LC-MS/MS determination and pharmacokinetic study of albiflorin and paeoniflorin in rat plasma after oral administration of Radix Paeoniae Alba extract and Tang-Min-Ling-Wan

A rapid, sensitive and selective liquid chromatography/tandem mass spectrometry method (LC‐MS/MS) was developed and validated for simultaneous determination of albiflorin and paeoniflorin in rat plasma using geniposide as an internal standard. Plasma samples were extracted by solid‐phase extraction. Chromatographic separation was carried out on a Zorbax SB‐C₁₈ analytical column (150 × 2.1 mm × 5 µm) with 0.1% formic acid–acetonitrile (70:30, v/v) as the mobile phase. Detection was performed by multiple reaction monitoring mode using electrospray ionization in the positive ion mode. The total run time was 3.0 min between injections. The calibration curves were linear over a range of 1–1000 ng/mL for albiflorin and 2–2000 ng/mL for paeoniflorin. The overall precision and accuracy for all concentrations of quality controls and standards were better than 15%. Mean recovery was determined to be 87.7% for albiflorin and 88.8% for paeoniflorin. The validated method was successfully applied to the pharmacokinetic study of albiflorin and paeoniflorin in rat plasma after oral administration of Radix Paeoniae Alba extract and Tang‐Min‐Ling‐Wan. The pharmacokinetic parameters showed that albiflorin and paeoniflorin from Tang‐Min‐Ling‐Wan were absorbed more rapidly with higher concentrations in plasma than that from Radix Paeoniae Alba extract. The results provided a meaningful basis for evaluating the clinical applications of traditional Chinese medicine. Copyright © 2010 John Wiley & Sons, Ltd.     

Studies on metabolism of total glucosides of paeony from Paeoniae Radix Alba in rats by UPLC‐Q‐TOF‐MS/MS

Total glucosides of paeony are the active constituents of Paeoniae Radix Alba. In this study, a novel strategy was proposed to find more metabolites and the differences between paeoniflorin, albiflorin and total glucosides of paeony (TGP). This strategy was characterized as follows: firstly, the animals were divided into three groups (paeoniflorin, albiflorin and TGP) to identify the source of TGP metabolites from paeoniflorin or albiflorin; secondly, a generic information‐dependent acquisition scan for the low‐level metabolites was triggered by the multiple mass defect filter and dynamic background subtraction; thirdly, the metabolites were identified with a combination of data‐processing methods including mass defect filtering, neutral loss filtering and product ion filtering; finally, a comparative study was used in the metabolism of paeoniflorin, albiflorin and TGP. Based on the strategy, 18 metabolites of TGP, 10 metabolites of paeoniflorin and 13 metabolites of albiflorin were identified respectively. The results indicated that the hydrolysis, conjugation reaction and oxidization were the major metabolic pathways, and the metabolic sites were the glycosidic linkage, the ester bond and the benzene ring. This study is first to explore the metabolism of TGP, and these findings enhance our understanding of the metabolism and the interactions of paeoniflrin and albiflorin in TGP. Copyright © 2015 John Wiley & Sons, Ltd.     

Pharmacokinetic comparison of five tanshinones in normal and arthritic rats after oral administration of Huo Luo Xiao Ling Dan or its single herb extract by UPLC‐MS/MS

