神经网络及其在药动学和药效学中的应用

神经网络是一种新型的信息处理系统和计算系统 ;它的应用日益渗透到许多领域 ,并引起了人们的广泛重视 .本文在简单介绍了神经网络、详细说明了神经网络的基本特征和基本结构的基础上 ,简要综述了国外将神经网络应用于药代动力学及药效学研究的方法和基本情况 ,说明了将神经网络应用于药代动力学及药效学的可行性 .

黄体酮乳膏剂经皮给药在大鼠体内的药动学研究

目的：观察黄体酮乳膏剂经皮给药在大鼠体内的药动学参数和生物利用度变化，为其临床应用提供依据。方法选择健康无卵巢的Wistar大鼠6只，随机分为口服组和经皮组，每组3只。两组均行双周期双交叉试验：分别单次给予黄体酮胶囊（灌胃）、黄体酮乳膏剂（贴覆）各50 mg／kg。口服组用药前，用药后0、5、10、20、30 min及1、2、4、6、8、10、12、24、48、72 h眼眶取血0．4 mL；经皮组用药前，用药后0、0．5、2、4、8、16、24、32、40、48、56、64、72 h眼眶取血0．4 mL。末次取血后停药至少2周，两组交叉给药，同首次给药途径相同时间再次取血。采用ELISA法检测黄体酮血药浓度，DAS药动学软件对数据进行处理，比较两种剂型的药动学参数及生物利用度。结果经皮组、口服组AUC0～72 h分别为（1131．43±369．10）、（161．44±94．63）μg／L ×h，AUC0～∞分别为（2364．05±289．25）、（180．90±12．78）μg／L ×h，tmax分别为（14．67±3．87）、（1．12±0．31） h，Cmax分别为（49．92±8．41）、（33．56±15．68）μg／L，t1／2ke分别为（63．11±114．81）、（18．71±8．18） h，二者比较P均＜0．05。黄体酮乳膏剂的生物利用度是黄体酮胶囊的353．7％。结论黄体酮乳膏剂经皮给药具有明显的长效、缓释特征，有望成为安全、长效且使用方便的制剂。

群体药动学用于大剂量甲氨蝶呤个体化给药研究进展

大剂量甲氨蝶呤方案广泛用于急性淋巴细胞白血病、恶性淋巴瘤和骨肉瘤的治疗。综述影响其吸收、分布、消除的各种因素,目前国内外大剂量甲氨蝶呤的群体药动学研究状况,以及运用群体药动学研究方法开展大剂量甲氨蝶呤个体化给药的研究进展。

Enhancing Na^(+) diffusion dynamics and structural stability of O3-NaMn_(0.5)Ni_(0.5)O_(2)cathode by Sc and Zn dual-substitution

Sc and Zn were introduced into O3-NaMn_(0.5)Ni_(0.5)O_(2)(NaMN)using the combination of solution combustion and solid-state method.The effect of Sc and Zn dual-substitution on Na^(+) diffusion dynamics and structural stability of NaMN was investigated.The physicochemical characterizations suggest that the introduction of Sc and Zn broaden Na^(+) diffusion channels and weaken the Na—O bonds,thereby facilitating the diffusion of sodium ions.Simulations indicate that the Sc and Zn dual-substitution decreases the diffusion barrier of Na-ions and improves the conductivity of the material.The dual-substituted NaMn_(0.5)Ni_(0.4)Sc_(0.04)Zn_(0.04)O_(2)(Na MNSZ44)cathode delivers impressive cycle stability with capacity retention of 71.2%after 200 cycles at 1C and 54.8%after 400 cycles at 5C.Additionally,the full cell paired with hard carbon anode exhibits a remarkable long-term cycling stability,showing capacity retention of 64.1%after 250 cycles at 1C.These results demonstrate that Sc and Zn dual-substitution is an effective strategy to improve the Na^(+) diffusion dynamics and structural stability of NaMN.

