《药用动物学》教学改革探索与实践

《药用动物学》是应用现代动物学及传统中药学的知识和手段,研究有药用价值的动物的外部形态、主要功效、分类鉴定等方面有关规律的学科。在教学大纲范围内,通过从分清教学内容的主次,抓住教学重点,整理与发掘对比教学知识点,理论联系实践,教学模式对比,突出地方特色几个方面进行探讨,为本课程在教学中开展提高教学质量、培养学生创新思维的研究提供理论依据。

Pharmacokinetics of nifedipine sustained-release tablets in healthy Chinese volunteers

Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 （5 μm, 4.6 mm ×150 mm） column and a mobile phase of methanol： 0.01 mol·L^-1ammonium acetate （60：40, V/V） were used to separate nifedipine, the detections was accuracy under atmosperic pressure electronic spray ionization （AP-ESI） mode and ion mass spectrum （m/z） of 314.9 [M＋H]^＋ for nifedipine, and 320.8 [M＋H]^＋ for lorazepam （Internal Standard, IS）. Results The linear range of nifedipine was 0.3 - 80 ng·mL^-1 （ r = 0.9997）, and the limit of quantitation （LOQ） was 0.3 ng·mL^-1. The nifedipine pharmacokinetic parameters after a single dose of 20 mg nifedipine sustained-release tablets test （T） or reference （R） were as the followings, t1/2 （6.73 ± 2.00） h and （7.04 ± 2.18） h, Tmax （4.28 ± 0.70） h and （4.48 ± 0.70） h, Cmax（39.66 ± 10.58） ng·mL^-1 and （40.19 ± 10.97） ng·mL^-1, AUC0-36 （391.63 ± 108.55） ng·mL^-1·h and （387.57 ± 121.51） ng·mL^-1·h, and AUC0-∞ （408.28 ± 121.16） ng·mL^-1·h and （406.15 ± 133.13） ng·mL^-1·h. The relative bioavailability of nifedipine sustained-release tablets （test） was （103.02 ± 13.93） %. Conclusion LC-MS method for the determination of concentrations of nifedipine in human plasma was sensitive and accurate, and could be used in nifedipine bioavailability and pharmacokinetic studies.

Determination of Loratadine in Human Plasma by High Performance Liquid Chromatography-Electrospray Mass Spectrometry and Studies on Its Pharmacokinetics and Relative Bioavailability

A new HPLC MS method to determine loratadine in human plasma was established. The method involved extracting drug with organic solvent under basic conditions. The samples were seperated by ODS column and determined by mass detector. The calibration curve of loratadine was linear within the range of 0.4～100 ng·mL -1 with r=0.9995 . The recovery of this method was within 95%～104%, within day and between day RSD were less than 12%. To study the pharmacokinetics and relative bioavailability of loratadine tablets, two formulations of loratadine tablets were given to 18 healthy male volunteers according to a randomized 2 way cross over design. The C max , AUC 0 t and T max values of the two formulations were 51.89±20.18 ng·mL -1 and 52.48±22.35 ng·mL -1 ; 140.75±88.42 ng·h·mL -1 and 147.24±92.33 ng·h·mL -1 ; 0.81±0.35 h and 0.81±0.27 h respectively. Results from statistic analysis showed that there were no significant difference between the C max , AUC 0-t and T max values of the two formulations. The relative bioavailability of tablets I with respect to tablets II was 97%±13% from the AUC 0 t measurement. Bioequivalance was observed between the two tablets.

Determination of Lovastatin Level in Human Plasma and Lovastatin Capsules Bioavailability in Healthy Volunteers Using HPLC-MS

Aim To establish a sensitive and specific liquid chromatography-mass spectrometry (HPLC-MS) method for measuring lovastatin level in human plasma and the relative bioavailability. Methods Lovastatin in the plasma was extracted with acetoacetate. Simvastatin was added as internal standard (IS). Samples were separated on a C_ 18 column with a mobile phase consisting of methanol and 50 mmol·L~ -1 sodium acetate (88 ∶ 12). The flow rate was 1 mL·min~ -1 . Sample was detected using an electrospray ionization (ES...

