5—氟脲嘧啶磁性微球的制备及其性能的探讨

将5—氟脲嘧啶，牛血清白蛋白和磁性液体混合乳化，在不同温度下固化，然后制成粒径l～2μm 的注射用磁性白蛋白微球(FMAM)．在体37℃的吐温80的生理盐水中。用各种不同固化温度的磁性微球进行释 放试验，结果表明：微球制备的固化温度越高，微球药物释放越缓慢。对磁性液体配比不同的微球药释试验结果 表明，磁性液体配比越高其释药越缓慢。另外，还对磁性徽球在不同磁感应强度下的磁应答性以及在小白鼠体内皮 下组织的分布情况作了初步研究.     

各型冠心病患者血浆5—羟色胺含量的变化

本文对82例各种类型冠心病患者血浆5-羟色胺(5—HT)含量进行了测定。结果表明,各组冠心病患者血浆5—HT 含量均高于对照组,且急性心肌梗塞,心绞痛及心力衰竭组增高更为明显。其中心绞痛组以自发型心绞痛血浆5—HT 含量增加较为显著。结果提示,自发型心绞痛时病理生理改变更为严重.预后不良。本观察表明血浆5—HT 水平与疾病严重程度有关,并为寻找有效降低血浆5—HT 的药物治疗冠心病等提供理论依据。     

新型可降解聚酯材料地西泮缓释微球的研制

目的　优化制备工艺,用新型的生物可降解材料聚羟基丁酸酯—羟基戊酸酯共聚物（PHBV）与D,L-聚乳酸（PLA）共混物为基材制备以地西泮（diazepam,DZP）为模型药物的缓释微球（MS）。方法　用正交设计优化微球制备工艺,用扫描电镜（SEM）观察微球表面形态。对微球粒径及其分布、体外释药、稳定性及在动物体内药动学进行了测定。结果　微球平均粒径为(20.45±4.50) μm,粒径在15.5～35.2 μm占总数88%以上。载药量为(16.95±0.80)%,包封率为(69.68±1.13)%;体外释药方程为Q=2.7027t+13.50(γ=0.9827),动物体内实验表明,微球的血药浓度-时间曲线下面积AUC是溶液对照组的2.35倍,平均驻留时间MRT是对照组的3.62倍。微球在冰箱4℃与室温（20～25℃）条件下性质稳定。结论　微球制备工艺稳定,与DZP针剂相比,具有明显缓释作用。     

反相高效液相色谱法测定养血生发胶囊中2,3,5,4’—四羟基二苯乙烯—2—O—β—D—葡萄糖苷的含量

目的 :建立以反相高效液相色谱法测定养血生发胶囊中2 ,3 ,5 ,4’—四羟基二苯乙烯—2—O—β—D—葡萄糖苷含量的方法。方法 :色谱柱为AlltimaC18,流动相为乙腈 -水 (15∶85) ,流速为1 0ml/min ,检测波长为320nm。结果 :2 ,3 ,5 ,4’—四羟基二苯乙烯—2—O—β—D—葡萄糖苷进样量在0.45μg～2.26μg 范围内与峰面积值呈良好的线性关系 (r=0 9996) ,平均回收率为98.32 % (RSD=1 58 % ,n=6)。结论 :本法简便、准确 ,可用于养血生发胶囊的含量测定与质量控制。     

载体的组成对地西泮微球释药性能的影响

以天然细菌合成的可降解生物材料聚 3 羟基丁酸酯 (poly 3 hydroxybutyrate ,PHB) ,羟基丁酸酯 羟基戊酸酯共聚物 (polyhydroxybutyrate hydroxyvalerate ,PHBV) ,以及PHBV与D ,L PLA共混物 ,PHBV与明胶 (gel)双层结构材料作为药物载体 ,以抗焦虑药物地西泮 (diazepam ,DZP)为模药 ,用O/W单乳化与O/W /O双乳化溶剂蒸发法 ,制备了地西泮缓释微球 (DZP MS)。微球平均粒径约 30～ 40 μm,平均载药量 15 %～ 2 0 % ,包封率 5 9%～ 81%。用扫描电镜观察与比较了 4种微球结构形态 ,阐述了载体材料机构对释药性能影响 ,初步研究了PHBV/PLA微球动物体内药代动力学     

