超临界CO2流体技术制备纳豆激酶肠溶微丸的初探

以异丁烯酸-丙烯酸乙酯共聚物Eudragit L100-55为包衣材料,利用超临界CO2流体技术制备纳豆激酶口服肠溶包衣微丸,考察包衣效果,为纳豆激酶口服制剂的研究和开发提供实验依据.采用正交表考察各种因素对试验结果的影响;并按药典规定考察微丸在不同pH释放介质中的药物活性及释放行为.结果显示最适反应条件为:包衣材料和载药微丸质量比为1:2,反应压力和温度分别为20 MPa、35℃,增塑剂柠檬酸三乙酯及助溶剂乙醇均为10%(V/m),抗粘剂滑石粉虽对包衣反应稍有影响.但能显著改善微丸粘连问题.体外实验结果表明所制备的最佳状态肠溶微丸在人工胃酸(pH1.2)环境中2 h仅释放9.7%,并能保持近90%的活性状态;在pH6.8的模拟肠液释放介质中2 h内快速释放达75%.以超临界CO2流体技术制备的纳豆激酶口服肠溶包衣微丸,在人工胃酸环境中几乎不释药,可避免胃酸环境对纳豆激酶活性的破坏;在pH6.8的类肠液环境中药物释放快速而完全,有利于纳豆激酶在肠道中的吸收.     

双氯芬酸钠肠溶微丸的制备与体外评价

目的制备双氯芬酸钠肠溶微丸并确定其制备工艺。方法利用离心造粒机制备双氯芬酸钠素丸,以丙烯酸树脂Ⅱ号和Ⅲ号为包衣材料,通过微型流化床包衣机对素丸包衣,并以释放度试验和稳定性试验评价其质量。结果所制得的双氯芬酸钠肠溶微丸在人工胃液中2 h内累积释放度小于10%,在人工肠液中45 min内累积释放度为(82.8±1.31)%。产品的稳定性试验结果符合要求。结论采用该法制备的双氯芬酸钠微丸有良好肠溶效果且稳定性较好。     

盐酸青藤碱肠溶缓释微丸的制备

目的：制备盐酸青藤碱肠溶缓释微丸。方法：分别以Eudragit NE30D为缓释膜材，HPMC E5为隔离层膜材，Eudragit L30D-55为肠溶层膜材，采用流化床包衣法制备盐酸青藤碱肠溶缓释微丸，并考察缓释层、隔离层和肠溶层包衣增重对药物释放的影响。结果：制备的肠溶缓释微丸在人工胃液中释放度<10%，人工肠液中缓慢释放8 h。结论：该制备工艺简单易行，重现性好，有望应用于工业化生产。     

兰索拉唑肠溶微丸胶囊的制备

目的:制备兰索拉唑肠溶微丸胶囊。方法:采用流化床包衣技术,在空白丸芯上依次包以主药层、隔离层和肠溶层,制备成兰索拉唑肠溶微丸,将肠溶微丸装入普通胶囊制成兰索拉唑肠溶微丸胶囊,并考察3批制剂的载药率及在人工肠液和人工胃液中的释放情况。结果:所制微丸圆整度高,外观亮泽,载药均匀、载药率高(平均值在96%以上),包衣效果好;其在人工肠液中45min的体外累积释放率大于(94.3±0.76)%,在人工胃液中2h的释放量小于(6.2±1.6)%。结论:所制兰索拉唑肠溶微丸胶囊工艺可行,重现性良好,质量稳定可靠,具有良好的体外释药性和耐酸力。     

埃索美拉唑镁肠溶微丸的制备与质量控制

目的:制备埃索美拉唑镁的肠溶微丸,并建立起埃索美拉唑镁肠溶微丸的质量控制方法.方法:采用流化床底喷包衣的方法,制备出埃索美拉唑镁肠溶微丸,同时评价其体外药物的耐酸力和释放度.结果:自制的埃索美拉唑镁肠溶微丸在pH 1.2的HCl中1h累积释放率小于2%,在pH 6.8的人工肠液中1h累积释放率大于85%.结论:在人工胃酸中,制备的埃索美拉唑镁肠溶微丸耐酸力较好;在人工肠液中,溶出较完全且迅速,说明该方法稳定可靠,可推广.     

