Pharmacokinetics and Bioequivalence Evaluation of Two Rosuvastatin Calcium 20 mg Tablets: A Single Oral Dose, Randomized-Sequence, Open-Label, Two-Period Crossover Study in Healthy Volunteers under Fasting Conditions

Objectives: To compare the rate and extent of absorption of Racor® 20 mg (Rosuvastatin calcium 20 mg) tablet of Laboratorios Leti, S.A.V., with Crestor® 20 mg (Rosuvastatin calcium 20 mg) tablet of AstraZeneca, UK Limited in healthy adult human subjects under fasting conditions. Method: This was an open label, analyst blind, balanced, randomized, two-treatment, two-period, two-sequence, single oral dose, crossover, bioequivalence study in healthy, adult, human subjects under fasting condition. Twenty-four (24) subjects were planned as per the protocol and all subjects completed both periods of the study. The concentrations of Rosuvastatin in plasma were quantitated using a validated LC-MS/MS method of analysis and plasma levels were submitted for statistical analysis. Cmax, AUC0-t, AUC0-∞, Tmax, t1/2, Kel (hrs-1), percent AUC extrapolated [100 * (AUC0-∞ - AUC0-t)/AUC0-∞] (AUC_%Extrapobs) were calculated for rosuvastatin in plasma using SAS® version 9.1.3, SAS Institute. Inc. USA.CARY. ANOVA, 90% confidence interval using Schuirmann’s two one-sided test for bioequivalence, power and ratio analysis, for lntransformed pharmacokinetic parameters Cmax, AUC0-t and AUC0-∞ were computed and reported for Rosuvastatin in plasma for BE. Results: Data showed that 90% confidence intervals for the test/reference geometric mean ratios (GMR) of Cmax (95.01 - 112.66), AUC0-t (93.38 - 111.67) and AUC0-∞ (93.65 - 111.29) were within the BE (80% - 125%) acceptance range. Conclusions: Two products formulation, reference (R) Crestor® (rosuvastatin calcium) of AstraZeneca and test (T), Racor® (rosuvastatin calcium) of Laboratorios Leti S.A.V., with a single dose of 20 mg, under fasting conditions were bioequivalent. No severe, serious or unexpected adverse events (AEs) were reported in this study.

GC-MS/MS Method for Determination and Pharmacokinetics of Main Components of Cang-Ai Volatile Oil in Rat Plasma after Intravenous Administration

[Objectives]To establish a gas chromatography-triple quadrupole mass spectrometry(GC-MS/MS)method based on multiple reaction monitoring(MRM)mode for the analysis of the major components in Cang-ai volatile oil(CAVO).[Methods]An ultrasensitive gas chromatography-tandem mass spectrometry(GC-MS/MS)method was developed and validated for the determination of three highly abundant components in rat plasma samples.Paeonol was used as an internal standard.A multiple reaction monitoring(MRM)model was employed for the quantification of the three major components of CAVO.[Results]The method demonstrated linearity over the range of 0.25 to 50μg/mL with a correlation coefficient(R 2)greater than 0.9998.The lower limit of quantification was 0.25μg/mL.Intra-day and inter-day accuracy and precision were within 15%.Extraction recovery and matrix effect values ranged from 90.1%to 110.6%and 0.1%to 2.1%,respectively.[Conclusions]This method was successfully applied to the simultaneous determination of the three components in high-level CAVO plasma samples,providing a basis for subsequent studies of CAVO.

Pharmacokinetics of Enrofloxacin and Its Metabolite in Carp (Cyprinus carpio) After a Single Oral Administration in Medicated Feed