High Resolution Determination of Ondansetron in Human Plasma by HPLC and Pharmacokinetics of Orally Disintegrating Tablets

Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved liquid-liquid extraction, separation on a CN column and ultraviolet detection at 310 ran with granisetron as an internal standard. Pharmacokinetics and bioequivalence of ondansetron in orally disintegrating tablets by direct compression and conventional 8 mg tablets were evaluated and compared in 20 healthy human male volunteers after a single oral dose in a randomized cross-over study. Results The limit of quantification was 0.25 ng· mL^-1. The recovery was about 85 % or over for ondan setron and about 90% for internal standard. Linearity was good within the concentration range of 0.5 - 50 ng·mL^-1 with r^2 ranging from 0.997 1 to 0.999 9. Intra- and inter-assay coefficients of variation ranged from 1.78% to 2.38% and 3.88% -5.19%, respectively. Accuracies for spiked concentrations of 2.0, 10.0, and 30.0 ng·mL^-1 were 104.7% ±4.4%, 102.2% ± 1.1%, and99.51% ±2.34%, respectively. Pharmacokinetic parameters of AUCo-t, AUCo-∞ , Cmax, Tmax, and T1/2 were 230.2 ± 78.0 ng·h·L^-1 , 265.2± 101.5 ng·h·mL^-1, 35.67 ± 8.94 ng·mL^-l, 1.51 ±0.79 h, and 5.00± 1.41 h for orally disintegrating tablets, respectively. The analysis of variance did not show any significant difference between orally disintegrating tablets and conventional tablets, and 90% confidence intervals fell within the acceptable range for bioequivalence. Conclusion High resolution HPLC method has been set up and applied in pharmacokinetic evaluation of ondansetron in orally disintegrating tablets.

Enantioselective assay of S(+)- and R(-)-propafenone in human urine by using RP-HPLC with pre-column chiral derivatization

The enantioselective assay for S(+)- and R(-)-propafenone (PPF) in human urine that developed in this work involves extraction of propafenone from human urine and using S(+)-propafenone as internal standard, chiral derivatization with 2,3,4,6-tetra-O-b-D-glucopranosyl isothiocyanate, and quantitation by an RP-HPLC system with UV detection (l=220 nm). A baseline separation of propafenone enantiomers was achieved on a 5-mm reverse phase ODS column, with a mixture of methanol:water:glacial acetic acid (25:12:0.02,v/v) as mobile phase. There was good linear relationship from 24.9 ng/ml to 1875.0 ng/ml for both of enantiomers. The regression equations of the standard curves based on CS-PPF (or CR-PPF ) versus ratio of AS-PPF/AS (or AR-PPF/AS ) were y=0.0032x-0.081, (r=0.999) for S-PPF and y=0.0033x+0.0039, (r=0.998) for R-PPF, respectively. The method抯 limit of detection was 12.5 ng/ml for both enantiomers, and the method抯 limit of quantitation was 28.20.52 ng/ml for S-PPF, 30.40.53 ng/ml for R-PPF (RSD<8%, n=5). The analytical method yielded average recovery of 98.9% and 100.4% for S-PPF and R-PPF, respectively. The relative standard deviation was no more than 6.11% and 6.22% for S-PPF and R-PPF, respectively. The method enabled study of metabolism of S(+)- and R(-)-propafenone in human urine. The results from 7 volunteers administered 150 mg racemic propafenone indicated that propafenone enantiomers undergo stereoselective metabolism and that in the human body, S(+)-propafenone is metabolized more extensively than R(-)- propafenone.