基于微透析技术及HPLC-ESI-MS测定大鼠关节腔透析液中双氯芬酸钠浓度及其应用

目的：利用微透析技术为采样平台,以双氯芬酸钠为工具药,建立大鼠膝关节腔透析液中双氯芬酸钠的HPLC—ESI—MS测定方法,满足非甾体类抗炎药物靶部位药物采集及测定的需求。方法：采用HPLC—MS单极四极杆联用技术,通过优化色谱、质谱条件,建立快速灵敏的双氯芬酸钠的液-质测定方法,并将该法应用于大鼠关节腔透析液中双氯芬酸钠浓度的测定。本法所用色谱柱为WatersSymmetry—C18（dp5扯m,150mm×2．1mmID）,流动相为甲醇－0．1％甲酸（80：20,V／V）。结果：本实验建立的大鼠膝关节腔透析液中双氯芬酸钠的HPLC—ESI-MS测定方法的最低定量限为1．95ng／mL,在1．95～125ng／mL范围内线性关系良好,批内批间精密度均小于10％。介质效应在99．9％～113．4％之间。结论：本实验成功地将微透析技术引入到大鼠关节腔部位的取样过程中,建立的大鼠关节腔透析液中双氯芬酸钠的HPLC—ESI—MS测定方法快速,灵敏。两者的结合有助于实现对以双氯芬酸钠为代表的非甾体类抗炎药物作用靶部位的取样及其药动学研究。     

环磷酰胺微乳制剂的研制

目的 :研究环磷酰胺微乳的制备、稳定性及微乳中药物含量的测定方法。方法 :选用油酸正丁酯和肉豆蔻酸异丙酯作为油相 ,聚山梨醇酯作为表面活性剂 ,正丁醇和正戊醇作为助表面活性剂 ,在制备三元相图的基础上 ,考察微乳的组分对微乳形成的影响 ;用HPLC法测定微乳中环磷酰胺的含量。结果 :以聚山梨醇酯为乳化剂形成的微乳系统所需表面活性剂的量为 13.6 2 %～ 40 .5 2 % ;用HPLC法测定两种破乳剂对环磷酰胺微乳破乳后 ,环磷酰胺的含量分别为 (10 .6± 1.1)mg·L-1和(10 .4± 1.1)mg·L-1,两结果差异无显著性 (P >0 .0 5 )。结论 :采用微乳作为药物载体制备口服环磷酰胺微乳 ,为开发环磷酰胺新型口服制剂提供了依据。     

(一)表没食子儿茶素没食子酸酯对活性氧自由基的清除作用机制

本文研究了(一)表没食子儿茶素没食子 酸酯[(—)-EGCG]清除O_(?)和·OH的半数清除率SC_(50)、清除速率常数k和清除反应的化学计量因子n,用体外模型分析了药物对活性氧自由基的清除机制和(—)-EGCG自由基的启动及结构特点,推论药物的清除反应中心为B、D和A环,每分子药物可捕捉6个O_(?)或·OH,与化学计量因子n=6相符。     

血浆LPO、TXA_2/PGI_2平衡与糖尿病微血管病变的关系

作者测定了50例正常人,94例糖尿病患者血浆过氧化脂(LPO)及血浆6—酮—前列腺素 F_1α(6—酮—PGF_1α)和血栓素 B_2(TXB_2)的浓度,并分析血浆 LPO、TXB_2/6—酮—PGF_1α比值与糖尿病微血管病变的关系。结果有微血管病变糖尿病患者血浆 LPO 显著高于无微血管病变糖尿病患者。有微血管病变糖尿病患者血浆 TXB_2/6—酮—PGF_1α比值显著高于对照组,无微血管病变糖尿病患者两者比值与对照组相比无显著差异。有微血管病变糖尿病患者血浆 LPO 与 TXB_2/6—酮—PGF_1α比值呈正相关。提示有微血管病变并发症的糖尿病患者存在血浆 LPO 升高和循环 TXA_2与前列环素 PGI_2的比例失衡.     