A precise and reliable analytical method of high performance liquid chromatography-tandem mass spectrometry(HPLCMS/MS)was developed to measure trace levels of enrofloxacin(ENR)and its major metabolite ciprofloxacin(CIP)in carp tissues.Optimized chromatographic separation was obtained on a Waters Xterra MS C_(18) reversed-phase column using gradient elution with methanol and 0.1%formic acid aqueous solution including 5mmolL^(-1) of ammonium acetate.The established method was applied to study the pharmacokinetics and distribution of ENR and CIP in tissues of carp following a single oral administration in feed at a dosage of 40mgkg^(-1) bw(body weight).Data were analyzed using DAS 2.0 dynamics software,and the experimental results suggest that ENR was rapidly absorbed and extensively distributed in carp tissues through systemic circulation,and the pharmacokinetic characteristics can be described with a two-compartment model.The elimination half-lives(t_(1/2β))from muscle,liver,gill,plasma and skin were 131,160,104,132 and 310 h,respectively.The areas under the drug concentration-time curves(AUC)for these tissues were 491,972,750,249 and 706hmgkg^(-1),respectively.The maximum concentration(C_(max))values were 13,29,37,9 and 5mgkg^(-1) with peak times(t_(max))of 8,4,4,2 and 4 h,respectively.Ciprofloxacin,the active metabolite of ENR,was also detected in carp tissues,indicating that only 1.54%of de-ethylation of ENR occurs in carp.At a water temperature of 18℃,the drug withdrawal time was determined to be no less than 24 d while the carp was fed at a single dosage of 40mgkg^(-1).

Eight Zhes Decoction ameliorates the lipid dysfunction of nonalcoholic fatty liver disease using integrated lipidomics, network pharmacology and pharmacokinetics

Nonalcoholic fatty liver disease(NAFLD)has developed into the most common chronic liver disease and can lead to liver cancer.Our laboratory previously developed a novel prescription for NAFLD,“Eight Zhes Decoction”(EZD),which has shown good curative effects in clinical practice.However,the pharmacodynamic material basis and mechanism have not yet been revealed.A strategy integrating lipidomics,network pharmacology and pharmacokinetics was used to reveal the active components and mechanisms of EZD against NAFLD.The histopathological results showed that EZD attenuated the degrees of collagen deposition and steatosis in the livers of nonalcoholic steatofibrosis model mice.Furthermore,glycerophospholipid metabolism,arachidonic acid metabolism,glycerolipid metabolism and linoleic acid metabolism with phospholipase A2 group IVA(PLA2G4A)and cytochrome P450 as the core targets and 12,13-cis-epoxyoctadecenoic acid,12(S)-hydroxyeicosatetraenoic acid,leukotriene B4,prostaglandin E2,phosphatidylcholines(PCs)and triacylglycerols(TGs)as the main lipids were found to be involved in the treatment of NAFLD by EZD.Importantly,naringenin,artemetin,canadine,and bicuculline were identified as the active ingredients of EZD against NAFLD;in particular,naringenin reduces PC consumption by inhibiting the expression of PLA2G4A and thus promotes sufficient synthesis of very-low-density lipoprotein to transport excess TGs in the liver.This research provides valuable data and theoretical support for the application of EZD against NAFLD.

Pharmacokinetics of fucoidan and low molecular weight fucoidan from Saccharina japonica after oral administration to mice

The brown seaweed,Sacchairna japonica,has been used in traditional Chinese medicine for over one thousand years.Oral administration of fucoidan or low molecular weight fucoidan(LMWF)from S.japonica could ameliorate kidney dysfunction in chronic kidney diseases and inhibit diabetic vascular complications.In many studies,LMWF was found to be more potent than fucoidan with high molecular weight.However,the pharmacokinetics of LMWF still remains unclear.The purpose of the research is to compare the pharmacokinetics of fucoidan with high molecular weight(136 kDa)with that low molecular weight(9.5 kDa)after oral administration to ICR mice.Since fucose is the main and representative monosaccharide of fucoidans,we evaluate the pharmacokinetics of fucoidan and LMWF by determining the fucose concentration in mice serum.Both fucoidan and LMWF were absorbed following oral administration.Fucoidan and LMWF were provided to mice by oral administration with 60 mg/kg and the maximum Concentration(C_(max))was found at 2.5 h(0.66±0.32 mg/L)for Fucoidan and 1.5 h(1.01±0.56 mg/L)for LMWF,respectively.It seems that LMWF had a higher area under the curve(AUC_(0–t))and was absorbed more quickly than fucoidan.The estimated bioavailability of LMWF was28.3%in the mice treated with a single dose of 30 mg/kg.In addition,LMWF was found widely spreaded into different tissues following oral administration and the highest concentration was found in kidney at 19.93±7.02μg/g.In this study,we first studied the pharmacokinetics of LMWF,in order to help to understand the function of LMWF.And our results shed light on the potential of development of drugs based on LMWF.