A fast, sensitive and reliable ultra performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method has been developed and validated for simultaneous quantitation and pharmacokinetic study of five tanshinones (tanshinone I, tanshinone IIA, tanshinone IIB, dihydrotanshinone I, cryptotanshinone), the bio‐active ingredients of Huo Luo Xiao Ling Dan (HLXLD) in rat plasma. After liquid–liquid extraction, chromatographic separation was accomplished on a Shim‐pack XR‐ODS column (75 × 3.0 mm, 2.2 µm particles) and eluted with a mobile phase consisting of acetonitrile–0.05% formic acid aqueous solution (80:20, v/v) at a flow rate of 0.4 mL/min, and the total run time was 7.0 min. The detection was performed on a triple quadrupole tandem mass spectrometry equipped with an electrospray ionization source in positive ionization and multiple reaction monitoring mode. The lower limits of quantification were 0.050–0.400 ng/mL for all the analytes. Linearity, precision and accuracy, the mean extraction recoveries and matrix effects all satisfied criteria for acceptance. This validated method was successfully applied to a comparative pharmacokinetic study of five bio‐active components in rat plasma after oral administration of HLXLD or Salvia miltiorrhiza extract in normal and arthritic rats. The results showed that there were different pharmacokinetic characteristics among different groups. Copyright © 2016 John Wiley & Sons, Ltd.     

Pharmacokinetic study of ardisiacrispin A in rat plasma after intravenous administration by UPLC–MS/MS

In this work, a sensitive and selective UPLC‐MS/MS method for determination of ardisiacrispin A in rat plasma was developed. Cyasterone used as an internal standard (IS) and protein precipitation by acetonitrile–methanol (9:1, v /v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C₁₈ column (2.1 × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring mode was used for quantification using target fragment ions m /z 1083.5 → 407.1 for ardisiacrispin A and m /z 521.3 → 485.2 for IS. Calibration plots were linear throughout the range 5–2000 ng/mL for ardisiacrispin A in rat plasma. Mean recoveries of ardisiacrispin A in rat plasma ranged from 80.4 to 92.6%. The values of RSD of intra‐ and inter‐day precision were both <11%. The accuracy of the method was between 97.3 and 105.6%. The method was successfully applied to pharmacokinetic study of ardisiacrispin A after intravenous administration in rats.     

Simultaneous quantification of multiple components in rat plasma by UPLC‐MS/MS and pharmacokinetic study after oral administration of Huangqi decoction

A rapid, sensitive and accurate UPLC‐MS/MS method was developed for the simultaneous quantification of components of Huangqi decoction (HQD), such as calycosin‐7‐O‐β‐d ‐glucoside, calycosin‐glucuronide, liquiritin, formononetin‐glucuronide, isoliquiritin, liquiritigenin, ononin, calycosin, isoliquiritigenin, formononetin, glycyrrhizic acid, astragaloside IV, cycloastragenol, and glycyrrhetinic acid, in rat plasma. After plasma samples were extracted by protein precipitation, chromatographic separation was performed with a C₁₈ column, using a gradient of methanol and 0.05% acetic acid containing 4mm ammonium acetate as the mobile phase. Multiple reaction monitoring scanning was performed to quantify the analytes, and the electrospray ion source polarity was switched between positive and negative modes in a single run of 10 min. Method validation showed that specificity, linearity, accuracy, precision, extraction recovery, matrix effect and stability for 14 components met the requirements for their quantitation in biological samples. The established method was successfully applied to the pharmacokinetic study of multiple components in rats after intragastric administration of HQD. The results clarified the pharmacokinetic characteristics of multiple components found in HQD. This research provides useful information for understanding the relation between the chemical components of HQD and their therapeutic effects.     

Determination of rhynchophylline and hirsutine in rat plasma by UPLC‐MS/MS after oral administration of Uncaria rhynchophylla extract

An ultra‐performance liquid chromatography with tandem mass spectrometry (UPLC–MS/MS) method was developed and validated to concurrently determine rhynchophylline and hirsutine in rat plasma. The sample preparation of rat plasma was achieved by alkalization and liquid–liquid extraction. The mass transition of precursor ion → product ion pairs were monitored at m/z 385.2 → 160.0 for rhynchophylline, m/z 369.3 → 144.0 for hirsutine and m/z 414.0 → 220.0 for noscapine (internal standard). This method revealed linear relationships from 2.5 to 50 ng/mL (r² > 0.997) for rhynchophylline and from 2.5 to 50 ng/mL (r² > 0.998) for hirsutine. The limit of quantification values for rhynchophylline and hirsutine in rat plasma were both 2.5 ng/mL. Intra‐day and inter‐day precisions were within 10.6% and 12.5%, respectively, for rhynchophylline and hirsutine, and the accuracy (bias) was <10%. Liquid–liquid extraction of rat plasma samples resulted in insignificant matrix effect, and the extraction recoveries were >83.6% for rhynchophylline, 73.4% for hirsutine and 90.7% for the internal standard. This method was applied successfully to a pharmacokinetic study of rhynchophylline and hirsutine in rats after oral administration. Copyright © 2013 John Wiley & Sons, Ltd.     

