替莫唑胺聚乳酸-羟基醋酸微球的制备及体外释药

目的:对替莫唑胺聚乳酸-羟基醋酸微球的制备工艺、含量测定及体外释药特性进行初步研究。方法:以人工合成可生物降解聚合物聚乳酸-羟基醋酸为载体,采用乳化-溶剂挥发法制备替莫唑胺聚乳酸-羟基醋酸微球,用紫外分光光度计测定其药物含量和体外释药量。结果:所制备的替莫唑胺聚乳酸-羟基醋酸微球外形圆整,算术平均球径为62.2μm,载药量为7.47%,包封率为83.53%,体外释放可达1个月。结论:替莫唑胺聚乳酸-羟基醋酸微球具有很好的控释能力,使用前景广阔。     

环丙沙星聚乳酸微球的制备、性状和体外释药性能的研究

目的采用乳化-溶剂蒸发法制备环丙沙星聚乳酸微球,并对其性状进行考察.方法通过正交设计试验筛选其最佳制备工艺, 用电子显微镜观察微球表面形态, 差示扫描热分析确证含药微球的形成, 并对微球的平均粒径、载药量、包封率、体外释药性能进行了研究.结果环丙沙星聚乳酸微球的形态圆整, 且药物确已被包裹在微球中, 微球的平均粒径为280.80±0.15 μm, 粒径在250-390 μm之间的占总数的90%以上. 包封率为68.5%±0.58, 载药量为34.1%±0.51,环丙沙星微球的体外释药情况为53.2小时的累积释药量为84.0%,T1/2为31.9 h, Higuchi方程为Q=-0.004 3 0.003 9 t1/2,r=0.994 1.结论本研究获得了较满意的制备环丙沙星聚乳酸微球的工艺, 且微球的体外释药性能具有明显的缓释效果.     

胸腺肽明胶微球的制备和体外释药的特性

目的:为提高胸腺肽的生物利用度,增强疗效,制备胸腺肽的明胶微球.方法:用乳化交联法制备胸腺肽明胶微球,正交设计法筛选其最佳制备工艺,Lowry法测定药物的含量,计算微球的载药量、包封率及体外释药量.结果:微球粒径范围为1.0～30.2 μm,平均粒径为14.64 μm,平均载药量为20.20%(w/w),平均包封率为80.82%,其体外释药符合Higuchi方程,稳定性考察实验结果表明其稳定性较好.结论:本法制备的胸腺肽明胶微球粒径分布集中,粒径大小符合设计要求,体外释药有明显的缓释作用,具有良好应用前景.     

甲睾酮聚乳酸微球的制备及其释药性能研究

目的制备甲睾酮聚乳酸微球,研究其体外释药过程。方法采用乳化-溶剂挥发法制备甲睾酮聚乳酸微球;以0.25%SDS-5%乙醇(pH3.4)为释放介质,采用高效液相色谱法测定甲睾酮聚乳酸微球的体外释药量。结果甲睾酮聚乳酸微球开始释药较快,存在一定突释效应,随后以缓慢的方式释药,可用双相动力学方程100-R=35.77e0.1321t+63.91e7.372E-4t描述。结论制成的甲睾酮聚乳酸微球具有明显的缓释作用。     

阿司匹林聚乳酸微球的体外加速释放试验

目的:考察不同载药量的阿司匹林聚乳酸微球在不同温度下的体外释药行为,建立体外加速释放试验方法.方法:用紫外分光光度法测定微球中阿司匹林药物含量,由聚乳酸玻璃化温度确定释放介质温度,在pH 7.4磷酸缓冲溶液中,考察温度及载药量对微球释药速度的影响.通过相关性评价建立加速与长期释放度数据的回归方程.结果:加速释放与长期累积释放数据之间线性相关性良好(r=0.999 8).不同载药微球在不同温度下释放动力学均符合一级释药方程,在pH 7.4条件下,55℃的加速释放与在37℃的长期释放相关性好.结论:阿司匹林聚乳酸微球的释放与温度有关.采用高于聚乳酸玻璃化温度2～3℃的体外加速试验方法可适用于快速考察微球的体外释放行为.微球载药量不影响加速释放行为.     

