介孔二氧化硅纳米粒的制备及对载药与药物溶出度的影响

目的为提高水难溶性药物的分散性及溶出度,制备介孔二氧化硅纳米粒作为水难溶性药物的载体。方法探索得到简单有效地制备球状介孔二氧化硅纳米粒的工艺条件,采用扫描电镜及氮气吸附-脱附等手段分析表征载体的外观形貌,比表面积及孔径分布,并选取水难溶性药物西洛他唑作为模型药物,以溶剂浸渍挥干法载药制得药物固体分散体,采用热分析、氮气吸附-脱附曲线以及溶出度实验研究药物固体分散体的基本性质。结果制得的二氧化硅载体的形貌近球状,粒径大小分布在200～250 nm,载体的比表面积最高可达1 101.54 m2.g-1,孔径分布主要集中在3.0～4.0 nm。载药过程对西洛他唑在载体中的存在形式没有影响,固体分散体中西洛他唑的溶出度得到显著提高,当药物与载体的质量比为1∶3时,药物60 min累计溶出达85%。结论介孔二氧化硅纳米粒有望成为水难溶性药物的优良载体。     

介孔复合硅微球的制备及载药性质

目的制备介孔复合硅(CaO-SiO2-P2O5)微球,考察其作为水难溶性药物载体提高水难溶性药物的分散性及溶出度的优势。方法采用sol-gel方法制备介孔CaO-SiO2-P2O5微球,以扫描电镜及氮气吸附-脱附等方法分析表征载体的外观形貌、比表面积及孔径分布;选取尼莫地平为模型药物,以溶剂浸渍挥干法载药制得药物固体分散体;采用热分析、氮气吸附-脱附曲线分析以及溶出度实验研究药物固体分散体的基本性质。结果制得的复合硅载体的形貌近球状,粒径大小主要分布在3～6μm,载体的比表面积为637.34 m2.g-1,孔容为1.371 8 cm3.g-1,孔径分布主要集中在10～12 nm。当药物和载体的质量比为1:4时,药物能够被包埋分散于载体内部,且以无定型的形式存在,45 min尼莫地平累计溶出达80%。结论介孔CaO-SiO2-P2O5微球有望成为水难溶性药物的优良载体。     

两种介孔二氧化硅载体用于改善西洛他唑溶出度的比较

目的研究两种介孔二氧化硅(MCM-48和MCM-41)作为西洛他唑(cilostazol,CLT)的载体在改善药物溶出度方面的作用。方法分别采用3种方法制备CLT/MCM-48和CLT/MCM-41固体分散体,以紫外分光光度法测定样品的载药量。以溶出度为评价指标,对载药方法、药物与载体的质量比和固体分散体粒径等因素进行了优化,并应用氮气吸附和低温DSC法分析样品中药物的存在状态。结果当药物与载体质量比为1∶3时,以共沉淀法制备的CLT/MCM-48和CLT/MCM-41样品,经150μm孔径筛处理后,药物的溶出度最高,分别达到78%和85%。与以PEG4000为载体制备的CLT/PEG相比,显示了更加优良的药物溶出的稳定性。氮气吸附结果表明药物已经成功分散于载体孔道中;DSC分析显示,药物极有可能以无定形存在,且介孔孔道对药物向稳定型转变有延缓和阻滞作用。结论 MCM-48和MCM-41作为药物载体制备固体分散体能够不同程度地提高CLT的溶出度。     

介孔二氧化硅微球的制备及用于吲哚美辛载药与溶出性质

目的制备介孔二氧化硅微球,以期提高吲哚美辛的溶出速率。方法以表面活性剂十六烷基三甲基溴化铵和普兰尼克三嵌段共聚物P123作为双模板,用软膜板法制备具有介孔孔道的介孔二氧化硅微球药物载体,采用扫描电镜及氮气吸附-脱附手段表征载体形貌、比表面积及孔径分布。用吸附平衡挥干法载药制得吲哚美辛固体分散体,并对该固体分散体的溶出性质进行研究。结果制得的介孔二氧化硅载体由粒径相对均一的球形粒子组成。其粒径主要集中在2～5μm,载体的比表面积为502.87 m²·g2·g^(-1),孔容为2.23 cm(-1),孔容为2.23 cm³·g3·g^(-1),孔径为23.75 nm。吲哚美辛/介孔二氧化硅固体分散体的药物溶出速率与累积溶出度与吲哚美辛原料药相比均有了显著提高。结论吲哚美辛已高度分散于微球载体中,药物的溶出速率明显加快,为提高吲哚美辛生物利用度的研究打下了基础。     