龟板体外抗氧化活性研究

目的:研究中药材龟板的体外抗氧化活性,为抗衰老药物的筛选提供参考。方法:将龟板分别用石油醚、乙酸乙酯、95%乙醇等极性递增的溶剂提取得不同提取部位溶出物,用1,1—二苯基—2—苦基肼基游离基法(DPPH法)进行体外抗氧化活性检测;并与抗坏血酸(VitC)进行比较。结果:龟板95%乙醇部位提取物与石油醚、乙酸乙酯部位提取物的抗氧化活性存在显著性差异(P<0.01);95%乙醇部位提取物的体外抗氧化活性最强,其清除半数DDPH所需样品用量(EC50)与VitC相比相差2.38个数量级。结论:龟板95%乙醇部位提取物具有很强的体外抗氧化活性,可进一步进行研究并加以开发利用。     

Preparation and in vitro release behaviour of 5-fluorouracil-loaded microspheres based on poly (L-lactide) and its carbonate copolymers

A modified oil-in-oil (o/o) emulsion solvent evaporation technique was adopted to prepare 5-fluorouracil (5-Fu)-loaded poly (L-lactide) (PLLA) or its carbonate copolymer microspheres. The disperse phase was a drug:polymer solution using a solvent mixture of N,N-dimethylformamide (DMF) and acetonitrile and the continuous phase was liquid paraffin containing 1-10% (w/v) Span 80(R). The effects of preparative parameters, such as the composition of the inner oil phase, drug:polymer ratio, polymer concentration and agitation rate, on 5-Fu entrapment efficiency and microsphere characteristics were investigated. By introducing 25% (v/v) DMF into the inner oil phase, microspheres with high drug entrapment efficiency and an ameliorated burst effect were achieved. Using this modified method, microspheres with various particle sizes could be produced with a high 5-Fu entrapment efficiency (about 80%). In vitro drug release tests showed a burst release of 5-Fu from PLLA microspheres, followed by a sustained release over 50 days. In the case of poly (L-lactide-co-1,3-trimethylene carbonate) (PLTMC) and poly (L-lactide-co-2,2-dimethyl-1,3-trimethylene carbonate) (PLDTMC), the drug release could be continued for over 60 days.     

5-氟尿嘧啶控释植入剂在小鼠肿瘤组织的分布

目的 建立5-氟尿嘧啶(5-Fu)在小鼠肿瘤组织中的分析方法,并用于考察5-Fu控释植入剂在小鼠肿瘤组织的分布.方法 荷瘤小鼠瘤周植入分别由PLGA 50/50和PLGA 75/25为载体制备的5-Fu控释植入剂,RP-HPLC测定小鼠肿瘤组织中的药物浓度.结果 肿瘤组织中5-Fu的线性范围为0.5～15.4 μg·g-1,准确度为97.5％～ 104.0％,提取回收率为81.9％～88.3％,日内RSD均＜2.0％,日间RSD均＜7.6％.以PLGA50/50、PLGA75/25为载体的5-Fu控释植入剂在荷瘤小鼠体内的药动学参数:tmax分别为9、15 d;Cmax分别为3.79、2.83 μg·g-1; AUC分别为41.15、43.50 (μg·g 1)×d.结论 该分析方法可用于5-Fu在肿瘤组织中的分布行为研究,2种载体的5-Fu控释植入剂均能维持小鼠肿瘤组织中较长时间的药物分布,延长药效作用时间.     

Prime-boost vaccination based on DNA and protein-loaded microspheres for tuberculosis prevention

We evaluated the use of a vaccine formulation based on a mixture of two different PLGA microspheres, composed by faster and slower release profiles, containing DNA encoding hsp65 and the recombinant hsp65 protein, respectively, aiming to DNA priming and protein boost after a single dose vaccination. The combination of PLGA50:50 microspheres containing DNA-hsp65 and trehalose dimycolate (TDM) with PLGA75:25 microspheres containing recombinant hsp65 (prime-boost Me) was able to induce high levels of anti-hsp65 specific antibodies. The serum levels of these specific antibodies remained high during 90 days after vaccination, whereas the DNA Me formulation based only in DNA-hsp65 plus TDM-loaded microspheres was not able to sustain the high antibody levels during the same period. Production of IFN-gamma was significant in animals vaccinated with both formulations, while the prime-boost Me vaccinated mice sustained higher levels of this cytokine during all the evaluation period. Thus, prime-boost strategy by using biodegradable microspheres seems to be a promising strategy to stimulate long-lasting immune response.     