炎琥宁肠溶微丸的制备工艺研究

目的用水分散体系包衣技术制备炎琥宁肠溶微丸给药系统。方法以微晶纤维素(MCC)为填充剂,SiO2为抗黏剂,40%乙醇为黏合剂,采用挤出滚圆法制备丸芯,正交试验设计优化处方和工艺;以Eudragit L 30 D水分散体为包衣材料,乙基纤维素(EC)为阻滞剂,PEG6000为增塑剂,采用流化床包衣法,包肠溶衣层。结果丸芯的最佳处方工艺为:炎琥宁∶MCC∶SiO2=7∶7∶5;挤出速度1 080 r/min,滚圆速度960 r/min,滚圆时间5 min;当EC与Eu-dragit L质量比为35∶65,增塑剂用量为1.71%,聚合物包衣增重为5%时,所制得炎琥宁肠溶微丸在人工胃液(pH1.0)中释放度<10%,在人工肠液(pH 6.8)中正常释放,2 h内释放大于80%,符合中国药典对肠溶制剂释放度的相关规定。结论调整丸芯及包衣的处方工艺参数可以制得体外释放行为符合药典规定的肠溶炎琥宁微丸。     

挤出滚圆法制备盐酸多西环素肠溶微丸

目的应用挤出滚圆法及包衣锅包衣制备盐酸多西环素肠溶微丸,并对其性质进行考察。方法用挤出滚圆法制备了盐酸多西环素微丸,采用单因素考察和L9（34）正交设计筛选最优处方和工艺条件,再用包衣锅将微丸包肠溶衣,考察了微丸的粉体学性质及不同包衣增重微丸的体外释放情况。结果制得的盐酸多西环素肠溶微丸圆整度好,大小均匀,收率高。15%包衣增重的微丸在0.1 mol&#8226;L 1盐酸释放度＜10%,在pH6.8的缓冲液中释放度＞80%,体外释放较理想。结论该法制备工艺简单易行,重复性好,采用适当的包衣工艺,制得的盐酸多西环素肠溶微丸具备较理想的肠溶特征。     

地红霉素肠溶微丸的制备及处方优化

目的制备地红霉素肠溶微丸.方法采用离心造粒法制备地红霉素微丸,流化床进行肠溶包衣.结果制备的地红霉素肠溶微丸在pH 1.2盐酸溶液中2 h的释放度＜10%,在pH 6.8磷酸盐缓冲液中45 min的释放度＞80%.结论本方法制备地红霉素肠溶微丸工艺可行,质量可靠.     

复方盐酸二甲双胍肠溶缓释微丸的制备

目的：制备复方盐酸二甲双胍肠溶缓释微丸,并考察制剂体外释放特性。方法：利用底喷式流化床包衣设备,以空白丸芯、羟丙基甲基纤维素、单硬脂酸甘油酯、Eudragit NE30D、Eudragit?L100-55等制备盐酸二甲双胍肠溶缓释微丸;羟丙基甲基纤维素等制备盐酸吡格列酮胃溶微丸。结果：制备的盐酸二甲双胍肠溶缓释微丸在肠液中缓慢释放12 h,盐酸吡格列酮胃溶微丸在人工胃液中30 min溶出85%以上。结论：优选出的复方盐酸二甲双胍肠溶缓释微丸的制备工艺简单易行,重现性好,有望应用于工业化生产。     

酶控渗透泵型结肠定位微丸的制备及体外释放度考察

目的制备以果胶钙和醋酸纤维素为包衣材料,5-氨基水杨酸（5-ASA）为模型药物的酶触发渗透泵型结肠定位微丸,并考察其体外释药特征及释药机制。方法采用包衣锅法制备含药丸芯,选用L9（3）4正交实验设计,以体外释放度为评价指标优化包衣液处方及丸芯中渗透剂的用量,并进行体外释药模型拟合。结果制备5-ASA渗透泵酶触发微丸最佳工艺参数为：包衣增重25%;药物与NaCl（丸芯）比为3∶1;醋酸纤维素与果胶钙（包衣液）用量比为2∶3。所得微丸在人工胃液中2 h,人工小肠液中4 h累计释放率〈8%,人工结肠液12 h累计释放率〉70%,表明结肠定位性较为突出,且可以在结肠持续释放药物以维持局部药物浓度,进一步研究释药机理表明为零级释放。结论采用果胶钙与醋酸纤维素为包衣材料制备渗透泵酶触发结肠定位微丸可实现结肠定位作用。     