管状介孔硅用于提高西洛他唑的溶出速率及对其物理稳定性的影响

目的以合成不同于传统球形介孔硅的管状硅(mesoporous silica tube,MST)为载体,制备西洛他唑(cilostazol,CLT)固体分散体系(CLT-MST),提高难溶性药物CLT的溶出速率和物理稳定性。方法采用多壁纳米碳管(carbon nanotube,CNT)为硬模板,以表面活性剂十六烷基三甲基溴化铵(cetyltrimethyl ammonium bromide,CTAB)为辅助模板制备MST,应用扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)和比表面积分析仪表征MST外在形貌和内部孔道特征。采用挥干载药的方法,将CLT载入制备的MST中,并测定所制备的固体分散体系的药物溶出度,以差示扫描量热仪(differential scanning calorimetry,DSC)和X射线衍射仪(X ray diffraction,XRD)分析药物在载体中的存在状态。最后对介孔硅固体分散体系进行稳定性试验。结果所制备CLT-MST在1 h时累计溶出度达到82%,且储存6个月后CLTMST的DSC和XRD表征图谱均没有显著变化。结论 MST可使难溶性药物CLT高度分散,能够改善CLT的溶出速率以及保持CLT的物理稳定性。     

介孔碳(CMK-3)载体用于提高非诺贝特溶出速率及物理稳定性的研究

目的以制备的介孔碳(CMK-3)为载体载入非诺贝特制备纳米药物分散体系,以期提高非诺贝特的溶出速率和纳米分散药物的稳定性。方法采用吸附平衡法将模型药物非诺贝特载入到碳载体中,应用扫描电子显微镜(SEM)来表征制备载体的形貌,透射电子显微镜(TEM)和氮吸附曲线表征载体的内部孔道结构,差示扫描量热(DSC)和X射线衍射(XRD)研究药物在载体中的存在状态,采取溶出度测定方法研究所制备的载药体系的药物溶出速度,并测定其长期稳定性。结果药物已载入碳载体的纳米孔道中,且药物粒子的高度分散和晶型的转变,显著提高了难溶性药物非诺贝特的溶出速率,并且碳载体的刚性结构有效阻止了分散药物粒子的再聚集,物理稳定性大大提高。结论制备的非诺贝特-CMK-3载药体系,为提高难溶性药物的生物利用度以及解决纳米分散药物的物理稳定性等问题,提供了一种可能。     

两种难溶性药物-纳米多孔ZnO固体分散体的制备与提高药物溶出度机制的研究

以自制的纳米多孔ZnO为载体制备药物固体分散体,并研究固体分散体提高药物溶出度的机制。采用熔融法分别制备吲哚美辛和西洛他唑固体分散体,扫描电镜、比表面分析仪、傅立叶红外光谱、差示扫描量热法和X-射线粉末衍射法表征结果显示纳米多孔ZnO与药物仅存在物理吸附作用,药物以无定型形式高度分散于ZnO纳米孔穴中且ZnO纳米孔穴可以抑制固体分散体中无定型药物于45℃、75%RH条件下的重结晶。体外溶出度测定结果表明,吲哚美辛固体分散体5 min时的累积溶出度可达到90%左右,西洛他唑固体分散体30 min时的累积溶出度可达到80%左右。研究探讨两种药物溶出度提高的机制与纳米多孔ZnO可增加药物分散性、控制药物以无定型形式存在并能抑制药物重结晶有关。     

固体分散体在提高难溶性药物口服生物利用度中的应用

固体分散体在提高难溶性药物溶出度和口服生物利用度中的应用引起了药学工作者的关注,本文综述了固体分散体常用载体、常用的溶剂、提高难溶性药物溶出速率的机制和制备方法以及其他替代的方法,以期将难溶性药物制备为固体分散体提供参考。     