Simultaneous determination of ten flavonoids of crude and wine‐processed Radix Scutellariae aqueous extracts in rat plasma by UPLC‐ESI‐MS/MS and its application to a comparative pharmacokinetic study

Radix Scutellariae (RS) is a herbal medicine with various pharmacological activities to treat inflammation, respiratory and gastrointestinal infections, etc. In this study, a rapid, sensitive and selective UPLC‐ESI‐MS/MS method was developed for simultaneous determination of 10 flavonoids – scutellarin, scutellarein, chrysin, wogonin, baicalein, apigenin, wogonoside, oroxylin A‐7‐O‐glucuronide, oroxylin A and baicalin – from RS aqueous extracts in rat plasma with propyl paraben as internal standard (IS). Chromatographic separation was achieved on a C₁₈ column using gradient elution with the mobile phase consisting of methanol and water (containing 0.1% formic acid) at a flow rate of 0.2 mL/min. The detection was performed in multiple reaction monitoring mode using electrospray ionization in negative mode. The validated method showed good linearity over a wide concentration range (r >0.9935). The intra‐ and interday assay variabilities were <9.5% and <12.4% for all analytes, respectively. The extraction recovery ranged from 71.2 to 89.7% for each analyte and IS. This method was successfully applied to pharmacokinetic comparision after oral administration of crude and wine‐processed RS aqueous extracts. There were significant differences in some pharmacokinetic parameters of most analytes between crude and wine‐processed RS. This suggested that wine‐processing exerted effects absorption of most flavonoids. Copyright © 2014 John Wiley & Sons, Ltd.     

Metabolic profile and pharmacokinetics of polyphyllin I,an anticancer candidate,in rats by UPLC‐QTOF‐MS/MS and LC‐TQ‐MS/MS

Polyphyllin I (PPI), a natural steroidal saponin originating from rihzome of Paris polyphylla , is a potential anticancer candidate. Previous pharmacokinetics study showed that the oral bioavailability of PPI was very low, which suggested that certain amount of PPI might be metabolized in vivo . However, to date, information regarding the final metabolic fates of PPI is very limited. In this study, metabolites of PPI and their pharmacokinetics in rats were investigated using UPLC‐QTOF‐MS/MS and LC‐TQ‐MS/MS. A total of seven putative metabolites, including six phase I and one phase II metabolites, were detected and identified with three exact structures by comparison with authentic standards for the first time. Oxidation, deglycosylation and glucuronidation were found to be the major metabolic processes of the compound in rats. The pharmacokinetics of prosapogenin A, trillin and diosgenin, three deglycosylation metabolites of PPI with definite anticancer effects, were further studied, which suggested that the metabolites underwent a prolonged absorption and slower elimination after intragastric administration of PPI at the dose of 500 mg/kg. This study provides valuable and new information on the metabolic fate of PPI, which will be helpful in further understanding its mechanism of action.     