水蛭素的给药途径及其相关剂型研究进展

作为一种抗凝防栓良药，水蛭素（hirudin）特别是重组水蛭素的研究日益深入。针对水蛭素存在的一些缺陷，如半衰期短、临床应用时还存在一定的出血危险、预防动脉血栓的效果并不理想等，一些新的水蛭素衍生物、重组水蛭素模拟肽都在研发中，同时对水蛭素的不同给药途径／方式及新剂型的研究也在深入开展。现结合水蛭素的药动学／药效学特征、药理作用等方面的研究对水蛭素（包括重组水蛭素）的不同给药途径，尤其是非注射给药途径如口服、肺部、鼻腔、眼部给药等，以及相关剂型如大分子结合物注射给药缓释系统、壳聚糖一藻酸盐或PEG．藻酸盐微囊、鼻腔喷雾剂、缓释微丸、PLGA微球等的研究进展进行综述，以期为水蛭素的进一步临床应用提供科学依据。     

Novel pH-sensitive citrate cross-linked chitosan film for drug controlled release

Turbidimetric titration revealed that there were electrostatic attractive interactions between citrate and chitosan in the pH region of 4.3-7.6, depending on their degree of ionization. Citrate cross-linked chitosan film was prepared simply by dipping chitosan film into sodium citrate solution. The swelling ratio of citrate/chitosan film was sensitive to pH, ionic strength etc. Under acidic conditions, citrate/chitosan film swelled and even dissociated in the pH less than 3.5, and the model drugs (brilliant blue and riboflavin) incorporated in the film were released quickly (usually within 2 h released completely in simulated gastric fluid at 37 degrees C) while under neutral conditions the swelling ratio of citrate/chitosan film was less significant and the release rate of brilliant blue and riboflavin was low (less than 40% released in simulated intestinal fluid in 24 h). Sodium chloride weakened the electrostatic interaction between citrate and chitosan, and therefore facilitated the film swelling and accelerated drug release. The parameters of film preparation such as citrate concentration, solution pH etc. influencing the film swelling and drug release profiles were examined. The lower concentration and the higher pH of citrate solution resulted in a larger swelling ratio and quicker riboflavin release. To improve the drug controlled release properties of citrate/chitosan film, heparin, pectin and alginate were further coated on the film surface. Among them only the coating of alginate prolonged riboflavin release noticeably (for 80% of drug released the time was extended from 1.5 to 3.5 h with 0.5% w/v alginate used). The results indicated that the citrate/chitosan film was useful in drug delivery such as for the site-specific drug controlled release in stomach.     

4-氨基水杨酸钠结肠定位片的研究

目的制备一种新型口服结肠定位制剂，并考察其体外释药行为与犬体内的结肠定位特性。方法本试验选择4-氨基水杨酸钠作为模型药物，应用丙烯酸树脂Eudragit RL30D，RS30D和Eudragit FS30D分别作为缓释和肠溶层包衣材料，制得包衣片剂，使系统可依赖pH和时间双重机制释药。在体外释放试验中，系统在0.1 mol·L^-1盐酸溶液中运转2 h后，分别在pH为6.5，7.0或7.4的磷酸盐缓冲液中继续运转12 h。体内验证以放射性同位素锝（^99mTc）做标记，用γ-射线显影法来确定系统在胃肠道内的释药时间和位置。结果体外实验中，系统在0.1 mol·L^-1盐酸溶液中运转2 h后无药物释放，在pH高于6.5的介质中缓慢释药，介质的pH越高，药物释放越快。体内实验中， 包衣片在胃肠道上半部无药物释放， 到达结肠后开始释药； 而非包衣片在犬胃部即迅速崩解。结论本文采用的包衣材料使包衣片到达升结肠时开始释放药物，药物释放时间可达10 h以上。     