DFT-Based Chemical Reactivity Descriptors, Pharmacokinetics and Molecular Docking Studies of Thymidine Derivatives

Thymidine-containing derivatives are considered to be among the most significant derivatives in medicinal chemistry. In this study, we employed a combined computational approach involving density-functional theory (DFT) calculations, molecular docking simulations, and absorption, distribution, metabolism, excretion, and toxicity (ADMET) property predictions. Prediction of activity spectra for substances (PASS) revealed promising antiviral, antimicrobial and anti-carcinogenic activities of these thymidine derivatives. Using Gaussian 09, we optimized the molecular structures of the thymidine derivatives to obtain their stable conformations and calculate their electronic properties. Subsequently, molecular docking simulations were performed to explore the binding interactions between the thymidine derivatives and the active site of the Candida albicans (PDB: 1IYL and 2Y7L) proteins. The docking results were evaluated based on docking scores, hydrogen bonding, and hydrophobic interactions and revealed favorable binding interactions between the thymidine derivatives and the proteins, suggesting their potential as antifungal agents. The thermodynamic properties, including binding free energy, enthalpy, and entropy changes were determined to assess the stability and strength of the ligands-protein complexes. The calculated pharmacokinetic parameters, such as ADMET properties, provided insights into the drug-likeness and potential bioavailability of the thymidine derivatives. These results offer a foundation for further experimental investigations and the design of novel antifungal agents targeting Candida albicans infections.

Pharmacokinetics of nitrogen-containing metabolites R-gentiandiol and S-gentiandiol in rat plasma after oral administration of swertiamarin

Objective:A chiral resolution method for enantiomers of two chiral nitrogen-containing metabolites R-gentiandiol and S-gentiandiol of swertiamarin in plasma was developed,and the pharmacokinetics of the metabolites were studied.Methods:The metabolites of swertiamarin in vivo were detected by LC-MS/MS using Astec CyclobondⅡCyclodextrin column(4.6 mm×100 mm,5μm),gradient elution with acetonitrile-water as mobile phase,and monitored by multiple reaction monitoring(MRM)method in positive mode.The ion pairs for quantitative analysis are R-gentiandiol(m/z 210.04→192.06),S-gentiandiol(m/z 210.04→192.06)and gentianone(m/z 192.02→162.08).Results:The linear correlation coefficients of the method developed were greater than 0.999,the precision was less than 7.00%,the recovery was 99.57%-102.65%,and the matrix effect was 90.94%-91.34%.The peak t_(max)of R-gentiandiol and S-gentiandiol in rat plasma after oral administration of swertiamarin were(1.63±0.23)h and(1.58±0.21)h,t_(1/2)was(6.23±0.52)h and(5.46±0.38)h,C_(max)was(86.79±20.81)ng/mL and(60.72±18.95)ng/mL,and the AUC_(0-24)were(1094.58±86.37))(ng·h)/mL and(724.67±58.38)(ng·h)/mL,respectively.Conclusion:The method was highly sensitive with good accuracy and precision,and it was successfully applied for chiral resolution and pharmacokinetics study of R-gentiandiol and S-gentiandiol in plasma.The method developed and experimental results will provide scientific basis for the study of pharmacodynamics and pharmacodynamic material basis of swertiamarin,and lay a foundation for clinical application and resource development of TCM monomer.

Transepithelial photorefractive keratectomy without mitomycin-C for irregular astigmatism after femtosecond laser-assisted in situ keratomileusisflap complications

Dear Editor,W e write to present a case report of transepithelial photorefractive keratectomy(TPRK)without mitomycin-C(MMC)for irregular astigmatism after femtosecond laser-assisted in situ keratomileusis(FS-LASIK)flap complications.Written informed consent was obtained from the patient to allow the publication of this case and associated accompanying images.The study was conducted in accordance with the Helsinki Declaration.TPRK is a surgical procedure which uses an excimer laser to ablation of both the corneal epithelium and stroma,which is widely used in clinic[1-2].The procedure may be conducted in cases where there is notable topographic irregularity or scarring following complications with the LASIK flap.Corneal haze is a potential complication following TPRK,and the use of MMC as a prophylactic agent against postoperative corneal haze has been demonstrated to significantly reduce its formation after TPRK/photorefractive keratectomy(PRK).