Simultaneous determination of the bioactive components in rat plasma by UPLC‐MS/MS and application in pharmacokinetic studies after oral administration of radix Scutellariae extract

A highly sensitive and rapid ultraperformance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method has been developed and validated for simultaneous quantification of the four main bioactive compounds, i.e. baicalin, baicalein, wogonoside and wogonin, in rat plasma after oral administration of Radix Scutellariae extract. Clarithromycin was used as an internal standard (IS). Plasma samples were processed by protein precipitation with methanol. The separation was performed on an Acquity BEH C₁₈ column (100 × 2.1 mm, 1.7 μm) at a flow rate of 0.4 mL/min, using 0.1% formic acid–acetonitrile as mobile phase. The MS/MS ion transit ions monitored were 447.5 → 270.1 for baicalin, 270.1 → 168.1 for baicalein, 461.2 → 284.0 for wogonoside, 284.2 → 168.1 for wogonin and 748.5 → 158.1 for IS. Method validation was performed according to US Food and Drug Administration guidelines and the results met the acceptance criteria. The lower limit of quantification (LLOQ) achieved was 1.13 ng/mL for baicalin, 1.23 ng/mL for baicalein, 0.82 ng/mL for wogonoside and 0.36 ng/mL for wogonin. The calibration curves obtained were linear (r > 0.99) over the concentration range ~ 1–1000 ng/mL. The intra‐ and inter‐day precision was <15% and the accuracy was within ±14.7%. After validation, this method was successfully applied to a pharmacokinetic study of Radix Scutellariae extract.     

Determination of armepavine in mouse blood by UPLC‐MS/MS and its application to pharmacokinetic study

The purpose of this study was to develop an ultra‐performance liquid chromatography with tandem mass spectrometry (UPLC‐MS/MS) method to determine armepavine in mouse blood. Nuciferine was used as internal standard. Chromatographic separation was performed on a UPLC BEH (2.1 × 50 mm, 1.7 μm) column with a gradient elution of acetonitrile and 10 mmol/L ammonium acetate solution (containing 0.1% formic acid). The quantitative analysis was conducted in multiple reaction monitoring mode with m/z 314.1 → 106.9 for armepavine and m/z 296.2 → 265.1 for nuciferine. Calibration curves were linear (r > 0.995) over the concentration range 1–1000 ng/mL in mouse blood with a lowest limit of quantitation of 1 ng/mL. The intra‐ and inter‐day precisions of armepavine in mouse were < 13.5 and 10.8%, respectively. The accuracy ranged between 86.8 and 103.3%. Meanwhile, the average recovery was >70.7% and the matrix effect was within the range 109.5–113.7%. All of the obtained data confirmed the satisfactory sensitivity and selectivity of the developed method which was then successfully applied to evaluate the pharmacokinetic behavior of armepavine in mouse for the first time. The bioavailability of armepavine in mouse was calculated to be 11.3%.     

Validated UPLC‐MS/MS method for quantification of seven compounds in rat plasma and tissues: Application to pharmacokinetic and tissue distribution studies in rats after oral administration of extract of Eclipta prostrata L.

A rapid, sensitive and specific ultra‐high‐performance liquid chromatography coupled with tandem mass spectrometry (UPLC‐MS/MS) method was developed to investigate the pharmacokinetics and tissue distribution of Eclipta prostrata extract. Rats were orally administrated the 70% ethanol extract of E. prostrata, and their plasma as well as various organs were collected. The concentrations of seven main compounds, ecliptasaponin IV, ecliptasaponin A, apigenin, 3′‐hydroxybiochanin A, luteolin, luteolin‐7‐O‐glucoside and wedelolactone, were quantified by UPLC‐MS/MS through multiple reactions monitoring method. The precisions (RSD) of the analytes were all <15.00%. The extraction recoveries ranged from 74.65 to 107.45% with RSD ≤ 15.36%. The matrix effects ranged from 78.00 to 118.06% with RSD ≤ 15.04%. To conclude, the present pharmacokinetic and tissue distribution studies provided useful information for the clinical usage of Eclipta prostrata L.     

