Gut microbiota-mediated metabolism of Panax notoginseng saponins and its role in pharmacokinetics and pharmacodynamics

Panax notoginseng saponins(PNS)are a class of effective ingredients in Notoginseng Radix et Rhizoma,a well-known herbal medicine called San-Qi in Chinese.After oral administration,PNS inevitably interacts with gut microbiota,and thus affect the pharmacokinetic profiles and pharmacological effects.To date,studies concering gut microbiota-mediated metabolism of PNS have not been reviewed systematically.Herein,we outline the metabolic profiles of Panax notoginseng saponins mediated by gut microbiota,as well as its role in the pharmacokinetics and pharmacodynamics on the basis of reported data.The metabolic pathways of primary saponins are proposed,and step-by-step deglycosylation is found to be the primary degradation pathways of PNS mediated by gut microbiota.Specific microorganisms and enzymes involved in the metabolic processes were summarized.Gut microbiota is deeply involved in the metabolism of PNS,affects the pharmacokinetic profiles,and produces a series of active metabolites.These metabolites were documented to play an essential role in the efficacy of the parent compounds.Future studies should focus on strengthening the real-world evidence,defining the interaction between gut microbiota and PNS,and developing the strategy for modulating gut microbiota to enhance the bioavailability and efficacy of PNS.These information would be useful for further research and clinical application of PNS.

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.

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.

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.

Population Pharmacokinetics of Propofol Administered by TCI in Chinese Elderly Patients

Aim To investigate the population pharmacokinetics of propofol administered by TCI in Chinese elderly patients. Methods Thirty-two patients with ASA Ⅰ - Ⅱ , 65 - 82 years old, undergoing selective lower abdominal operation were studied. Propofol was administered by target-controlled infusion with Marsh parameter. The target plasma concentration was 3 μg＇ mL^-1. Radial arterial blood samples were collected and analyzed by reversed phase HPLC with fluorescence detection. Population pharmacokinetic modeling was performed using NONMEM. Inter-individual variability and intra-individual variability of propofol were estimated for clearances and volumes of distribution. The effects of age, body weight, lean body mass, gender, height, hemoglobin, total protein, albumin, creatinine, alanine aminotrans ferase （ALT）, and aspartate aminotransferase （AST） were investigated. The effects of coadministered opioid drugs were also studied. Results The pharmacokinetics of propofol in the Chinese elderly patients was best described by a three-compartment open model. Lean body mass was found to be a covariate for system clearance at significant level （ P 〈 0.005）. The clearance decreased linearly with age as well （ P 〈 0. 005）. The apparent volume of distribution for deep peripheral compartment （V3） was influenced by gender. Elderly female patients showed a higher value for V3. Conclusion The pharmacokinetics of propofol administered by TCI in Chinese elderly patients can be well described by a three-compartment open model. Inclusion of age, lean body mass and gender as covariates significantly improved the model. To ensure the accuracy and precision of target-controlled infusion, the population pharmacokinetic model applied to the individual patient should be adjusted reasonably.

Population pharmacokinetics of paeoniflorin in guanxin Ⅱ prescription

To evaluate the effect of components in Guanxin Ⅱ prescription on the pharmacokinetic profiles of paeoniflorin. Plasma concentration of Paeoniflorin in rats after intravenous injection of Paronia Pall Extract （PPE） and oral administration of PPE and three types of decoctions in Guanxin Ⅱ prescription, respectively, were determined by HPLC analyses. NONMEM （nonlinear mixed-effect modeling） method was used to analyze full set of pharmacokinetic data directly. A two-compartment model with first-order degradation in absorption compartment was employed for the data analysis. The mean of population parameters, CL1, V1, CL2, V2, Ka0, and Kal, were measured to be 0.509 L/h, 0.104 L, 0.113 L/h, 0.123 L, 0.135/h, and 0.0135/h, respectively. Inter-individual variabilities were estimated and dose formulation （DF） was identified as a significant covariate of Ka 1, Ka0, and V1. It is concluded that the pharmacokinetic behaviors of paeoniflorin in rats can alter with different dose formulations.

