西洛他唑微粉化片剂的制备和溶出度测定

目的研究提高西洛他唑溶出度的方法。方法使用球磨机制备西洛他唑微粉化混合物,并以此添加适合的辅料制备片剂。结果经测定制剂的溶出度达到《中国药典》要求。初步稳定性试验,结果表明本品稳定。结论该制备方法简单可行,溶出度合格。     

西洛他唑/介孔碳固体分散体的制备及体外溶出性质的考察

目的为了提高难溶性药物西洛他唑的溶出度,制备西洛他唑/介孔碳固体分散体。方法以表面活性剂F127为胶束模板,以酚醛树脂的乙醇溶液为碳源制备介孔碳,选用西洛他唑作为模型药,采用吸附平衡挥干法和溶液吸附法载药制得西洛他唑固体分散体,采用扫描电镜、氮气吸附-脱附和热分析手段表征介孔碳及西洛他唑/介孔碳固体分散体的性质。结果制得的介孔碳孔径均一,其孔径主要集中在6.3 nm,载体的比表面积为1 255.4 m2.g-1,孔容为1.441 cm3.g-1,载体的载药质量可高达33.1%,溶出数据表明西洛他唑/介孔碳固体分散体的溶出速率与累积溶出度与药物西洛他唑相比均有了显著提高。结论介孔碳有望成为能提高难溶性药物溶出度的优良载体。     

SOTAX自动溶出仪与普通溶出仪测定西洛他唑片溶出度比较

目的以西洛他唑片为例,利用SOTAX自动溶出仪对溶出度方法作方法学验证。方法采用中国药典西洛他唑的溶出度方法,手动稀释改为自动循环测定（1mm比色皿）。结果回收率100．1％,重复性RSD为0．4％,回归方程为A=3．7655C-0．0151,r=0．9999,并对自动溶出法和手动溶出法作了比较试验,两者无显著差异。结论自动取样溶出法可以用于西洛他唑片的溶出度检测。     

高效液相色谱法测定西洛他唑片的溶出度

目的：建立西洛他唑片的溶出度试验方法高效液相色谱法。方法：以40%乙醇为溶出介质,采用转篮法进行溶出度测定,转速为75r/min,温度为（37±0.5）℃,进行累积溶出百分率测定。采用Hypersil BDS C18柱（5μm,4.6mm×200mm）,以水-乙腈（55∶45）为流动相,流速为1.0mL·min-1,254nm波长下测定。结果：片剂辅料及其他杂质在该法测定范围内对西洛他唑的测定无干扰;在0.63~20.14μg/mL范围内线性关系良好。西洛他唑片各时间累积溶出量基本符合要求。结论：高效液相色谱测定方法简便,结果准确可靠,可用于西洛他唑片的溶出度测定。     

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。     

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。     

复方磺胺甲噁唑分散片处方工艺优选

目的优选胺甲噁唑分散片的处方工艺。方法采用正交设计试验优选处方工艺，制备复方磺胺甲噁唑分散片，以溶出度为考察指标测定其溶出度并与普通片进行比较。结果按优选处方工艺的复方磺胺甲噁唑分散片各项指标合格，溶出度较普通片快。结论优选的复方胺甲噁唑分散片处方工艺合理可行。     

复方磺胺甲噁唑分散片处方工艺优选

目的优选胺甲噁唑分散片的处方工艺。方法采用正交设计试验优选处方工艺，制备复方磺胺甲噁唑分散片，以溶出度为考察指标测定其溶出度并与普通片进行比较。结果按优选处方工艺的复方磺胺甲噁唑分散片各项指标合格，溶出度较普通片快。结论优选的复方胺甲噁唑分散片处方工艺合理可行。     

伊曲康唑-羟丙基-β-环糊精包合物颗粒的制备与质量控制

目的制备伊曲康唑-羟丙基-β-环糊精包合物颗粒，并对其进行质量控制。方法采用加热搅拌法，在酸性条件下将伊曲康唑制备成羟丙基-β-环糊精包合物，采用制备颗粒一般方法制备伊曲康唑-羟丙基-β-环糊精包合物颗粒。采用紫外分光光度法对其进行质量控制。 结果伊曲康唑-羟丙基-β-环糊精包合物颗粒制备工艺简单，增加伊曲康唑的溶出度，质量控制方法简单易行。结论该制备工艺简便，增加了伊曲康唑的溶出度。     