Metabolic study of paeoniflorin and total paeony glucosides from Paeoniae Radix Rubra in rats by high‐performance liquid chromatography coupled with sequential mass spectrometry

A clear understanding of the metabolism of Traditional Chinese Medicines is extremely important in their rational clinical application and effective material foundation research. A novel and reliable strategy was performed to find more metabolites of paeoniflorin, determine the metabolites of total paeony glucosides (TPG) by means of determining those metabolites of paeoniflorin, and compare the metabolism differences between paeoniflorin and TPG by intragastric administration. This strategy was characterized as follows. Firstly, the rats were divided into two groups (the paeoniflorin group and the TPG group) to find differences in metabolism mechanisms between paeoniflorin and TPG. Secondly, UPLC‐FT‐ICR MS and UPLC‐Q‐TOF MS² were applied to obtain accurate molecular weight and structural information, respectively. Thirdly, the metabolites were tentatively identified by a combination of data‐processing methods including mass defect screening, characteristic neutral loss screening and product ion screening. Finally, a comparative study was employed in the metabolism of paeoniflorin and TPG. Based on the strategy, 18 metabolites of paeoniflorin (including four new compounds) and 11 metabolites of TPG (including two new compounds) were identified. In all of the identified metabolites of paeoniflorin, two metabolites in rat plasma, four metabolites in rat urine and six metabolites in rat feces were found for the first time after paeoniflorin administration. The results indicate that hydrolyzation of the ester bond and glucosidic band and conjugation with glucuronide were the major metabolic pathways of paeoniflorin. The metabolites of paeoniflorin and TPG in rat plasma, urine and feces have been detected for the first time after intragastric administration. The results may contribute to a better understanding of the metabolism mechanism and provide a scientific rationale for researching the material basis of paeoniflorin and TPG in vivo.     

Determination and validation of chikusetsusaponin IVa in rat plasma by UPLC‐MS/MS and its application to pharmacokinetic study

A novel, sensitive and rapid ultra‐performance liquid chromatography–tandem mass spectrometric method for the quantification of chikusetsusaponin IVa (CHS‐IVa) in rat plasma was established and validated. Plasma samples were pre‐treated by precipitation of protein with acetonitrile and chromatographed on a Waters Symmetry C₁₈ analytical column (4.6 × 50 mm, i.d., 3.5 μm) using a mobile phase consisting of methanol and water containing 0.05% formic acid (55:45, v/v) at a flow rate of 0.4 mL/min. The deprotonated molecular ions [M ? H]^– were employed in electrospray negative ionization mode and selected reaction monitoring transitions were performed for detection. The calibration curves exhibited good linearity (r > 0.99) over the range of 0.5–1000 ng/mL for CHS‐IVa. The recoveries of CHS‐IVa were >92.5% and exhibited no severe matrix effect. This method was successfully applied in the pharmacokinetic study of CHS‐IVa in rats. For oral administration, the plasma concentrations of CHS‐IVa increased to a peak value at 0.35 ± 0.14 h, followed by a gradual decrease to the lower limit of quantitation in 24 h. For intravenous administration, the plasma concentrations of CHS‐IVa decreased quickly (t_1/2, 1.59 ± 0.25 h). The absolute bioavailability of CHS‐IVa in rats was 8.63%. Copyright © 2016 John Wiley & Sons, Ltd.     

Studies on excretion kinetics of ten constituents in rat urine after oral administration of Shensong Yangxin Capsule by UPLC‐MS/MS

A rapid and sensitive ultra‐high performance liquid chromatography–mass spectrometry (UPLC‐MS/MS) method was developed and validated for the quantification of 10 major active constituents in rat urine after oral administration of Shensong Yangxin Capsule (SSYX) using diazepam as an internal standard (IS). The urine samples were pretreated and extracted by solid‐phase extraction prior to UPLC. Chromatographic separation was achieved on a Waters C₁₈ (2.1 × 50 mm, 1.7 µm) column using a gradient elution program with 0.1% formic acid aqueous solution and acetonitrile at a flow rate of 0.4 mL/min. Detection and quantitation were accomplished by a hybrid quadrupole mass spectrometer using electrospray ionization source and multiple reaction monitoring in the positive ionization mode. The mass transition ion‐pairs (m/z) for quantitation were all optimized and the total run time was 4.50 min. The specificity, linearity, accuracy, precision, recovery, matrix effect and stabilities were all validated for the analytes in urine samples. The validation results indicated that this method was simple, rapid, specific and reliable. The proposed method was successfully applied to investigate the urinary excretion kinetics of 10 compounds in rat after oral administration of SSYX. Copyright © 2013 John Wiley & Sons, Ltd.     