Pharmacokinetics of recombinant human parathyroid hormone after subcutaneous administration in Rhesus monkeys by immunoradiometric assay

The purpose of this research was to study the pharmacokinetics and the bioavailability of recombinant human parathyroid hormone [rhPTH （1-34）] in Rhesus monkeys after single and multiple subcutaneous administration. An immunoradiometric assay （IRMA） was used to determine the plasma drug concentration of rhFFH （1-34） after giving single dose of 10, 20 and 40 ug/kg and daily dose of 40 ug/kg for 7 d by subcutaneous administration, and intravenous injection of 20 ug/kg in Rhesus monkeys. The pharmacokinetic parameters were calculated by noncompartmental analysis. The drug plasma level quantitation range was from 0.027 to 2.22 ng/mL. The intra- and inter-assay precision （CV） of analysis were less than 15%, and the average recovery was about 93.0% ± 8.6% - 116.5% ± 14.0%. After subcutaneous administration of rhPTH（1-34） at dose of 10, 20 and 40 ug/kg, the average Tmax was 0.67, 0.5 and 0.83 h, Cmax were 1.85 ± 0.05, 3.23 ± 0.25 and 7.15 ± 1.19 ng/mL, the AUC（0-∞） were 3.4 ± 0.6, 10.7 ± 1.3 and 12.6 ± 1.5 ng/h/mL, and terminal-phase elimination T1/2 were 0.72 ± 0.10, 1.15 ± 0.10 and 1.03 ± 0.06 h, respectively. The absolute bioavailability of rhPTH （1-34） was 46.96% after subcutaneous administration of 20 ug/kg. There was no evidence of accumulation during systemic exposure of rhPTH （1-34） upon multiple dosing in Rhesus monkeys. The IRMA assay method provide reasonable sensitivity and specificity for the pharrnacokinetic study of rhPTH （1-34） after subcutaneous or intravenous administration in Rhesus monkeys. The pharmacokinetic characteristic of rhPTH （1-34） in monkeys shows linear relationship with the dose administered subcutaneously.

Pharmacokinetics and Bioavailability of 2-Amino-6-Cyclopropylamino-9-(2,3 -Dideoxy-β-D-glyceropent-2-enofuranosyl) Purine (Cyclo-D4G) in Rats

AimTo characterize the pharmacokinetics of 2 -amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuran osyl) purine (Cyclo-D4G) following intravenous administration and oral administ ration to rats. MethodsThe concentrations of Cyclo-D4G in rat (Sprague-Dawley male rats) plasma and urine were analyzed by high performance liquid chromatography (HPLC). ResultsFollowing intravenous adm inistration to rats, concentrations of Cyclo-D4G in plasma declined with a term inal phase half-life of 0 78±0 14 h (±s). Total clearance was 0 90±0 21 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximately 20% of total clearance. Steady state volume of distr ibution was 0 91±0 07 L·kg -1 . After oral administration to rats, conce ntrations of Cyclo-D4G in plasma declined with a terminal phase half-life of 0 83±0 13 h (±s). Total clearance was 3 81±2 03 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximat ely 9% of total clearance. Oral bioavailability of Cyclo-D4G in rat was 26 9%. ConclusionThe favorable pharmacokinetic profiles and lower to xicity provide support for further development of Cyclo-D4G clinical trials.

P-glycoprotein mediated interactions between Chinese materia medica and pharmaceutical drugs

P-glycoprotein(P-gp)is an important transmembrane ATP-binding cassette(ABC)drug efflux transporter expressed in various human tissues such as the intestines,liver,kidneys,and bloodbrain barrier.It limits the intracellular concentration of xenobiotics by pumping them out of the cells,affecting drug pharmacokinetics and therapeutic effects.With its broad substrate specificity,it has the potential to remove a wide range of drugs from Chinese materia medica(CMM),including conventional medicines and active compounds.Increasing evidence has confirmed the superior therapeutic effectiveness of CMM in treating a wide range of diseases worldwide,as well as in conjunction with western drugs.As a result,herbal medicine-drug compounds have prompted widespread concern,with the majority of these interactions involving transporters such as P-gp.This review systematically summarizes the inhibition or induction of P-gp expression/function by active CMM compounds and the underlying regulatory mechanisms.It will aid in improving understanding of the synergistic or inhibiting effects associated with transporter P-gp as well as rational safety concerns for using CMM,particularly in combination with drugs.

