骨架型别嘌醇缓释微丸的制备及其质量评价

目的：优化骨架型别嘌醇缓释微丸的处方及制备工艺,并对其进行质量评价。方法：采用挤出滚圆法制备微丸;以得率为指标,考察骨架材料、致孔剂、崩解剂及制备工艺过程的滚圆速度和滚圆时间对释放度的影响,并验证处方;以圆整度及粒度分布、流动性、脆碎度为指标,对其进行质量考察。结果：优化的处方以微晶纤维素（Mcc）为骨架材料,以乳糖为致孔剂,交联羧甲基纤维素钠为崩解剂,控制滚圆速度为50Hz,滚圆时间为20rain。通过调节MCC、乳糖和崩解剂的配伍使用,可以起到调节药物释放的作用,得到释放度符合要求的微丸。验证试验所得微丸的平均圆整度为10．2,粒度分布在22~26目最多,占95．63％;平均休止角为23．15,流动性良好;脆碎度为0．08％;其他各项质量指标良好。结论：所选处方及制备工艺合理、可行,所制备微丸质量良好。     

挤出滚圆法制备吲哚美辛缓释微丸

目的:制备吲哚美辛(IMC)缓释微丸并考察其体外释放行为。方法:采用挤出滚圆法制备微丸,以微丸收率为考察指标,优选挤出速率、滚圆速度和滚圆时间参数水平;以体外释药曲线为考察指标,崩解剂微晶纤维素(MCC)、骨架材料羟丙甲基纤维素(HPMC)和润湿剂水的处方用量为因素,设计单因素试验筛选辅料处方,并进行处方验证试验及其释药机制研究。结果:优选的较佳工艺参数为挤出速度65r.min-1、滚圆速度650r.min-1、滚圆时间3min;优选的处方为MCC19、HPMC20、水6mL;验证试验表明所制得的IMC缓释微丸释放度重现性好且符合缓释制剂的要求,其释药机制为药物扩散和骨架溶蚀的混合型机制。结论:挤出滚圆法制备IMC缓释微丸方法可行,且制剂具有良好的体外缓释效果。     

阿奇霉素缓释微丸体外释药影响因素考察

考察影响阿奇霉素缓释微丸体外释药的各种因素,为阿奇霉素缓释制剂的研制提供实验依据。方法选用微晶纤维素为空白丸芯,将阿奇霉素制成缓释微丸,通过测定体外释放度,考察EC粘度及增重、致孔剂用量、释放介质pH值对阿奇霉素缓释微丸体外释药速率的影响。结果 EC粘度、包衣增重、致孔剂用量、释放介质pH值对释药速率有显著影响。结论选用适宜包衣材料及致孔剂,调节包衣增重,可制备具有理想释药行为的阿奇霉素缓释微丸。     

Box-Behnken效应面法优化烟酸缓释微丸处方

目的应用Box-Behnken效应面法对烟酸缓释微丸进行处方优化,以达到12 h缓释效果。方法以微晶纤维素(MCC)、乙基纤维素(EC)和硬脂酸的用量为考察因素,以微丸收率和体外释放度为评价指标,采用Box-Behnken试验设计,通过方程拟合建立因素和响应值之间的数学模型以优化处方,并对体外释药数据进行方程拟合,探讨其释药机制。结果最佳处方为MCC用量50.92%,EC用量5.49%,硬脂酸用量10.93%,试验的实测值与模型的预测值之间偏差较小。药物的体外溶出具有明显的缓释作用,体外释放曲线符合Higuchi和Riger-Peppas方程。结论 Box-Behnken效应面法可用于烟酸缓释微丸的处方优化,所建模型具有较好的实用性和预测能力。     

阿奇霉素缓释微丸体外释药影响因素考察

目的 考察影响阿奇霉素缓释微丸体外释药的各种因素,为阿奇霉素缓释制剂的研制提供实验依据。方法 选用微晶纤维素为空白丸芯,将阿奇霉素制成缓释微丸,通过测定体外释放度,考察EC粘度及增重、致孔剂用量、释放介质pH值对阿奇霉素缓释微丸体外释药速率的影响。结果 EC粘度、包衣增重、致孔剂用量、释放介质pH值对释药速率有显著影响。结论 选用适宜包衣材料及致孔剂,调节包衣增重,可制备具有理想释药行为的阿奇霉素缓释微丸。     

他克莫司口服自微乳骨架缓释微丸的制备及其释药机制研究

目的 制备他克莫司自微乳骨架缓释微丸,并探讨其释药机制。方法 采用星点设计-效应面法筛选他克莫司自微乳最优处方,在此基础上,采用挤出滚圆技术,以微晶纤维素(microcrystalline cellulose,MCC)为吸附剂和填充剂、乙基纤维素(ethyl cellulose,EC)与硬脂酸(stearic acid,SA)为骨架材料,以5%羟丙基甲基纤维素(hypromellose,HPMC)溶液为黏合剂,制备他克莫司自微乳骨架缓释微丸,并考察其体外溶出情况。结果 他克莫司自微乳最优处方为Crodamol EO∶Solutol HS15∶Transcutol P=15%∶52.5%∶32.5%。骨架缓释微丸最优处方为MCC用量为45%,EC∶SA用量比为3∶2,5%HPMC溶液用量为12 mL。制得的他克莫司自微乳骨架缓释微丸符合市售他克莫司缓释胶囊的体外释放标准,释药机制为溶蚀与扩散相结合。结论 优选的处方稳定可行,他克莫司自微乳骨架缓释微丸体外释放符合预期目的。     

