in water and methanol （60：40, v/v）. The chromatographic separation was performed isocratically on a Phenomenex C18 （4.6 mm×150 mm, 5 μm）, and analytes were analyzed in multiple reaction monitoring （MRM） mode with positive electrospray ionization （ESI） interface using the respective [M＋H] ＋ ions, m/z 288.2→m/z 176.1 for tenofovir and m/z 278.1→m/z 152 for entecavir. The calibration curve （r2 = 0.9962） of tenofovir was established within the range of 4.096-1000 μg/L. The intra- and inter-day precisions were less than 10%. This validated method was successfully applied to a pharmacokinetic study in 12 healthy Chinese volunteers after the oral administration of tenofovir disonroxil fumarate.展开更多
A sensitive LC-ESI-MS/MS method for determination of isochlorogenic acid B in rat plasma was developed and validated in the present study. Plasma samples were prepared by a simple protein precipitation with methanol c...A sensitive LC-ESI-MS/MS method for determination of isochlorogenic acid B in rat plasma was developed and validated in the present study. Plasma samples were prepared by a simple protein precipitation with methanol containing resveratrol as internal standard (IS). The chromatographic separation was performed on a Zorbax SB-Cjg column (3.5 pm, 2.1 mmx 100 mm, Agilent, USA) at a flow rate of 0.2 mL/min using methanol/water containing 0.1% formic acid (v/v) as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with Electronic Spray Ion by selected reaction monitoring (SRM) of the transitions at m/z 515.3->352.9 for isochlorogenic acid B and m/z 227.1-143.1 for IS, respectively. The calibration curve of the method was linear over the range of 5-2500 ng/mL (r^2= 0.9982). The intra- and inter-day precisions (R.S.D.%) were less than 12.46%, and the accuracy (R.E.%) was within ±5.80%. Isochlorogenic acid B was sufficiently stable under all relevant analytical conditions. The validated method was successfully applied to the plasma pharmacokinetic studies of isochlorogenic acid B in rats. It was found that isochlorogenic acid B had non-linear pharmacokinetic characteristics in rats within the dosage ranges from 5 to 20 mg/kg.展开更多
A rapid, sensitive and selective UPLC-MS/MS method was developed to determine paeoniflorin and astragaloside IV, This method was validated via a pharmacokinetic study using rat plasma. The internal standard was clarit...A rapid, sensitive and selective UPLC-MS/MS method was developed to determine paeoniflorin and astragaloside IV, This method was validated via a pharmacokinetic study using rat plasma. The internal standard was clarithromycin. A simple one-step deproteinization procedure was used to prepare plasma samples. Separation was achieved on a CAPCELL CORE ADME CI8 column with a gradient mobile phase consisting of solution A （water containing 0.1% formic acid） and solution B （acetonitrile） at a flow rate of 0.3 mL/min. Multiple reaction monitoring （MRM） was used with an electrospray ionization source （ESI） in positive mode. A good linear response was observed within the ranges of 0.01 to 5.00 ~g/mL for paeoniflorin and 0.000l to 0.05 ~tg/mL for astragaloside IV. The accuracy （RE） was within the range of-3.5% to 6.3%, and the intra- and inter-day precisions （RSD） were within 14.2%. The extraction recoveries were all above 78.9%. The pharmacokinetic study of the two analytes in rats after oral administration of Huangqi Guizhi Wuwu Decoction （HGWD） was successfully completed through this method. The method develooed in this studv will fill a gap in oharmacokinetic studies of HGWD.展开更多
文摘A new HPLC MS method to determine loratadine in human plasma was established. The method involved extracting drug with organic solvent under basic conditions. The samples were seperated by ODS column and determined by mass detector. The calibration curve of loratadine was linear within the range of 0.4～100 ng·mL -1 with r=0.9995 . The recovery of this method was within 95%～104%, within day and between day RSD were less than 12%. To study the pharmacokinetics and relative bioavailability of loratadine tablets, two formulations of loratadine tablets were given to 18 healthy male volunteers according to a randomized 2 way cross over design. The C max , AUC 0 t and T max values of the two formulations were 51.89±20.18 ng·mL -1 and 52.48±22.35 ng·mL -1 ; 140.75±88.42 ng·h·mL -1 and 147.24±92.33 ng·h·mL -1 ; 0.81±0.35 h and 0.81±0.27 h respectively. Results from statistic analysis showed that there were no significant difference between the C max , AUC 0-t and T max values of the two formulations. The relative bioavailability of tablets I with respect to tablets II was 97%±13% from the AUC 0 t measurement. Bioequivalance was observed between the two tablets.