药效学及药动学原理在氟喹诺酮类药物合理应用中的指导作用

氟喹诺酮类是人工合成的抗菌药物，通过抑制DNA拓扑异构酶IV和DNA旋转酶作用，阻碍DNA合成而导致细菌死亡，其抗菌谱广、抗菌活性强、易于吸收、分布广泛、使用方便、不良反应少，对多种革兰阴性、阳性菌均具有较强的抗菌活性，广泛用于泌尿系、呼吸道、胃肠道感染等多种疾病的治疗。目前其广泛、大量及不合理应用导致的细菌耐药性日益受到关注。研究表明，氟喹诺酮类药物具有交叉耐药性，其主要耐药机制：①DNA旋转酶变异；②细菌的细胞膜通透性下降使进入细胞内的药物减少；

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.

Pharmacokinetics of Oxiracetam in Healthy Volunteers

Aim To study the pharmacokinetics of oxiracetam after single and multipleintravenous administrations in healthy volunteers. Method A HPLC method was used to determine theserum concentration of oxiracetam after intravenous single dose and daily dose of 2 000 mg for 7 din ten Chinese healthy volunteers. Pharmacokinetic analysis was carried out using Drug And Statisticsoftware. Results The AUC_(0-12), AUC_(0-∞), K_e, t_(1/2), MRT after a single dose of 2 000 mgoxiracetam were 256.26 ± 16.84 μg·mL^(-1)·h, 276.74 ±18.11 μg·mL^(-1)·h, 0.18 ±0.03 h^(-1),3.84±0.64 h, and 4.39 10.39 h, and after multiple doses of oxiracetam were 259.36 ±25.43μg·mL^(-1)·h, 285.59 ±27.38 μg·mL^(-1)·h, 0.17 ±0.04 h^(-1), 4.14 ± 0.82 h, and 4.87 ±0.69 h, respectively. Conclusion The pharmacokinetic parameters of oxiracetam do not differremarkably after single and multiple intravenous administration and there is accumulation in serumafter 2 000 mg multiple intravenous administration once a day fof 7 d.

Pharmacokinetics of Remifentanil in Chinese Patients Undergoing Elective Surgery

Aim To study the pharmacokinetics of remifentanil in Chinese aduh patients undergoing elective surgery and compare the results with the data already published. Methods The pharmacokinetics of remifentanil was determined in 10 aduh patients undergoing elective surgery. Remifentanil 5 - 6 μg·kg^-1 was administered within 1 min after the induction of anesthesia. One point five millilitre of arterial blood samples were collected at 0 （baseline）, 1,2, 3, 5,7, 10, 15, 20, 25, 30, 45, 60, and 90 min after drug administration. Remifentanil concentration was assayed by HPLC/MS/MS. Resuits The concentration-time course of remifentanil was best described by a two-compartment model. Total clearance （CL = 2. 149 ± 0. 431 L·min^-1） of remifentanil was greater than the normal hepatic blood flow. The distribution half-life （t1/2α） [ 1.56 ± 0. 52 min （0.73 - 2.31 ） ] and the elimination half-life （t1/2β） [22.07 ± 10.30 min （9, 71 -36.07）] were similar with those in previous reports. Volume of distribution （ Vd = 65. 766 ± 29. 100 L） was about two times greater than that reported in previous studies of other ethnics. Conclusion In the present study, the volume of distribution is significantly greater than thai reported in previous studies of other ethnics, indicating that there are some differences in the pharmacokinetics of remifentanil among different ethnics.

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.

Preparation and evaluation of ophthalmic thermosensitive in situ gels of penciclovir

Aim To develop pluronic F127 （PF127） based formulations of penciclovir （PCV） aimed at enhancing its ocular bioavailability. Methods Thermosensitive in situ gels of penciclovir were prepared through combination of HPMC K4M or carbopol 934P and pluronic F127. Optimized formulations were examined through measuring gelation temperature, rheology speciality, drug release behavior, pharmacokinetics and ocular irritation. Results The gelation temperature was reduced by adding HPMC K4M or carbopol 934P, and the viscosity was enhanced slightly. Either HPMC K4M or carbopol 934P delayed the release of PCV from in situ gel. PCV was released by non-Fickian diffusion. The study of ocular irritation for different PCV formulations did not show any irritation or damage for the cornea. PCV bioavailability from combination of carbopol 934P and pluronic F127 gels was higher than that obtained from any other gels. Conclusion Pluronic F127 formulations of PCV can be used as liquid for administration by instilling into the eye. Facilitated by the appropriate eye temperature, the formulations were transformed to gel phase. On the basis of in vitro and in vivo results, PCV formulations containing HPMC K4M or carbopol 934P and low concentration of pluronic F127 （12%） showed potential for use as a drug delivery system with improved ocular bioavailability.

