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 C 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. 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.
Animals ; Bilobalides ; blood ; pharmacokinetics ; Chromatography, High Pressure Liquid ; methods ; Disaccharides ; blood ; pharmacokinetics ; Drugs, Chinese Herbal ; administration & dosage ; analysis ; pharmacokinetics ; Flavonoids ; blood ; pharmacokinetics ; Glucosides ; blood ; pharmacokinetics ; Kaempferols ; blood ; pharmacokinetics ; Pyrazines ; blood ; pharmacokinetics ; Quercetin ; analogs & derivatives ; blood ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley ; Tandem Mass Spectrometry ; methods

To establish a method for detecting microdialysis recovery of tetramethylpyrazine (TMP) and ferulic acid (FA) and investigating the influencing factors, providing the basis for further in vivo microdialysis experiments. The concentration of FA and TMP in dialysates were determined by high pressure liquid chromatography ( HPLC) and probe recovery were calculated respectively. The influence of the flow rates, medium concentration, temperature and in vivo probe stability on the recovery of FA and TMP were investigated by using concentration difference method (incremental method and decrement method). The recovery obtained by incremental method were similar to by decrement method. The in vitro recovery rate of FA and TMP decreased with the increase of 1-2.5 μL min(-1), and increased obviously with the temperature of 25-42 degrees C under the same conditions. The concentration of FA and TMP had no obvious effect on the probe recovery under the same flow rate. In addition, the recovery of TMP and FA remained stable and showed similar trends under the condition of four concentration cycles, indicating that the intra day reproducibility of the concentration difference method was good. The recovery of brain microdialysis probes in vivo 8 h maintained a relatively stable, but certain differences existed between different brain microdialysis probes, demonstrating that each probe was required for recovery correction in vivo experiment. Microdialysis sampling can be used for the local brain pharmacokinetic study of FA and TMP, and retrodialysis method can be used in probe recovery of FA and TMP in vivo.
Animals ; Brain ; metabolism ; Chromatography, High Pressure Liquid ; Coumaric Acids ; analysis ; isolation & purification ; pharmacokinetics ; Drugs, Chinese Herbal ; Humans ; Microdialysis ; methods ; Pyrazines ; analysis ; isolation & purification ; pharmacokinetics ; Rats

The metabolic characteristics of ligustrazin (TMPz) in liver microsomes were investigated in the present study. The reaction phenotyping of TMPz metabolism was also identified by in vitro assessment using recombinant human cytochrome P450 enzymes (CYP) and UDP glucuronosyltransferases (UGT). TMPz was incubated at 37 degrees C with human (HLM) and rat liver microsomes (RLM) in the presence of different co-factors. The metabolic stability and enzyme kinetics of TMPz were studied by determining its remaining concentrations with a LC-MS/MS method. TMPz was only metabolically eliminated in the microsomes with NADPH or NADPH+UDPGA. In the HLM and RLM with NADPH+UDPGA, t1/2, K(m) and V(max) of TMPz were 94.24 +/- 4.53 and 105.07 +/- 9.44 min, 22.74 +/- 1.89 and 33.09 +/- 2.74 micromol x L(-1), 253.50 +/- 10.06 and 190.40 +/- 8.35 nmol x min(-1) x mg(-1) (protein), respectively. TMPz showed a slightly higher metabolic rate in HLM than that in RLM. Its primary oxidative metabolites, 2-hydroxymethyl-3, 5, 6-trimethylpyrazine (HTMP), could undergo glucuronide conjugation. The CYP reaction phenotyping of TMPz metabolism was identified using a panel of recombinant CYP isoforms (rCYP) and specific CYP inhibitors in HLM. CYP1A2, 2C9 and 3A4 were found to be the major CYP isoforms involved in TMPz metabolism. Their individual contributions were assessed b) using the method of the total normalized rate to be 19.32%, 27.79% and 52.90%, respectively. It was observed that these CYP isoforms mediated the formation of HTMP in rCYP incubation. The UGT reaction phenotyping of HTMP glucuronidation was also investigated preliminarily by using a panel of 6 UGT isoforms (rUGT). UGT1A1, 1A4 and 1A6 were the predominant isoforms mediated the HTMP glucuronidation. The results above indicate that the metabolism of TMPz involves multiple enzymes mediated phase I and phase II reactions.
Animals ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP2C9 ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 Enzyme Inhibitors ; Cytochrome P-450 Enzyme System ; metabolism ; Drug Interactions ; Glucuronosyltransferase ; metabolism ; Humans ; Ligusticum ; chemistry ; Microsomes, Liver ; enzymology ; NADP ; metabolism ; pharmacology ; Pyrazines ; metabolism ; pharmacokinetics ; Rats ; Uridine Diphosphate Glucuronic Acid ; metabolism ; pharmacology

