5-氨基水杨酸结肠定位给药时控微丸的制备与体外释放

目的　用水分散体包衣技术制备5-氨基水杨酸结肠定位微丸给药系统。方法　以低粘度HPMC为内层溶胀材料,乙基纤维素水分散体Aquacoat为外层控释包衣材料,柠檬酸三乙酯为增塑剂,使用流化床包衣设备,制备时间控制的微丸,用释放度测定法研究微丸在不同pH介质中的释放度。结果　溶胀层的加入对制备时控微丸是必要的,药物是通过外膜破裂释放的,溶胀层厚度增加,释药时滞有一定程度的缩短,外层厚度增加以及增塑剂用量增加,可显著延长释药时滞。微丸释药随介质pH增加而加快,在模拟胃肠道pH情况下延迟5 h释药,之后10 h内释药完全。结论　通过调整内外层的包衣厚度可制备5-氨基水杨酸结肠定位给药微丸。     

多索茶碱脉冲控释微丸的研制

目的 研究多索茶碱脉冲控释微丸的制备工艺,并考察其释药性能。方法 以微晶纤维素为骨架材料采用挤出滚圆法制备载药丸芯,通过流化床包衣法分别覆上交联羧甲基纤维素钠作为溶胀层、乙基纤维素和羟丙甲纤维素作为控释层制备多索茶碱脉冲微丸,通过单因素考察筛选丸芯、溶胀层、控释层的处方组成对体外释药性能的影响。结果 以微晶纤维素、羧甲基淀粉钠和乳糖为添加剂可制得性能良好的高载药微丸。随着溶胀层厚度的增加,药物释放时滞变短,速率显著增加;随着控释层包衣厚度的增加,时滞延长,释药减慢;控释层中羟丙甲纤维素用量或分子量增加,时滞缩短;控释层中增塑剂用量增加,时滞延长。结论 所得包衣微丸具有良好的脉冲释药性能,有广阔的应用前景。     

硫酸沙丁胺醇脉冲控释微丸的制备

为制备硫酸沙丁胺醇脉冲控释微丸，采用挤出滚圆法制备载药丸芯，使用水溶胀性材料为内包衣溶胀层，乙基纤维素水分散体为外包衣控释层制备脉冲控释微丸，并考察溶胀层材料类型、十二烷基硫酸钠(SDS)含量、溶胀层和控释层包衣增重对药物释放的影响。结果表明．药物通过控释层衣膜破裂而释放，溶胀层材料类型、内包衣层中SDS的加入与否、溶胀层和控释层厚度对脉冲控释微丸的释药时滞和释药速率均具有显性影响。结论：采用低取代羟丙基纤维素为溶胀性材料．并加入1．5％SDS，共同作为内包衣层．制备的脉冲控释微丸，当内包衣层和外包衣层增重均为18％时。在模拟人体内胃肠道pH值变化条件下达到了时滞为4．5h，时滞后1．5h累积释药80％以上的脉冲释药效果。     

硫酸沙丁胺醇脉冲控释微丸的制备

目的制备硫酸沙丁胺醇脉冲控释微丸。方法采用挤出滚圆法制备载药丸芯 ,使用水溶胀性材料为内包衣溶胀层 ,乙基纤维素水分散体为外包衣控释层制备脉冲控释微丸 ,并考察溶胀层材料类型、十二烷基硫酸钠 (SDS)含量、溶胀层和控释层包衣增重量对药物释放的影响。结果药物通过控释层衣膜破裂而释放 ,溶胀层材料类型、内包衣层中SDS的加入与否、溶胀层和控释层厚度对脉冲控释微丸的释药时滞和释药速率均具有显著性影响。结论采用低取代羟丙基纤维素为溶胀性材料 ,并加入 0 0 5 2mol LSDS ,共同作为内包衣层 ,制备的脉冲控释微丸 ,当内包衣层和外包衣层增重均为 1 8%时 ,在模拟人体内胃肠道pH值变化条件下达到了时滞为 4 5h ,时滞后 1 5h累积释药 80 %以上的脉冲释药效果     

