Simultaneous determination of tapentadol and its carbamate prodrug in rat plasma by UPLC‐MS/MS and its application to a pharmacokinetic study

A prodrug of tapentadol, namely tapentadol carbamate (WWJ01), was synthesized to improve the bioavailability of tapentadol owing to its extensive first‐pass metabolism. In this study, a highly rapid and sensitive UPLC‐MS/MS method was developed and validated for the simultaneous determination of tapentadol and WWJ01 in rat plasma with fluconazole as an internal standard. The analytes and internal standard were treated by methanol and then separated on a Phenomenex Kinetex® XB‐C₁₈ (2.1 × 50 mm × 2.6 μm) column at a flow rate of 0.3 mL/min. The mobile phase comprised methanol and water with a gradient elution. The mass transition ion‐pairs were m/z 222.2 → 107.0, m/z 293.2 → 71.9 and m/z 307.1 → 220.0 for tapentadol, WWJ01 and IS, respectively. Excellent linearity was observed over the concentration range of 2–1250 ng/mL (r = 0.995) with a lower limit of quantification of 2 ng/mL for both tapentadol and WWJ01. The intra‐ and inter‐day accuracy and precision for all quality control samples were within ±15%. The validated method was accurate, rapid and reproducible, and was successfully applied to a pharmacokinetic study of tapentadol and WWJ01.     

UPLC‐MS/MS determination of voriconazole in human plasma and its application to a pharmacokinetic study

A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method was developed to determine voriconazole in human plasma. Sample preparation was accomplished through a simple one‐step protein precipitation with methanol. Chromatographic separation was carried out on an Acquity UPLC BEH C₁₈ column using an isocratic mobile phase system composed of acetonitrile and water containing 1% formic acid (45:55, v/v) at a flow rate of 0.50 mL/min. Mass spectrometric analysis was performed using a QTrap5500 mass spectrometer coupled with an electrospray ionization source in the positive ion mode. The multiple reaction monitoring transitions of m/z 351.0 → 281.5 and m/z 237.1 → 194.2 were used to quantify voriconazole and carbamazepine (internal standard), respectively. The linearity of this method was found to be within the concentration range of 2.0–1000 ng/mL with a lower limit of quantification of 2.0 ng/mL. Only 1.0 min was needed for an analytical run. This fully validated method was successfully applied to the pharmacokinetic study after oral administration of 200 mg voriconazole to 20 Chinese healthy male volunteers. Copyright © 2014 John Wiley & Sons, Ltd.     

Simultaneous determination of etonogestrel and ethinyl estradiol in human plasma by UPLC‐MS/MS and its pharmacokinetic study

A selective, sensitive and rapid ultra‐performance liquid chromatography tandem mass spectrometry method was developed and validated for the simultaneous determination of etonogestrel (ENG) and ethinyl estradiol (EE) in human plasma. The analytes and their deuterated internal standards, ENG‐d7 and EE‐d4, were extracted from plasma samples by solid‐phase extraction on HyperSep™ Retain PEP cartridges. The chromatographic analysis was performed on an Acquity UPLC HSS Cyano column, 100 Å (50 × 2.1 mm, 1.8 μm), column using gradient mobile phase, acetonitrile and 2.0 mm ammonium trifluoroacetate at 0–1.7 min (65:35, v/v) and 1.8–2.7 min (95:5, v/v) with 0.250 mL/min flow rate. Analytes and IS protonated precursor → product ion transitions (ENG, m/z 325.2 → 257.2; EE, m/z 530.2 → 171.2; ENG‐d7, m/z 332.2 → 263.2; EE‐d4, m/z 534.2 → 171.2) were monitored on a Triple Quadrupole Mass spectrometer (TQMS), operating in multiple reaction monitoring and positive ionization mode. The calibration curves were established at 10.00–2500 pg/mL for ENG and 1.500–150.0 pg/mL for EE with a correlation coefficient (r²) ≥0.9996 for both. The validated method was successfully applied to support a bioequivalence study of 0.15 mg ENG and EE 0.03 mg tablet formulation, administered in 24 healthy Indian females. Method reliability was assessed by reanalysis of 94 incurred study samples.     