青蒿琥酯肠溶纤维的制备及体外释放研究

目的 制备青蒿琥酯肠溶纤维,考察其体外释放行为。方法 以尤特奇S100和L100-55为聚合物基质,添加一定量的青蒿琥酯,通过静电纺丝方法制备得到一系列载有青蒿琥酯的尤特奇纤维S100/ART和L100-55/ART。以紫外-可见分光光度法测定青蒿琥酯含量,计算S100/ART和L100-55/ART纤维的载药量和包封率,用SEM、TG和FTIR对其形貌、热稳定性和药物在纤维载体中状态进行表征,用溶出度测定仪以桨法测定其体外药物释放。结果 载药尤特奇纤维S100/ART和L100-55/ART结构均一,热稳定性良好,载药量可控,包封率高,药物以非晶态分散在纤维中;在pH=1.2人工胃液中释放的药物量较少,而在pH=6.8人工肠液中释放出大部分药物。在pH=1.2环境下S100/ART比L100-55/ART释放出更少的青蒿琥酯,在pH=6.8时释放出更多的青蒿琥酯。S100/ART和L100-55/ART亦具有一定的青蒿琥酯缓释作用。结论 载药尤特奇纤维S100/ART和L100-55/ART可以用作青蒿琥酯肠溶制剂,作为青蒿琥酯肠溶纤维,S100/ART比L100-55/ART效果更好。制备得到的青蒿琥酯肠溶纤维,可以用于青蒿琥酯的肠道靶向递送和释放,并有望提高青蒿琥酯的口服生物利用度。     

结肠定位壳聚糖包衣氟尿嘧啶脂质体的制备、形态与体外释放

目的探讨药物结肠定位壳聚糖包衣脂质体的制备、形态及其在体外释药特性。方法用罗丹明B异硫氰酸(RBITC)和Bodipy-PC分别标记壳聚糖和磷脂,用前体脂质体方法制备氟尿嘧啶脂质体,利用激光扫描共聚焦显微镜观察壳聚糖包衣脂质体的形态;考察壳聚糖包衣脂质体在人工胃液、人工肠液和人工结肠液中的释放。结果 脂质体包衣前后粒径分别为2.071和2.750 μm。壳聚糖能较好地包覆脂质体;3种脂质材料不同的包封率分别为99%,61%,72%。未包衣的脂质体在人工胃液中4 h已释放完全,而包衣脂质体在人工胃液4 h释放6.3%,在人工肠液中8 h仅释放6.8%,但在人工结肠液中释药明显加快,t1/2为3.63 h。结论结肠定位壳聚糖包衣脂质体制备可行,在人工结肠液中,体外释放符合Higuchi方程。     

双氯芬酸钠肠溶微丸型片剂的研制

本文制备了双氯芬酸钠肠溶微丸型片剂。以丙烯酸树脂EudragitNE30D和EudragitL30D-55不同比例的混合物作为衣膜材料，对不同粒径大小的双氯芬酸钠速释丸芯进行不同增重水平的包衣，并与不同压缩特性和用量比例的缓冲微丸混合，压片。所得的双氯芬酸钠肠溶微丸型片剂在人工胃液中2 h内累积释放百分数<10%，在人工肠液中1 h内累积释放百分数为(83±2.42)%。结果表明EudragitNE30D与EudragitL30D-55以一定比例混合制备得到适合压片的肠溶微丸，硬脂酸制备的缓冲微丸可用于微丸型片剂的制备。     

硝苯地平胃漂浮型延迟缓释微丸的制备

目的:制备硝苯地平胃漂浮型延迟缓释微丸并考察其体外漂浮行为.方法:挤出滚圆法制备漂浮型空白丸芯,空白丸芯上药法制备载药丸芯,分别以Surelease水分散体和Eudragit L30D-55为包衣材料,进行流化床包衣.采用正交试验设计对处方进行优化.结果:模拟人体胃肠道条件下溶出,自制漂浮型微丸在人工胃液中6 h累计释放小于10%,换人工肠液后12 h释放完全,体外漂浮10 h以上. 结论:自制微丸达到了漂浮和延迟缓释的效果.     