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 Plasma Concentration of Cinnamic Acid by High-Performance Liquid Chromatography and Its Pharmacokinetics in Rats after Oral Administration of Zi-Shen Pill

Aim To develop a simple and sensitive high-performance liquid chromatographicmethod for determination of plasma concentration of cinnamic acid and pharmacokinetic study in ratsafter a single oral dose of traditional Chinese medicinal preparation Zi-Shen pill. Method Plasmasamples were acidified with hydrochloric acid and extracted with ethyl acetate . Cinnamic acid wasdetermined by HPLC using a G_(18) column. A mobile phase ofmethanbl-acetonitrile-water-triethyl-amine (7:22:73 = 0.2, V/V), with the pH adjusted to 4.0 withphosphoric acid, and with a UV detector set at 340 nm. Results The standard curve was linear overthe range of 1.92- 192.0 μg·mL^(-1). The LLOQ was 1.92 μg·mL^(-1) . The RSDs of within-day andbetween-day precision were < 8%. The mean recovery was 82.0% . Conclusion After validation, themethpd has been used to investigate the pharmacokinetic profiles of the traditional Chinesemedicinal preparation Zi-Shen pill.

Determination of Zolmitriptan in Human Plasma by High-Performance Liquid Chromatography-Electrospray Mass Spectrometry and Study on Its Pharmacokinetics

Aim To establish a new and sensitive HPLC-MS method for the determination ofzolmitriptan in human plasma and study the pharmacokinetics of zolmitriptan in healthy volunteers.Methods A single oral dose of 5 mg of zolmitriptan tablet was given to 20 healthy male volunteers.After dosing, blood samples were collected for a period of 24 h, and zolmitriptan concentration inplasma was analyzed by HPLC-MS. Results The plasma concentration-time course fitted well atwo-compartment open model with a lag time, giving the following pharmacokinetic parameters: T_(max)1.60 ± 0.24 h, C_(max) 9.73 ± 1.43 ng·mL^(-1). T_(1/2α)1.72±0.46 h, T_(1/2β) 4.52 + 0.97 h,and AUC_(0-t) 55.59 ± 5.12 ng·mL^(-1)·h. Conclusion The improved analytical method forzolmitriptan is rapid, sensitive and suitable for application to pharmacokinetic studies and routinedetermination of numerous samples.

Tamsulosin alters ievofloxacin pharmacokinetics in prostates derived from rats with acute bacterial prostatitis

The combination of levofloxacin and a1 adrenergic antagonist treatment is the current preferred choice for both bacterial and non-bacterial prostatitis. The aim of this study is to explore the influence of a1 adrenergic antagonists on the pharmacokinetics of levofloxacin using rat models with acute bacterial prostatitis （ABP） induced by direct injection with Escherichia coil （ATCC25922）, A total of 96 model rats were randomly assigned into two groups： the experimental group （treated with both tamsulosin and levofloxacin, n=48） and the control group （treated with levofloxacin and solvents, n=48）. Six rats from each group were euthanized to collect blood, liver, kidney and prostate samples at the time points of 0. 125, 0.25, 0.5, 1,2, 4, 8 and 12 h after drug administration. The levofloxacin concentrations were detected by high performance liquid chromatography （HPLC）, and the pharmacokinetic parameters were calculated using the 3p97 software program. There were no obvious differences （P〉0.05） between the experimental and control groups in the major pharmacokinetic parameters of levofloxacin, including the halftime （t1/2）, time to peak （tpeak）, clearance rate （CL）, maximum concentration （Cmax） and area under the curve （AUC0-12）, in the plasma or in the hepatic and kidney tissues of the model rats. However, in the prostatic tissues, tamsulosin increased the Cmax, prolonged the t1/2 and decreased the CL of levofloxacin （P〈0.05）. These results indicate that tamsulosin may enhance the effect of levofloxacin in the treatment of bacterial prostatitis without changing the drug concentration in the liver and kidney.

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.

Effect of severe acute pancreatitis on pharmacokinetics of Da-Cheng-Qi Decoction components

AIM:To investigate the effect of severe acute pan- creatitis(SAP)on pharmacokinetics of Da-Cheng-Qi Decoction(DCQD)components in rats. METHODS:Rats were divided into SAP group and sham-operation group as a control group(n=6). Rhein,chrysophanol,rheochrysidin,magnolol,hesperidin and naringin in DCQD were quantified in rat serum by high performance liquid chromatography tandem mass spectrometry for studying their pharmacokinetics. RESULTS:Early absorption of each DCQD component was tended to degrade in SAP group after treatment with DCQD by gavage.The Cmax(chrysophanol,P= 0.0059;rheochrysidin,P=0.0288;magnolol,P= 0.0487;hesperidin,P=0.0277;naringin,P=0.0023) and AUC(rhein,P=0.0186;chrysophanol,P=0.0013; magnolol,P=0.001;hesperidin,P=0.0081;naringin, P=0.0272)of DCQD component were obviously lower in SAP group than in control group.The T1/2α of chrysophanol and rheochrysidin(P=0.0467 and 0.0005,respectively)and Tmax of chrysophanol and rheochrysidin(P=0.0101 and 0.0037,respectively) lasted longer in SAP group than in control group. CONCLUSION:SAP can significantly impact the ab-sorption of DCQD components in rats and their phar-macokinetic parameters.

