纳米介孔分子筛用于吡格列酮长效缓释的研究

主要研究以CTAB（十六烷基三甲基溴化铵）为模板剂,TEOS（正硅酸乙酯）为硅源的二氧化硅介孔材料（MCM-41）作为药物盐酸吡格列酮输送体系的可能性,研究药物在这种介孔材料中的吸附/释放特性及其影响因素。采用粉末X射线衍射法（XRD）,傅里叶变换红外光谱法（FT-IR）和扫描电子显微镜（SEM）来表征吸附前后的介孔分子筛。将合成的分子筛用作吡格列酮药物的载体,实时检测制备药物在模拟胃液中的释放过程发现,在药物释放开始后的第1h内,吡格列酮释放速率非常快,1h后释放率达到17.93%,在9h后释放率达到37.88%,在释放34h后,释放率达到62.74%。     

介孔分子筛表面功能化研究进展

对介孔分子筛表面功能化的修饰方法及工艺进行综述,得到一些关于研究方向上的建议.介孔分子筛的表面功能化的主要工艺有化学修饰法、杂原子取代法.酸催化杂合、金属有机化合物表面接枝反应等.金属有机化合物近几年得到广泛应用,效果良好,作为研发重点,生产方向得以向这方面转移.     

全硅介孔分子筛MCM-41的表面修饰及其疏水性

在极性溶剂(丙酮)或非极性溶剂(甲苯)中,用三甲基氯硅烷对全硅介孔分子筛MCM-41进行了表面修饰。利用IR、XRD和低温N2吸附-脱附等手段对样品进行了结构分析;并通过测定样品在水或正庚烷饱和蒸汽中的吸附量,研究了它们的疏水性。实验结果表明,表面改性后的MCM-41仍保持完好的介孔结构,由于有机官能团接枝在MCM-41的内表面,占据了孔道内部空间,使其比表面积、孔容和孔径都减小。样品的疏水性与其硅烷化程度成正关系,且在非极性溶剂中表面修饰的样品表现出更好的疏水性能。     

磷酸铝介孔分子筛的合成

选用了不同类型的表面活性剂作为模板剂合成磷酸铝介孔分子筛,实验结果表明,脂肪胺模板剂的浓度不会影响分子筛介孔相构型,介孔分子筛的孔径随烷基胺的链长增加而增大,其比表面积均达到了200 m2/g以上.类型相同的表面活性剂作模板剂时,分子筛的孔径和比表面积并不随其浓度增加而增加.所合成的磷酸铝分子筛TG和DTA曲线表明,磷酸铝分子筛在850 ℃以前具有一定的热稳定性.     

活性纳米金颗料在介孔分子筛SBA-15上的分散

Chemical modification （CM） and deposition-precipitation （DP） methods were used for the dispersion of active Au nanoparticles on mesoporous silica materials in this work. XRD, TEM, N2 adsorption isotherms and UV-Vis absorption spectra were used to characterize in detail Au-SBA-15 materials prepared by the two methods. The analysis results showed that high loading （1.7%, by mass） and uniform Au nanoparticles （approximately 3 nm） were dispersed in the channels of mesoporous SBA-15 by the CM method. While for the DP method, most of Au nanoparticles with the size of 10—15nm were aggregated outside of the channels of SBA-15 and the actual loading of Au was only 0.38% （by mass）.     

介孔分子筛合成中模板剂的研究与应用

对介孔分子筛催化剂中的模板剂的研究进展进行了综述,重点介绍了模板剂的发展过程、分类以及模板剂在介孔分子筛合成中的机理。     

含Co介孔分子筛的合成与稳定性研究

两步法进行含Co介孔分子筛的合成,采用XRD,FT-IR,TPR,TEM,N2吸附-脱附等方法对样品的物化性能进行表征结果表明:合成出了具有介孔结构的CoMCM-41,550℃焙烧可以将模板剂有效去除并不影响介孔结构,CoMCM-41的比表面积大于700m2/g,孔径分布在3.4～4.5 nm范围内.650℃热处理3 h或100℃水热处理5 d后CoMCM-41的比表面、孔径和孔体积变化较小,表明CoMCM-41的热稳定性和水热稳定性较好.     