A Laminated Polymer Film Formulation for Enteric Delivery of Live Vaccine and Probiotic Bacteria

Live bacterial cells (LBCs) are administered orally as attenuated vaccines to deliver biopharmaceutical agents and as probiotics to improve gastrointestinal (GI) health. However, LBCs present unique formulation challenges and must survive GI antimicrobial defenses including gastric acid after administration. We present a simple new formulation concept, termed polymer film laminate (PFL). LBCs are ambient dried onto cast acid-resistant enteric polymer films that are then laminated together to produce a solid oral dosage form. LBC of a model live bacterial vaccine and a probiotic were dried directly onto a cast film of enteric polymer. The effectiveness at protecting dried cells in a simulated gastric fluid (SGF, pH 2.0) depended on the composition of enteric polymer film used, with a blend of ethylcellulose plus Eudragit L100 55 providing greater protection from acid than Eudragit alone. However, although PFL made from blended polymer films completely released low-molecular-weight dye into intestinal conditions (pH 7.0), they failed to release LBCs. In contrast, PFL made from Eudragit alone successfully protected dried probiotic or vaccine LBC from SGF for 2 h, and subsequently released all viable cells within 60 min of transfer into simulated intestinal fluid. Release kinetics could be controlled by modifying the lamination method.     

A Comparison of Aerosolization and Homogenization Techniques for Production of Alginate Microparticles for Delivery of Corticosteroids to the Colon

Alginate microparticles incorporating hydrocortisone hemisuccinate were produced by aerosolization and homogenization methods to investigate their potential for colonic drug delivery. Microparticle stabilization was achieved by CaCl₂ crosslinking solution (0.5 M and 1 M), and drug loading was accomplished by diffusion into blank microparticles or by direct encapsulation. Homogenization method produced smaller microparticles (45-50 μm), compared to aerosolization (65-90 μm). High drug loadings (40% wt/wt) were obtained for diffusion-loaded aerosolized microparticles. Aerosolized microparticles suppressed drug release in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) prior to drug release in simulated colonic fluid (SCF) to a higher extent than homogenized microparticles. Microparticles prepared using aerosolization or homogenization (1 M CaCl₂, diffusion loaded) released 5% and 17% of drug content after 2 h in SGF and 4 h in SIF, respectively, and 75% after 12 h in SCF. Thus, aerosolization and homogenization techniques show potential for producing alginate microparticles for colonic drug delivery in the treatment of inflammatory bowel disease.     

Alginate microspheres of isoniazid for oral sustained drug delivery

In the present study, spherical microspheres able to prolong the release of INH were produced by a modified emulsification method, using sodium alginate as the hydrophilic carrier. The shape and surface characteristics were determined by scanning electron microscopy using gold sputter technique. Particle sizes of both placebo and drug-loaded formulations were measured by SEM and the particle size distribution was determined by an optical microscope. The physical state of the drug in the formulation was determined by differential scanning calorimetry (DSC). The release profiles of INH from microspheres were examined in simulated gastric fluid (SGF pH 1.2) and simulated intestinal fluid (SIF pH 7.4). Gamma-scintigraphic studies were carried out to determine the location of microspheres on oral administration and the extent of transit through the gastrointestinal tract (GIT). The microspheres had a smoother surface and were found to be discreet and spherical in shape. The particles were heterogeneous with the maximum particles of an average size of 3.719mum. Results indicated that the mean particle size of the microspheres increased with an increase in the concentration of polymer and the cross-linker as well as the cross-linking time. The entrapment efficiency was found to be in the range of 40-91%. Concentration of the cross-linker up to 7.5% caused increase in the entrapment efficiency and the extent of drug release. Optimized isoniazid-alginate microspheres were found to possess good bioadhesion (72.25+/-1.015%). The bioadhesive property of the particles resulted in prolonged retention in the small intestine. Microspheres could be observed in the intestinal lumen at 4h and were detectable in the intestine 24h post-oral administration, although the percent radioactivity had significantly decreased (t(1/2) of (99m)Tc=4-5h). Increased drug loading (91%) was observed for the optimized formulation suggesting the efficiency of the method. Nearly 26% of INH was released in SGF pH 1.2 in 6h and 71.25% in SIF pH 7.4 in 30h. No significant drug-polymer interactions were observed in FT-IR studies. Dissolution and gamma-scintigraphy studies have shown promising results proving the utility of the formulation for enteric drug delivery.