Identification of bioactive anti-angiogenic constitutes targeting tumor endothelial cells in Shenmai Injection using multidimensional pharmacokinetics

OBJECTIVE To identify the bioactive anti-angiogenic constitutes targeting tumor endothelial cells(TECs)in Shenmai Injection(SMI).METHEODS For pharmacokinetic(PK)studies,Balb/c mice harboring human colorectal cancer(LoVo)xenografts were treated with SMI 10 mL·kg^-1 daily for 1 or 8 d.Multidimensional PK profiles of ginsenosides in plasma,subcutaneous tumors,and TECs were investigated.For PD studies,the tumor-bearing mice Intravital multi-photon imaging and CD31 immunofluorescence staining were used to evaluate the number of microves⁃sels and braches.Double staining of CD31 and α-SMA was performed to evaluate pericytes coverage ratios around vessels.ELISA was performed to determine the concentrations of VEGF and FGF in tumor tissues.For synergistic anti-tumor study,the tumor-bearing mice were treated with SMI 10 mL·kg^-1 daily,Rd 5 mg·kg^-1 daily with or without 5-FU 15 mg·kg^-1 every 3 d for 20 d.HPLC-MS/MS was used to determine the concentrations of 5-FU in plasma and tumor tissues.RESULTS SMI decreased the number of microvessels(P<0.05)and vessel branches(P<0.05)and improved vascular pericytes coverage(P<0.05).PK studies showed that the concentrations of protopanaxadiol-type(PPD)ginsenosides(Rb1,Rb2/Rb3,Rc,and Rd)in both,plasma and tumors,were higher than those of protopanaxatriol-type(Rg1 and Re)and oleanane-type(Ro)ginsenosides.Among PPD ginsenosides,Rd exhibited the greatest concentrations in tumors and TECs after repeated injection.In fact,the proportion of Rd in the detectable components of SMI gradually increased in the following order:SMI formula(2.8%),plasma(16.0%),tumor tissues(34.3%),and TECs(40.3%).In vivo bioactivity results showed that Rd 5 mg·kg^-1 daily significantly decreased the number of microvessels(P<0.05)and vessel branches(P<0.05)and increased pericytes coverage(P<0.05)while Rd 0.5 mg·kg^-1 daily,Rb1 and Rg1 had no significant effect on them.Rd 5 mg·kg^-1 suppressed the expression of VEGF and FGF simultaneously.Rd 5 mg·kg^-1 enhanced the antitumor effect of 5-FU via increasing the distribution of 5-FU in tumor tissues(P<0.05)in xenograft mice.CONCLUSION Ginsenoside Rd may be the major bioactive anti-angiogenic constituent targeting TECs after SMI treatment.

Comparison of pharmacokinetics of different oral Panax notoginseng saponins using ultra-high performance liquid mass spectrometry

Objective:To discuss and compare the plasma pharmacokinetics after three oral Panax notoginseng saponin(PNS)administrations in beagle dogs.PNS is the main active ingredient of the traditional Chinese medicine(TCM)Panax notoginseng.Although its outstanding therapeutic efficacy has been demonstrated by various researchers,its broader application is restricted by the low bioavailability of PNS.Methods:An ultra-high performance liquid chromatographyetandem mass spectrometry(UPLC-MS/MS)method for the simultaneous quantification of notoginsenoside R1,ginsenoside Rg1,ginsenoside Rb1,ginsenoside Rd,and ginsenoside Re in beagle dog plasma was developed and validated.The plasma samples were subjected to liquideliquid extraction with acetone and methanol,and separated on an ACQUITY C18 column(100×2.1 mm ID,1.7 mm)using acetonitrile and water as the mobile phase with a run time of 4.5 min.Results:The analytes were detected without interference in Selected Reaction Monitoring mode with positive electrospray ionization.The validated method was successfully used in comparative pharmacokinetic studies of the five saponins in beagle dogs after oral administration of three PNS preparations.Blood samples were collected up to 192 h after administration and pharmacokinetic parameters were calculated using DAS 3.20 and SPSS 17.0.The AUC_(0-t)values of Re and R1 were significantly higher in soft capsules than in hard capsules.However,the AUC_(0-t)values between hard and soft capsules were not significantly different for the other three componentsdRb1,Rd and Rg1.Conclusion:Our intuitive analysis suggests that the bioavailability of PNS in soft capsules is greater than in hard capsules.