Pharmacokinetics of Ferulic Acid in Rabbits with BloodStasis

To test and study the Syndrome and Treatment Pharmacokinetics (S & TRK),we studied the pharmacokinetics of ferulic acid in healthy and blood stasis (microcirculation dysfunction)rabbits by RP-HPLC. After a single intravenous injection offenilic acid(5mg/kg)to healthy and blood stasis rabbits, compartment model of ferulic acid serum concentration was fitted and then pharmacokinetic parameters were calculated with a MCPKP program on a COMPAQ 386 compute Important parameters are as follows: In healthy rabbits V_B=0.9525±0.0211 L/kg,V_1=0.2462±0.0381 L/kg, CL_B=1.8133±0.9512 L/h·kg, T_(1/2β)=0.3639±0913, AUC=2.7566±0.8232 μg·h/ml; In blood stasis rabbits V_B=0.7882±0.0321 L/kg,V_1=0.1966±0.0537 L/kg,CL_B=0.8820±0.5481 L/h·kg,T_(1/2β)=0.6193±0.1216 h, AUC=5.6690±2.3541μg·h/ml.Through this experiment we found the sig-nificant differences in the FA's pharmacokinetic parameters between healthy and blood stasis rabbits.The results obtained correspond with S & TPK.

Pharmacokinetics of Scutellarin in Dogs

Aim To establish an RP-HPLC method for the determination of scutellarin in plasma and study its pharmacokinetics in dogs. Methods Scutellarin was given to dogs by intravenous injection and determined by RP-HPLC, the mean plasma concentration-time curve was plotted and pharmacokinetic parameters were calculated by program 3p87. Resu;ts The concentration-time curve of scutellarin could be fitted to three-compartment model with T1/2 pi, T1/2 α and T1/2 β being 1.05 ± 0.80 min, 6.99 + 2.76 min and 51.61 + 28.78 min, respectively, Vc being 880.1 + 508.3 mL, CL being 189.6 + 53.8 mL@ min- 1, and AUC0-90 and AUC0-∞ being 574.43 + 133.95 μg@ min@ mL - 1 and 599.34 ± 132.00μg@ min@mL- 1, respectively. Conclusion The fact that the concentrations of scutellarin in plasma declined rapidly after the medication suggested that the T1/2 of scutellarin should be taken into account in drug administration and preparation development.

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.

Enhanced hydrogen storage kinetics of nanocrystalline and amorphous Mg_2N-type alloy by substituting Ni with Co

In order to improve the hydrogen storage kinetics of the Mg2Ni-type alloys, Ni in the alloy was partially substituted with element Co. The Mg2Ni-type Mg2Ni1-xCox （x=0, 0.1, 0.2, 0.3, 0.4） alloys were fabricated by melt-spinning technique. The structures of the as-spun alloys were characterized by XRD and TEM. The gaseous and electrochemical hydrogen storage kinetics of the alloys was measured. The results show that the substitution of Co for Ni notably enhances the glass forming ability of the Mg2Ni-type alloy. The amorphization degree of the alloys visibly increases with rising of Co content. Furthermore, the substitution of Co for Ni significantly improves the hydrogen storage kinetics of the alloys. With an increase in the amount of Co substitution from 0 to 0.4, the hydrogen absorption saturation ratio of the as-spun （15 m/s） alloy increases from 81.2% to 84.9%, the hydrogen desorption ratio from 17.60% to 64.79%, the hydrogen diffusion coefficient increases from 1.07×10-11 to 2.79×10-11 cm2/s and the limiting current density increases from 46.7 to 191.7 mA/g, respectively.