Bioavailability and pharmacokinetics of alantolactone from Inula helenium in rats following intravenous and oral administrations

Alantolactone, as the principal constituent oflnula Helenium L, has been shown various pharmacologic activities, such as anti-inflammatory and deworming. In the present study, we developed a high performance liquid chromatography （HPLC） method for the determination of alantolactone in rat plasma, and pharmacokinetics of alantolactone was investigated after intravenous and oral administrations to Wistar rats. Separation was achieved on C18 column （4.6 mm×250 mm, 5.0 μm） using a mobile phase consisting of methanol-water （70：30, v/v） at a flow rate of 1.0 mL/min. The wavelength of the ultraviolet detector was set at 239 nm. The excellent linearity was found over a concentration range of 0.08-10 μg/mL （R2 = 0.9998）. The intra- and inter-day precisions were good, and the RSD was lower than 2.27%. The mean absolute recovery of alantolactone in plasma ranged from 88.09% to 95.57%. After intravenous administration, alantolactone showed rapid systemic clearance （CL （0.11±0.014） L/h/kg） and small volume of distribution （Vd （0.71±0.14） L/kg）. The biological half life （t1/2） was 56.24 min. After oral administration, alantolactone showed rapid oral absorption in rats, with a short Tmax of （45.02±0.88） and （45.13±0.39） min for 14 and 28 mg/kg, respectively. The bioavailability of alantolactone in rats was 50.88%, indicating that alantolactone was orally available.

Influence of voriconazole on pharmacokinetics and safety of combined drugs: a systematic review

We performed a systematic review to evaluate pharmacokinetics changes of drugs when concomitantly used with voriconazole, including randomized controlled trials（RCTs）, randomized cross-over trials, self-controlled before-and-after studies, cohort studies and case reports. Literature databases, including Medline, Embase, Cochrane library, were searched to identify eligible studies（until Jan, 2016）. A modified risk of bias tool specially developed in this research was used to evaluate the quality of pharmacokinetic randomized crossover trials and self-controlled before-and-after studies. Cochrane risk of bias tool provided by Cochrane Library and Cochrane Reviewer＇s handbook was used to evaluate the quality of RCTs and non-randomized controlled studies. Pharmacokinetic parameters, such as area under curve（AUC）, Cmin, and Cmax before and after using voriconalzole were collected. Meta-analysis was conducted to synthesize results if possible. Among 41 studies included in our search, 17 were randomized crossover trials, 3 were RCTs, 13 were self-controlled before-and-after study（SBAs）, 1 was cohort studies and 7 were case reports. A total of 12 classes of drugs were involved, including opiates, non-steroidal anti-inflammatory drugs（NSAIDs）, psychopathic drugs, anti-HIV drugs, immunosuppressors, oral contraceptive, digoxin, warfarin, oral hypoglycemic agents, antihypertensive agents, lipid regulating agents and cytotoxic agents. According to our results, the impacts of voriconazole on tilidine, buprenorphine, etoricoxib, meloxicam, venlafaxine, midazolam, zolpidem, etravirine and sirolimus were different from the package insert. Our systematic review provided comprehensive data on the pharmacokinetics changes of drugs when used in combination with voriconazole.