乳化剂对阿司匹林微球制备的影响

目的:用溶剂挥发法以聚乳酸为载体制得阿司匹林聚乳酸微球。方法:选择不同的乳化剂,用正交设计安排实验。并以微球包埋率、载药量、表面形态、体外释放为指标优化微球的制备工艺。结果:按优化条件制得的微球包埋率39.5%,载药量7.25%,体外释药t1/2为3d。结论:制备微球缓释效果明显。     

载羟基喜树碱聚乳酸微球的制备与体外释药研究

目的:研究载羟基喜树碱的聚乳酸微球的制备方法并考察其体外释药性质。方法:以PLA为成膜材料,采用改良乳化-溶剂挥发法,制备载羟基喜树碱的聚乳酸微球并优化制备工艺;对载药微球进行表征;超声介导下进行载药微球的体外释药试验。结果:微球粒径在1～7μm,大小均一;羟基喜树碱浓度在10mg.mL-1下,载药微球包封率为62.2%,载药量为1.69%;药物体外释药符合Higuchi方程。结论:采用乳化-溶剂挥发法,以PLA为成膜材料可制得具有较高包封率的羟基喜树碱微球,有望实现降低羟基喜树碱给药量、减少不良反应,提高靶向性的目标。     

肺靶向阿霉素微球的体外释放度测定方法的建立

目的建立肺靶向阿霉素明胶微球(ADM-GMS)体外释放度测定的方法。方法以透析法考察阿霉素明胶微球的体外释放度,采用紫外分光光度法在波长254nm处测定阿霉素明胶微球的体外释药量。结果阿霉素微球体外释药量在1~40mg/L浓度范围内线性关系良好,平均回收率为99.63%,RSD为1.16%。结论该方法简便、快速、准确,可作为阿霉素微球体外释放度的测定方法。     

干扰素-α微球的制备及其体外释药性能研究

目的:通过正交设计试验优化干扰素-a聚乳酸-羟乙酸共聚物微球的制备工艺,并考察其体外释药性能.方法:采用复乳-溶剂挥发法制备干扰素微球,通过L9(3)4正交试验设计优选微球最佳制备工艺条件,并对制备工艺的重现性、微球的性质及体外释药性能进行了考察.结果:干扰素微球的最佳制备工艺稳定、重现性好,微球的形态圆整,粒度分布均匀,平均粒径为10.71μm,干扰素被证明包裹在微球中,载药量为8.06%,包封率为36.97%.干扰素微球在61 h的累积释药量约为86%,t1/2为10.8 h.结论:本研究获得了较满意的干扰素微球制备工艺,其体外释药性能符合长效制剂特征.     

碱性成纤维细胞生长因子缓释微球的制备及其性质研究

目的 通过碱性成纤维细胞生长因子(bFGF)缓释微球的制备研究,为bFGF的缓释制剂提供科学依据。方法 以聚乳酸-聚乙二醇共聚物为包裹材料,采用复乳包囊法制备bFGF-聚乳酸-聚乙二醇共聚物缓释微球,并对微球的形态学、粒径分布、载药量、包封率和体外释药等进行研究。结果 所制备的微球表面光滑圆整,球体均匀度好;微球平均粒径为1.543±0.070 μm,平均径距为1.273±0.08;载药量和包封率分别为0.0267％和65.32％;微球的体外释药过程较为稳定,两周释药率为59.98％。结论 bFGF缓释微球比bFGF有明显的缓释作用。     

Nachweis einiger Heilmittel in der Kniegelenksynovialflüssigkeit

Zusammenfassung Mittels Gaschromatographie und Dünschichtchromatographie wiesen die Autoren 11 Substanzen nach, welche durch Injektion oder nach Verabreichung per os in die Kniegelenksynovialflüssigkeit eindrangen. In ihrer Aufstellung konnten sie eine direkte Beziehung zwischen Struktur sowie chemischphysikalischen Eigenschaften der Substanz und ihrer Fähigkeit, aus dem Blut in die Kniegelenksynovialflüssigkeit einzudringen, nicht nachweisen, außer der Tatsache, daß Substanzen mit starker Affinität zu Eiweißstoffen erst in höheren Dosen nachweisbar waren.     

Emerging drugs for epilepsy

Epilepsy affects ≤ 1% of the world's population. Antiepileptic drugs (AEDs) are the mainstay of treatment, although more than a third of patients are not rendered seizure free with existing medications. Uncontrolled epilepsy is associated with increased mortality and physical injuries, and a range of psychosocial morbidities, posing a substantial economic burden on individuals and society. Limitations of the present AEDs include suboptimal efficacy and their association with a host of adverse reactions. Continued efforts are being made in drug development to overcome these shortcomings employing a range of strategies, including modification of the structure of existing drugs, targeting novel molecular substrates and non-mechanism-based drug screening of compounds in traditional and newer animal models. This article reviews the need for new treatments and discusses some of the emerging compounds that have entered clinical development. The ultimate goal is to develop novel agents that can prevent the occurrence of seizures and the progression of epilepsy in at risk individuals.     

