Simultaneous quantification and rat pharmacokinetics of formononetin‐7‐O‐β‐d‐glucoside and its metabolite formononetin by high‐performance liquid chromatography–tandem mass spectrometry

Formononetin‐7‐O‐β‐d ‐glucoside has been proved to have significant anti‐inflammatory effect. To evaluate its rat pharmacokinetics, a rapid, sensitive, and specific liquid chromatography–tandem mass spectrometry method has been developed and validated for the quantification of formononetin‐7‐O‐β‐d ‐glucoside and its main metabolite formononetin in rat plasma. Samples were pretreated using a simple protein precipitation and the chromatographic separation was performed on a C₁₈ column by a gradient elution using a mobile phase consisting of water and acetonitrile both containing 0.1% formic acid. Both analytes were detected using a tandem mass spectrometer in positive multiple reaction monitoring mode. The assay showed wide linear dynamic ranges of both 0.10–100 ng/mL, with acceptable intra‐ and inter‐batch accuracy and precision. The lower limits of quantification were both 0.10 ng/mL using 50 μL of rat plasma for two analytes. The method has been successfully used to investigate the oral pharmacokinetic profiles of both analytes in rats. After oral administration of formononetin‐7‐O‐β‐d ‐glucoside at the dose of 50 mg/kg, it was rapidly absorbed in vivo and metabolized to its metabolite formononetin. The plasma concentration‐time profiles both showed double‐peak phenomena, which would be attributed to the strong enterohepatic circulation of formononetin‐7‐O‐β‐d ‐glucoside.     

Simultaneous determination of seven ginsenosides in rat plasma by high‐performance liquid chromatography coupled to time‐of‐flight mass spectrometry: application to pharmacokinetics of Shenfu injection

A high‐performance liquid chromatography coupled to time‐of‐flight mass spectrometry (HPLC‐TOF MS) method was successfully developed and validated for the identification and determination of seven ginsenosides, R_e, R_f, R_b1, R_c, R_b2, R_o and R_d, in a Chinese herbal preparation, Shenfu injection, and rat plasma. Based on the method, the pharmacokinetic profiles of the seven ginsenosides were investigated following intravenous administration of single dose of Shenfu injection to six rats. The established method had high linearity, selectivity, sensitivity, accuracy and precision. The pharmacokinetic results showed that R_b1, R_c and R_b2 had similar pharmacokinetic profiles and relatively long half‐life values (19.29 ± 6.36, 29.54 ± 22.91 and 35.60 ± 30.66 h). The half‐lives of R_f and R_d were 4.21 ± 3.68 and 8.49 ± 5.20 h, respectively, indicating that they could be metabolized more rapidly than R_b1, R_c and R_b2. Copyright © 2014 John Wiley & Sons, Ltd.     

Development of a sensitive LC‐MS/MS method for simultaneous quantification of eleven constituents in rat serum and its application to a pharmacokinetic study of a Chinese medicine Shengmai injection

A sensitive LC‐MS/MS method was developed and validated for simultaneous quantification of 11 constituents, ginsenoside Rg1, Re, Rf, Rg2, Rb1, Rd, Rc, ophiopogonin D, schisandrin, schisandrol B and schizandrin B, in rat serum using digoxin as the internal standard (IS). The serum samples were pretreated and extracted with a two‐step liquid–liquid extraction. Chromatographic separation was achieved on a C₁₈ analytical column with a proper gradient elution using 0.02% acetic acid aqueous solution and 0.02% acetic acid–acetonitrile as mobile phase at a flow rate of 0.5 mL/min. MS detection was performed using multiple reaction monitoring via an electrospray ionization source. Good linearity was observed in the validated concentration range for every analyte (r² ≥0.9929), and the lower limits of quantitation of the analytes were in the range of 0.044–1.190 ng/mL in rat serum. Intra‐ and inter‐day precisions were <14.2%. The accuracy expressed as recovery was within the range of 85.1–112.8%. The extraction recoveries were >75.8%.The validated method was successfully applied to a pharmacokinetic study of all analytes in rats after single intravenous administration of Shengmai injection. Copyright © 2014 John Wiley & Sons, Ltd.     