文摘Aim To develop and validate a sensitive and specific liquid chromatography electrospray ionization ion-trap mass spectrometry （LC-ESI-MS/MS） method for the identification and concentration of rupatadine in human plasma. Methods After the addition of the internal standard （IS, loratadine） and 0.01 mol·L^-1 sodium hydroxide solution, plasma samples were extracted with methylene chloride： ethyl acetate mixture （20：80, V/V）. The organic layer was evaporated under vacuum drying at 37 ℃. The residue was reconstituted with 200 μL mobile phase. Chromatography was performed on an Agilent Eclipse XDB-C18 （4.6 mm × 150 mm, 5 μm） column with a mobile phase consisting of acetonitrile （1% formic acid） -20 mmol·L^-1 ammonium acetate （76：24, V/V） at a flow-rate of 0.6 mL·min^-1. Detection was performed on Agilent MSD Trap XCT ion-trap mass spectrometry connected to a Agilent 1100 high performance liquid chromatography （HPLC） by selected reaction monitoring （SRM） mode via electrospray ionization （ESI） source. Rupatadine （MRM m/z 416 → 309） and loratadine （MRM m/z 383 → 337） were detected by Agilent MSD Trap XCT ion-trap mass analyser. Results The method was proved to be sensitive and specific by testing 20 different plasma batches. Linearity was established for the range of concentrations 0.05 - 14.0 ng·mL^ -1 with a coefficient of determination （r） of 0.998. The intra-and inter-day precision （RSD %） were lower than 15% and accuracy ranged from 85.1% to 114.0%. The lower limit of quantitation （LLOQ） was identifiable and reproducible at 0.05 ng·mL^-1 with a precision of 9.22% （n =5）. Conclusion The proposed method is sensitive and reproducible enough to be used in pharmacokinetic, bioavailability or bioequivalence studies of rupatadine.
文摘A new pre-column derivation HPLC method with solid-phase extraction to determine captopril in human plasma was established. Derivation products were extracted by a solid-phase extraction method after the reagent, p-a-dibromoacetophenone(p-BPB), was added in the plasma samples. The samples were analyzed in a VP-ODS column with UV-detector. The calibration curve of captopril was linear within the range of 5~1000 ngmL-1 with r=0.9987, the recovery of this method was 98.652.04%, within day and between day RSD were no more than 3.4% and 8.4% respectively. To study the pharmacokinetics and the relative bioavailability of captopril tablets, two formulations of captopril tablets were given to 18 healthy male volunteers according to a randomized 2-way cross-over design with a 1-week washout period. The respective AUC0~6 , Cmax and Tmax values of the two formulations were 424.5125.7 and 439.4113.3 mghL-1; 505.9244.6 and 504.8172.2 mgL-1; 0.6620.181 and 0.5280.176 h. Results from statistics analysis showed that there were no significant difference between the AUC0~6 , Cmax and Tmax values of the two formulations, The relative bioavailability of tablets I with respect to II was 96.114.6% from AUC0~6 measurement. Bioequivalance was observed between the two tablets.
文摘A simple and sensitive high-performance liquid chromatography mass spectrometry（LC-MS）method for the simultaneous determination of irbesartan and hydrochlorothiazide in human plasma was developed and applied to a pharmacokinetic study. Acetaminophen was used as the internal standard（IS）.Sample pretreatment using liquid-liquid extraction with ethyl acetate was used.The analysis was carried out on an Elite SinoChrom ODS-BP C_（18）column with a mobile phase composed of acetonitrile-water （35：65,v/v）.Target ions were [M-H]^-m/z 427.25 for irbesartan,[M-H]^-m/z 295.95 for hydrochlorothiazide and [M-H]^- m/z 150.05 for the IS via an electrospray ionization（ESI）source.The intra-and inter-day precision（RSD%）was below 14.5% for irbesartan and hydrochlorothiazide,and the accuracy（RE%）was less than 1.9% and-2.0% for irbesartan and hydrochlorothiazide,respectively.The linear calibration curves were obtained in the concentration range of 10-5000 ng/mL （r0.99）for irbesartan and 1-200 ng/mL（r0.99）for hydrochlorothiazide with the lower limit of quantification（LLOQ）of 10 ng/mL and 1 ng/mL,respectively.The method was applied to a clinical pharmacokinetic study of a tablet containing irbesartan and hydrochlorothiazide in healthy Chinese volunteers after oral administration.