Efficacy of adjuvant mitomycin-C and triamcinoloneimpregnated nasal packing for endoscopic dacryocystorhinostomy

●AIM:To compare the success rate and complications of adjuvant use of mitomycin C and triamcinoloneimpregnated biodegradable nasal packing(TABP)in endoscopic dacryocystorhinostomy(DCR).And to evaluate the efficacy of combining intraoperative mitomycin C and TABP for endoscopic DCR.●METHODS:A total of 198 eyes of 148 patients who underwent endoscopic DCR for acquired nasolacrimal duct obstruction were retrospectively analysed.The patients were randomly divided into three groups:Group A included patients treated without intraoperative mitomycin C but with TABP,Group B included patients treated without triamcinolone but with intraoperative mitomycin C and normal saline-impregnated nasal packing,and Group C included patients treated with intraoperative mitomycin C and TABP.●RESULTS:The results revealed no significant difference in the overall success rates between Groups A(86.8%)and B(89.2%;P=0.377).However,Group C(97.5%)showed a significantly higher overall success rate than Groups A and B.The incidence of granulomas was significantly lower in group C(5%)than in Groups A(20.8%)and B(15.2%;P=0.009).Other complications,such as crust,synechiae,and revision surgery,did not differ significantly among the three groups.●CONCLUSION:The combination of intraoperative mitomycin C and TABP effectively prevents granulomas and enhances surgical success rate.Additionally,there is no statistically significant difference observed between the use of mitomycin C or TABP alone.

Pharmacokinetic Characterization of Xylazine in Goats with Simultaneous Anesthesia Studies

The aim was to study the pharmacokinetics of xylazine as a stable anesthetic in goats.In this study,goats were injected with xylazine at the rate of 0.3 mL·kg-1 intramusculally,and blood samples were collected at 1,3,5,10,20,30,45,60,90,120,180,and 240 min after administration,respectively.Xylazine was extracted by liquid-liquid extraction and separation method,and blood concentration was determined by high performance liquid chromatography(HPLC).The pharmacokinetic characteristics of xylazine in healthy goats were analyzed by pharmacokinetic software.The results showed that the chromatographic peak time of xylazine chromatography was 9-11 min.The specificity of the method was good.The linear correlation coefficient R2 of the standard curve was 0.9982 when the concentration of xylazine was in the range of 10-1×1000 ng.The pharmacokinetic model of xylazine in goats was a one-chamber model with first-order rate absorption,distribution half-life t1/2Ka was(0.49±0.041)min,elimination half-life t1/2Ke was(23.3±2.5)min,and the peak time(Tp)of the highest concentration was(2.8±0.2)min.The total drug clearance CL/F was(0.00016±0.000016)mg·kg-1·min-1(ng·mL-1),and the minimum effective blood concentration was 56.6 ng·mL-1,which was consistent with the clinical anesthetic effect.The results showed that xylazine had the characteristics of rapid absorption,wide distribution,short peak time,slow clearance rate,and long anesthetic time in goats,which could be used as the basic drug for the development of goat complex anesthetic preparation.

Enhancement in Bioavailability of CurCousin®, A Minor Metabolite from Curcuma longa by Addition of BioPerine® —A Pharmacokinetic Study

In recent years, metabolic syndrome has been a growing health concern across the world. The role of nutraceuticals and functional foods in this area has a significant place due to the adverse effects of contemporary modes of treatment. CurCousin® is a nutritional ingredient containing bioactive Calebin A, (analog of Curcumin) with self-affirmed GRAS status. CurCousin® has been a clinically studied dietary supplement ingredient with a positive impact on body weight, lipid levels and metabolic health. Bioenhancers play an important role in increasing the bioavailability of the active in turn enhancing efficacy as well as reducing the dosage required to achieve the therapeutic effect. This study investigated the possible pharmacokinetic interaction between CurCousin® at two different doses (2.25 and 4.5 mg/kg) in the presence and absence of BioPerine® (0.27 mg/kg), a natural bioenhancer in Sprague-Dawley rats. The results revealed that the addition of BioPerine® into CurCousin® (2.25 mg/kg) half the dose when administered enhances the bioavailability and was equipotent to CurCousin® (4.5 mg/kg) double the dose without BioPerine®. Thus, leading to future clinical studies to evaluate its improved pharmacological efficacy as well as reduced therapeutic dosage.