A liquid chromatography-tandem mass spectrometric method for the determination of axitinib in nude mouse plasma: development, validation and application to a pharmacokinetic study

In the present study, a simple, rapid, and sensitive liquid chromatography-tandem mass spectrometric method for the determination of axitinib in nude mouse plasma was developed, validated, and applied to a pharmacokinetic study. Plasma samples were pre-treated by protein precipitation with acetonitrile spiked with erlotinib as an internal standard. The chromatographic separation was accomplished by using a reversed phase C18 column （50 mm×2 mm, 5 μm） with a simple mobile phase system composed of methanol and water （60：40, v/v） at an isocratic flow rate of 0.4 mL/min. The analyte was detected by a triple-quadrupole tandem mass spectrometer via electrospray ionization and multiple reaction monitoring was employed to select both axitinib and erlotinib in the positive ion mode. The calibration curves were linear （r〉0.99） ranging from 1 to 1000 ng/mL, and the lowest level of this range was the lower limit of quantification. The intra- and inter-day precision were 7.7%-12.0%, and the accuracies ranged from 88.6% to 110.4%. This method was successfully applied to a preclinical pharmacokinetic study on female nu/nu nude mice administrated with a single oral dose of axitinib at 120 mg/kg, and the pharmacokinetics was characterized by a one-compartment model with first-order absorption.

A highly sensitive LC-MS/MS method for the determination of 21-hydroxy deflazacort in nude mice plasma and its application to a pharmacokinetic study

In the current study, we established and validated a simple and sensitive liquid chromatography-tandem mass spectrometric method for the determination of 21-hydroxy deflazacort in nude mice plasma, and such a method was applied to a pharmacokinetic study. Using betamethasone as the internal standard, the plasma samples were pre-treated by precipitation with acetonitrile and then analyzed on a reversed-phase C18 column （50 mm×2 mm, 5 μm） with a mobile phase consisting of acetonitrile and 4.0 mM ammonium formate （pH was adjusted to 3.5 with formic acid （40：60, v/v））. The analyte was detected by a triple quadrupole tandem mass spectrometer using electrospray, and multiple reaction monitoring was employed to select 21-hydroxy deflazacort at m/z 400.2/124.0 and betamethasone at m/z 393.3/147.0 in the positive ion mode. The calibration curves were linear （r〉0.99） over the range of 0.5~,00 ng/mL. The intra- and inter-day precisions and accuracies were 4.5%-10.1% and -1.7%-10.7% respectively. This method was successfully applied to a preclinical administered with a single oral dose of 4 mg/kg deflazacort, and its pharmacokinetic study of deflazacort on female nude mice pharmacokinetics was characterized by a two-compartment model with first-order absorption.

Preparation, characterization and pharmacokinetic studies of total paeony glycoside nanocrystals

Total paeony glycoside（TPG） is obtained from Radix Paeoniae Rubra with a variety of bioactivities. However, the low solubility and bioavailability limit its application. The present study aimed to develop TPG nanocrystals to increase the dissolution and then improve the oral bioavailability. TPG nanocrystals were prepared via precipitation and high-pressure homogenization method. The physical-chemical properties of the optimal TPG nanocrystals in terms of particle size, zeta potential, morphology and crystallinity were evaluated. The results showed that TPG nanocrystals had a mean particle size of（210.2±2.5） nm, a polydispersity index of 0.191±0.033 and a zeta potential of（–22.4±1.2） mV. The result of differential scanning calorimetry showed that the nanocrystals were still in crystalline state after the preparation procedure. Transmission electron microscopy（TEM） results showed that the nanosuspension was in spherical shape. The pharmacokinetics of TPG nanocrystals for rats was investigated by liquid chromatography-tandem mass spectroscopy（LC-MS/MS）. Compared with the TPG coarse suspension, TPG nanocrystals exhibited significant increase in AUC0–∞（approximately 1.85-fold）. Taken together, TPG nanocrystals could be used as a promising drug delivery system due to the enhanced oral bioavailability of TPG.

