Application of TQSM polypharmacokinetics and its similarity approach to ascertain Q-marker by analyses of transitivity in vivo of five candidates in Buyanghuanwu injection.

BACKGROUND: It is well-known that the public still have been facing on a severe issue about the inconsistency of quality and therapeutic efficacy of traditional medicines. Recently, Professor Chang-Xiao Liu has created a new promising concept for identifying relevant quality-markers (Q-marker) from herbs, their formulas and manufacturing products. Therefore, building up a new approach is necessary for us to bridge over quality to efficacy of pharmaceutical products. STUDY DESIGN: In this paper, five candidate Q-markers, astragaloside IV, paeonflorin, amygdalin, tetramethylpyrazine, ferulic acid in Buyanghuanwu injection (BYHWI) had been designed to carry out in rat by using single and polypharmacokinetic models for total quanta to ascertain adequate Q-marker. METHODS: The Q-marker transitivity in vivo was studied with polypharmacokinetic model and its similarity approach, which were modeled with TQSM principle. The Q-marker was ascertained with transitive similarity and bioavailability in polypharmacokinetics. Their concentrations in plasma sample of white rat were determined by RP-HPLC. Data analyses were used by the DAS software for singles and myself-written-program with EXCEL for multiples. RESULTS: In BYHWI, five candidate Q-marker pharmacokinetic profiles were singly fixed to two compartmental models in rat using classical compartmental analysis, but there were tremendous differences among which the candidate parameters were fluctuated from nearly 3552 folds to equivalency. The theoretical value of TQSM polypharmacokinetic parameters such as AUCT, MRTT, VRTT, CLT, VT over the mixure of five drugs were 110.8 ±â€¯51.91 mg min ml-1, 176.0 ±â€¯36.5 min, 39,921 ±â€¯4311 min2, 0.3116 ±â€¯0.02347 ml min-1 kg-1, 54.83 ±â€¯7.683 ml kg-1 respectively. The TQSM polypharmacokinetic parameters in astragaloside Ⅳ ordered by AUCT, MRTT, VRTT, CLT, VT were 110.8 ±â€¯51.91 mg min ml-1, 176.0 ±â€¯36.5 min, 39,921 ±â€¯4311 min2, 0.3116 ±â€¯0.02347 ml min-1 kg-1, 54.83 ±â€¯7.683 ml kg-1, respectively, which were closed to the theoretical values. TQSM similarity versus astragaloside Ⅳ was 0.9661. CONCLUSION: The results represented that the optimum Q-marker in BYHWI is astragaloside Ⅳ, whose transitivity in vivo similarity was close to the behavior of polypharmacokinetics with maximum bioavailability to the total quanta. It is feasible for Q-marker in CMMs to screen on the comparison of single pharmacokinetic behavior and bioavailability to the total quanta.

An UHPLC-MS/MS method for simultaneous determination of quercetin 3-O-rutinoside, kaempferol 3-O-rutinoside, isorhamnetin 3-O-rutinoside, bilobalide and ligustrazine in rat plasma, and its application to pharmacokinetic study of Xingxiong injection.

The present study was designed to develop and validate a rapid, sensitive, and reliable ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of five major active constituents in the traditional Chinese medicinal preparation Xingxiong injection (XXI) in rat plasma, including quercetin 3-O-rutinoside (QCR), kaempferol 3-O-rutinoside (KFR), isorhamnetin 3-O-rutinoside (ISR), bilobalide (BB), and ligustrazine (LGT). The plasma samples were pretreated by protein precipitation with acetonitrile. The chromatographic separation was achieved on a Waters Symmetry C18 analytical column (2.1 mm × 100 mm, 3.5 µm) with a mobile phase of 0.1% aqueous formic acid (A)-acetonitrile (B). Quantitation of the five bioactive constituents was achieved. Naringin was used as the internal standard (IS). All the calibration curves showed good linearity (r > 0.996) over the concentration range, with the lowest limit of quantification (LLOQ) between 2-18 ng·mL-1. The intra- and inter-day accuracy and precision of the analytes were both within acceptable limits. Moreover, satisfactory extraction recoveries (90.92%-104.03%) were obtained by protein precipitation. The validated method was successfully applied to a pharmacokinetic study of XXI in rats after intravenous administration at three doses. The pharmacokinetic parameters of the five compounds varied in a dose-dependent manner within the tested dosage range. The present study was the first report of pharmacokinetic study for XXI.