A novel UPLC‐MS/MS method for sensitive quantitation of boldine in plasma,a potential anti‐inflammatory agent: application to a pharmacokinetic study in rats

Boldine is a potential anti‐inflammatory agent found in several different plants. Published bioanalytical methods using HPLC with ultraviolet and fluorescent detection lacked enough sensitivity and required tedious sample preparation procedures. Herein, we describe the development of a novel ultra‐high performance LC with MS/MS for determination of boldine in plasma. Boldine in plasma was recovered by liquid–liquid extraction using 1 mL of methyl tert‐butyl ether. Chromatographic separation was performed on a C₁₈ column at 45°C, with a gradient elution consisting of acetonitrile and water containing 0.1% (v/v) formic acid at a flow rate of 0.3 mL/min. The detection was performed on an electrospray triple‐quadrupole MS/MS by positive ion multiple reaction monitoring mode. Good linearity (r² > 0.9926) was achieved in a concentration range of 2.555–2555 ng/mL with a lower limit of quantification of 2.555 ng/mL for boldine. The intra‐ and inter‐day precisions of the assay were 1.2–6.0 and 1.8–7.4% relative standard deviation with an accuracy of ?6.0–8.0% relative error. This newly developed method was successfully applied to a single low‐dose pharmacokinetic study in rats and was demonstrated to be simpler and more sensitive than the published methods, allowing boldine quantification in reduced plasma volume. Copyright © 2014 John Wiley & Sons, Ltd.     

Development and validation of a highly sensitive LC‐MS/MS method for the determination of dexamethasone in nude mice plasma and its application to a pharmacokinetic study

In the current study, a simple, sensitive and rapid analytical method for the determination of dexamethasone was developed and applied to a pharmacokinetic study in nude mice. Using testosterone as an internal standard, a liquid chromatography–tandem mass spectrometry (LC‐MS/MS) approach after one‐step precipitation with acetonitrile was validated and used to determine the concentrations of dexamethasone in nude mice plasma. The method utilized a simple isocratic reverse phase separation over a Dionex C₁₈ column with a mobile phase composed of acetonitrile–water (40:60, v/v). The analyte was detected by a triple quadrupole tandem mass spectrometer via electrospray and multiple reaction monitoring was employed to select both dexamethasone at m/z 393.0/147.1 and testosterone at m/z 289.5/97.3 in the positive ion mode. The calibration curves were linear (r >0.99) ranging from 2.5 to 500 ng/mL with a lower limit of quantitation of 2.5 ng/mL. The relative standard deviation ranged from 1.69 to 9.22% while the relative error ranged from ?1.92 to ?8.46%. This method was successfully applied to a preclinical pharmacokinetic study of dexamethasone and its pharmacokinetics was characterized by a two‐compartment model with first‐order absorption in female nude mice. Copyright © 2014 John Wiley & Sons, Ltd.     

Simultaneous quantification of two steroidal glycosides after oral gavage of Marsdenia tenacissima extract in rats using a LC‐MS/MS method

A specific, sensitive and accurate analytical LC‐MS/MS assay was developed for the simultaneous determination of two steroidal glycosides, tenacissoside H and tenacissoside I, in rat plasma. An Agilent ZORBAX SB‐C₁₈ column was used with an isocratic mobile phase system composed of methanol–water–formic acid (70:30:0.1, v/v/v) at a flow rate of 0.3 mL/min. The analysis was performed on a positive ionization electrospray mass spectrometer via selected reaction monitoring mode scan. One‐step protein precipitation with acetonitrile was chosen to extract the analytes from plasma. The lower limits of quantification were 0.9 ng/mL for tenacissoside H and tenacissoside I. The intra‐ and inter‐day precisions were 2.03–11.56 and 3.76–11.62%, respectively, and the accuracies were <110.28% at all quality control levels. The validated method was applied to a pharmacokinetic study in rats after oral gavage of Marsdenia tenacissima extract. Copyright © 2014 John Wiley & Sons, Ltd.     

Quantification of heteroclitin D in rat plasma: validation of an LC/MS/MS method and its application in a preclinical pharmacokinetic study

A rapid, sensitive and specific liquid chromatography tandem mass spectrometry (LC/MS/MS) method was developed and validated for the quantification of heteroclitin D in rat plasma after using gambogic acid as internal standard (IS). Chromatographic separation was done on a Thermo Hypersil GOLD column (30 × 2.1 mm, 3 µm) using a mobile phase consisting of methanol–water–formic acid (80:20:0.1, v/v/v). The mass spectrometer worked with positive electrospray ionization in multiple reaction monitoring mode, using target ions at [M + H]⁺ m/z 483.3 for heteroclitin D and [M + H]⁺ m/z 629.3 for the IS. The standard curve was linear (R² ≥0.995) over the concentration range 9.98–2080 ng/mL and had good back‐calculated accuracy and precision. The intra‐ and interday precision and accuracy determined on three quality control samples (29.94, 166.4 and 1872 ng/mL) were ≤12.8 and –8.9–3.6%, respectively. The extraction recovery was ≥88.2% and the lower limit of quantification was 9.98 ng/mL. The method was successfully applied to evaluate pharmacokinetics of heteroclitin D in Sprague–Dawley rats following a single intravenous bolus injection of 2.0 mg/kg heteroclitin. Copyright © 2014 John Wiley & Sons, Ltd.     