Preparation and Pharmacokinetic Characterization of Sustained Release Melatonin Tablet

Aim To prepare the sustained release melatonin tablet with HPMC matrix and study its pharmacokinetics and bioavailatility. Methods HPMC was used as matrix to formulate the sustained release tablet. The influences of the size of melatonin, type and amount of HPMC, drug loading, type and amount of additives, and compressing pressure were investigated. Plasma concentration of melatonin in dogs after intravenous injection of two doses and oral administration of sustained release tablets and unmodified release capsules was detected by HPLC using fluorescence detector. Results The drug release from sustained release tablets was influenced by the size of melatonin, type and amount of HPMC, drug loading, and type and amount of additives. Melatonin was found to fit two compartment model after intravenous injection, AUC was proportional to doses, and t(1/2β) of two doses has no significant difference. Relative bioavailability of melatonin sustained release tablet to normal capsule was 83.8%, and absolute bioavailability was 3.75% for sustained release tablet and 4.49% for capsule. Conclusion The melatonin sustained release tablet was well formulated. The absolute bioavilability for oral administration of either sustained release tablet or unmodified release capsule of melatonin was less than 5%. The bioavailability of melatonin sustained release tablet was lower than that of unmodified release capsule, but MRT of sustained release tablet was significantly longer than that of capsule.

Determination of Sulphonylurea Glimepiride in Dog Serum by RP-HPLC with Pre-column Derivatization

Aim A simple, sensitive and rapid RP HPLC method with pre column derivatization has been developed for the determination of sulphonylurea glimepiride in dog serum. Methods The sulphonylurea glimepiride was extracted from the dog serum using dichlromethane followed by derivatization with DNBF for 20 min at 100℃. The solvent was then evaporated at 60℃ under nitrogen, and the residue was taken up in 100 μL of mobile phase consisting of acetonitrile water (75∶30, v/v). The separation was performed on a Hypersil BDS C18 column with a flow rate of 0 8 mL·min -1 , and the ultraviolet detector wavelength was set at 350 nm. Results Extraction recovery ranged from 75.9% to 83.2%, and methodological recovery was between 96.5% and 109.3%. Within day RSD ranged from 1.5% to 6.3%, and inter day RSD was between 2 9% and 14.8%. The method showed good linearity (R=0.9998). Conclusion The method was simple, convenient and sensitive. The reaction of derivatization was reproducible.

Sensitive liquid chromatography electrospray ionization ion-trap mass spectrometry for the determination of rupatadine in human plasma

Aim To develop and validate a sensitive and specific liquid chromatography electrospray ionization ion-trap mass spectrometry （LC-ESI-MS/MS） method for the identification and concentration of rupatadine in human plasma. Methods After the addition of the internal standard （IS, loratadine） and 0.01 mol·L^-1 sodium hydroxide solution, plasma samples were extracted with methylene chloride： ethyl acetate mixture （20：80, V/V）. The organic layer was evaporated under vacuum drying at 37 ℃. The residue was reconstituted with 200 μL mobile phase. Chromatography was performed on an Agilent Eclipse XDB-C18 （4.6 mm × 150 mm, 5 μm） column with a mobile phase consisting of acetonitrile （1% formic acid） -20 mmol·L^-1 ammonium acetate （76：24, V/V） at a flow-rate of 0.6 mL·min^-1. Detection was performed on Agilent MSD Trap XCT ion-trap mass spectrometry connected to a Agilent 1100 high performance liquid chromatography （HPLC） by selected reaction monitoring （SRM） mode via electrospray ionization （ESI） source. Rupatadine （MRM m/z 416 → 309） and loratadine （MRM m/z 383 → 337） were detected by Agilent MSD Trap XCT ion-trap mass analyser. Results The method was proved to be sensitive and specific by testing 20 different plasma batches. Linearity was established for the range of concentrations 0.05 - 14.0 ng·mL^ -1 with a coefficient of determination （r） of 0.998. The intra-and inter-day precision （RSD %） were lower than 15% and accuracy ranged from 85.1% to 114.0%. The lower limit of quantitation （LLOQ） was identifiable and reproducible at 0.05 ng·mL^-1 with a precision of 9.22% （n =5）. Conclusion The proposed method is sensitive and reproducible enough to be used in pharmacokinetic, bioavailability or bioequivalence studies of rupatadine.