OBJECTIVETo verify established the total quantum statistic moments model with astragaloside IV, paeoniflorin, tetramethylpyrazine in Buyanghuanwu injection, in order to establish a pharmacokinetic experimental method with multi-component traditional Chinese medicine (TCM) compound system.

METHODThe RP-HPLC was adopted, with the chromatographic column of C18, 4.6 mm x 250 mm, 5 microm. As for astragaloside IV, the ELSD detector was adopted with acetonitrile-water (35: 65) as the mobile phase at 1 mL x min(-1); the pressure of column was (15.0 +/- 0.408) MPa, the column temperature was 30 degrees C. Regarding paeoniflorin and tetramethylpyrazine, the detection of wavelengths was 254 nm, with acetonitrile-water (35:65) as the mobile phase at 1 mL x min(-1), the column pressure of (15.17 +/- 0.41) MPa. The pharmacokinetic parameters for single component were dealt with DAS and the total quantum statistical moment (TQSM) parameters were calculated using formulations.

RESULTAll of the three components followed the two compartmental pharkacokinetic model (P < 0.01) in rats. Compared with the superimposed total concentration, each single component showed difference in parameters up to 10 000 times at most, whereas the RSD of TQSM parameters was 3.510%. The TQSM pharmacokinetic parameters of the three components in Buyanghuanwu injection showed that AUC(t), MRT(t), VRT(t), CL(t), V(t), were (119.8 +/- 27.20) g x min x L(-1), (210.0 +/- 54.49) min, (5.608 +/- 2.723) x 10(4) min2, (0.319 6 +/- 0.068 8) mL x min(-1) x kg(-1) and (64.12 +/- 8.243) mL x kg(-1), respectively, suggesting that the half-life time for the three components were (145.5 +/- 37.76) min and 95% of them were metabolized within 0-674. 2 min.

CONCLUSIONThe TQSM can be used to study pharmacokinetic parameters of multi-component TCM compound, because the method can characterize the pharmacokinetic regularity of quantum-time change in a multi-component system.

Animals ; Benzoates ; pharmacokinetics ; Bridged-Ring Compounds ; pharmacokinetics ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; pharmacokinetics ; Glucosides ; pharmacokinetics ; Male ; Medicine, Chinese Traditional ; Models, Statistical ; Monoterpenes ; Pyrazines ; pharmacokinetics ; Rats ; Saponins ; pharmacokinetics ; Triterpenes ; pharmacokinetics

OBJECTIVETo prepare ligustrazine (TMPZ) ocular sustained-release implant, and investigate its in vitro drug release, pharmacokinetics in rabbit vitreum and in vitro correlation.

METHODLigustrazine ocular sustained-release implants were prepared by micro-twin conical screw mixers with hot-melting extrusion method, with polyactic-co-glycolic acid (PLGA) as the matrix. HPLC was adopted to determine the concentration in vitreum after ligustrazine was implanted in rabbit eyes, in order to examine its in vivo sustained-release behavior, and study the correlation between in vitro and in vivo.

RESULTLigustrazine implants were prepared with a drug-loading rate between 10% and 30%, which was in conformity to the pharmacopoeia in terms of the content uniformity. Its in vitro release was in conformity to the zero-order release model. With PLGA 5050, 2. 5A as a vector, ligustrazine implants with a drug-loading rate of 30% could slowly release drug for more than 3 weeks, indicating a good correlation between in vitro and in vivo release.