布比卡因缓释微球的制备及体外释药特性评价

目的研究布比卡因缓释微球制备方法并对其体外释药特性进行评价。方法采用紫外分光光度法测定布比卡因微球载药量、包封率;采用HPLC法测定微球体外释放;通过正交设计优选微球制备工艺;以乳酸羟基乙酸共聚物为载体,使用乳化溶剂挥发法制备布比卡因微球;用扫描电镜观察所得微球的粒径和形态;通过体外释药实验考察布比卡因乳酸羟基乙酸共聚物微球的缓释作用。结果微球载药量、包封率和体外释放的测定方法符合方法学要求;按照优选处方制备所得的微球为圆整球体,表面多孔,呈蜂窝状,粒径50~100μm之间的微球占80%;体外释放符合Ritger-Peppas方程,t1/2=242.05 h。结论乳化溶剂挥发法适用于布比卡因乳酸羟基乙酸共聚物微球的制备,所制得的微球形态圆整,在体外具有明显缓释作用。     

Prime-boost Vaccination based on DNA and Protein-loaded Microspheres for Tuberculosis Prevention

We evaluated the use of a vaccine formulation based on a mixture of two different PLGA microspheres, composed by faster and slower release profiles, containing DNA encoding hsp65 and the recombinant hsp65 protein, respectively, aiming to DNA priming and protein boost after a single dose vaccination. The combination of PLGA50:50 microspheres containing DNA-hsp65 and trehalose dimycolate (TDM) with PLGA75:25 microspheres containing recombinant hsp65 (prime-boost Me) was able to induce high levels of anti-hsp65 specific antibodies. The serum levels of these specific antibodies remained high during 90 days after vaccination, whereas the DNA Me formulation based only in DNA-hsp65 plus TDM-loaded microspheres was not able to sustain the high antibody levels during the same period. Production of IFN-γ was significant in animals vaccinated with both formulations, while the prime-boost Me vaccinated mice sustained higher levels of this cytokine during all the evaluation period. Thus, prime-boost strategy by using biodegradable microspheres seems to be a promising strategy to stimulate long-lasting immune response.     

Nanoporous multilayer poly(L-glutamic acid)/chitosan microcapsules for drug delivery

Nanoporous poly(L-glutamic acid)/chitosan (PLGA/CS) multilayer microcapsules were fabricated by layer-by-layer (LbL) assembly using the porous silica particles as sacrificial templates. The LbL assembled nanoporous PLGA/CS microcapsules were characterized by Zeta-potential analyzer, FTIR, TGA, SEM, TEM and CLSM. 5-Fluorouracil (5-FU) was chosen as model drug. The drug loading content of PLGA/CS microcapsules depends on loading time, loading temperature, pH value and NaCl concentration. High loading capacity of microcapsules can be achieved by simply adjusting pH value and salt concentration. Moreover, 5-Fu loaded microcapsules take on a sustained release behavior, especially in an acid solution, in contrast to burst release of bare 5-Fu. The kinetics of 5-Fu release from PLGA/CS microcapsules conforms to Korsmeyer-Peppas and Baker-Lonsdale models, the mechanism of which can be ascribed to priority of drug diffusion and subordination of polymer degradation. The MTT cytotoxicity assay in vitro reveals the satisfactory anticancer activity of the drug-loaded PLGA/CS microcapsules. Therefore, the novel nanoporous PLGA/CS microcapsules is expected to find application in drug delivery systems.     