Pharmacokinetics of Active Metabolite of Prulifloxacin in Healthy Chinese

Aim To investigate the pharmacokinetics of NM394 （an active metabolite of prulifloxacin） and evaluate the dose relationship and accumulation characteristics after single and multiple doses of prulifloxacin. Methods Twelve healthy volunteers were given 132.1 mg, 264.2 mg, and 396.3 mg of prulifloxacin tablets in a randomized 3 × 3 crossover design test for single doses trial. With one-week washout period, 264.2 mg of prulifloxacin tablets were given for multiple doses trial. NM394 in plasma was determined by a sensitive HPLC method and its pharmacokinetic parameters were analyzed and evaluated by Drug and Statistics saftware （version 1.0）. Results The Cmax, Tmax, t 1/2, AUC0-24, and AUC0-∞ of NM394 after single doses of 132.1 mg, 264.2 mg, and 396.3 mg of prulifloxacin tablets were 0.64 ± 0.25 μg· mL^-1, 1.06 ± 0.35 μg· mL^-1, and 1.45 ± 0.44 μg· mL^-1 , respectively; Tmax 0.94±0.22 h, 1.02±0.17 h, and 0.98±0.23 h, respectively; t 1/2 8.37±0.70 h, 7.70±0.82 h, and 7.78 ± 0.77 h, respectively; AUC0-24 2.93 ± 0.78 μg· mL^-1· h, 4.39 ± 1.05 μg· mL^-1· h, and 5.55± 1.32 μg·mL^-1 ·h, respectively; AUC0-∞ 3.32±0.84 μg·mL^-1 ·h, 4.82± 1.06 μg·mL^-1 ·h, and 6.10 ± 1.38 μg·mL^-1· h, respectively. And the Cmax, Tmax, t,1/2, AUC0- 24, and AUC0-∞ after multiple doses of 264.4 mg prulifloxacin tablets were 1.20 ± 0.33 μg· mL^- 1, 0.67 ± 0.12 h, 7.38 ± 1.03 h, 5.58 ± 1.25 μg· mL^-1·h, and 6.09 ± 1.24 μg· mL^-1· h, respectively. Conclusion The Cmax and AUC of NM394 are in high correlation with given prulifloxacin doses. There are no differences in pharnacokinetic characteristics of NM394 between single and multiple doses. No accumulation in plasma is observed after multiple doses of 264.2 mg per day for 7 d.

Determination of fleroxacin in human plasma by HPLC with fluorescence detection and the pharmacokinetic study

Aim To develop a sensitive and accurate HPLC method for the determination of fleroxacin in human plasma, and study its pharmacokinetics in healthy subjects. Methods The analytes were isolated fi＇om plasma by simple protein precipitation with methanol, separated on a Diamonsil C18 column by isocratic elution with the mobile phase consisted of 1% triethylamine at pH 4.8 （adjusted with phosphoric acid） and acetonitrile （80/20, V/V） at a flow rate of 1.0 mL.min^-1 and analyzed by fluorescence detector with an excitation at 290 nm and emission 458 nm. The pharmacokinetic study of fleroxacin was performed according to a double period crossover design. Results The weighted （1/x） calibration curve was linear over the plasma concentration range of 0.025 - 8.00 μg.mL^-1 The inter- and intra-day precisions （RSD/%） were no more than 5.16%, and the method accuracies and extraction recoveries at three concentrations ranged firom 99.1% to 100.9%, and 86.7% to 92.0%, respectively. Following oral administration at a dose of 400 mg fleroxacin, the main pharmacokinetic parameters for test and reference capsules were Cmax5.08 ± 0.78 and 5.38 ± 1.40 μg.mL^-1, tmax 1.72 ±0.79 and 1.82 ± 0.78 h, t1/2 11.68 ± 1.27 and 11.38 ± 1.51 h^-1, AUC0-∞ 78.44 ± 11.44 and 76.53 ± 13.24 μg.mL^-1.h, respectively. Conclusion The method is sensitive and accurate, and suitable for human pharmacokinetic study of fleroxacin.