Pharmacokinetics of Mequindox and Its Metabolites in Swine

The present study was carried out to investigate the pharmacokinetics of mequindox （MEQ）, a new synthetic quinoxaline 1,4-dioxide derivative and its two main metabolites M1 [2-isoethanol mequinoox], M2 [2-isoethanol 1-desoxymequindox] in healthy swine. MEQ （10 mg kg-1 body weight） was administered to nine healthy cross-bread swine via oral, intramuscular, and intravenous routes in a randomized 3x3 crossover design with a 1-wk washout period. A sensitive high-performance liquid chromatography （HPLC） method was used for the determination of plasma concentrations of MEQ and its metabolites M1 and M2. Plasma concentration versus time profiles of MEQ and its metabolites, M1 and M2, were analyzed by noncompartmental analysis using WinNonlin 5.2 software. The mean maximum concentrations （Cmax） of M1 and M2 after intravenous administration of MEQ were （5.27±1.59） lag mL-1 at 1.78 h and （1.01±0.29） μg mL-1 at 0.92 h, respectively. The mean maximum concentrations （Cmax） ofMEQ, M1, and M2 were found to be （6.96±3.23）, （6.61±1.56）, and （0.78 ±0.25） lag mL-1 respectively at 0.15, 1.61, and 1.30 h after intramuscular administration of MEQ, respectively and （0.75±0.45）, （6.90±1.52）, and （0.62±0.21） lag mL-1, respectively at 0.40, 1.57, and 2.00 h, respectively after oral administration of MEQ. The apparent elimination half-lives （b2） ofMEQ, M1, and M2 were （0.84±0.35）, （7.57±3.93）, and （9.56±6.00） h, respectively after intravenous administration of MEQ; （0.50±0.25）, （6.30±3.00）, and （5.94±2.54） h, respectively after intramuscular administration of MEQ; and （1.64± 1.17）, （5.59±1.93）, and （16.25±10.27） h, respectively after oral administration of MEQ. The mean areas under the plasma concentration-time curve （AUC0-∝） of MEQ, M1, and M2 were （4.88±1.54）, （36.93±17.50）, and （5.16±94） μg h mL-1, respectively after intravenous administration of MEQ; （4.18±0.76）, （48.25±20.82）, and （4.88±2.21） μg h mL-1 , respectively after intramuscular administration of MEQ; and （1.01±0.40）, （48.83±20.71）, and （5.54±2.23） μg h mL-1, respectively after oral administration of MEQ. MEQ was rapidly absorbed and metabolized in swine after oral, intramuscular, and intravenous administration. Further studies are required to investigate the double-peak phenomenon observed in the plasma concentration-time profile after oral administration and the pharmacokinetics of other metabolites of MEQ.

Pharmacokinetics and pharmacodynamics of Da-Cheng-Qi decoction in the liver of rats with severe acute pancreatitis

AIM To explore the pharmacokinetics and pharmacodynamics of Da-Cheng-Qi decoction(DCQD) in the liver of rats with severe acute pancreatitis(SAP) based on an herbal recipe tissue pharmacology hypothesis.METHODS Healthy male Sprague-Dawley rats were randomly divided into a sham operation group(SOG); a model group(MG); and low-, median- and high-dose treatment groups(LDG, MDG, and HDG, respectively). Different dosages(6, 12 and 24 g/kg for the LDG, MDG, and HDG, respectively) of DCQD were administered to the rats with SAP. The tissue concentrations of aloeemodin, rhein, emodin, chrysophanol, honokiol, rheo chrysophanol, magnolol, hesperidin, naringenin and naringin in the liver of the treated rats were detected by high-performance liquid chromatography tandem mass spectrometry. Alanine transaminase(ALT) and aspartate transaminase(AST) in serum, inflammatory mediators in the liver and pathological scores were evaluated.RESULTS The major components of DCQD were detected in the liver, and their concentrations increased dosedependently. The high dose of DCQD showed a maximal effect in ameliorating the pathological damages, decreasing the pro-inflammatory mediators tumor necrosis factor-α and interleukin(IL)-6 and increasing anti-inflammatory mediators IL-4 and IL-10 in the liver. The pathological scores in the pancreas for the MG were significantly higher than those for the SOG(P < 0.05). DCQD could reduce the pathological scores in the pancreas and liver of the rats with SAP, especially in the HDG. Compared to the SOG, the ALT and AST levels in serum were higher in the MG(P < 0.05), while there was no statistical difference in the MG and HDG.CONCLUSION DCQD could alleviate liver damage by altering the inflammatory response in rats with SAP based on the liver distribution of its components.