A UPLC-MS/MS method for simultaneous determination of danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine in rat plasma, and its application to pharmacokinetic studies of Shenxiong glucose injection in rats.

A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of the four major active ingredients, danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine, in the traditional Chinese medicine Shenxiong glucose injection in rat plasma. Acidified and alkalized plasma samples were extracted using ethyl acetate, and separated on a Waters C18 column (2.1mm×50mm, 1.7µm) by using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid and luteoloside as an internal standard. Electrospray ionization in the positive-ion mode and multiple reaction monitoring were used to identify and quantitate the active components. All calibration curves showed good linearity (r>0.994) over the concentration range, with a lower limit of quantification (LLOQ) between 0.02 and 0.21µg/mL. The precision of the in vivo study was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation was within 15%. Moreover, satisfactory extraction efficiency was obtained (between 83.94 and 117.81%) by liquid-liquid extraction. The validated method was successfully applied in a pharmacokinetic study in rats after intravenous administration of Shenxiong glucose injection. The results showed that the four bioactive ingredients in Shenxiong glucose injection have linear pharmacokinetic properties in rats after intravenous injection within the administered dose range and partially different ones compared to single ingredient.

An automated dual-gradient liquid chromatography-MS/MS method for the simultaneous determination of ferulic acid, ligustrazine and ligustilide in rat plasma and its application to a pharmacokinetic study.

An automated on-line SPE and innovative fast polarity switch bioanalysis method employing dual-gradient liquid chromatography (DGLC) coupled with mass spectrometry (DGLC-MS/MS) was established and validated for the simultaneous determination of ferulic acid, ligustrazine and ligustilide in rat plasma after administration of Rhizoma Chuanxiong, Angelica sinensis extract or monomer. The proteins in plasma samples were precipitated using acetonitrile: methanol (1:1, v/v). Sulfamethoxazole was used as an internal standard. The DGLC system contains two high-pressure pumps. The first pump was used for on-line solid phase extraction with a Cyclone™ SPE column. Chromatographic separations were performed with the other pump on a Syncronis C18 rapid analytical column. The analytical column was eluted by a gradient program that featured an acetonitrile/methanol/water gradient (flow-rate, 0.4ml/min). DGLC afforded greater convenience for bioanalysis. All analytes were simultaneously monitored in positive- and negative-ion mode by SRM (selective reaction monitoring) using the fast polarity switch speed of TSQ Vantage™. Method validation of the assay was implemented. No significant matrix effect was observed. The LLOQ of all analytes were <1.0ng/ml. The precision, recovery and linearity of the analysis met the pre-established requirements. The method was applied to the pharmacokinetics of ferulic acid, ligustrazine and ligustilide in Rhizoma Chuanxiong or Angelica sinensis extracts or monomers.

Prediction of oral pharmacokinetics of cMet kinase inhibitors in humans: physiologically based pharmacokinetic model versus traditional one-compartment model.

