超临界流体增强溶液分散度法制备阿莫西林缓释微囊

采用超临界流体增强溶液分散度法,对制备阿莫西林-乙基纤维素-卡波谱缓释微囊进行了初步研究,探索了制备微米级缓释药物微囊的新方法。在对制备乙基纤维素空白微粒影响因素研究的基础上,选择了较为适合的工艺参数:CO2流速0.42 m/s,温度40℃,压力9.0或12.0 MPa。在2种压力下分别得到平均粒径为5.48μm和2.85μm的药物微囊,其载药量为9.53%和9.70%,同时还考察了制得微囊药物的释放度曲线,结果表明阿莫西林微囊具有明显的缓释效果。超临界流体增强溶液分散度法是制备微米级药物微囊的极有前途的方法。     

超声传质增强式超临界溶液快速膨胀技术制备类胡萝卜素超细微粒

类胡萝卜素的低溶解性和在肌体中较低的生物利用度限制了其商业应用,微粒化是解决这些问题的有效途径。普通超临界微粒化技术受到类胡萝卜素低溶解性的限制,难以产业化。综述了超临界溶液快速膨胀微粒化技术的研究进展,建议将超声波应用于超临界微粒化技术领域,提出了超声传质增强式超临界溶液快速膨胀技术概念,设计研制出超声传质增强式超临界微粒化装置和喷嘴,对于低溶解性和对氧化高敏感性的药物制剂化有重要的工业应用价值。     

超临界流体抗溶剂技术及微粒成形机理的研究进展

超临界抗溶剂技术是一种新型的超细微粒制备技术,在药物、超导、颜料、炸药和聚合物等领域已有广泛的应用。本文主要介绍了超临界抗溶剂过程和该技术在单组分和多组分无机氧化物纳米粒子制备上的应用,并对超临界抗溶剂微粒成形机理的研究现状和微粒的成形机理进行了简要的概括总结。最后对超临界抗溶剂微粒化技术的发展做了进一步展望。     

新型超临界流体技术

介绍了超临界流体制备超细微粒、超临界流体中的酶催化反应、超临界水氧化等新型超临界流体技术及应用。     

应用超临界流体重结晶技术制备药物微粒

总结了超细药物微粒的常规制备方法,对超临界重结晶技术的两种常用方法,即超临界流体快速膨胀法和抗溶剂法进行了介绍,阐述了它们的应用进展情况,回顾了两种方法在国内中药药材领域的研究情况。并对超临界重结晶技术进行了展望,指出该技术为我国中药材有效成分的精细制备提供了一条富有前景的道路,但需要解决制备产量低、成本高、工艺和设备尚不完善等问题。     

超临界溶液快速膨胀技术在微细粒子制备上的应用

超临界流体快速膨胀法 (RESS)是近 1 0年发展起来的一项制备超细粒子的新技术 ,可生产粒径达到纳米至微米级且粒径和形态分布均匀的超细粒子。虽然理论研究目前还处于探索阶段 ,但该方法已经在很多领域展示了诱人的应用前景。就近年来超临界溶液快速膨胀技术的原理、典型的实验装置、工艺特点和应用研究成果进行了扼要的论述     

基于超临界流体抗溶剂原理的造粒技术及其装置研究进展

超临界抗溶剂造粒技术由于具有操作条件温和、制得的微粒有机溶剂残留少、微粒粒径和形态可控等优点,已广泛地应用于药物运输体系的研究当中。本文简要介绍了超临界抗溶剂造粒技术的基本原理、装置组成和基本分类;从技术发展、喷嘴改进、技术结合、产品收集等方面,详细阐述了GAS、ASES、SEDS、SEDS-PA、SpEDS、SAS-EM、SAS-IJ、连续式RESS以及RESAS等基于超临界流体抗溶剂原理的造粒技术及其装置的改进过程;然后对目前其中存在的颗粒团聚、产品收集难和装置资源没有充分利用等问题提出了可能的解决方案;最后从数学模型的建立和规模化两方面,对超临界抗溶剂造粒技术基础理论的完善及其装置的改进进行了展望。     

Morphologies of blends of isotactic polypropylene and ethylene copolymer by rapid expansion of supercritical solution and isobaric crystallization from supercritical solution

Isotactic polypropylene (iPP) and ethylene‐butene (EB) copolymers were dissolved in supercritical propane and precipitated by rapid expansion of supercritical solution (RESS) and isobaric crystallization from SS (ICSS). The cloud‐point pressures of the ternary solutions were found to increase as the immiscibility of PP and EB copolymer increased (i.e., as the number of ethyl branches in the EB copolymers decreased). The RESS process resulted in microfibers and a trace of microparticles, and the EB copolymer domains in the blends decreased in size as the ethyl branch content in the EB copolymers increased. The thermal stability of the copolymer domains was improved by synthesizing thermoplastic vulcanizate (TPV) from PP and ethylene‐propylene‐diene terpolymer in a supercritical propane solution followed by RESS. The ICSS process produced microcellular polymeric foamlike materials, but the two polymers were precipitated independently by thermally induced phase separation. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1478–1487, 2000     

Rapid stereocomplex formation of polylactide using supercritical fluid technology

It is generally believed that stereocomplex polylactide is a prospect for rigorous application in the future due to enhancement of the physical properties of its homopolymers. There have been many studies about the formation and characterization of this stereocomplex. However, we are the first to report that supercritical fluid technology can yield a high‐degree stereocomplex polylactide (ca 98%) in a relatively short time (1 min). “This method generated a dry product and feasible for polylactide with weight‐average molecular weight (Mw) up to 70 000–160 000 g mol^?1 or higher by modifying the material feed of the homopolymer.” The “feasible” term is used to explained that our system is suitable for stereocomplexation of the polylactide material with molecular weight 70 000–160 000 or above. We also discovered that modification of the material feed did not affect the properties of the stereocomplex polylactide generated. The process and outcome of this research indicate that supercritical fluid technology is suitable for a continuous stereocomplex polylactide formation process. Copyright © 2012 Society of Chemical Industry     

RESS用于药物微细化的研究进展

药物颗粒尺寸对药物生物利用度有很大影响,通过减小颗粒粒径可以提高药物的生物利用度。本文主要介绍了超临界药物微细化的方法和药物的选择性。超临界流体快速膨胀法(RESS)的原理、过程及最新的研究进展。