环氧树脂/纳米介孔分子筛复合材料的制备及性能研究

通过溶液共混法制备出环氧树脂（EP）／纳米介孔分子筛MCM-41（with template）（以下简称MCM-41）复合材料。研究了不同的MCM-41粒子含量对其在EP中的分散性和EP／MCM-41复合材料拉伸性能的影响。结果表明,这种具有独特的有机-无机复合结构的MCM-41直接用作填料时,能与EP形成新型网络复合结构,当MCM-41粒子的用量为1．5～2．5份时,它能均匀地分散在EP基体中,有效地提高EP／MCM-41复合材料的拉伸性能。     

介孔二氧化硅花球的制备及药物缓释性能研究

采用溶胶-凝胶法,以正硅酸乙酯为硅源、十六烷基三甲基溴化铵(CTAB)为模板,在碱性条件下合成了尺寸均匀、形状规则的花状形貌的介孔状二氧化硅微球。基于二氧化硅花球特殊的表面褶皱和内部的介孔孔道,将其作为载体负载模型药物布洛芬,探究其药物缓释性能。结果表明,所制备的介孔二氧化硅花球对布洛芬模型药物的负载量为701.63 mg·g~(-1),明显高于传统药物载体材料。此外,对介孔二氧化硅/布洛芬复合粒子进行缓释实验研究,发现10 h后布洛芬的释放量为74.60%,表明其具有较好的药物缓释性能。     

介孔分子筛催化剂应用研究进展

介孔分子筛催化剂作为一类新型催化材料,与传统的质子酸催化剂相比,其优点突出,已应用于炼油技术、化工和精细化学品的合成领域,文章对介孔分子筛的应用进展进行了综述并展望了微孔—介孔复合分子筛的发展远景,同时指出了存在的问题和不足。     

MODELING OF DRUG RELEASE FROM A SWELLABLE MATRIX

In many polymeric controlled release systems (CRSs) the drug release kinetics is mainly ruled by the penetrant absorption characteristics which, in turn, depend on the viscoelastic properties of the polymer/penetrant system. The kinetics of the drug release process can follow either a typical Fickian behavior or a non-Fickian one (anomalous release), depending on the polymer/ penetrant viscoelastic properties. The aim of this work is to model such physical evidences by means of the appropriate flux equations describing the penetrant uptake and the corresponding drug release.

As a main result of our work we prove that, by resorting to the Sarti and Camera-Roda flux equation for the penetrant, and to the Fick flux equation for the drug, it is possible to simulate both Fickian and non-Fickian drug release from swelling CRSs characterized by different viscoelastic properties of the polymer/penetrant system. Furthermore, we demonstrate that the effect of the density gradient developing inside the matrix during the drug release does not sensibly affect the drug release kinetics.     

PROLONGED DRUG RELEASE FROM A CYLINDRICAL MATRIX DEVICE WITH A SMALL RELEASE HOLE

Prolonged drug release from a simple cylindrical device with a small release hole was investigated by a dynamic mathematical simulation model based on the two-dimensional Fick's law of diffusion. Effects of the release hole radius, height and radius of the device, and hydrodynamic diffusion boundary layer formed on the device surface were numerically analyzed. The calculated results indicated that the release rate from the present device can be easily controlled within an effective level of release for a prolonged period of time by an optimum selection of the release hole radius, device radius and device length. The release profiles of numerical calculation were well agreed with the experimental release data of benzoic acid impregnated in the 1% agar gel at the saturated concentration.     

PROLONGED DRUG RELEASE FROM A CYLINDRICAL MATRIX DEVICE WITH A SMALL RELEASE HOLE

Prolonged drug release from a simple cylindrical device with a small release hole was investigated by a dynamic mathematical simulation model based on the two-dimensional Fick's law of diffusion. Effects of the release hole radius, height and radius of the device, and hydrodynamic diffusion boundary layer formed on the device surface were numerically analyzed. The calculated results indicated that the release rate from the present device can be easily controlled within an effective level of release for a prolonged period of time by an optimum selection of the release hole radius, device radius and device length. The release profiles of numerical calculation were well agreed with the experimental release data of benzoic acid impregnated in the 1% agar gel at the saturated concentration.     

Mn掺杂的介孔氧化硅材料的合成与表征

在室温碱性条件下合成了Mn掺杂的介孔氧化硅MCM－41材料,并利用XRD,FTIR,N2吸会,HREM等测试手段对其进行了表征。研究发现：随着Mn掺杂量的增加,XRD图谱中材料的特征衍射峰（100）强度逐渐减弱,比表面SBET值随之减小,表明Mn掺杂可以使介孔结构稳定性下降;红外光谱中968cm^-1附近吸收峰的出现,表明Mn离子已进入Si-O骨架并引起Si-O-Mn键的振动;HREM的结果证实了介孔结构的存在,Mn的掺杂可造成有序介孔结构发生扭曲并趋向混乱。     