盐酸达泊西汀中甲磺酸甲酯、甲磺酸乙酯及甲磺酸异丙酯的顶空毛细管GC-ECD法测定

建立了衍生化顶空毛细管气相色谱-电子捕获检测器(ECD)法测定盐酸达泊西汀中的甲磺酸甲酯(MMS)、甲磺酸乙酯(EMS)和甲磺酸异丙酯(IMS).应用碘化钠衍生技术,使用PW-5毛细管柱,载气为氮气,ECD检测,程序升温.MMS、EMS和IMS分别在0.03～0.30、0.05～0.50和0.05～0.50 μg/ml浓度范围内线性关系良好,平均回收率分别为63.5％、100.3％和96.2％,最低检测限分别为0.30、0.50和0.50 ng/ml.     

血管内皮生长因子的异常与子(癎)前期发病的关系

目的:研究血浆可溶性细胞间黏附分子-1(sICAM-1)浓度和胎盘组织血管内皮生长因子(VEGF)、胎盘生长因子(PLGF)及其血管内皮生长因子受体1(VEGFR1,Flt-1)、可溶性血管内皮生长因子受体1(sVEGFR1,sFlt-1)mRNA的表达与子前期的关系.方法:采用酶联免疫吸附测定法(ELISA)检测45例子前期患者和45例健康产妇血清sICAM-1的浓度,逆转录-聚合酶链反应(RT-PCR)方法检测胎盘组织中VEGF、PLGF、Flt-1、sFlt-1 mRNA的表达.结果:(1)子前期组sICAM-1水平为(218.45±29.93) μg/L,显著高于对照组的(168.84±19.39) μg/L(P < 0.01).(2)子前期患者胎盘组织VEGF、PLGF、Flt-1、sFlt-1 mRNA的相对表达量显著高于对照组(均P < 0.01).(3)血清sICAM-1浓度与胎盘组织中sFlt-1mRNA的相对表达量呈正相关(r = 0.90,P < 0.01).结论:子前期患者血清sICAM-1浓度升高,其胎盘组织VEGF、PLGF、Flt-1、sFlt-1 mRNA的相对表达量也升高.胎盘组织sFlt-1mRNA的高表达与子前期内皮损伤等有密切关系.     

Antiparasitic protozoan vaccines

Parasitic infections caused by pathogenic protozoa affect over 1 billion people worldwide and impose a substantial health and economic burden, particularly on inter-tropical less-developed countries where they are more prevalent. Despite encouraging progress in vaccine development, chemotherapy remains the single most effective, efficient and inexpensive means to control most parasitic infections [1]. However, day to day parasites are becoming increasingly resistant to drugs currently in use, such as Plasmodium towards chloroquine, lending to the start of a promising future for vaccines. Patent applications regarding vaccines for the prevention, control and diagnosis of parasitic protozoan infections are reviewed for the period December 1996 - October 2000. However, vaccines for some of the protozoan infections do not appear in the literature in the period reviewed; only, vaccines against malaria, leishmaniasis, trypanosomiasis, cryptosporidiosis, pneumocystosis, eimeriosis, toxoplasmosis and neosporosis, as well as Babesia microti infections have been found.     

Binding affinity in drug design: experimental and computational techniques

ABSTRACT

Introduction: In pharmaceutical design where future drugs are developed by targeting a specific chosen protein, the evaluation of ligand affinity is crucial. For this very purpose are a multitude of diverse methods which are continuously being improved, which, in turn, makes it difficult to choose which techniques to use in practice.

Areas covered: In this review, the authors discuss both experimental and computational approaches for affinity evaluation. Basic principles, general limitations and advantages, as well as main areas of application in drug discovery, are overviewed for some of the most popular ligand binding assays. The authors further provide a guide to affinity predictions, collectively covering several techniques that are used in the first stages of rational drug design.

Expert opinion: All affinity estimation methods have limitations and advantages that partially overlap and complement one another. Some of the suggested best practices include cross-verification of data using at least two different techniques and careful data interpretation.