Pharmacokinetics and pharmacodynamics of Shengjiang decoction in rats with acute pancreatitis for protecting against multiple organ injury

AIM To explore the pharmacokinetics and pharmacodynamics of Shengjiang decoction(SJD) in rats with acute pancreatitis(AP) for protecting against multiple organ injury.METHODS An AP model was established by retrograde perfusion of 3.5% sodium taurocholate into the biliopancreatic duct, and a control group(CG) received 0.9% sodium chloride instead. Twelve male Sprague-Dawley rats were randomly divided into a CG treated with SJD(CG + SJD) and a model group treated with SJD(MG + SJD), both of which were orally administered with SJD(5 g/kg) 2 h after surgery. Blood samples were collected via the tail vein at 10, 20, and 40 min and 1, 2, 3, 4, 6, 8, and 12 h after a single dose of SJD to detect its main components using high-performance liquid chromatography-tandem mass spectrometry. The pharmacokinetic parameters were compared. In the pharmacodynamic experiment, 18 male SpragueDawley rats were randomly divided into a CG, an AP model group(MG), and an SJD treated AP group(SJDG). Serum amylase, lipase, and inflammatory cytokines were measured, and heart, lung, liver, spleen, pancreas, kidney, and intestine tissues were collected for pathological examination.RESULTS The MG + SJD displayed significantly shorter mean residence time(MRT) and higher clearance(CL) for emodin and aloe-emodin; significantly shorter time of maximum concentration and T1/2 and a lower area under curve(AUC) for aloe-emodin; a significantly higher AUC and lower CL for rhein; and longer MRT and lower CL for chrysophanol than the CG + SJD. In the pharmacodynamic experiment, the amylase, interleukin(IL)-6, IL-10, and tumor necrosis factor(TNF)-α levels in the MG were higher than those in the CG(P < 0.05). After the herbal decoction treatment, the SJDG had higher IL-10 and lower TNF-α levels than the MG(P < 0.05). The MG had the highest pathological scores, and the pathological scores of the lung, pancreas, kidney, and intestine in the SJDG were significantly lower than those in the MG(P < 0.05).CONCLUSION AP may have varying effects on the pharmacokinetics of the major SJD components in rats. SJD might alleviate pathological injuries of the lung, pancreas, kidney, and intestine in rats with AP via regulating pro-and antiinflammatory responses, which might guide the clinical application of SJD for AP treatment.

Pharmacokinetics of traditional Chinese syndrome and recipe:a hypothesis and its verification(Ⅰ)