A quantitative determination of fluorochloridone in rat plasma by UPLC‐MS/MS method: application to a pharmacokinetic study

A precise, high‐throughput and sensitive ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method has been developed for the determination of fluorochloridone (FLC) in rat plasma. The extraction of analytes from plasma samples was carried out by protein precipitation procedure using acetonitrile prior to UPLC‐MS/MS analysis. Verapamil was proved as a proper internal standard (IS) among many candidates. The chromatographic separation based on UPLC was well optimized. Multiple reaction monitoring in positive electrospray ionization was used with the optimized MS transitions at: m/z 312.0 → 292.0 for FLC and m/z 456.4 → 165.2 for IS. This method was well validated with good linear response (r² > 0.998) observed over the investigated range of 3–3000 ng/mL and with satisfactory stability. This method was also characterized with adequate intra‐ and inter‐day precision and accuracy (within 12%) in the quality control samples, and with high selectivity and less matrix effect observed. Total running time was only 1.5 min. This method has been successfully applied to a pilot FLC pharmacokinetic study after oral administration. Copyright © 2016 John Wiley & Sons, Ltd.     

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.     

Development and validation of UPLC‐MS/MS method for determination of domperidone in human plasma and its pharmacokinetic application

A sensitive, rapid and selective ultra‐performance liquid chromatography–tandem mass spectrometric (UPLC‐MS/MS) method was developed for the determination and pharmacokinetic study of domperidone in human plasma. Diphenhydramine was used as the internal standard. Plasma sample pretreatment involved a one‐step liquid–liquid extraction with a mixture of diethyl ether–dichloromethane (3:2, v/v). The analysis was carried out on an Acquity UPLC^TM BEH C₁₈ column. The mobile phase consisted of methanol–water containing 10 mmol/L ammonium acetate and 0.5% (v/v) formic acid (60:40, v/v). The detection was performed on a triple quadrupole tandem mass spectrometer in multiple reaction monitoring mode via electrospray ionizationsource with positive mode. Each plasma sample was chromatographed within 2.1 min. The standard curves for domperidone were linear (r² ≥ 0.99) over the concentration range of 0.030–31.5 ng/mL with a lower limit of quantification of 0.030 ng/mL. The intra‐ and inter‐day precision (relative standard deviation) values were not higher than 13% and accuracy (relative error) was from ?7.6 to 1.2% at three quality control levels. The method herein described was superior to previous methods and was successfully applied to the pharmacokinetic study of domperidone in healthy Chinese volunteers after oral administration. Copyright © 2012 John Wiley & Sons, Ltd.     

Development and validation of a UPLC‐MS/MS method for the determination of cucurbitacin B in rat plasma and application to a pharmacokinetic study

Cucurbitacin B (CuB), one of the most abundant forms of cucurbitacins, is a promising natural anticancer drug candidate. Although the anticancer activity of CuB has been well demonstrated, information regarding the pharmacokinetics is limited. A rapid, selective and sensitive UPLC‐MS/MS for CuB was developed and validated using hemslecin A (HeA) as internal standard (IS). Plasma samples were pre‐treated by liquid–liquid extraction with dichloromethane. Separation was achieved on a reversed‐phase C₁₈ column (50 × 4.6 mm, 5 µm) at 35°C using isocratic elution with water–methanol (25:75, v/v) at a flow rate of 0.3 mL/min. The analytes were monitored by a triple quadrupole tandem mass spectrometer with positive electrospray ionization mode. The calibration curve was linear (r > 0.995) in a concentration range of 0.3–100 ng/mL with a limit of quantification of 0.3 ng/mL. Intra‐ and inter‐day accuracy and precision were validated by percentage relative error and relative standard deviation, respectively, which were both lower than the limit of 15%. This assay was successfully applied to a pharmacokinetic study of CuB in Wistar rats. Copyright © 2015 John Wiley & Sons, Ltd.     

Development of a sensitive and rapid UPLC‐MS/MS method for the determination of koumine in rat plasma: application to a pharmacokinetic study

A rapid, selective and sensitive method using UPLC‐MS/MS was first developed and validated for quantitative analysis of koumine in rat plasma. A one‐step protein precipitation with methanol was employed as a sample preparation technique. Plasma samples were separated on an Acquity UPLC BEH C₁₈ column (50 × 2.1 mm, i.d. 1.7 µm) with a gradient mobile phase consisting of methanol with 0.1% (v/v) formic acid and water containing 0.1% (v/v) formic acid at a flow rate of 0.3 mL/min. Detection and quantification were performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring mode via positive eletrospray ionization. Good linearity (r > 0.9997) was achieved using weighted (1/x²) least squares linear regression over a concentration range of 0.025–15 µg/mL with a lower limit of quantification of 0.025 µg/mL for koumine. The intra‐ and inter‐ precisions (relative standard deviation) of the assay at all three quality control samples were 5.6–14.1% with an accuracy (relative error) of 5.0–14.0%, which meets the requirements of the US Food and Drug Administration guidance. This developed method was successfully applied to an in vivo pharmacokinetic study in rats after a single intravenous dose of 20 mg/kg koumine. Copyright © 2012 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 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.     