Quantification of an antitumor agent (copen) in rat plasma by liquid chromatography–electrospray ionization tandem mass spectrometry and its application in a preclinical pharmacokinetic study

Copen is a derivative obtained from the structural modification of osthole, which inhibits tumoral proliferation in many tumor cell lines. A rapid and sensitive liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method was established for the quantification of copen in rat plasma. After a simple sample preparation procedure by one‐step protein precipitation with methanol, copen and bicalutamide (internal standard, IS) were chromatographed on a Zorbax SB‐C₁₈ (4.6×100 mm, 1.8 µm) column with a mobile phase consisting of methanol–5 mm ammonium formate water with 0.1% formic acid (80:20, v/v). MS detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring mode with a positive eletrospray ionization source. The assay was validated in the concentration range of 51.58–20630 ng/mL, with a limit of quantitation (LOQ) of 51.58 ng/mL. The intra‐ and inter‐day precisions (relative standard deviation) were ≤3.21 and ≤11.3%, respectively, with accuracy (%) in the range of 94.66–102.1%. The method was fully validated in a study of the pharmacokinetics of copen (25 mg/kg) after intragastric administration in rats. Copyright © 2014 John Wiley & Sons, Ltd.     

Comparative pharmacokinetics of three monoester‐diterpenoid alkaloids after oral administration of Acontium carmichaeli extract and its compatibility with other herbal medicines in Sini Decoction to rats

Sini decoction (SND) is an important traditional Chinese multiherbal formula, which is widely used to treat cardiovascular disease. Acontium carmichaeli (AC) is a leading herb in SND, whose main components are monoester‐diterpenoid alkaloids (MDAs). The aim of this study is to compare the pharmacokinetics of three MDAs in rat plasma after oral administration of AC extract and its compatibility with other herbal medicines in SND. A sensitive, accurate and specific LC‐MS/MS method was developed to determine the contents of three MDAs in rat plasma. Male Sprague–Dawley rats were randomly assigned to four groups: AC, AC + ZO, AC + GU and SND groups. There were significant differences in the pharmacokinetic parameters (C_max, T_max, t_1/2, AUC_(0–24), MRT and CL). Compared with the AC group, C_max, AUC_(0–24) and CL of three MDAs increased and t_1/2 decreased in AC + ZO, AC + GU and SND groups. Little changed in the AC + GU group in comparison with AC + ZO group, which indicated that other ingredients in ZO may promote the absorption rate and accelerate excretion rate of MDAs. The results could be helpful for revealing the compatibility mechanism of Chinese multiherbal medicine and providing clinical medication guidance on AC and its compatibility with other herbal medicines in SND. Copyright © 2014 John Wiley & Sons, Ltd.     

Determination of a novel anticancer c‐Met inhibitor LS‐177 in rat plasma and tissues with a validated UPLC‐MS/MS method: application to pharmacokinetics and tissue distribution study

LS‐177 is a novel small‐molecule kinase inhibitor employed to interrupt the c‐Met signaling pathway. A rapid and sensitive ultraperformance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method was developed and validated for determination of LS‐177 in rat plasma and tissues. The biosamples were extracted by liquid–liquid extraction with methyl tert‐butyl ether and separated on a C₁₈ column (50 × 4.6 mm, 2.6 µm) using a gradient elution mobile phase consisting of acetonitrile–0.1% formic acid water. Under the optimal conditions, the selectivity of the method was satisfactory with no endogenous interference. The intraday and interday precisions (relative standard deviation) were <10.5% and the accuracy (relative error) was from ?12.5 to 12.5% at all quality control levels. Excellent recovery and negligible matrix effects were observed. Stability studies showed that LS‐177 was stable during the preparation and analytical processes. The UPLC‐MS/MS method was successfully applied to pharmacokinetic and tissue distribution studies. The results indicated that there was no significant drug accumulation after multiple‐dose oral administration of LS‐177. The tissue distribution study exhibited significant higher uptakes of LS‐177 in stomach, intestine, lung and liver among all of the tissues. The results in pharmacokinetics and tissue distribution may provide a meaningful basis for clinical application. Copyright © 2014 John Wiley & Sons, Ltd.