Preparation and immunological effectiveness of a Swine influenza DNA vaccine encapsulated in PLGA microspheres

Optimal preparation conditions of DNA vaccine against swine influenza encapsulated in Poly (D,L)-lactic-co-glycolic acid (PLGA) microspheres were determined. The microspheres were prepared by an emulsion-evaporation method using PLGA as the biodegradable matrix forming polymer. Using the optimal preparation conditions, PLGA microspheres containing the DNA vaccine were produced with good morphology as evident from scanning electron micrographs, high encapsulation rate and high stability. The transfection test indicated that the vaccine could be expressed as an antigen in cells and maintained good bioactivity. Moreover, these results demonstrated that the PLGA microspheres containing DNA vaccine can be used to achieve prolonged release of plasmid DNA. These results have laid a foundation for further development before ultimate industrial application.     

乳酸羟乙醇酸共聚物微球中蛋白包封率的测定

目的:寻求一种合适的方法测定蛋白在乳酸羟乙醇酸共聚物(PLGA)微球中的包封率。方法:采用复乳 溶剂挥发法制备 BSA的PLGA微球,应用考马斯亮蓝法测定总蛋白浓度,根据文献报道的7种不同方法进行包封率测定。结果:不同的测定方法对 PLGA微球中真实的药物包封率的反映程度不同,相互间差异很大。结论:以水解法测定BSA在PLGA微球中包封率的方法提取 最完全。水解法中,又以乙腈作溶剂、再用氢氧化钠水解两步提取法最为简便、快速、准确。     

PLGA黏度及PVA浓度对微球形成过程中物理性质的影响

采用复乳.溶剂蒸发法制备乳酸.羟基乙酸共聚物(PLGA)微球,并用激光粒度仪测定制备过程中乳滴的体积平均粒径、粒径分布(d_(0.1)、d_(0.5)、d_(0.9))和重量比表面积(SSA)等物理性质的动态变化,考察PLGA特性黏度及聚乙烯醇(PVA)浓度对上述性质的影响.结果表明,在0.5%PVA的体系中,乳滴的平均粒径在60 S内均呈线性急剧下降,SSA迅速增加,粒径下降速度随PLGA黏度的增加而减慢,但5 min后高黏度PLGA体系的粒径升高,SSA减小.增加外水相PVA浓度至2.0%,则高黏度PLGA体系乳滴的物理性质变化趋势与低、中黏度PLGA体系相似.     

Preparation of ONO-1301-loaded poly(lactide-co-glycolide) microspheres and their effect on nerve conduction velocity

Objectives The aim of this study was to prepare poly(lactide‐co‐glycolide) (PLGA) microspheres containing ONO‐1301, a novel long‐acting prostacyclin agonist with thromboxane synthase inhibitory activity, with 10% of drug released in the initial burst and a sustained‐release period of about 3 weeks after administration. The effect of PLGA type (molecular weight and the lactide/glycolide (L/G) ratio in PLGA), the preparative conditions and the particle size on the in‐vitro release profile were examined. The effect of optimized ONO‐1301‐loaded PLGA microspheres on delayed nerve condition velocity (NCV) was investigated in streptozotocin (STZ) induced diabetic rats. Methods ONO‐1301 PLGA microspheres were produced by the oil‐in‐water emulsion/solvent evaporation method. Drug release from the prepared microspheres was monitored in phosphate buffer solution at 37°C for 4 weeks by high‐performance liquid chromatography. The in‐vivo study was performed in STZ‐induced diabetic rats treated with optimized ONO‐1301 PLGA microspheres (10 mg/kg by intramuscular or subcutaneous injection every 3 weeks). NCV was measured in the thigh 4, 8 and 12 weeks after induction. Key findings The molecular weights of PLGA, the L/G ratio in PLGA and the particle diameter all affected the length of the sustained release period. Drug release from microspheres containing PLGA 5050 (MW 50 000, L/G 50/50), with an average diameter of about 30 µm, could be sustained for 3 weeks in vitro. In the in‐vivo study, delayed NCV was significantly increased by treatment with these ONO‐1301 PLGA microspheres once every 3 weeks, in comparison with vehicle only. Conclusion Local intramuscular injection of sustained‐release ONO‐1301 PLGA microspheres improved delayed NCV in STZ‐induced diabetic rats.