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.     

Development of a validated UPLC–MS/MS method for determination of humantenmine in rat plasma and its application in pharmacokinetics and bioavailability studies

Humantenmine (HMT), the most toxic compound isolated from Gelsemium elegans Benth , is a well‐known active herbal compound. A rapid and sensitive ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was developed and validated to estimate the absolute oral bioavailability of HMT in rats. Quantification was performed by multiple reaction monitoring using electrospray ionization operated in positive ion mode with transitions of m/z 327.14 → m/z 296.19 for HMT and m/z 323.20 → m/z 236.23 for gelsemine (internal standard, IS). The linear range of the calibration curve was 1–256 nmol/L, with a lower limit of quantification at 1 nmol/L. The accuracy of HMT ranged from 89.39 to 107.5%, and the precision was within 12.24% (RSD). Excellent recovery and negligible matrix effect were observed. HMT remained stable during storage, preparation and analytical procedures. The pharmacokinetics of HMT in rats showed that HMT reached the concentration peak at 12.50 ± 2.74 min with a peak concentration of 28.49 ± 6.65 nmol/L, and the corresponding area under the concentration–time curve (AUC_0–t ) was 1142.42 ± 202.92 nmol/L min after 200 μg/kg HMT was orally administered to rats. The AUC_0–t of HMT given at 20 μg/kg by tail vein administration was 1518.46 ± 192.24 nmol/L min. The calculated absolute bioavailability of HMT was 7.66%.     

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.     

UPLC‐MS/MS method for the determination of tobacco‐specific biomarker NNAL,tamoxifen and its main metabolites in rat plasma

Cigarette smoke is known to interact with tamoxifen‐metabolizing enzymes and transporters and potentially affect its treatment outcome. 4‐(N‐ nitrosomethylamino)‐1‐(3‐pyridyl)‐1‐butanol (NNAL) is an important metabolite of 4‐(methylnitro‐samino)‐1‐(3‐pyridyl)‐1‐butanone (NNK) because it is frequently used as a biomarker to assess human smoke exposure. In order to study the potential pharmacokinetic interaction between cigarette smoke and tamoxifen in rats a UPLC‐MS/MS method for the simultaneous determination of NNAL and tamoxifen along with its metabolites in rat plasma has been developed and validated. Analytes were extracted with methanol and separated on a HSS T3 column by a gradient elution with the mobile phase consisting of acetonitrile and water. The lower limits of quantitation ranged from 0.05 to 0.62 ng/mL. Precisions showed RSD <15.8% and accuracy in the range 80.6–116.0%. Mean analyte recoveries ranged from 76.9 to 108.4%. The method was successfully applied to study the effects of cigarette smoke condensate (CSC), NNK and benzo(a)pyrene pre‐treatment on the pharmacokinetics of tamoxifen and its metabolites in rats. Significant effects of CSC, NNK, benzo(a)pyrene were observed on pharmacokinetics of tamoxifen and its metabolites. We also found that plasma NNAL levels are statistically significant correlated with plasma 4‐hydroxy‐tamoxifen and endoxifen.     

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%.     

A UPLC‐MS/MS method for simultaneous determination of five flavonoids from Stellera chamaejasme L. in rat plasma and its application to a pharmacokinetic study

Stellera chamaejasme L. has been used as a traditional Chinese medicine for the treatment of scabies, tinea, stubborn skin ulcers, chronic tracheitis, cancer and tuberculosis. A sensitive and selective ultra‐high liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method was developed and validated for the simultaneous determination of five flavonoids (stelleranol, chamaechromone, neochamaejasmin A, chamaejasmine and isochamaejasmin) of S. chamaejasme L. in rat plasma. Chromatographic separation was accomplished on an Agilent Poroshell 120 EC‐C₁₈ column (2.1 × 100 mm, 2.7 μm) with gradient elution at a flow rate of 0.4 mL/min and the total analysis time was 7 min. The analytes were detected using multiple reaction monitoring in positive ionization mode. The samples were prepared by liquid–liquid extraction with ethyl acetate. The UPLC‐MS/MS method was validated for specificity, linearity, sensitivity, accuracy and precision, recovery, matrix effect and stability. The validated method exhibited good linearity (r ≥ 0.9956), and the lower limits of quantification ranged from 0.51 to 0.64 ng/mL for five flavonoids. The intra‐ and inter‐day precision were both <10.2%, and the accuracy ranged from −11.79 to 9.21%. This method was successfully applied to a pharmacokinetic study of five flavonoids in rats after oral administration of ethyl acetate extract of S. chamaejasme L.     