特布他林脉冲控释微丸体外释放度影响因素的研究

目的:考察硫酸特布他林脉冲控释微丸释放度的影响因素.方法:采用滚制法制备载药丸芯,使用水溶胀性材料为内包衣溶胀层,乙基纤维素水分散体为外包衣控释层制备脉冲控释微丸,并考察十二烷基硫酸钠(SDS)含量、溶胀层和控释层包衣增重量对药物释放的影响.结果:药物通过控释层衣膜破裂而释放,内包衣层中SDS的加入与否、溶胀层和控释层厚度对脉冲控释微丸的释药时滞和释药速率均具有显著性影响.结论:制备的脉冲控释微丸,在模拟人体内胃肠道pH值变化条件下达到了时滞为4.5 h,时滞后1.5 h累积释药80%以上的脉冲释药效果.     

5-氟尿嘧啶结肠定位释药微丸的研制及释药特性

采用流化床喷雾包衣法,研制了2种5-氟尿嘧啶结肠定位释药微丸.以羟丙甲纤维素为溶胀层,乙基纤维素水分散体为控制层,制备时间依赖型包衣微丸;另以肠溶型丙烯酸树脂Eudragit S100为包衣材料,制备pH依赖型微丸.测定了2种微丸在模拟胃肠道各区段pH环境下的释放度.结果表明,时间依赖型包衣微丸体外持续、缓慢释放;pH依赖型包衣微丸在模拟胃和小肠中上部pH的介质中基本不释药,在模拟回盲部区段pH介质中脉冲释药,即后者在体外显示出较好的结肠定位释药特性.     

阿莫西林脉冲释药微丸的研制

目的:制备阿莫西林脉冲释药微丸。方法:取空白丸芯分别以含药层、溶胀层(羧甲基淀粉钠)和控释层(乙基纤维素水分散体)顺序依次进行包衣制备阿莫西林脉冲释药微丸。采用紫外法和篮法考察溶胀层(12%、16%、20%)和控释层包衣增重(24%、28%、32%)及不同介质(水、盐酸、pH6.8磷酸盐缓冲液)对药物释放的影响。结果:溶胀层和控释层包衣增重对脉冲控释微丸的释药时滞和释放速率具有显著影响,药物释放情况不受介质pH值的影响;溶胀层和控释层包衣增重分别为16%、28%时制备的微丸时滞时间约为4h,时滞后4h累积释药率达到80%。结论:所制备的阿莫西林脉冲释药微丸具有体外脉冲释放作用。     

盐酸可乐定脉冲释药微丸的制备工艺研究

目的研究盐酸可乐定脉冲释药微丸的制备方法。方法采用挤出-滚圆工艺和流化床包衣法制备,用正交试验设计优化处方,考察产品的体外释放度。结果各考察因素均对药物的释放影响显著。优选工艺结果为,含药丸芯采用微晶纤维素,溶胀层材料采用低取代羟丙纤维素,控释层采用乙基纤维素水分散体,溶胀层和控释层包衣增重分别为10％和15％。制备的微丸时滞时间为4．2h左右,时滞后1h内累积释药百分率达到90％。结论盐酸可乐定微丸在体外具有有脉冲释药特性。     

扎来普隆脉冲释放微丸的制备及体外释放

目的制备扎来普隆脉冲释放微丸,并对其进行处方筛选与优化。方法以交联羧甲基纤维素钠(CC-Na)为内包衣溶胀层,乙基纤维素水分散体为外包衣控释层制备扎来普隆脉冲释放微丸,考察处方因素及介质pH对药物释放的影响,用Box-Behnken效应面设计法对处方进行优化。结果溶胀层厚度、组成及控释层包衣增重对微丸的时滞和释药速率均有显著影响。结论按Box-Behnken效应面设计法所得最优处方制备的微丸具有良好的延时脉冲释药效果。     

