双载体制备青蒿素速释型固体分散体工艺优化研究

对载体类型影响青蒿素固体分散体中药物溶出度进行研究及优化制备工艺。以大豆卵磷脂与PEG 6000或聚乙烯吡咯烷酮为双分散载体,采用溶剂法制备青蒿素速释型固体分散体,以溶出度为考察指标,单因素试验筛选载体类型及最佳制备工艺;并采用红外吸收光谱法(IR)、差示扫描量热法(DSC)进行物相表征,明确载体-药物存在状态。结果表明在50 min内卵磷脂-PVP K30双载体比卵磷脂-PEG 6000药物溶出度更高,制备固体分散体为速释型,50 min内总溶出度87%以上,显著高于原料药和物理混合物,且优化最佳工艺条件为卵磷脂与PVP K30比为1∶7,搅拌时间30 min,无水乙醇用量20 mL。IR及DSC结果显示在固体分散体中药物可能以无定型状态存在。双载体制备青蒿素速释型固体分散体工艺简单可行,可显著提高药物溶出度,为提高青蒿素疗效奠定重要基础。     

基于固体分散技术的阿司匹林肠溶微丸的制备

目的:制备阿司匹林固体分散体肠溶微丸。方法:以Eudragit L(EL)作为载体,采用固体分散技术制备阿司匹林肠溶微丸。运用X射线衍射法,扫描电镜法等分析方法研究其晶体性质,并考察其体外释放性能。结果:阿司匹林以无定形分散于固体分散体肠溶微丸中,药物体外释放曲线在胃液中符合零级动力学方程,在肠液中符合一级动力学方程。结论:阿司匹林固体分散体肠溶微丸可以较好地在肠道吸收,从而减少对胃部的刺激。     

薰衣草精油缓释固体分散体的制备及其体外释药性能研究

目的：优化薰衣草精油（LEO）缓释固体分散体的制备工艺,并探讨体外释药模型。方法：以芳樟醇及乙酸芳樟酯为指标,建立气相-色谱质谱联用（GC-MS）技术测定溶出度的方法;选用硬脂酸、聚乙二醇6000(PEG 6000)和单硬脂酸甘油酯为辅料,优化辅料配比,采用熔融法制备LEO缓释固体分散体,考察其体外释药性能。结果：LEO缓释固体分散体的最佳处方配比为硬脂酸∶PEG 6000∶单硬脂酸甘油酯：LEO=3∶5∶1∶1,该条件下所制备的固体分散体在体外能够持续释药12 h,体外释药符合一级动力学模型。结论：所优选的处方配比工艺稳定可靠,所得缓释固体分散体能显著改善药物溶出,缓释效果令人满意。     

牡荆苷纳米混悬剂冻干粉的制备及表征

为提高牡荆苷的水溶性和体外溶出度,采用反溶剂结合高压均质法制备了牡荆苷纳米混悬液及其冻干制剂,并对其理化性质进行表征及体外溶出度分析。激光粒度仪测得牡荆苷纳米混悬剂冻干粉复溶后平均粒径为(135.7±10)nm,Zeta电位为(-17.05±1.40)mV,SEM扫描结果显示牡荆苷纳米粒子以近球形形态存在,X射线衍射、差示扫描量热法及红外光谱证实牡荆苷纳米混悬剂冻干粉中牡荆苷纳米粒化学性质没有改变。牡荆苷纳米混悬液冻干粉的体外溶出度与原药相比显著提高,5 min内其体外溶出量为药物原药的4.5倍。     

非诺贝特固体自乳化制剂（S-SEDDS）体外评价及生物利用度研究

目的:以S-SEDDS替代液态自乳化制剂中的表面活性剂制备非诺贝特固体自乳化制剂。方法:比较了固体自乳化制剂与市售产品、液体自乳化制剂的体外溶出情况及体内生物利用度。结果:表明本研究的固体自乳化制剂用水分散后平均粒径为820.2±26.5(nm);溶出度试验结果显示,30min累积溶出度达到80%以上,本研究制备的非诺贝特固体自乳化制剂AUC(0-24)为22.7±8.2 mgoL-1oh与SEDDS的AUC(0-24)(24.9±7.6mgoL-1oh)没有显著性差异(P>0.05),与市售微粉化胶囊(13.8±10.5mgoL-1oh)相比能够显著提高药物的生物利用度(P<0.05)。结论:S-SEDDS有液体自乳化给药系统的效果。     