A rapid UPLC‐MS/MS method for the determination of oleanolic acid in rat plasma and liver tissue: application to plasma and liver pharmacokinetics

A reliable high‐throughput ultra‐high performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method was developed and validated for oleanolic acid (OA) determination in rat plasma and liver tissue using glycyrrhetic acid as the internal standard (IS). Plasma and liver homogenate samples were prepared using solid‐phase extraction. Chromatographic separation was achieved on a C₁₈ column using an isocratic mobile phase system. The detection was performed by multiple reaction monitoring mode via positive electrospray ionization interface. The calibration curves showed good linearity (R² > 0.9997) within the tested concentration ranges. The lower limit of quantification for plasma and liver tissue was ≤0.75 ng/mL. The intra‐ and inter‐day precision and accuracy deviations were within ±15% in plasma and liver tissue. The mean extraction recoveries ranged from 80.8 to 87.0%. In addition, the carryover, matrix effect, stability and robustness involved in the method were also validated. The method was successfully applied to the plasma and hepatic pharmacokinetics of OA after oral administration to rats. Copyright © 2015 John Wiley & Sons, Ltd.     

Development of a rapid and sensitive UPLC‐MS/MS assay for the determination of TM‐2 in beagle dog plasma and its application to a pharmacokinetic study

A simple and sensitive method based on ultra‐high‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) has been developed for the determination of TM‐2, which was a novel semi‐synthetic taxane derivative in beagle dog plasma. Cabazitaxel was chosen as internal standard. Following extraction by methyl tert‐butyl ether, the chromatographic separation was achieved on a Thermo Syncronis C₁₈ column (50 × 2.1 mm, 1.7 µm) by gradient elution within a runtime of 3.5 min. The mobile phase consisted of (A) acetonitrile and (B) 2 mmol/L ammonium acetate in water. The detection was accomplished using positive ion electrospray ionization in multiple reaction monitoring mode. The MS/MS ion transitions were monitored at m/z 812.39 → 551.35 for TM‐2 and 836.36 → 555.26 for IS, respectively. The method was linear for TM‐2 (r = 0.9924) ranging from 2.5 to 1000 ng/mL. The intra‐day and inter‐day precisions (relative standard deviation) were within 8.0 and 17.6%, respectively, and the accuracy (relative error) was less than 2.3%. The extraction recovery ranged from 83.1 to 97.1%. The reliable method was successfully applied to a pharmacokinetic study of TM‐2 in beagle dogs after intravenous drip with different doses of 0.6, 1.2, and 2.4 mg/kg, respectively. 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.     

A UPLC/MS/MS method for determination of protosappanin B in rat plasma and its application of a pharmacokinetic and bioavailability study

Caesalpinia sappan L . is a traditional medicinal plant which is used for promoting blood circulation and cerebral apoplexy therapy in China. Previous reports showed that the extracts of Caesalpinia sappan L . could exert vasorelaxant activity and anti‐inflammation activity. Protosappanin B is a major constituent of C. sappan L. , and showed several important bioactivities. The separation was achieved by an Acquity UPLC BEH Symmetry Shield RP₁₈ column (1.7 μm, 2.1 × 100 mm) column with the gradient mobile phase consisting of 5 mm ammonium acetate aqueous solution and acetonitrile. Detection was carried out by using negative‐ion electrospray tandem mass spectrometry via multiple reaction monitoring. Plasma samples were preprocessed by an extraction with ethyl acetate, and apigenin was used as internal standard. The current UPLC–MS/MS assay was validated for linearity, accuracy, intraday and interday precisions, stability, matrix effects and extraction recovery. After oral and intravenous administration, the main pharmacokinetic parameters were as follows: peak concentrations, 83.5 ± 46.2 and 1329.6 ± 343.6 ng/mL; areas under the concentration–time curve, 161.9 ± 69.7 and 264.9 ± 56.3 μg h/L; and half‐lives, 3.4 ± 0.9 and 0.3 ± 0.1 h, respectively. The absolute bioavailability in rats of protosappanin B was 12.2%. The method has been successfully applied to a pharmacokinetic and bioavailability study of protosappanin B in rats.