热熔挤出技术制备伊曲康唑固体分散体及体外溶出考察

以羟丙甲纤维素(HPMC E5)为分散载体,利用热熔挤出技术制备难溶性药物伊曲康唑固体分散体,并探究不同挤出工艺参数和增塑剂1,2-丙二醇(PG)含量对固体分散体溶出度的影响。结果表明,二次挤出制得的固体分散体中药物的溶出率大于直接挤出的固体分散体,且二者均明显大于物理混合物。使用PG作增塑剂后伊曲康唑固体分散体的溶出率得到了显著提高,当PG用量较高(10%)时,固体分散体在0.1 mol/L盐酸介质中的溶出率可达到93%。本研究可以为热熔挤出的工艺开发提供更多的思路,同时为进一步制备高规格(200 mg)伊曲康唑片剂提供帮助。     

依折麦布混悬剂的制备及药物动力学研究

目的制备依折麦布/介孔硅固体分散体,以该固体分散体制备混悬剂,研究固体分散体和三甲基壳聚糖(TMC)对依折麦布药物动力学的影响。方法采用溶剂挥发法制备依折麦布/介孔硅固体分散体,以溶出度为指标筛选制备方法,采用差示扫描量热(DSC)、扫描电镜(SEM)等技术考察药物存在状态及物理稳定性。以甲基纤维素和TMC分别为助悬剂,将依折麦布/介孔硅固体分散体制成混悬液,研究大鼠口服各混悬液的药物动力学。结果依折麦布与介孔硅质量比为1∶5,搅拌时间为6h,制得固体分散体的载药量为16.5%,药物以非晶状态存在,溶出度可达92.2%,AUC和Cmax提高显著,tmax无明显变化。结论应用该固体分散技术和三甲基壳聚糖能改善依折麦布的口服吸收,提高生物利用度。     

穿心莲内酯聚丙烯酸树脂Ⅱ固体分散体的制备及表征

目的：研究无定形聚合物聚丙烯酸树脂Ⅱ（Eudragit Ⅱ）制备的穿心莲内酯固体分散体的优良性质,为固体分散体的载体选择提供参考依据。方法：以无定形聚合物Eudragit Ⅱ为载体材料,按穿心莲内酯-载体质量比为1：3,采用喷雾干燥法制备穿心莲内酯固体分散体,并用傅里叶变换红外光谱（FTIR）、热重分析（TG）、X-射线衍射（XRD）、差示扫描量热（DSC）、扫描电镜（SEM）、比表面积、粒径和溶出度测定穿心莲内酯固体分散体的理化性质及溶出行为。结果：FTIR光谱和TG分析说明在穿心莲内酯固体分散体和物理混合物中穿心莲内酯与Eudragit Ⅱ之间都存在分子间相互作用,其中穿心莲固体分散体具有更好的热稳定性;DSC和XRD分析说明无定形载体Eudragit Ⅱ制备的固体分散体中穿心莲内酯主要以无定形形式存在;SEM显示,固体分散体中穿心莲内酯由块状晶体形态变为了不规则的圆形形态;同时与物理混合物相比,穿心莲内酯固体分散体具有更大的比表面积、更大的孔体积和更小的粒径等粉体学性质;溶出实验表明穿心莲内酯固体分散体具有增大溶出的优势,效果明显。结论：以无定形载体Eudragit Ⅱ制备的穿心莲内酯固体分散体具有优良的理化性质,同时比表面积大,孔体积大的特征更有利于水分子的进入,从而有效地增大穿心莲内酯的溶出速率。     

Preparation and characterization of pelletized solid dispersion of resveratrol with mesoporous silica microparticles to improve dissolution by fluid-bed coating techniques

With hydrophilic surface and high surface area, porous silica has been applied to load insoluble drugs. Compared to solvent equilibrium method, resveratrol (RES)–mesoporous silica microparticles (MSM) solid dispersion prepared by fluid bed demonstrated higher drug loading and more complete dissolution. Pore volume and diameter have more remarkable effects than surface area to the drug loading and in vitro dissolution profiles. RES–polyethylene glycol solid dispersion with high drug loading showed fast but incomplete dissolution due to the recrystallization. The combination of fluid bed and MSM was an effective strategy to improve drug loading as well as dissolution for poorly water-soluble drugs.     