The objective of this study was to assess the physiologically based pharmacokinetic (PBPK) model for predicting plasma concentration-time profiles of orally available cMet kinase inhibitors, (R)-3-[1-(2,6-dichloro-3-fluoro-phenyl)-ethoxy]-5-(1-piperidin-4-yl-1H-pyrazol-4-yl)-pyridin-2-ylamine (PF02341066) and 2-[4-(3-quinolin-6-ylmethyl-3H-[1,2,3]triazolo[4,5-b]pyrazin-5-yl)-pyrazol-1-yl]-ethanol (PF04217903), in humans. The prediction accuracy of pharmacokinetics (PK) by PBPK modeling was compared with that of a traditional one-compartment PK model based on allometric scaling. The predicted clearance values from allometric scaling with the correction for the interspecies differences in protein binding were used as a representative comparison, which showed more accurate PK prediction in humans than the other methods. Overall PBPK modeling provided better prediction of the area under the plasma concentration-time curves for both PF02341066 (1.2-fold error) and PF04217903 (1.3-fold error) compared with the one-compartment PK model (1.8- and 1.9-fold errors, respectively). Of more importance, the simulated plasma concentration-time profiles of PF02341066 and PF04217903 by PBPK modeling seemed to be consistent with the observed profiles showing multiexponential declines, resulting in more accurate prediction of the apparent half-lives (t(1/2)): the observed and predicted t(1/2) values were, respectively, 10 and 12 h for PF02341066 and 6.6 and 6.3 h for PF04217903. The predicted t(1/2) values by the one-compartment PK model were 17 h for PF02341066 and 1.9 h for PF04217903. Therefore, PBPK modeling has the potential to be more useful and reliable for the PK prediction of PF02341066 and PF04217903 in humans than the traditional one-compartment PK model. In summary, the present study has shown examples to indicate that the PBPK model can be used to predict PK profiles in humans.

[Pharmacokinetics studies on tetramethylpyrazine by intravenous administration in rats].

OBJECTIVE: To investigate the pharmacokinetics behaviour of tetramethylpyrazine (TMP) by intravenous administration in rats. METHODS: Methanol-0.05 mol/L acetate buffer solution (50:50,V/V) was used as mobile phase with a flow rate of 1.0 mL/min. The UV detection wavelength was 280 nm. RESULTS: The profile of TMP in blood fitted a two-compartment model. The half time of drug distribution and elimination was short. The mean residence time MRT 0-infinity was 141.61 min, and the AUC0-infinity was 7521.70 microg x min/ mL. CONCLUSION: After intravenous injection, the pharmacokinetics behaviour of TMP fit a two-compartment model in rats. Both the distribution and the elimination are fast.

Synthesis and evaluation of N-acylsulfonamide and N-acylsulfonylurea prodrugs of a prostacyclin receptor agonist.

N-Acylsulfonamide and N-acylsulfonylurea derivatives of the carboxylic acid prostacyclin receptor agonist 1 were synthesized and their potential as prodrug forms of the carboxylic acid was evaluated in vitro and in vivo. These compounds were converted to the active compound 1 by hepatic microsomes from rats, dogs, monkeys, and humans, and some of the compounds were shown to yield sustained plasma concentrations of 1 when they were orally administered to monkeys. These types of analogues, including NS-304 (2a), are potentially useful prodrugs of 1.

[Study on metabolism of tetramethylpyrazine in system of rat liver microsomes].

OBJECTIVE: The metabolic character of tetramethylpyrazine (TMPz) in rat liver microsomes was studied in vitro and in vivo to identify which isoforms of cytochrome P450 were responsible for TMPz metabolism in rats, offer the theoretical foundation for the fact that it is rational to use medicine in clinic. METHOD: Set up UV- HPLC method of TMPz, determine concentration of TMPz and its formation in rat plasma and liver microsomes incubation solution, analyze the correlation between TMPz's metabolic eliminate rate and each inducer. Erythromycin( ERY) N-demethylase activity of each sample in rat liver microsomes was measured using N-demethylation reaction of ERY as probe. The correlation between the rate of TMPz metabolite formation and the demethylase activity was analysed. After the SD rats who had been treated with inducer, inhibitor, or untreated, received administration of TMPz in vein, the plasma concentration of TMPz were determined by HPLC. Pharmacokinetic parameters of TMPz were computed and compared. RESULT: The disppearing rate of TMPz in the incubation solutions of the rats liver microsomes, which treated with DEX, were markedly quicker than that of control group (P < 0. 01) , while no obvious difference between P-NF group or PB and control group was observed (P > 0. 05). The activity of ERY-N-demethylase in DEX-induced group was corespondingly enhanced, was much higer than that in control group. The correlation between the rate of TMPz metabolic product formation and the activity of N-demethylase was significant. After using Ket, the CYP3A inhibitor, the metabolism of TMPz could be significantly inhibited the metabolism of TMPz in rat liver microsomes. In vivo, CL( s) were larger than that of the control group,t,/2 were smaller than the control group in DEX group; By contrary, CL(s) was smaller than the control group,t1/2 was larger than the control group in Ket group. CONCLUSION: Results suggest that CYP3A plays a major role in TMPz metabolism in rats, TMPz lie in the possibility of Interaction among the medicines between TMPz and CYP3A inducers or inhibitors when they are used in clinic.