Chemical UPLC‐ESI‐MS/MS profiling of aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Aconitum carmichaelii Debx. Root extract

In this paper, an ultra high performance liquid chromatography tandem mass spectrometric (UPLC‐ESI‐MS/MS) method in positive ion mode was established to systematically identify and to compare the major aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Fuzi extract. A total twenty‐nine components including twenty‐five C19‐diterpenoid alkaloids and four C20‐diterpenoid alkaloids were identified in Fuzi extract. Thirteen of the parent components and five metabolites were detected in rat plasma and sixteen parent compounds and six metabolites in urine. These parent components found in rat plasma and urine were mainly C19‐diterpenoid alkaloids. All of the metabolites in vivo were demethylated metabolites (phase I metabolites), which suggested that demethylation was the major metabolic pathway of aconitum alkaloids in vivo. A comparison of the parent components in rat plasma and urine revealed that 3‐deoxyacontine was found in plasma but not in urine, while kalacolidine, senbusine and 16‐β‐hydroxycardiopetaline existed in urine but not in plasma, which indicated that most alkaloids components were disposed and excreted in prototype form. This research provides some important information for further metabolic investigations of Fuzi in vivo.     

Identification of the constituents and metabolites in rats after oral administration of Zi Shen Formula by UPLC‐Q‐TOF/MS combined pattern recognition analysis

An ultra‐high‐performance liquid chromatography mass spectrometry method was established to detect and identify the chemical constituents of Zi Shen Formula (ZSF) and its metabolites in serum, urine and feces, after oral administration to rats. A total of 68 compounds were characterized in ZSF extracts. In vivo, 38 prototype components and 32 metabolites of ZSF were tentatively identified in rat serum, urine and feces. Seven metabolic pathways including demethylation, hydroxylation, oxidation, sulfation, glucuronidation, methylation and de‐caffeoyl were proposed to be involved in the generation of these metabolites. It was found that glucuronidation, methylation and demethylation were the major metabolic processes of alkaloids, while demethylation, methylation, sulfation and de‐caffeoyl were the major metabolic pathways of phenylethanoid glycosides. The main metabolic pathways of steroidal saponins were oxidation and isotype reactions. These findings are significant for our understanding of the metabolism of ZSF. The proposed metabolic pathways of bioactive components might be crucial for further studies of the mechanisms of action and pharmacokinetic evaluations of ZSF.     

LC‐MS/MS analysis of Gegen Qinlian Decoction and its pharmacokinetics after oral administration to rats

A liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the simultaneous determination of 12 constituents of Gegen Qinlian Decoction (GQD), namely puerarin, daidzein, baicalin, wogonoside, wogonin, liquiritin, liquiritigenin, berberine, jatrorrhizine, palmatine, coptisine and glycyrrhetic acid, in rat plasma. The plasma samples were spiked with the internal standard (IS) carbamazepine acidified with HCl and extracted by liquid–liquid extraction with ethyl acetate. Chromatographic separation was achieved on a Shiseido Capcell PAK C₁₈ column utilizing a gradient elution profile and a mobile phase consisting of (A) 0.1% formic acid in water and (B) acetonitrile. Detection was performed in the multiple reaction monitoring mode using electrospray ionization in the positive ion mode at a flow rate of 0.3 mL/min and a run time of 8 min. All of the calibration curves gave good linearity (r > 0.9930) over the concentration range from 0.6–360 to 16.2–9720 ng/mL for all components. The intra‐ and inter‐day precisions were <15.0% in terms of the relative standard deviation, and the accuracies were within ±13.7% in terms of the relative error. The method was successfully applied to investigate the pharmacokinetics of the major active compounds of Gegen Qinlian Decoction after its oral administration to rats. Copyright © 2014 John Wiley & Sons, Ltd.     