锰掺杂有序介孔氧化硅材料的合成研究

采用十六烷基三甲基溴化铵和十六胺为混合模板剂，在碱性条件下水热合成锰掺杂氧化硅有序介孔材料Mn-MCM-41。借助XRD，IR，HRTEM，N2吸附等测试手段对其有序介孔结构及孔结构进行表征。XRD和HRTEM检测表明：所合成材料具有高度的长程有序结构；依据样品的N2吸附曲线，合成材料具有毛细凝聚的陡峭台阶和狭窄的孔径分布。实验结果表明：十六胺的适量加入，可提高Mn掺杂介孔氧化硅材料的长程有序程度，并初步从界面作用和表面活性剂堆积准数两方面分析了混合模板剂在Mn掺杂有序介孔氧化硅材料合成中的作用机理。     

THE EFFECT OF DRUG DISSOLUTION ON DRUG RELEASE FROM SWELLING POLYMERIC MATRICES: MATHEMATICAL MODELING

A mathematical model of simultaneous dissolution and diffusion controlled drug release from swellable, non-erodible viscoelastic polymer matrices is developed. The model assumes that the drug is loaded into the dry matrix as a solid phase. Two unsteady-state mass balances are required for both the drug and the incoming external penetrant. The Camera-Roda and Sarti equation is considered for the determination of the penetrant uptake, while Ficlc's equation accounting for the density gradient developing in the matrix is considered for the drug diffusion. Assuming that upon dissolution a drug phase transition may occur which affects the drug solubility without altering the diffusion coefficient. This analysis revealed that the features of the drug release kinetics are sensibly affected by the viscoelastic properties of the swollen matrices and by the drug dissolution and phase transition rates.     

MATHEMATICAL ANALYSIS OF DRUG RELEASE FROM PLANAR MATRIX WHEN DRUG IS LOADED UNDER THE SOLUBILITY

1 INTRODUCTIONThe release of a drug from a diffusional matrix has been investigated by variousresearchers for different conditions [1-4].The drug loading in the matrix may beabove or below its solubility limit.If it is beyond,the release boundary is generated bythe dissolution of drug,and the concentration in the released region may be propor-tional to the distance and kept at saturation in the unreleased region.Otherwise,the     

不同孔径介孔分子筛MCM-41的合成及载药释药性能

通过添加辅助剂1,3,5-三甲基苯合成不同孔径的介孔分子筛(mesoporous molecular sieves,MCM-41)。将利尿性氢氯噻嗪引入到MCM-41的孔道内,采用低温N2吸附-脱附、X射线衍射、Fourier红外光谱仪、热重分析等表征MCM-41材料,并测定了氢氯噻嗪在模拟体液中的释放率。结果表明:合成的MCM-41具有均一的介孔结构,孔径在4.0～5.6nm,氢氯噻嗪在MCM-41-B(具有最大的孔径)中的释放速率较快,10h释放了79%,其他材料的需20h,而且氢氯噻嗪的释放速率随着孔径的增加而减小,表明已制得了氢氯噻嗪的缓释体系,并且可以通过控制孔径来调节氢氯噻嗪的释放速率。     

棒状有序介孔锌掺杂氧化硅的合成与性能

采用共沉淀法经水热反应合成了棒状有序介孔锌掺杂氧化硅(mesoporous zinc-doped silica,MZS)材料,借助X射线衍射、Fourier变换红外光谱、光电子能谱、透射电镜、N2吸附-脱附、光致发光光谱等测试手段对有序介孔结构及光学性能进行了表征.结果表明:合成材料具有高度的长程有序结构,虽然锌的掺杂引起材料的比表面积的减小,但仍能保持介孔材料的有序性.合成材料中的Zn2 已经进入Si-O骨架并产生大量Si-O-Zn交联键,进而引发了MZS介孔材料的蓝色荧光发射强度显著增强且有明显蓝移.     

含铌六方介孔二氧化硅的气相硅烷化改性

用水热法合成了含铌六方介孔二氧化硅(njobium.containing hexagonal mesoporous silica,Nb-HMS),并对其进行气相硅烷化改性.采用X射线衍射、N2-吸附、Fourier红外光谱、29Si核磁共振和紫外-可见光分光光度法等对样晶进行表征,并用1-己烯、环己烯和苯乙烯的坏氧化反应(以异丙苯过氧化氧作为氧化剂)进行催化性能评价.结果表明:硅烷化后的Nb-HMS具有典型介孔结构、更低的亲水性和较高的铌分散性;硅烷化后催化 剂显示更高的环氧化活性和选择性.