盐酸维拉帕米择时缓释微丸的研制及犬体内药代动力学

目的制备盐酸维拉帕米择时缓释微丸(VH-COERP)；研究VH-COERP在犬体内的药代动力学，并与市售的盐酸维拉帕米缓释微丸(VH-DRP)进行比较。方法采用空白丸芯上药法制备含药丸芯，并用流化床对其包衣，其中羟丙基甲基纤维素为内层包衣溶胀层，乙基纤维素水分散体为外层包衣控释层，通过改变内外层衣膜的厚度达到择时缓释的效果。用RP-HPLC测定6只Beagle犬口服VH-COERP后不同时间血浆中盐酸维拉帕米的浓度，并与VH-DRP比较，通过3P97程序计算药代动力学参数。结果溶胀层和控释层的包衣厚度、溶胀层中添加剂的种类会影响药物释放的时滞、释药行为以及最终释药量，所制得的微丸释放不受介质pH及后处理的影响。体外溶出经5 h时滞后缓慢释药达24 h。与VH-DRP相比，VH-COERP体内释药具有明显的时滞(4 h)，达峰时间明显延长(8 h)，相对生物利用度为(94.56±7.64)%。结论VH-COERP在体内外经过明显的时滞后均能缓慢释放，达到了睡前服药，凌晨发挥疗效的目的。     

5-氨基水杨酸结肠定位给药pH与时间同时控释小丸的制备与体外释放

目的:用水分散体包衣技术制备5-氨基水杨酸 (5-ASA) 结肠定位小丸给药系统.方法:以Eudragit(R) RL30D作为时间控释包衣内层,Eudragit(R) S水分散体作为pH控释外层,三乙酸甘油酯为增塑剂,使用流化床包衣设备,制备pH值与时间同时控释的小丸,用释放度测定法研究小丸在不同pH介质中的释放度.结果:小丸在模拟胃酸情况下不释药,在变换pH 7.5条件下9h内释药完全.Eudragit(R) S层保证小丸安全通过胃;而药物释放速度是由丸心、Eudragit(R) RL30D时间控释层来控制.利用小肠相对恒定的转运时间(3～4h)和小肠末端高pH(7～8),及不同Eudragit(R)聚合物的pH性质制备了较可靠的多剂量结肠给药系统.结论:通过调整内外层包衣厚度可制备5-ASA结肠定位释放小丸.     

A novel pH- and time-based multi-unit potential colonic drug delivery system. I. Development

A novel delivery system was developed for delivering drugs to the colon by selecting polymethacrylates with appropriate pH dissolution characteristics for the distal end of the small intestine and relying upon the relatively constant transit time of the small intestine. Pellets were prepared by powder layering of 5-aminosalicylic acid (5-ASA) on nonpareils (0.5-0.6 mm) in a conventional coating pan. Drug-layered pellets were coated with an inner layer of a combination of two pH-independent polymers Eudragit RL and RS (2:8), and an outer layer of a pH-dependent polymer, Eudragit FS. Scanning electron micrograph (SEM) pictures of the coated pellets showed the uniformity of both the coatings. The release profile of 5-ASA was studied in three phosphate buffers after a simulated gastric pre-soak for 2 h in pH 1.2 media. There was no drug release for 12 h at pH 6.5. There was a sustained release of 5-ASA for over 12 h both at pH 7.0 and 7.5 after a lag time at pH 7.0 and no lag time at pH 7.5. The release rate was faster at pH 7.5 than at pH 7.0. The delivery system demonstrated its potential for colonic delivery by resisting drug release until pH 6.5 and the combination of Eudragit RL and RS proved successful for the sustained delivery of 5-ASA at the expected pH of the colon.     

盐酸罗沙替丁醋酸酯脉冲控释微丸的研制

目的:制备盐酸罗沙替丁脉冲控释微丸(ROXPCP)。方法:取空白丸芯分别以含药层、溶胀层(含交联羧甲基纤维素钠)和控释层(含乙基纤维素水分散体)顺序包衣制备ROXPCP,通过考察不同类型空白丸芯、溶胀层材料及溶胀层与控释层的不同包衣增重对药物释放的影响来优选工艺,并进行处方验证试验。结果:各考察因素均对药物的释放影响显著。优选工艺结果为:空白丸芯采用蔗糖型,溶胀层材料采用交联羧甲基纤维素钠,溶胀层和控释层包衣增重分别为15%、24%。以此制备的微丸时滞时间为4h左右,时滞后4h内累积释药百分率达到80%。结论:所制备的ROXPCP具有体外脉冲控释作用。     

Erodible Time‐Dependent Colon Delivery Systems with Improved Efficiency in Delaying the Onset of Drug Release