Determination of Naftopidil in Dog Plasma by High Performance Liquid Chromatography and Study on Its Pharmacokinetics

建立HPLC方法测定犬血浆中的萘哌地尔浓度，研究萘哌地尔胶囊在犬体内的药物动力学。单剂量给予5只健康犬萘哌地尔胶囊200mg,血浆样品碱化后，经乙醚提取以乙腈：磷酸盐缓冲液（0．05mol·L^-1的磷酸二氢钾溶液，以0．1mol·L^-1的NaOH调节pH至6．5）＝60：40（v/v)为流动相，由ODS C18分析柱分离测定，紫外230nm为检测波长，维拉帕米为内标。线性范围为10ng·L^-1;方法回收率为：100．23±3．00％；检测限：8ng·mL^-1;日间RSD≤5.56%,日内RSD≤3．30％。本法简便，回收率和灵敏度高，可用于萘哌地尔制剂的药动学研究。单剂量给予犬萘哌地尔胶囊200mg后血药浓度随时间变化规律符合一级吸收一室模型，T1／2Ke为3．19±1．27h,Tmax为1.15±0.59h,Cmax为697.48±94.22ng·mL^-1.

Preparation of stealthy etoposide proliposomes and the pharmacokinetics in rabbits

The objectives of the present study were to prepare stealthy etoposide proliposomes and study the pharmacokinetics in rabbits. Blank stealthy liposomes were prepared by film dispersion method. Stealthy etoposide liposomes were prepared by using the ammonium sulfate gradient loading procedure. Vacuum freeze-drying technique was used to dry stealthy etoposide liposomes. Encapsulation efficiency of stealthy etoposide proliposomes was determined by Sephadex chromatography. The morphology was observed by transmission electronic microscope. The particle size and zeta potential were measured by using electrophoretic light scattering technology. The pharmacokinetics in rabbits was evaluated by comparison with etoposide injection and conventional liposomes, respectively. Mean encapsulation efficiency of stealthy etoposide proliposomes was 83.92% ± 3.65% （n = 3）. The liposomes were round or oval. Mean particle size was （124.5 ±26.9） nm, and zeta potential was （-39.50 ±1.04） mV. Following intravenous injection administration at a dose of 1.5 mg/kg etoposide, the three kinds of etoposide preparations were fitted with the two-compartment model. T1/2 β and A UC values of stealthy etoposide proliposomes were （19.26 ± 3.16） h and （26.04 ±3.53） μg/h/mL, respectively. T1/2 β and AUC values of etoposide injection were （0.94 ± 0.21） h and （0.98 ± 0.26） μg/h/mL, respectively. T1/2β and AUC values of conventional liposomes were （7.99 ± 1.36） h and （11.65 ± 1.70） μg/h/mL, respectively. Results indicated that the stealthy etoposide proliposomes could significantly extend the duration of etoposide in blood circulation.

Determination of 6258-70,a new semi-synthetic taxane,in rat plasma and tissues:Application to the pharmacokinetics and tissue distribution study

Cancer is the leading cause of death all over the world.Among the chemotherapy drugs,taxanes play an important role in cancer treatment.6258-70 is a new semi-synthetic taxane which has a broad spectrum of antitumor activity.A fast and reliable high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） method was developed for quantification of 6258-70 in rat plasma and tissues in this paper.After extraction by liquid-liquid extraction method with methyl tert-butyl ether,the samples were separated on a Kinetex C_（18） column（50 mm × 2.1 mm,2.6 μm,Phenomenex,USA） within3 min.The method was fully validated with the matrix effect between 87.7%and 99.5%and the recovery ranging from 80.3%to 90.1%.The intra- and inter-day precisions were less than 9.5%and the accuracy ranged from-3.8%to 6.5%.The reliable method was successfully applied to the pharmacokinetics and tissue distribution studies of 6258-70 after intravenous administration in rats.The pharmacokinetic results indicated that the pharmacokinetic behavior of 6258-70 in rats was in accordance with linear features within tested dosage of 1 to 4 mg/kg,and there was no significant difference between the two genders.The tissue distribution study showed that 6258-70 had an effective penetration,spread widely and rapidly and could cross blood-brain barrier.The results of pharmacokinetics and tissue distribution may provide a guide for future study.