基金Laboratory for Rare Disease of Shandong Province
文摘Geniposide is a major bioactive constituent isolated from Gardeniajasminoides Ellis. To evaluate the pharmacokinetics of geniposide in pre-clinical studies, a rapid and specific liquid chromatography-tandem mass spectrometry （LC-MS/MS） method was developed and validated. After simple protein precipitation, geniposide was analyzed on a DiamonsilR C18 column with a mobile phase of 10 mM ammonium acetate and methanol （20：80, v/v） at a flow rate of 0.6 mL/min. Detection was performed in ＂Truncated＂ multiple-reaction monitoring （MRM） mode with positive electrospray ionization （ESI） at m/z 411→411 for geniposide, and MRM mode with negative ESI ionization at m/z 415→295 for puerarin （internal standard, IS）. Linearity was established in the concentration range from 10.0 to 5000 ng/mL. The extraction recoveries ranged from 84.8% to 90.5% at concentrations of 10.0, 500 and 4.5x 103 ng/mL. The lower limit of quantification （LLOQ） was 10.0 ng/mL with 50 ~tL plasma. The validated method was successfully applied to the pharmacokinetic study of geniposide in rats at a dose of 200 mg/kg by oral administration.
基金National Integrity Innovational Technology Platform of New Drug and Research and Development (Grant No. 2009ZX09301-010)National Fund for Talent Training in Basic Science
文摘A new high-performance liquid chromatography （HPLC） method for the quantitative determination of sitagliptin in rat plasma was developed and validated for pharmacokinetics study. The plasma was spiked with the internal standard （hydrocortisone, IS）, treated with sodium hydroxide, and extracted with ethyl acetate. The extracted analyte was injected into an Agilent Zorbax Extend-C18 column （250 mm×4.6 mm, 4 μm） maintained at 30℃ and monitored at 267 nm. The mobile phase consisting of methanol-water （60：40, v/v, containing 10 mM Tris and 10 mM triethylamine） was titrated to pH 9.0 using 1 mol/L hydrochloric acid. The flow rate was 1.0 mL/min. The method showed high specificity. Calibration curves of the peak area ratio of each analyte/IS versus sitagliptin concentration were linear in the range of 0.75-100.0μg/mL （r〉0.9957）. The lower limit of quantification （LLOQ） was 0.75 μg/mL. The intra-day and inter-day coefficient of variation was lower than 10%. The accuracy （relative recovery） at three levels was 105.3% （0.75 μg/mL）, 99.8% （10.0 μg/mL） and 99.0% （100.0 μg/mL）. The extraction recovery was 81.5%, 82.4% and 84.5% at the concentrations of 0.75, 10.0 and 100.0 μg/mL, respectively. The short-term, long-term, freeze-thaw storage stability of plasma samples and the stability of standard solutions were satisfactory. This HPLC method is suitable for determining the concentration of sitagliptin in rat plasma and it was applied to determine the concentration-time profiles of sitagliptin in rat plasma following oral administration of sitagliptin.
基金National Integrity Innovational Technology Platform of New Drug and Research and Development (Grant No.2009ZX09201-010)Innovation Team of Ministry of Education(Grant No. BMU20110263)
文摘An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deproteinated with 10% （v/v） perchloric acid. Separation was achieved on a UltimateTM AQ-C18 column （250 mm×4.6 mm, 5 μm） with a mobile phase （pH 5.05） composed of acetonitrile-water （31：69, v/v, containing 0.002 M sodium dodecyl sulfate, 0.0125 M potassium dihydrogen phosphate, 0.015 M triethylamine） at a flow rate of 1.0 mL/min. The calibration curve was linear （r〉0.994） between 7.5 and 4000 ng/mL. The lower limit of quantification （LLOQ） was 7.5 ng/mL. The precision was validated and the relative standard deviation was in the range of 1.87% to 15.70%; the accuracy was between 93.98%-106.89%. The mean recoveries were 95.40% and 95.31% for metformin and IS, respectively. The relative error （RE） of stability at different storage conditions was within ±9.00%. This method was used to determine the concentration-time profile of metformin in diabetic rat plasma following an oral administration of metformin at the dose of 10 mg/kg. Our results indicated that ion-pair HPLC-UV method using UltimateTM AQ-C18 column was effective for the pharmacokinetic studies of high polarity compounds like metformin.