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

A sensitive,rapid and simple liquid chromatography-tandem mass spectrometric（LC-MS/MS） method was developed and validated for the determination of letrozole（LTZ） in nude mouse plasma in the current study,which was successfully applied to a pharmacokinetic study.Using anastrozole as internal standard（IS）,plasma samples went through a one-step protein precipitation with acetonitrile before determination.The analyte and IS were analyzed on a reversed-phase ZORBAX-SB-C18 column（4.6 mm×250 mm,5 μm） with an isocratic mobile phase consisting of acetonitrile and water containing 0.1% formic acid（v/v） at a flow rate of 1.0 mL/min.The analyte and IS were detected by a triple-quadrupole tandem mass spectrometer,and electrospray and multiple reaction monitoring（MRM） were employed to select LTZ at m/z 286.4/217.1 and IS at m/z 294.1/225.3 simultaneously in the positive ion mode.The calibration curve showed good linearity ranging from 0.8–2000.0 ng/mL（r〉0.99）.The intra-day and inter-day precisions of LTZ were 4.0%–8.4%,with an accuracy of 98.6%–104.9%.Using this method,we successfully characterized the pharmacokinetics（PK） of LTZ by a one-compartment model with first-order absorption in female BALB/c nude mice.

A pharmacokinetic study of puerarin formulated in mixed micelles in Beagle dogs by HPLC

We developed an HPLC method to study the pharmacokinetics ofpuerarin in Beagle dogs after oral administration of puerarin or puerarin mixed micelles （PMMS）. Beagle dogs were divided into two groups randomly, and the blood samples were collected at fixed time intervals after single oral administration ofpuerarin or PMMS at a dosage of 120 mg/kg. Following sample preparation, analytes were separated on a C18 column （DIKMA, 150 mm×4.6 mm, 5 μm） with a guard column （DIKMA, 8 mm×4 mm） and eluted with methanol-water （25：75, v/v）. Theophylline was used as the internal standard. WinNonlin 6.1 （Pharsight, USA） was used to calculate the pharrnacokinetic parameters. The pharmacokinetic parameters for puerarin and PMMS in Beagle dogs were as follows： AUC, 515.96 and 2796.43 min μg/mL; Tmax, 61.48 and 202.91 min; CL/F, 232.58 and 42.91 mL/min/kg, respectively. The relative bioavailability of PMMS to puerarin was 542.0%. Our results showed that the mixed micelle preparation significantly improved the bioavailability of puerarin by delaying absorption and reducing clearance.

Relative bioavailability and pharmacokinetic comparison of two different enteric formulations of omeprazole

In order to comply with the requirements for a drug listed in China, the study was developed to compare the pharmacokinetics and relative bioavailability of two different enteric formulations of omeprazole (OPZ) in healthy Chinese subjects. A total of 32 volunteers participated in the study. Plasma concentrations were analyzed by non- stereospecific liquid chromatography/tandem mass spectrometric (LC-MS/MS) method. After administration of a single 40-mg dose of the two OPZ formulations, the comparative bioavailability was assessed by calculating individual AUC0-t (the area under the concentration-time curve from time zero to the last measurable concentration), AUC0-∞ (the area under the concentration-time curve extrapolated to infinity), Cmax (the maximum observed concentration), and Tpeak (the time to Cmax) values of OPZ, 5-hydroxyomeprazole (OH-OPZ), and omeprazole sulfone (OPZ-SFN), respectively. The 90% confidence intervals (CIs) of AUC0-t, AUC0-∞, and Cmax were 85.4%-99.0%/88.8%-98.6%/87.6%-99.4%, 85.5%-99.2%/89.0%-98.6%/88.5%-101.3%, and 72.3%-87.6%/79.6%-91.1%/88.4%-99.1% for OPZ/OH-OPZ/ OPZ-SFN, respectively, and Tpeak values did not differ significantly. In this study, the test formulation of OPZ in fasting healthy Chinese male volunteers met the Chinese bioequivalance standard to the reference formulation based on AUC, Cmax, and Tpeak.

