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1.
为制备龙血竭总黄酮(RDF)固体分散体,提高其溶出度,并对固体分散体进行表征,以聚乙烯比咯烷酮K30(PVP K30)和泊洛沙姆188(F68)为辅料,采用溶剂法制备了三相固体分散体,以体外溶出试验考察了固体分散体制备工艺,并以X射线衍射(XRD)、红外光谱(IR)、差示扫描量热法(DSC)及扫描电子显微镜法(SEM)等手段对固体分散体进行了性能表征.结果表明:以TFDB,PVP K30,F68质量比为181时制得固体分散体的溶出效果较好,药物和辅料间无相互作用力,药物溶出的改善主要归结于固体分散体中药物的粒径减小和F68的润湿与增溶作用.故采用三相固体分散体技术能显著提高龙血竭总黄酮的体外溶出度,为改善中药难溶性成分的溶出奠定了理论基础.  相似文献   

2.
为提高胡椒碱(Piperine,Pip)的体外溶出,本文对Pip的双载体无定型态固体分散体制备技术进行研究。将醋酸羟丙基甲基纤维素琥珀酸酯(HPMC-AS)的3种异构体(HPMC-AS-HF、HPMC-AS-MF、HPMCAS-LF,分别简称为HF、MF和LF)和聚乙烯吡咯烷酮PVP K30(K30)按一定比例混合作为载体,并通过超饱和测试测定其对Pip溶液超饱和度的影响。使用溶剂法制备Pip双载体无定型态固体分散体,并运用差示扫描量热法(DSC)和红外光谱(IR)对Pip双载体固体分散体进行表征。实验结果显示K30/HF、K30/LF、K30/MF 3种组合均对Pip有一定的增溶作用,HF与MF可以提高溶液的超饱和度。当双载体固体分散体载药量为10%时,其溶出速度和稳定性按比例顺序为K30/HFK30/MFK30/LF。当MF/HF比例为1∶1或4∶1时效果最佳。随着MF占比增大,双载体固体分散体的溶出速度加快,稳定性下降。因此,双载体无定型态固体分散体对于维持胡椒碱的超饱和作用和提高体外溶出度都有显著效果。  相似文献   

3.
采用混合载体制备姜黄素固体分散体以提高姜黄素的溶解度和溶出度.实验采用溶剂法制备姜黄素固体分散体,以体外溶出度和饱和溶解度为评价指标,结合傅里叶红外光谱和差示扫描量热法,单因素试验筛选载体种类、单一载体与混合载体以及载药量,优化处方.最终处方为以尤特奇?聚丙烯酸树脂和羟丙基甲基纤维素为混合载体,姜黄素和两种载体的质量比例为1∶2∶2,此时姜黄素的溶出效果最佳.姜黄素以无定形态分散在载体中,姜黄素与载体间形成较强的相互作用,15 min的溶出度可到90%以上,饱和溶解度是原料药的9.7倍.实验结果表明,姜黄素三元固体分散体可提高姜黄素的溶解度和溶出度,为姜黄素制剂的研究提供了有效的实验参考.  相似文献   

4.
以聚维酮K30为载体,采用溶剂熔融法制备氟苯尼考固体分散体,用红外光谱法、显微鉴别法、差示热分析法和溶出速率法验证固体分散体,比较氟苯尼考原料、物理混合物和固体分散体的溶解度,并建立紫外法测定其含量.结果表明,氟苯尼考、混合物、固体分散体的差热曲线、红外光谱和溶出速率有很大区别,固体分散体可以显著提高药物的溶解度,在50.0~350.0 μg/mL浓度范围内吸收度与浓度间线形关系良好.氟苯尼考聚维酮K30固体分散体制备方法简单,质量可控,可以显著提高药物的溶解度,便于临床应用.  相似文献   

5.
乌索酸固体分散体的制备与分析   总被引:2,自引:1,他引:2  
采用聚乙烯吡咯烷酮(PVP-K30)作为载体,用溶剂法制备乌索酸(UA)固体分散体,以提高制剂中UA的溶出度;建立高效液相色谱(HPLC)法测定固体分散体的体外溶出度,并进行红外和紫外光谱分析,鉴别药物在载体中的存在状态.研究结果表明,HPLC法测定UA的溶出度准确可靠、稳定、无载体的干扰;选择PVP-K30作为载体制备成固体分散体,能显著地提高UA的体外溶出速度.  相似文献   