Simultaneous determination of neochlorogenic acid,chlorogenic acid,cryptochlorogenic acid and geniposide in rat plasma by UPLC‐MS/MS and its application to a pharmacokinetic study after administration of Reduning injection

A simple, specific and sensitive ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method was established and validated for simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma using puerarin as an internal standard (IS). Plasma samples were pretreated by a one‐step direct protein precipitation procedure with acetonitrile after acidified using as little as 50 μL plasma. Chromatographic separation was performed on an Acquity BEH C₁₈ column (100 × 2.1 mm, 1.7 µm) at a flow rate of 0.2 mL/min by a gradient elution, using 0.2% acetic acid–methanol as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via electrospray ionization source with negative ion mode. Calibration curves showed good linearity (r > 0.995) over wide concentration ranges. The intra‐ and inter‐day precisions were <15%, and the accuracy was within ±8.0%. The validated method was successfully applied to a pharmacokinetic study of the four bioactive components in rats after intravenous administration of Reduning injection. Copyright © 2014 John Wiley & Sons, Ltd.     

Simultaneous determination of three active components in rat plasma by UPLC–MS/MS: Application to pharmacokinetic study after oral administration of Herba Sarcandrae extract

A rapid, specific and sensitive ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method was developed and validated for determination of isofraxidin, rosmarinic acid and kaempferol‐3‐O ‐glucuronide in rat plasma using warfarin as an internal standard (IS). Separation was conducted on a Thermo Hypersil GOLD C₁₈ column with linear gradient elution using methanol and water. Mass spectrometric detection was conducted using selected reaction monitoring (SRM) via an electrospray ionization (ESI) source. All analytes exhibited good linearity within their concentration ranges (r > 0.9990). The lower limits of quantitations of isofraxidin, rosmarinic acid, and kaempferol‐3‐O‐ glucuronide were 1.31, 0.67 and 0.92 ng/mL, respectively. Intra‐ and inter‐day precisions of these investigated components exhibited an RSD within 11.7%, and the accuracy ranged from −12.5 to 15.0% at all QC levels. The developed method was successfully applied to a pharmacokinetic study of isofraxidin, rosmarinic acid, and kaempferol‐3‐O‐ glucuronide in rats after oral administration of Herba Sarcandrae Extract.     

Determination of sunitinib and its active metabolite,N‐desethyl sunitinib in mouse plasma and tissues by UPLC‐MS/MS: assay development and application to pharmacokinetic and tissue distribution studies

A simple, sensitive and specific method using ultraperformance liquid chromatography/tandem mass spectrometry (UPLC‐MS/MS) was developed to determine sunitinib and N‐desethyl sunitinib in mouse plasma and tissues. The analytes were separated by an isocratic mobile phase consisting of acetonitrile and buffer solution (water with 0.1% formic acid and 5 m m ammonium acetate; 40: 60, v/v) running at a flow rate of 0.35 mL/min for 2 min. Quantification was performed using a mass spectrometer by multiple reaction monitoring in positive electrospray ionization mode. The transition was monitored at m/z 399 → 283, m/z 371 → 283 and m/z 327 → 270 for sunitinib, N‐desethyl sunitinib and internal standard, respectively. Calibration curves were linear over concentration ranges of 2–500, 0.5–50 and 1–250 ng/mL for plasma, heart and other biosamples. The method was successfully applied to animal experiments. The pharmacokinetic study indicated that sunitinib was eliminated quickly in mice with a half‐life of 1.2 h; tissue distribution data showed more sunitinib and its metabolite in liver, spleen and lung, which provided reference for further study. Copyright © 2014 John Wiley & Sons, Ltd.