中药缓控释微丸制剂的研究进展

微丸作为一种多单元释药系统,具有流动性好,释药稳定、可靠、均匀等特点。随着现代制备工艺的逐渐成熟及辅料的发展,微丸在缓控释制剂中的应用备受瞩目。作者对中药缓控释微丸制剂释药机制、制备方法、辅料及其体内过程等方面的研究进行了综述,旨在为研究开发中药口服缓控释制剂提供思路和方法。     

硝苯地平缓释微丸的研制

用滚动凝聚法制备硝苯地平缓释微丸,微丸中硝苯地平体外释药前段呈零级,后段符合Ｈｉｇｕｃｈｉ方程,持续释药时间达８ｈ。     

快速搅拌制备肠必清微丸的工艺研究

目的：制备肠必清微丸。方法：采用正交试验设计,考察肠必清处方提取物配比微晶纤维素作赋形列比例、润湿剂乙醇浓度、粘合剂PVP浓度及快速搅拌制粒时间对微丸质量的影响。结果：优选出快速搅拌制备肠必清微丸工艺,提取物配比赋形剂比例为2：1,乙醇浓度为90％,PVP浓度为3％,搅拌时间为15min。结论：其工艺制备微丸符合设计要求,适合工业化生产。     

美沙芬缓释微丸的制备

[目的 ]开发美沙芬新剂型 .[方法 ]利用正交设计法 ,以释放度实验为根据 ,筛选出最佳处方 ,制备美沙芬缓释微丸 .[结果 ]制备的美沙芬缓释微丸释药规律符合Higuchi方程 .[结论 ]乙基纤维素 10 0mg ,羟内基甲基纤维素 10 0mg ,蜂蜡 2 0mg ,聚乙烯咯烷酮 5mg为制备美沙芬缓释微丸的最佳处方 ,利用该处方制得的缓释微丸在体外释放时间为 11h .     

Optimal Moving Angle of Pusher Plate in Occlusive‐Type Pulsatile Blood Pump

Since the occlusive‐type pulsatile extracorporeal blood pump (Twin‐Pulse Life Support System; Seoul National University, Seoul, Korea) received the CE mark of the European Directives and Korea Food and Drug Administration approval (2004) for short‐term applications as an extracorporeal life support system, the pump system has been tested for hemolysis. This pump system was recently upgraded with an ameliorated pusher plate to reduce hemolysis. In this study, numerical analysis and in vitro tests were performed to determine the optimal conditions for increasing the durability of the blood sac and pump output. During the simulation, the minimum sliding interface force (SIF) for the angle of the pusher plate movement (PPM) was calculated (40–70°). In the in vitro durability test, the angle of the PPM was increased gradually from 40 to 70° in 10° increments, and the mean time to failure (MTTF) of the blood sac was calculated. Fifteen tests were conducted for each case: 40, 50, 60, and 70° (n = 15 each). The MTTF of the blood sac was defined as the time when a crack of the blood sac occurred. The longer lifetime of the blood sac at 60° of the PPM (297.0 h) than that at 50° (197.6 h) was attributed to the lower SIF value (?0.13, normalized value) at 60° of the PPM.     

Development of Mechanical Circulatory Support Devices in China

Myocardial dysfunction leading to low cardiac output syndrome is a common clinical pathophysiological state. Currently, the use of mechanical circulatory support (MCS) is an essential aspect of the treatment of patients with cardiac failure. Several groups in China are engaged in the design and development of MCS devices. These devices can be classified as pulsatile, rotary, and total artificial heart (TAH). There are two types of pulsatile pump, which are driven by air (pneumatic). One of these pumps, the Luo‐Ye pump, has been used clinically for short‐term support since 1998. The other is a push‐plate left ventricular device, which has a variable rate mode. Various rotary devices are classified into axial and centrifugal pumps, depending on the impeller geometry. Most rotary pumps are based on the maglev principle, and some types have been used clinically. Others are still being studied in the laboratory or in animal experiments. Furthermore, certain types of total implantable pump, such as the UJS‐III axial pump and the UJS‐IV aortic valvo‐pump, have been developed. Only one type of TAH has been developed in China. The main constituents of this artificial heart are two axial pumps, two reservoir tanks mimicking the right and left atria, flow meters, two pressure gauges, and a resistance adaptor. Although the development of mechanical assist devices in China is still in a nascent stage, a number of different types of MCS devices are currently being studied.     

GnRH neurons and episodic bursting activity

Our understanding of the cellular mechanisms underlying bursting activity in mammalian GnRH neurons and how these mechanisms relate to pulsatile hormone release continue to grow. However, the wide variability of phasic bursting patterns of GnRH neurons still leaves some unanswered questions about how cellular models translate into pulsatile hormone release.     

黄体生成激素释放激素促排卵治疗前后促性腺激素脉冲形态研究

观察黄体生成激素释放激素(LHRH)小剂量脉冲给药前、后下丘脑性闭经妇女黄体生成激素(LH)与卵泡刺激素(FSH)脉冲分泌形态的变化。给药前的LH与FSH均不呈脉冲式分泌,经过小剂量脉冲式注入人工合成LHRH后,LH均值明显上升,由3.7±2.6u/L至1206±3.1u/L(<0.01),并呈脉冲式释放,FSH均值增加不明显。静脉给药4例中2例有排卵,2例卵泡发育至10～15mm直径,皮下给药4例中3例卵泡发育至10～14mm直径,1例无反应。卵泡发育受挫的原因可能与剂量,脉冲投药频率有关。