Hepatoprotective and therapeutic effects of tetramethylpyrazine on acute econazole-induced liver injury.

2,3,5,6-Tetramethylpyrazine (TMP) is well known as a true calcium antagonist. The aim of this study was to investigate the hepatoprotective and therapeutic effects of TMP on acute econazole-induced liver injury. The hepatological effect of various concentrations of TMP was first assessed by the biochemical assays of SGOT and SGPT and then by hepatohistological microscopic examination. The dose-response relationship of liver injury induced by various doses of econazole was observed simultaneously from serum biochemical assay of SGOT and SGPT, and also from hepatohistological microscopic examination, by determination of the hepatoprotective effects of various concentrations of TMP on SGOT and SGPT elevation induced by a hepatotoxic dose of econazole (300 mg/kg). The inhibitory effect of various concentrations of TMP or vitamin E (positive control, 0.5 mM in vitro, 0.69 mM in vivo) on FeCl 2 -induced (in vitro) or econazole-induced (in vivo) lipid peroxidation was also investigated. The superoxide scavenging activity of various concentrations of TMP in econazole-damaged rat liver homogenate was assessed by the cytochrome C reduction method. Results showed that the hepatoprotective effect of TMP might be, at least in part, due to its inhibitory ability on membrane lipid peroxidation and free radical formation, or due to its free radical scavenging ability. Improvement of serum transaminases and MDA levels in rat liver homogenate, hepatohistological microscopic examination, and assessment of free radical scavenging activity by the cytochrome C reduction method were used to detect hepatoprotective and therapeutic effects of TMP on acute econazole-induced liver injury.

[Determination of tetramethylpyrazine in animal serum and cerebrospinal fluid by high performance liquid chromatography].

A reversed-phase high performance liquid chromatographic (RP-HPLC) method for the determination of the tetramethylpyrazine(TMP) in Chuanxiong extract, the animal(mouse) serum and cerebrospinal fluid has been developed. The TMP was separated on an ODS column Zorbax SB-C18(4.6 mm i.d. x 250 mm, 5 microns) at room temperature and detected by using UV detector at 270 nm. The mobile phase was methanol-water (50:50, V/V) containing 0.2 mmol/L of NH4H2PO4 flowing at a rate of 0.8 mL/min and 20 microL samples were injected. The detection limit of TMP was 1 mg/L and the calibration curve is linear between 5 and 500 mg/L with a correlation coefficient (r) of 0.999. The recovery of TMP ranged 98%-103%. The extract of Chuanxiong and pretreated serum and cerebrospinal fluid sample are stable for a week at room temperature.

Measurement and pharmacokinetic study of tetramethylpyrazine in rat blood and its regional brain tissue by high-performance liquid chromatography.

We used a rapid, sensitive and reliable high-performance liquid chromatographic method for the determination of tetramethylpyrazine in rat brain tissue and plasma. The lower limit of quantification in plasma and brain tissue was 0.1 microgram/ml and 0.1 microgram/g, respectively, and only a small amount of plasma (100 microliters) or brain tissue (100 micrograms) was required for analysis. The decline in the concentration of tetramethylpyrazine in plasma was generally two-exponential at a dose of 2, 5, or 10 mg/kg administered intravenously. Concentrations of tetramethylpyrazine in various regions of the brain (cerebral cortex, brainstem, striatum, hippocampus, cerebellum and midbrain) were not significantly different at 15 min following drug administration (10 mg/kg, i.v.). In additional analysis, mean concentration of the tetramethylpyrazine in rat plasma was approximately five-times greater than the drug in brain tissue.