AIM To propose a hypothesis defining theabsorption,distribution,metabolism andelimination of traditional Chinese recipe（TCR）-component in blood of healthy subjects andpatients,and estimate its correctness.METHODS The pharmacokinetics（PK）of samedose of drug was studied in the animal model oftraditional Chinese syndrome（S）and healthyanimals.The classification,terminology,concept and significance of the hypothesis wereset forth with evidence provided in the presentstudy.The hypotheses consisted of traditionalChinese syndrome PK（S-PK）and traditionalChinese recipe PK（R-PK）.Firstly,the observedtetramethylpyrazine（TMP）PK in healthy,chronically reserpinized rats（rat model ofspleen deficiency syndrome,RMSDS）andRMSDS treated with Sijunzi decoction（SJZD）forconfirmation were used to verify S-PK; secondly,the ferulic acid（FA）PK in healthy andhigh molecular weight dextran（HMWD）-inducedrabbit model with blood stasis syndrome（RDBSS）was also used to verify S-PK;andlastly,TMP PK parameters in serum of healthyrats after orally taken Ligusticum wallichii（LW）,LW and Salvia miltiorrhiza（LW&SM）decoctions were compared to verify R-PK.RESULTS The apparent first-order absorption[Ka,（13.61±2.56）h-1,area under the blooddrug concentration-time curve[AUC,（24.88±9.76）μg.h-1mL-1],maximum drug concentration[Cmax,（4.82±1.23）μg·mL-1]of serum TMP inRMSDS were increased markedly（P【0.05）compared with those[Ka=（5.41±1.91）h-1,AUC=（5.20±2.57）μg·h-1·mL-1,Cmax=（2.33±1.77）μg·mL-1]of healthy rats（HR）.Theapparent first-order rate constant for α and βdistribution phase[α=（0.38±0.09）h-1,β=（0.06±0.03）h-1,the apparent first-orderintercompartmental transfer rate constants[K10=（0.24±0.07）h-1,K12=（0.11±0.02）h-1,K21=（0.11±0.02）h-1]of serum TMP in RMSDS weredecreased significantly（P【0.01）comparedwith those[K10=（0.88±0.20）h-1,K12=（1.45±0.47）h-1,K21=（0.72±0.22）h-1]of HR.However,no apparent differences occurredbetween HR and RMSDS treated with SJZD.Theserum FA concentration and its AUC[（5.6690±2.3541）μg·h-1·mL-1] in RMBSS were also higherthan those[AUC=（2.7566±0.8232）μg·h-1·mL-1]of healthy rabbits（P【0.05）.The Ka（11.51±2.82）h-1,AUC（0.84±0.17）μg·h-1·mL-1of LW & SM-derived TMP in serum weremuch lower（P【0.05）than those[Ka=（19.58±4.14）h-1,AUC=（1.27±0.26）μg·h-1·mL-1]ofLW-derived TMP in serum after oral decoctions.CONCLUSION The SDS and blood stasissyndrome state could affect significantly thepharmacokinetic parameters of drugs and theabnormal SDS pharmacokinetic parameters couldbe normalized by SJZD.The combination ofChinese medicine in TCR could reciprocallyaffect the pharmacokinetic parameters of othercomponents absorbed into the systemiccirculation.These results support the S-and R-PK hypothesis.

Comparative pharmacokinetics of chlorogenic acid after oral administration in rats

The present study was aimed at the comparison of the pharmacokinetics of pure chlorogenic acid and extract of Solanum lyratum Thunb. The animals were allocated to two groups, and were administered chlorogenic acid or extract of S. lyratum Thunb. at a dose of 50.0 mg/kg orally. Blood samples were collected up to 8 h post-dosing. Plasma chlorogenic acid analyses were performed using an HPLC method with UV detector. The pharmacokinetic parameters were evaluated using non-compartmental assessment. Significant differences existed in the two groups for AUCo-t, AUCo-∞ and CLz/F. The reliable HPLC method was successfully applied to the determination of chlorogenic acid in rat plasma at dosting of 50.0 mg/kz.

Pharmacokinetics and enterohepatic circulation of jervine,an antitumor steroidal alkaloid from Veratrum nigrum in rats

Jervine,a novel steroidal alkaloid from Veratrum nigrum L.,exhibits both antitumor effect and potential toxicity.The aim of study was to characterize the pharmacokinetic behaviors and enterohepatic circulation of jervine in rats.A rapid and simple ultra-high performance liquid chromatography-tandem mass spectrometric method was developed and validated for quantification of jervine and alpinetin (internal standard) in rat plasma.After extraction from rat plasma by a simple protein-precipitation method,the analyte was separated on a C18 column (2.1 mm×50 mm,1.7μm) using water with 0.1%formic acid and acetonitrile as the mobile phase delivered at a flow rate of 0.4mL/min.Jervine and alpinetin were determined in the positive mode with multiple reaction monitoring (MRM) of the ion transitions at m/z426.3→108.8 and m/z 271.0 166.9,respectively.Molecular docking method was used to investigate the binding of jervine to p-glycoprotein and dehydroepiandrosterone sulfotransferase.The method was well validated within acceptance limits including specificity,matrix effect,recovery,precision,accuracy,and stability,and was successfully applied to the pharmacokinetic study of jervine after oral and intravenous administration to rats.Jervine presented a small volume of distribution,fast absorption,high oral bioavailability,and enterohepatic circulation.The enterohepatic circulation was first observed in veratrum alkaloids,and was further investigated by molecular docking studies,which was related to the binding of jervine to p-glycoprotein and dehydroepiandrosterone sulfotransferase.The pharmacokinetic properties and enterohepatic circulation of jervine in rats provided a significant basis for the drug-drug interaction and toxicity study in the future.