To prepare swellable/erodible time‐dependent colon delivery systems with improved efficiency in delaying drug release, the application of an outer Eudragit® NE film, which contained the superdisintegrant Explotab® V17 as a pore former, was attempted. Tablet cores were successively spray‐coated with a hydroxypropyl methylcellulose (HPMC) solution and diluted Eudragit® NE 30 D, wherein fixed amounts of Explotab® V17 were present. The resulting two‐layer systems yielded lag phases of extended duration as compared with formulations provided with the HPMC layer only. By raising the thickness of the outer film, longer lag times were generally observed, whereas the effectiveness in deferring the drug liberation was reduced by increasing the pore former content, which, however, also resulted in a lower data variability. The films containing 20% of Explotab® V17 effectively and consistently prolonged the in vitro lag phase imparted by HPMC as a function of their thickness. Stored for 3 years under ambient conditions, a two‐layer system with this outer film composition pointed out unmodified release patterns. The same system proved to meet gastroresistance criteria when enteric coated. The results obtained indicated that the proposed strategy would enable the preparation of erodible delivery systems with reduced size, possibly suitable as multiple‐unit dosage forms. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3585–3593, 2014     

Characterization of 5-fluorouracil release from hydroxypropylmethylcellulose compression-coated tablets

Hydrogel compression-coated tablets are able to release the core drug after a period of lag time and have potential for colon-specific drug delivery based on gastrointestinal transit time concept. This study investigated the factors influencing in vitro release characteristics of a model drug 5-fluorouracil from hydroxypropylmethycellulose (HPMC) compression-coated tablets. The core tablet, prepared by a wet granulation compression method, was designed to disintegrate and dissolute quickly. To prepare the compression-coated tablets, 50% of the HPMC/lactose coat powder was precompressed first, followed by centering the core tablet and compressing with the other 50% of the coat powder. Release characteristics were evaluated in distilled water by using a Chinese Pharmacopoeia rotatable basket method. Effect of HPMC viscosity, lactose content in outer shell, and overall coating weight of outer shell on release lag time (T(lag)), and zero-order release rate (k) were studied. Release of drug from compression-coated tablets began after a time delay as a result of hydrogel swelling/retarding effect, followed by zero-order release for most of the formulations studied. HPMC of higher viscosity (K4M and K15M) provided better protection of the drug-containing core, showing increased release lag time and slower release rate. Incorporating lactose in outer shell led to decrease of T(lag) and increase of k. T(lag) and k are exponentially and linearly correlated to lactose content, expressed as weight percentage of the outer shell. Larger coating weight (W) of outer shell produced larger coating thickness (D) around core tablet, which resulted in increase in T(lag) and decrease in k. There was good fitting of a linear model for each of the four variables W, D, T(lag), and k. Hardness of the compression-coated tablets and pHs of the release media had little effect on drug release profile. It is concluded that the release lag time and release rate are able to be tailored through adjusting the formulation variables to achieve colon-specific drug delivery of 5-fluorouracil.     

Chitosan/Kollicoat SR 30D film-coated pellets of aminosalicylates for colonic drug delivery

The purpose of the study was to (i) prepare the chitosan/Kollicoat SR 30D film-coated pellets for colonic drug delivery, and (ii) evaluate the colonic delivery and efficacy of these coated pellets in the rat. The pellets were coated to different film thickness with chitosan/Kollicoat SR 30D formulations. In vitro drug release was assessed in simulated gastrointestinal (GI) tract conditions. Biodistribution of aminosalicylates (5-ASA) in GI tract and plasma was measured after oral administration of coated or uncoated 5-ASA pellets. Efficacy of the coated or uncoated 5-ASA pellets was tested in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced rat colitis model. Healing of induced colitis was assessed by measuring the myeloperoxidase activities, colon wet weight/body weight, and damage score. The coating was susceptible to bacteria digestion, resulting in an increase in the release of 5-ASA from the coated pellets. After administration of the coated pellets, the drug concentration in the large intestine was higher than those of uncoated pellets. In plasma, the observed mean C_max from the coated pellets was significantly lower than that of the uncoated pellets. Chitosan/Kollicoat SR 30D film-coated pellets could deliver the 5-ASA to the targeted site, providing effective treatment for inflammatory bowel disease. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:186–195, 2010