An established LC-MS/MS method and a developed PK model for the study of pharmacokinetic properties of benapenem in infected mice

Benapenem is a new parenteral beta-lactam antibacterial with a broad antibacterial spectrum. In the present study, we developed and validated a simple, rapid and sensitive assay method using D6-benapenem as internal standard(IS) after one-step precipitation with methanol to determine benapenem in the plasma of infected mice. Separation was achieved on a reverse phase C18 column with a mobile phase composed of acetonitrile containing 0.2% formic acid–water(0.2% formic acid) and 10 mmol/L ammonium acetate in gradient elution mode. A triple quadrupole tandem mass spectrometer with electrospray ionization source was used as detector and operated by multiple reaction monitoring(MRM) in the positive ion mode. Calibration curves were linear(r>0.99) between 10 and 2000 ng/m L. The quantitative limit was 10 ng/m L, and the intra-and inter-precisions were <4.85% and <1.47%, respectively. The extraction recovery of benapenem and IS was 97.07%–107.09% and 92.47%–111.59%, respectively. The intra-and inter-accuracies were –9.70%– –11.00%, and the matrix effects of benapenem and IS were 85.68%–92.04% and 83.17%–92.04%, respectively. The method was successfully applied to the preclinical pharmacokinetic(PK) studies of benapenem. We also developed a two-compartment model to characterize the PK profiles of benapenem in infected mice, which could provide a better understanding of the PK properties of benapenem.

Study on the interactions of pharmacokinetics and liver distributions between rosuvastatin and repaglinide in rats

In the present study,we aimed to investigate the interactions of pharmacokinetics and liver distributions between rosuvastatin and repaglinide in rats.Coadministration of repaglinide（0.5 mg/kg,1 mg/kg and 2 mg/kg） for 7 d significantly increased the AUC0–24 and Cmax of rosuvastatin（P〈0.01）,but dramatically decreased the CL/F of rosuvastatin（P〈0.01） after a single dose of rosuvastatin（10 mg/kg）.There were no obviously changes in the parameters of Tmax and t1/2.Coadministration of repaglinide also decreased the liver distribution of rosuvastatin（P〈0.01）.Coadministration of rosuvastatin（20 mg/kg） for 7 days significantly increased the AUC0–12 and Cmax of repaglinide（P〈0.05）,and decreased the CL/F of repaglinide（P〈0.01） after a single dose of repaglinide（1 mg/kg）.The liver distribution of repaglinide was also decreased（P〈0.01）.Our animal study indicated that repaglinide could significantly affect the pharmacokinetics and liver distribution of rosuvastatin in rats and vice versa.

Determination and pharmacokinetic study of p-hydroxyphenethyl anisate following intravenous and oral administration in rats by RP-HPLC method

In the present study,we developed a rapid and specific reversed-phase high-performance liquid chromatographic(RP-HPLC)method for the quantification of p-hydroxyphenethyl anisate(HPA),one of the main bioactive constituents of the roots and rhizomes of Notopterygium incisum and N.franchetii,in rat plasma after an intravenous(20 mg/kg,i.v.)and an intragastrical(200 mg/kg,i.g.)administration to rats,respectively.The method involved a plasma clear-up step using liquid-liquid extraction by EtOAc,followed by RP-HPLC separation and detection.Separation of HPA was performed on an analytical DiamonsilTM ODS C18 column with the mobile phase of MeOH-H2 O at ratios of 75:25(v/v)for i.v.and 70:30(v/v)for i.g.administration.The flow-rate was 1.0 mL/min,and UV detection was performed at 256 nm.The calibration curves were linear over the ranges of 0.05-5.0μg/mL(r2=0.9984)for i.v.and 0.5-10.0μg/mL(r2=0.9995)for i.g.administration in rat plasma.The extraction recoveries were in the range of82.01%-87.97%.The intra-and inter-day precisions were between 1.71%and 3.99%,with accuracies ranging from 91.22%to110.5%.The absolute bioavailability of an orally administered HPA in rats was about 48.17%.The developed method was suitable for the determination and pharmacokinetic study of HPA in rat plasma.