盐酸阿夫唑嗪口崩片的制备及体外溶出度影响因素考察

目的制备盐酸阿夫唑嗪口崩片,考察其体外溶出特性,并对影响其体外溶出度的因素进行考察。方法采用正交试验设计方案,以体外溶出度为考察指标,对盐酸阿夫唑嗪口崩片进行处方筛选,最后考察可能影响体外溶出度和崩解时限的因素。结果按优化处方制备的口崩片体外溶出度较好,崩解较快。结论制备的口崩片溶出度好,影响体外溶出度的主要因素为PVPP用量、PVP浓度及压力。     

Comparison of methods for predicting dissolution and the theoretical implications of particle-size-dependent solubility

Experimental dissolution data of cilostazol suspensions and hydrocortisone powders were simulated using either the Wang-Flanagan equation (1999. J Pharm Sci 88:731-738; 2002. J Pharm Sci 91:534-542) or the method of Johnson and coworkers (1989. Int J Pharm 51:9-17; 1993. Pharm Res 10:1308-1314; 1996. Pharm Res 13:1795-1798; 2003. Drug Dev Ind Pharm 29:833-842). Both methods were able to simulate experimental data with similar accuracy. For the method of Johnson and coworkers (1989. Int J Pharm 51:9-17; 1993. Pharm Res 10:1308-1314; 1996. Pharm Res 13:1795-1798; 2003. Drug Dev Ind Pharm 29:833-842), a single set of hydrodynamic assumptions was able to simulate both cilostazol and hydrocortisone with similar accuracy. For the Wang-Flanagan equation (1999. J Pharm Sci 88:731-738; 2002. J Pharm Sci 91:534-542), significantly different diffusion layer thicknesses gave the best simulations for cilostazol and hydrocortisone, but a single value of 38 μm provided good overall simulation of dissolution. The general computational method was enhanced to make solubility dependent on particle size, according to the Ostwald-Freundlich equation; it was also able to simulate Ostwald ripening. The enhanced computational method provided no way to explain the large increase in bioavailability of cilostazol in dogs when the drug was dosed as a nanoparticle versus micronized preparation. The method provides a computational tool for exploring theoretical implications and explaining the behavior of nanoparticles.     

Evaluation of Selected Micronized Poloxamers as Tablet Lubricants

The primary objective of this study was to compare the lubrication properties of micronized poloxamer 188 (Lμ trol micro 68®) and micronized poloxamer 407 (Lμ trol micro 127®) with certain conventional lubricants such as magnesium stearate and stearic acid. The secondary objective was to use these micronized poloxamers as water-soluble tablet lubricants in preparation of effervecsent tablets. The results showed that these micronized poloxamers have superior lubrication properties compared with stearic acid, with no negative effect on tablet hardness, friability, disintegration, or dissolution. Moreover, lubricant mixing time had no significant effect on tablet properties when poloxamers were used as lubricants. Effervescent tablets also were produced successfully using micronized poloxamers as lubricants. The micronized poloxamers had a better lubrication effect in compariason with that of water-soluble lubricant l-leucine.     

Evaluation of selected micronized poloxamers as tablet lubricants

The primary objective of this study was to compare the lubrication properties of micronized poloxamer 188 (Lμ trol micro 68^®) and micronized poloxamer 407 (Lμ trol micro 127^®) with certain conventional lubricants such as magnesium stearate and stearic acid. The secondary objective was to use these micronized poloxamers as water-soluble tablet lubricants in preparation of effervecsent tablets. The results showed that these micronized poloxamers have superior lubrication properties compared with stearic acid, with no negative effect on tablet hardness, friability, disintegration, or dissolution. Moreover, lubricant mixing time had no significant effect on tablet properties when poloxamers were used as lubricants. Effervescent tablets also were produced successfully using micronized poloxamers as lubricants. The micronized poloxamers had a better lubrication effect in compariason with that of water-soluble lubricant l-leucine.     