CONCLUSIONLigustrazine ocular implants prepared with hot-melting extrusion method is practicable. Ligustrazine ocular implants release drug smoothly in rabbit vitreous vitreums, suggesting good sustained-release effect.

Animals ; Biological Availability ; Drug Implants ; Eye ; Female ; Male ; Polyglycolic Acid ; chemistry ; Pyrazines ; administration & dosage ; chemistry ; pharmacokinetics ; Rabbits ; Vitreous Body

The purpose of this study was to prepare tetramethylpyrazine hydrochloride transdermal gel and to study its permeation ability in vitro. The skin permeation ability was evaluated by Valian-Chien permeation cells with isolated rat skin. The concentration of tetramethylpyrazine in samples was determined by HPLC. The optimal formulation was composed with 5% azone, 5% peppermint oil, 8% sodium carboxymethylcellulose and 8% tetramethylpyrazine hydrochloride. The accumulative permeation amount of the gel was (6 731.87 +/- 102.31) microg x cm(-2) in 12 h,and the permeation rate was (535.02 +/- 33.89) microg x cm(-2) x h(-1). The release profile in vitro was in line with zero-order formulation. Tetramethylpyrazine hydrochloride gel prepared in the study would be developed as a novel transdermal preparation.
Administration, Cutaneous ; Animals ; Chemistry, Pharmaceutical ; Gels ; In Vitro Techniques ; Male ; Permeability ; Pyrazines ; administration & dosage ; chemistry ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the pharmacokinetics of single administration and different compatibility of tetramethylpyrazine (TMP) in rats.

METHODThirty two Sprague-Dawley rats were randomly divided into 4 groups: the TMP (30 mg x kg(-1)) group, the TMP+FA (30 mg x kg(-1) + 50 mg x kg(-1)) group, the TMP+TET (30 mg x kg(-1) mg x kg(-1)) group and the TMP+FA+TET (30 mg x kg(-1) + 50 mg x kg(-1) + 20 mg x kg(-1)) group. After the oral administration, their blood samples were collected to detect plasmas concentrations by HPLC method and to calculate pharmacokinetic parameters DAS 2.0 program.

RESULTIn compatibility with FA, AUC(0-t), Cmax and Tmax showed no significant difference with the single administration of TMP, but t(1/2) and MRT,, were obviously longer than the single administration. In compatibility with TET and FA + TET, AUC (0-t), Cmax and Tmax showed significant increase than the single administration of TMP, whereas t(1/2) and MRT0, did not notably vary from the single administration.

CONCLUSIONFA can prolong TMP's action time in rats, and TET can accelerate TMP's absorption in rats.

Animals ; Chromatography, High Pressure Liquid ; Coumaric Acids ; pharmacokinetics ; Diterpenes ; pharmacokinetics ; Drug Interactions ; Female ; Pyrazines ; pharmacokinetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley

The study is to investigate the brain pharmacokinetics change of nasal tetramethylpyrazine phosphate (TMPP) pH-sensitive in situ gel in normal and model rats. Acute cerebral ischemia rat model was successfully established by middle cerebral artery occlusion (MCAO) method. Both normal and model rats were given nasal TMPP pH-sensitive in situ gel (10 mg x kg(-1)). Perfusates of brain striatum area were collected at each time point by microdialysis. The content of TMPP was determined by HPLC. The pharmacokinetics parameters were calculated by Kinetica 4.4 software at each time point of the brain drug concentration. The main pharmacokinetics parameters of TMPP were fitted with compartments 2. After nasal TMPP pH-sensitive in situ gel the values of C(max) and AUC of both components in brain showed as follows: the value of model group > that of normal group. Significant difference can be observed in the process of brain pharmacokinetics in normal and model rats after giving nasal TMPP pH-sensitive in situ gel.
Administration, Intranasal ; Animals ; Area Under Curve ; Brain ; metabolism ; pathology ; Brain Ischemia ; metabolism ; Chromatography, High Pressure Liquid ; Gels ; Hydrogen-Ion Concentration ; Infarction, Middle Cerebral Artery ; Male ; Microdialysis ; Phosphates ; administration & dosage ; pharmacokinetics ; Pyrazines ; administration & dosage ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley

The purpose of this study is to investigate the impacts of bicyclo-monoterpene promoters (i.e., borneol and camphor) on the in vitro permeation of ligustrazine (LGT) through the hairless porcine dorsal skin. Fourier transform-infrared (FT-IR), scanning electron microscope (SEM) and transdermal delivery kinetics in vitro were performed to investigate the effect of the promoters on the biophysical changes to the stratum corneum (SC), the surface changes to porcine skin and the in vitro percutaneous fluxes of ligustrazine through procine skin. FT-IR results revealed that the peak shift and the decrease in the peak area with borneol were higher than those with camphor. SEM studies demonstrated that the morphological change to SC was related to the chosen enhancer. It was observed that the SC lipid extraction with borneol and camphor led to disruption of the SC and the scutella desquamation. Apparent density (AD) was utilized to describe the desquamation extent of the scutella. Percutaneous fluxes of ligustrazine through porcine skin were evaluated in vitro by the Franz-type diffusion cells. Use of borneol led to greater penetration of ligustrazine across porcine skin. It was shown that the permeation enhancement mechanism of bicyclo-monoterpenes to ligustrazine included extracting and disordering lipids which involved the shift changes in C-H stretching and H-bonding action between enhancers and cermaide. The penetration capability of the hydroxy groups in bicyclo-monoterpenes was better than that of the ketone groups.
Administration, Cutaneous ; Animals ; Bornanes ; chemistry ; pharmacology ; Camphor ; chemistry ; pharmacology ; Drug Carriers ; Ligusticum ; chemistry ; Microscopy, Electron, Scanning ; Monoterpenes ; chemistry ; Plants, Medicinal ; chemistry ; Pyrazines ; administration & dosage ; chemistry ; isolation & purification ; pharmacokinetics ; Skin ; drug effects ; Skin Absorption ; drug effects ; Spectroscopy, Fourier Transform Infrared ; Swine ; Vasodilator Agents ; administration & dosage ; chemistry ; isolation & purification ; pharmacokinetics

OBJECTIVETo study the pharmacokinetics of tetramethylpyrazine (TMP), ferulic acid and their compatibility.

METHODTwenty-four Sprague-Dawley rats were randomly divided into 3 groups: TMP 20 mg x kg(-1), ferulic acid 20 mg x kg(-1) and TMP 20 mg x kg(-1) + ferulic acid 20 mg x kg(-1). All the rats were given intragastric administration then blood samples were obtained from fossa orbitalis at several time points. All the plasmas concentrations were analyzed by HPLC method and the data were treated by DAS 2.0 program.

RESULTThe main pharmacokinetics parameters of TMP 20 mg x kg(-1) group, ferulic acid 20 mg x kg(-1) and TMP 20 mg x kg(-1) + ferulic acid 20 mg x kg(-1) were as follows: t(max) 0.5 h, t1/2 0.856 h,MRT 1.321 h, AUC 5.112 microg x h(-1) x L(-1), C(max) 2.834 microg x L(-1); t(max) 0.083 h, t1/2 1.024 h, MRT 1.324 h, AUC 1.581 microg x h(-1) x L(-1), C(max) 1.492 microg x L(-1); t(max) 0.583 h, t1/2 37.901 h, MRT 3.798 h, AUC 4.097 microg x h(-1) x L(-1), C(max)1.571 microg x L(-1); t(max) 0.6 h, t1/2 7.860 h, MRT 2.894 h, AUC 1.984 microg x h(-1) x L(-1), C(max) 1.03 microg x L(-1), respectively.

CONCLUSIONThe experiments suggested that the compatibility of TMP and ferulic acid had interaction in pharmacokinetics; all the t1/2 and MRT were prolonged and had the effect of lente liberates.

Animals ; Area Under Curve ; Calibration ; Coumaric Acids ; pharmacokinetics ; Female ; Linear Models ; Pyrazines ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley ; Reproducibility of Results