反溶剂重结晶法制备牡荆苷微粉工艺及其表征

为了提高牡荆苷溶出度,本实验采用反溶剂重结晶法（以N-甲基吡咯烷酮为溶剂,水为反溶剂）对牡荆苷原粉进行超细化研究。考察了药物浓度、溶剂与反溶剂体积比、搅拌转速及表面活性剂(PVP、Tween80、SDS)对牡荆苷微粉粒径的影响,确定牡荆苷微粉的最佳制备条件为：药液浓度为30 mg·mL^-1,反溶剂与溶剂体积比为15∶1,搅拌转速为1 500 r·min^-1,反溶剂中表面活性剂PVP浓度为8 mg·mL^-1,上述条件下制备的牡荆苷微粉平均粒径为291.1 nm;采用扫描电镜(SEM)、X射线衍射(XRD)、差示扫描(DSC)、红外光谱(FTIR)对牡荆苷原粉与微粉进行了表征,与原粉相比牡荆苷微粉粒径变小,结晶度降低,其化学性质未发生改变,体外溶出度显著提高。     

可德兰多糖载药微粒的构建、表征及其缓释作用

利用具有三螺旋结构的可德兰多糖作为载体,制备二十二碳六烯酸(DHA)的载药微粒。利用粒径、表面电位测定、红外光谱法、粉末X-射线衍射法等方式表征其载药微粒,并分析了载药微粒的体外缓释作用。结果表明,载药微粒平均载药量为6.4%,包封率为56.6%,平均有效粒径为291 nm。红外光谱法、粉末X-射线衍射等分析均表明形成了以可德兰多糖为主体的载药微粒,结晶度的降低能够增加载药微粒的溶解度。另外,体外缓释实验也证明了载药微粒具有一定的缓释性能。可德兰多糖作为载体制备的载药微粒具有一定的缓释性,在食品或医药行业中有广泛的利用前景。并为多糖作为载体构建具有一定缓释性的载药微粒的研究提供了理论依据。     

固体分散技术增溶的新工艺研究进展

增加难溶性药物的溶出是药剂学设计的重点.提高难溶性药物溶出的途径包括应用混合溶剂、加入助溶剂、固体分散技术、超微粉碎技术等.本文就应用固体分散技术提高难溶性药物的研究做一综述,重点介绍了近年来制备固体分散体的新工艺.     

非诺贝特固体自乳化制剂（S-SEDDS）体外评价及生物利用度研究

目的：以S-SEDDS替代液态自乳化制剂中的表面活性剂制备非诺贝特固体自乳化制剂。方法：比较了固体自乳化制剂与市售产品、液体自乳化制剂的体外溶出情况及体内生物利用度。结果：表明本研究的固体自乳化制剂用水分散后平均粒径为820.2±26.5（nm）;溶出度试验结果显示,30min累积溶出度达到80%以上,本研究制备的非诺贝特固体自乳化制剂AUC（0-24）为22.7±8.2 mgoL-1oh与SEDDS的AUC（0-24）（24.9±7.6mgoL-1oh）没有显著性差异（P〉0.05）,与市售微粉化胶囊（13.8±10.5mgoL-1oh）相比能够显著提高药物的生物利用度（P〈0.05）。结论：S-SEDDS有液体自乳化给药系统的效果。     

水/乙醇溶剂中阿奇霉素的热力学及多晶型研究

在278.2~308.2 K温度范围内,测定阿奇霉素在水/乙醇混合溶剂中的溶解度,根据固液平衡理论建立了该体系的溶解度修正模型。采用X线粉末衍射法和差示扫描量热法,对阿奇霉素在不同温度、不同体积比的水/乙醇混合溶剂中得到的晶体进行鉴别。同时利用溶解度数据估算了阿奇霉素在水/乙醇体系中的溶解热(-25.26~-16.11 k J/mol)、混合热(-9.94~-3.25 k J/mol)。通过溶液化学理论推导了阿奇霉素溶剂化平衡常数K与活度系数γ2的方程:γ2=1/(1+K),建立了溶剂化焓与温度、水/乙醇两者体积比(φ)之间的关系式,为ΔH=RTln(17.86exp(3.4φ)-1)。采用溶析结晶方法得到的6种阿奇霉素晶体,均属单斜晶系,但具有不同的晶胞参数且其密度和熔点也不同。同时发现温度越高,水/乙醇体积比越大,得到的晶体稳定性越差(晶体的熔点和密度降低)。在水/乙醇混合溶剂的溶析结晶体系中,产生阿齐霉素多晶型的现象与溶剂化作用的强弱有关。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.