6.
为了提高盐酸特比萘芬的体外溶出度,制备盐酸特比萘芬的固体分散体微丸。采用流化床包衣技术中的喷雾干燥功能将盐酸特比萘芬和聚乙二醇6000(PEG6000)喷载于空白丸芯的表面,使固体分散体形成于微丸的表面。采用单因素法考察制备工艺。以上药效率、粘连率和体外溶出度作为效应值,采用星点设计-效应面法优化固体分散体微丸的制备处方。对盐酸特比萘芬固体分散体进行鉴别,并对固体分散体微丸进行溶出度考察和质量评价。结果表明:采用经优化后的制备工艺(雾化压力250 k Pa,进风量8 m3/min,泵液速率1. 0 mL/min,物料温度55℃)并按处方(盐酸特比萘芬与PEG6000质量比为1∶3. 96,丸芯增重72. 75%)制得的固体分散体微丸在30 min内体外溶出度达90%以上,上药效率为89. 9%,粘连率为0. 51%。傅里叶变换红外光谱仪(FT-IR)、X线粉末衍射仪(XRD)和差示扫描量热仪(DSC)表征了固体分散体的形成。盐酸特比萘芬的固体分散体微丸平均含药质量分数为6. 17%,粒径为0. 83~0. 88 mm,平均减重率仅0. 28%。以上结果表明制得的盐酸特比萘芬固体分散体微丸质量稳定,可显著改善盐酸特比萘芬的体外溶出度。  相似文献   

7.
以PVP作为载体,利用旋转蒸发法制备了大豆素固体分散体,通过XRD对固体分散体进行表征,采用紫外-可见分光光度计考察了固体分散体的溶解度。研究结果表明,大豆素与PVP形成固体分散体后,以无定型的形式高度分散在PVP载体中,大豆素在水中的溶解度显著提高;当大豆素与PVP的质量比为1:1时,固体分散体中大豆素在水中溶解度与大豆素的相比提高了32倍;加入盐酸水苏碱可以和大豆素、PVP形成三元固体分散体,且溶解度进一步提高,是大豆素的57倍,有利于改善大豆素的生物利用度。  相似文献   

8.
对比不同制备方法制备的布洛芬固体分散体的溶出行为,优选制备方法。采用溶剂分散法、熔融法和喷雾干燥法制备布洛芬固体分散体,将3种方法制得的布洛芬固体分散体与布洛芬原料、布洛芬物理混合物进行溶出行为对比研究。3种方法制备的布洛芬固体分散体溶出行为均较好,其中以溶剂法最优,显著地提高了布洛芬的溶出速度,其溶出行为明显优于原料及物理混合物。  相似文献   

9.
以聚乙二醇为载体材料,制备了葛根黄豆苷元固体分散体,采用紫外分光光度法测定其体外溶出度,分别研究了聚乙二醇的相对分子质量、药物和载体的比例和固体分散体的制备方法对药物溶出的影响.实验结果发现:固体分散体中药物的溶出度均高于原料药;药物的溶出度随聚乙二醇相对分子质量的增大而增大、随载体用量提高而增大;不同的固体分散体制备方法对药物的溶出度影响不大.  相似文献   

10.
针对某些中药有效成分因水溶性差而引起药物生物利用度低的问题,选取具有抗肝炎活性的花锚总苷为研究对象,运用熔融法或溶剂法分别制备了4种不同载体组成的花锚总苷固体分散体,通过HPLC方法测定溶出度.研究结果表明,聚乙二醇4000、聚乙二醇6000、泊洛沙姆188、聚乙烯基吡咯烷酮k30均能与花锚总苷制备固体分散体,相对于花...  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

18.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
The non-orthogonal localized molecular orbital(NOLMO)is the most localized representation of electronic degrees of freedom.As such,NOLMOs are thus potentially the most efficient for linear scaling calculations of electronic structures for large systems.However,direct ab initio calculations with NOLMO have not been fully implemented and widely used,partly because of the slow convergence issue in the optimization of NOLMO.We devel-  相似文献   

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