Capillary electrophoresis with electrochemiluminescence detection for the analysis of quinolone drugs and pharmacokinetics study

A novel method for the determination of two quinolone drugs norfloxacin （NOR） and levofloxacin （LVX） was described by capillary electrophoresis with electrochemiluminescence detection. The good relationship （r ≥ 0.9991） between peak area and concentration of analytes was established over two orders of magnitude. The limits of detection （LOD, S/N = 3） in standard solution are 4.8 × 10^-7 mol/L for NOR and 6.4 × 10^-7 mol/L for LVX, respectively. The limits of quantitation （LOQ, S/N = 10） in real human urine samples are 1.2 × 10^-6 mol/L for NOR and 1.4 × 10^-6 mol/L for LVX, respectively. The present method was successfully applied to the determination of NOR and LVX in human urine and the studv of oharmacokinetics of NOR.

Sensitive and Rapid Quantification of Felodipine by High-performance Liquid Chromatography-tandem Mass Spectrometry(HPLC-MS/MS) and Its Pharmacokinetics in Healthy Chinese Volunteers

To investigate the pharmacokinetics of felodipine in the plasma of healthy Chinese volunteers, 30 healthy volunteers received a single oral dose of 5 mg of extended release felodipine tablets. The felodipine was extracted from the matrix with a liquid-liquid extract procedure and analyzed by high-performance liquid chromatography-tandem mass spectrometry in the multiple reaction monitoring（MRM） mode using an electrospray ion source with positive ion detection. The method was validated over a felodipine concentration range of 0. 05-10.00 ng/mL in human plasma. Its main pharmacokinetic parameters values were： ρmax = （ 1.67 ± 0. 84 ） ng/mL, occurring at （ 3.93 3± 2. 49 ） h; the plasma elimination half-life： （23. 08 3± 9. 48） h and the area under the plasma concentration versus time curve： （29. 94 ± 14. 39） ng · h/mL. The validation results demonstrated that this method showed a satisfactory precision and accuracy across the calibration range. The procedure involved minimal drug administration, sample preparation, and a 2. 5-min chromatographic run time. It was well suited to clinical studies of the drug involving large numbers of samples.

Improved anti-tumor efficacy and pharmacokinetics of bufalin via PEGylated liposomes

OBJECTIVE To determine the characterization,anti-tumor efficacy and pharmacokinetics of bufalin-loaded PEGylated liposomes compared with bufalin entity.METHODS Bufalin-loaded PEGylated liposomes and bufalin-loaded liposomes were prepared reproducibly with homogeneous particle size by the combination of thin film evaporation method and high pressure homogenization method.The particle size and zeta potential of the liposomes were determined by dynamic light scattering technique.The direct imaging of morphology of liposomes was charactered by transmission electron microscope.The content of bufalin in liposomes was analysed by HPLC method.The entrapment efficiency and the particle size was applied to assess the stability profile,after storage at 4℃ on day 0,7,15,30 and 90.The in-vitro release behaviours of bufalin from liposomes were conducted using dialysis bag technique at 37℃.In-vitro cytotoxicity studies were carried out using MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]assay on several kinds of tumor cel lines including SW620,PC-3,MDA-MB-231,A549,U251,U87 and HepG2.In-vivo pharmacokinetic study of bufalin liposomes was evaluated by HPLC method.RESULTS Their mean particle sizes were 127.6 nm and 155.0 nm,mean zeta potentials were 2.24 m V and-18.5 m V,entrapment efficiencies were 76.31%and 78.40%,respectively.In-vitro release profile revealed that the release of bufalin in bufalin-loaded PEGylated liposomes was slower than that of bufalin-loaded liposomes.The cytotoxicity of blank liposomes has been found within acceptable range,whereas bufalin-loaded PEGylated liposomes showed enhanced cytotoxicity to U251 cells compared with bufalin entity.In-vivo pharmacokinetics indicated that bufalinloaded PEGylated liposomes could extend eliminate half-life time of bufalin in plasma in rats.CONCLUSION The results suggested that bufalin-loaded PEGylated liposomes improved the solubility and increased the drug concentration in plasma.