Micronization of drugs using supercritical carbon dioxide.

Particles from gas saturated solutions, a novel method for high pressure material processing, has been used for micronization of practically insoluble calcium-channel blockers nifedipine and felodipine and the hypolipidemic agent fenofibrate with the aim of increasing their dissolution rate and hence their bioavailability. Dependent on the pre-expansion conditions, a mean particle size of between 15 and 30 microm was achieved for micronized nifedipine and 42 microm for micronized felodipine. The particle size of processed fenofibrate, on the other hand, increased due to agglomeration. The highest dissolution rate was achieved by preparation of drug coprecipitates with PEG 4000. Copyright     

不同固体制剂中白杨素的溶出度评价

目的考察白杨素不同固体制剂的体外溶出度,并建立白杨素制剂的溶出度HPLC测定方法。方法分别以体积分数40%和50%乙醇溶液,5和10g·L~(-1)十二烷基硫酸钠(SLS)溶液为溶出介质,对制备的3种白杨素固体制剂进行体外溶出度考察,并建立白杨素溶出度HPLC测定方法。结果 10g·L~(-1)十二烷基硫酸钠溶液更适合作为本研究中制备的3种白杨素固体制剂的溶出介质,白杨素微粉化胶囊剂的溶出度最高。此外,初步探讨了白杨素固体制剂体外溶出标准。结论不同制剂的白杨素溶出度差异较大,微粉化工艺能显著提高白杨素的溶出度。     

Micronization and microencapsulation of felodipine by supercritical carbon dioxide

Felodipine (FLD) is a poorly water-soluble drug. To improve its dissolution rate, the rapid expansion of supercritical solutions (RESS) technique was used to prepare micronized FLD drug particles, which were encapsulated in poly-(ethylene glycol) 4000 (PEG 4000). The physical properties of the encapsulated drug particles were characterized by a variety of analytical methods, including optical light microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and powder X-ray diffraction (powder-XRD) and the dissolution behaviour of FLD was studied in the microparticles. The supercritical condition of micronized FLD occurred at a relatively high pressure and moderate temperature. FLD–PEG 4000 microparticles compared well with micronized FLD. RESS was effective in reducing the particle size of FLD; spot-shaped micronized FLD and popcorn-shaped FLD–PEG 4000 microparticles were observed. The particulate properties of the microparticles included a narrow distribution and uniform size. Thermodynamic analysis showed an implantation interaction between FLD and PEG 4000 molecules, but no polymorphism in the micronized FLD or FLD–PEG 4000 microparticles. FLD–PEG 4000 microparticles had a significantly faster drug dissolution rate than micronized FLD. These data show that RESS can be used to prepare FLD–PEG 4000 microparticles with small particle size (2–6?µm) and enhanced dissolution rate.     

Micronization and microencapsulation of felodipine by supercritical carbon dioxide

Felodipine (FLD) is a poorly water-soluble drug. To improve its dissolution rate, the rapid expansion of supercritical solutions (RESS) technique was used to prepare micronized FLD drug particles, which were encapsulated in poly-(ethylene glycol) 4000 (PEG 4000). The physical properties of the encapsulated drug particles were characterized by a variety of analytical methods, including optical light microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and powder X-ray diffraction (powder-XRD) and the dissolution behaviour of FLD was studied in the microparticles. The supercritical condition of micronized FLD occurred at a relatively high pressure and moderate temperature. FLD-PEG 4000 microparticles compared well with micronized FLD. RESS was effective in reducing the particle size of FLD; spot-shaped micronized FLD and popcorn-shaped FLD-PEG 4000 microparticles were observed. The particulate properties of the microparticles included a narrow distribution and uniform size. Thermodynamic analysis showed an implantation interaction between FLD and PEG 4000 molecules, but no polymorphism in the micronized FLD or FLD-PEG 4000 microparticles. FLD-PEG 4000 microparticles had a significantly faster drug dissolution rate than micronized FLD. These data show that RESS can be used to prepare FLD-PEG 4000 microparticles with small particle size (2-6 microm) and enhanced 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.