PLASMA AND URINARY PLATINUM PHARMACOKINETICS:RELATIONSHIP TO CISPLATIN NEPHROTOXICITY FOR PATIENTS WITH BREAST CANCER

Studies were performed in 20 patients with breast cancer, who received 26 cycles of high-dose cisplatin (100 mg/m2, IV. drip). In twenty-five cycles of them urinary Alb, IgG and NAG showed abnormal values. The patients were divided into low-nephrotoxicity and high-nephrotoxicity groups by the degree of renal dysfunction. Thirty-five percent of the patients exhibited high-nephrotoxicity. These patients had significantly higher plasma and/ or urinary Pt peak levels during cisplatin (CP) infusion than did low-nephrotoxicity. 70 - 80% of the patients developed significant nephrotoxicity when urinary Pt peak level rose up to 40 fig/ml or plasma Pt peak level >4 μg/ml. It is quite important to reduce nephrotoxicity that urinary Pt level is controlled below 40 μg/ml and plasma Pt level <4 μg/ml. It is suggested that urine output should be maintained over 300 ml/hr during 2 hours before and after the end of infusion and >100 ml/hr during 3 days after the infusion. That may keep the nephrotoxicity of CP in less serious degree and easy to recover.

Tissue distribution,excretion and pharmacokinetics of R-hap in rats

The purpose of this study is to characterize the tissue distribution, excretion and pharmacokinetics profiles of R-hap in healthy Wistar rats. R-hap was radiolabeled by the IODO-GEN method. Tissue distribution and urinary, fecal and biliary excretion patterns of ^125I-R-hap were investigated following a single i.v. bolus injection. Pharmacokinetics properties of ^125I-R-hap were also examined after a single i.v. bolus injection. The trichloroacetic acid （TCA） precipitated radioactivity was widely distributed and rapiclly diminished in most tissues. Kidney contained the highest radioactivity among all organs and the distribution of ^125I-R-hap to fat was minimal. The cumulative excretion of ^125I-R-hap reached 71.81% ± 2.15% of the administered radioactivity at 48 h and 94.71% ± 1.50% at 120 h. Urinary excretion was the dominant route of elimination following i.v. administration, as 80.64% ± 1.47% and 14.07% ± 0.95% of administered radioactivity were recovered in urine and feces, respectively, in intact rats over 120 h. The mean areas under the plasma concentration-time curve was （8818.4 ± 576.1） Bq/h/mL. The results of tissue distribution, excretion and pharmacokinetics of R-hap in rats provided biopharmaceutical basis for the design of future clinical trials.

Development of a New Azithromycin Glutamate for Parenteral Preparation, the Toxicity in Sprague-Dawley Rats and Pharmacokinetics in Human Healthy Volunteers

Aim In order to improve the solubility of azithromycin, the objectives of the present study were to screen an appropriate salt for azithromycin by comparing acute hepatic and renal toxicities in animals, and study the pharmacokinetics of final chosen azithromycin salt. Methods Various salts of azithromycin, such as glutamate, citrate, hydrochloride, sulphate, dihydrogen phosphate, lactobionate, tartrate, and aspartate were given intravenously to Sprague Dawley rats at a dose of 10 mg once daily for 14 consecutive days via tail vein. The acute hepatic and renal indicators were measured before and after administration. A pharmacokinetic study was performed on 12 healthy human volunteers. The subjects were equally divided into two groups by a randomized crossover design. Azithromycin glutamate injection was administered by intravenous infusion or intramuscular injection at a single dose of 500 mg, respectively. Azithromycin concentrations in plasma were determined by microbial inhibition zone assay, and the pharmacokinetic parameters were calculated using a practical pharmacokinetic software 3P87 program. Results Azithromycin glutamate was least toxic to the liver and kidney of the rats, thus being selected as a final salt for parenteral preparation of azithromycin. Pharmacokinetic results showed that the area under the plasma concentration-time curves （AUC0-120h） were 21.47 ± 1.57 h·μg·mL^-1 for intravenous infusion, and 19.36 ± 2.44 h·μg·mL^-1 for intramuscular injection. The absolute bioavailability of intramuscular injection was 92.59%. Conclusion Azithromycin glutamate is suitable for the future clinical application, and its pharmacokinetics is characterized in human volunteers in the present study.