基金Program for Shanghai Technology Innovation Action Plan,the Modernization of Chinese Medicine Special Project (Grant No.08DZ1971900)111 Program of China(Grant No. B07023)
文摘A selective and sensitive HPLC method has been developed and validated for the quantification of ganoderic acid T in rat plasma. A reverse-phase column was used with UV detection at 245 nm. The mobile phase consisted of methanol-water-acetic acid （95.5：4.5：0.5, v/v/v） run at a flow rate of 1 mL/min. Testosterone propionate was used as the internal standard. The standard curve was linear over the range of 0.05-50 ~tg/mL in rat plasma with a linear correlation coefficient greater than 0.999. The lower limit of quantification of this assay was 20 ng/mL. The recoveries of samples at 0.05, 2 and 40 μg/mL were 97.6%, 98.4% and 103.2%, respectively. The relative standard deviations of intra- and inter-day assay variations were less than 8.2%. The usefulness of the assay was confirmed by the successful analysis of plasma samples from a pharmacokinetics study in rats. Following a single dose of ganoderic acid T （5 mg/kg for i.v. or 14 mg/kg for p.o.）, the main pharmacokinetic parameters by intravenous injection were： t1/2α （5.46±1.25） min; t1/2β：（227.18±11.40） min; CL： （1.09±0.16） mL/（kg·min）; A UC0-12 h： （3939.13±311.14） μg.min/mL; AUC0-12h （4681.96±710.70）μg.min/mL and the absolute bioavailability was 41.98%±2.40%. This method is simple, sensitive, and accurate. It is suitable for pharmacokinetic studies of ganoderic acid in rats.
基金The Science and Technology Development Plan Project of Wujin District,Changzhou City,Jiangsu Province(Grant No.WS201413)the Research Funds for the Teachers of Central South University(Grant No.2014JSJJ028)
文摘In the present study, we developed and validated a selective, specific and sensitive liquid chromatography-electrospray ionization mass spectrometry （LC-ESI-MS/MS） method for the determination of tenofovir in human plasma. Entecavir was used as an internal standard, and plasma samples were prepared by solid-phase extraction performed on Phenomenex Strata cartridges （30 mg）. The mobile phase consisted of 10 mM ammonium acetate in water and methanol （60：40, v/v）. The chromatographic separation was performed isocratically on a Phenomenex C18 （4.6 mm×150 mm, 5 μm）, and analytes were analyzed in multiple reaction monitoring （MRM） mode with positive electrospray ionization （ESI） interface using the respective [M＋H] ＋ ions, m/z 288.2→m/z 176.1 for tenofovir and m/z 278.1→m/z 152 for entecavir. The calibration curve （r2 = 0.9962） of tenofovir was established within the range of 4.096-1000 μg/L. The intra- and inter-day precisions were less than 10%. This validated method was successfully applied to a pharmacokinetic study in 12 healthy Chinese volunteers after the oral administration of tenofovir disonroxil fumarate.
基金Chinese Academy of Medical Sciences(Grant No.CAMS-2017-I2M-1-011)
文摘A sensitive LC-ESI-MS/MS method for determination of isochlorogenic acid B in rat plasma was developed and validated in the present study. Plasma samples were prepared by a simple protein precipitation with methanol containing resveratrol as internal standard (IS). The chromatographic separation was performed on a Zorbax SB-Cjg column (3.5 pm, 2.1 mmx 100 mm, Agilent, USA) at a flow rate of 0.2 mL/min using methanol/water containing 0.1% formic acid (v/v) as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with Electronic Spray Ion by selected reaction monitoring (SRM) of the transitions at m/z 515.3->352.9 for isochlorogenic acid B and m/z 227.1-143.1 for IS, respectively. The calibration curve of the method was linear over the range of 5-2500 ng/mL (r^2= 0.9982). The intra- and inter-day precisions (R.S.D.%) were less than 12.46%, and the accuracy (R.E.%) was within ±5.80%. Isochlorogenic acid B was sufficiently stable under all relevant analytical conditions. The validated method was successfully applied to the plasma pharmacokinetic studies of isochlorogenic acid B in rats. It was found that isochlorogenic acid B had non-linear pharmacokinetic characteristics in rats within the dosage ranges from 5 to 20 mg/kg.
文摘A rapid, sensitive and selective UPLC-MS/MS method was developed to determine paeoniflorin and astragaloside IV, This method was validated via a pharmacokinetic study using rat plasma. The internal standard was clarithromycin. A simple one-step deproteinization procedure was used to prepare plasma samples. Separation was achieved on a CAPCELL CORE ADME CI8 column with a gradient mobile phase consisting of solution A （water containing 0.1% formic acid） and solution B （acetonitrile） at a flow rate of 0.3 mL/min. Multiple reaction monitoring （MRM） was used with an electrospray ionization source （ESI） in positive mode. A good linear response was observed within the ranges of 0.01 to 5.00 ~g/mL for paeoniflorin and 0.000l to 0.05 ~tg/mL for astragaloside IV. The accuracy （RE） was within the range of-3.5% to 6.3%, and the intra- and inter-day precisions （RSD） were within 14.2%. The extraction recoveries were all above 78.9%. The pharmacokinetic study of the two analytes in rats after oral administration of Huangqi Guizhi Wuwu Decoction （HGWD） was successfully completed through this method. The method develooed in this studv will fill a gap in oharmacokinetic studies of HGWD.