Development,characterization and solubility enhancement of comparative dissolution study of second generation of solid dispersions and microspheres for poorly water soluble drug

The poor dissolution characteristics of water-insoluble drugs are a major challenge for pharmaceutical scientists. Reduction of the particle size/increase in the surface area of the drug is a widely used and relatively simple method for increasing dissolution rates. The objective of this study was to improve solubility, release and comparability of dissolution of a poorly soluble drug using two different types of formulations (solid dispersions and microspheres). Hydrochlorothiazide was used as a model drug. The solid dispersions and microspheres were prepared by solvent evaporation method using ethyl cellulose, hydroxypropyl methylcellulose in different drug-to-carrier ratios (1:1, 1:2 w:w). The prepared formulations were evaluated for interaction study by Fourier transform infrared spectroscopy, differential scanning calorimetry, percentage of practical yield, drug loading, surface morphology by scanning electron microscopy, optical microscopy and in-vitro release studies. The results showed no interaction between the drug and polymer, amorphous state of solid dispersions and microspheres, percentage yield of 42.53% to 78.10%, drug content of 99.60 % to 99.64%, good spherical appearance in formulation VI and significant increase in the dissolution rate.     

Enhancement of solubility and dissolution of cilostazol by solid dispersion technique

Cilostazol is practically insoluble in water and thus results in poor bioavailability. Only a few approaches have been reported for improving the bioavailability of cilostazol. Solid dispersion technique via solvent evaporation method was applied to improve the solubility and dissolution of cilostazol. Various polymers, mixture of polymer and surfactant, and mixture of polymers were screened as a carrier for the solid dispersion. Solubility of cilostazol was improved significantly when Eudragit^® L100 was used as a carrier. However, addition of surfactant to Eudragit^® L100 decreased the solubility slightly. Whereas, the mixture of Eudragit^® L100 and Eudragit^® S100 as a carrier system further increased the solubility. Based on the highest solubility obtained among the carriers screened, 1:1 ratio of Eudragit^® L100 and Eudragit^® S100 was selected as a carrier, and drug to carrier ratio was optimized to 1:5. Differential scanning calorimetry and X-ray diffraction studies showed that the characteristic peak of cilostazol disappeared in the solid dispersion, indicating that cilostazol existed in amorphous form in this formulation. Spray drying method was superior to vacuum drying method in terms of dissolution rate. Meanwhile, it was observed that the disintegration rate and the concentration of polymer had some effect on the crystallization of cilostazol in dissolution medium. Tablet formulation containing spray dried solid dispersion showed significant improvement in dissolution as compared to the commercial tablet.     

索拉非尼固体分散体的制备及性质研究

目的制备索拉非尼(sorafenib,SFN)/介孔硅的固体分散体,并进行体内外性质研究。方法利用溶剂挥发法制备固体分散体,以溶出度为指标筛选药物和介孔硅比例;采用差示扫描量热法(DSC)和粉末X射线衍射(XRD)技术,考察药物存在状态及物理稳定性;通过电镜观察样品形貌;以大鼠为实验动物,以自制SFN粉末为对照,对固体分散体进行体内药动学研究。结果原料药为结晶态,溶出度<10%;随着介孔硅的比例增大,固体分散体的溶出度增加,当SFN与介孔硅的比例为1∶5时,SFN以非晶态存在,溶出度>90%,在6个月的加速实验中,药物存在状态和溶出度未见明显改变。固体分散体组的cmax是SFN粉末组的1.8倍,相对生物利用度为175%。结论 SFN/介孔硅固体分散体物理稳定性良好,能提高SFN的溶出度,改善其口服吸收效果。     

Carvedilol dissolution improvement by preparation of solid dispersions with porous silica

Impregnation of porous SiO(2) (Sylysia) with carvedilol from acetone solution was used to improve dissolution of this poorly water-soluble drug. Solvent evaporation in a vacuum evaporator and adsorption from acetone solution were the methods used to load various amounts of carvedilol into the Sylysia pores. The impregnated carriers were characterized using nitrogen-adsorption experiments, X-ray diffraction, wettability measurements, attenuated total reflectance FTIR spectroscopy and thermal analysis. The impregnation procedures resulted in a significant improvement of drug release compared to dissolution of pure carvedilol or its physical mixtures with Sylysia. The results showed that when the drug precipitated in a thin layer within the carrier the dispersion retained a high specific surface area, micropore volume, and drug-release rate from the solid dispersion. Increasing the amount of drug in the solid dispersion caused particle precipitation within the pores that decreased the carrier's specific surface area and pore volume and decreased the release rate of the drug. The results also suggest that the amorphous form of carvedilol, the improved wettability and weak interactions between the drug and carrier in the solid dispersion also contribute to improved dissolution of the drug from the dispersion.