扎托布洛芬缓释微丸的制备及释放特性

目的 以不同处方制备扎托布洛芬缓释微丸,考察包衣层处方对药物释放的影响及其释药特性.方法 采用空白丸芯流化床混悬液上药法制备扎托布洛芬载药微丸,以HPMC为隔离材料包隔离衣、以乙基纤维素水分散体为缓释材料,考察不同种类、用量的致孔剂以及包衣增重对药物释放行为的影响.结果 以10％ HPMC为致孔剂、缓释衣层包衣增重为4.5％时,制得的微丸具明显的缓释效果,其释放曲线符合一级动力学,且批内及批间重复性良好.结论 制得的扎托布洛芬缓释微丸具有较理想的体外缓释效果.     

双嘧达莫缓释微丸的研制及其体外释放特性

目的：制备双嘧达莫pH非依赖型缓释微丸，使药物释放不受胃肠道pH值变化及个体差异的影响。方法：采用固体分散技术，将药物与联合载体（Eudragit L、EC和PEG 6000）的混和有机液喷包于微晶纤维素（MCC）空白丸芯上形成膜衣骨架型共沉淀物结构，以正交设计进行处方优化，考察不同pH条件下缓释微丸的释放特性。结果：缓释微丸的体外药物释放呈pH非依赖型释放特征，符合一级动力学方程。结论：具有溶解度pH依赖性的药物，以固体分散技术处理，通过不同性质载体的调节作用，可以制成pH非领带型的缓释制剂。     

地拉罗司分散片的处方筛选研究

目的：筛选和优化地拉罗司分散片的处方。方法：以崩解时限和30min累积溶出度为考察指标,以稀释剂微晶纤维素（MCC）和乳糖用量、崩解剂交联聚维酮（PVPP）内加质量比、助溶剂十二烷基硫酸钠（SDS）用量为因素,以L（3。）正交试验表对试验方案进行设计,对地拉罗司分散片处方进行筛选,并进行处方验证。结果：优化处方为MCC用量为12．5％、乳糖用量为27．5％、PVPP添加比例为18％（内加）、SDS用量为1．0％;验证试验中地拉罗司分散片在120S内完全崩解,平均30min累积溶出度为86．O％,与普通片相比具有较大优势。结论：按该处方制备的地拉罗司分散片溶出度、崩解时限等各项指标均符合要求。     

烟酸缓释微丸的制备及体外释放度考察

目的:制备24 h烟酸缓释微丸,考察其体外释放度。方法:使用离心造粒机,采用空白丸芯粉末上药法制备烟酸载药素丸;使用国产流化床包衣机,以乙基纤维素为包衣材料进行包衣。考察包衣处方因素、热处理条件和释放介质对释放度的影响。结果:烟酸素丸圆整度良好,光滑;16～20目收率约90%。包衣增重、致孔剂类型以及用量是影响药物释放的关键因素。烟酸缓释微丸在pH 1.2的盐酸溶液中释放较快,在水,pH 4.5的醋酸盐缓冲溶液,pH 6.8和pH 7.9的磷酸盐溶液中释放无明显区别。以乙基纤维素包衣增重9%,以PEG 4000为致孔剂用量37%,得到的缓释微丸具备体外24 h缓释特征。结论:该缓释微丸的体外释放符合缓释制剂要求。     

尼群地平缓释微丸的制备及释药机理探讨

目的制备尼群地平缓释微丸,并对其释药机制进行探讨。方法采用挤出滚圆法制备尼群地平缓释微丸,并进行体外释放度试验。将释放度数据分别代入各药物释放模型,计算各模型的拟合方程及相关系数,并进行比较。结果尼群地平缓释微丸的释药过程符合Higuchi平面扩散方程、Baker-Lonsdale球形扩散方程和Ritger-Peppas方程,相关系数r>0.99。结论本文制备的尼群地平缓释微丸的释药机制以扩散为主,释药速度主要由药物的扩散速率决定。     

Tableting of coated ketoprofen pellets

Ketoprofen pellets were prepared by the method of extrusion-spheronization, and a film coating of guar gum and Eudragit NE was applied to drug cores using pan technology. In an attempt to design a tablet which, on peroral administration, disintegrates rapidly, releasing intact coated pellets which maintain the integrity of both the cores and their release retarding membrane, Avicel PH101, lactose DT and magnesium stearate were used as excipients to prepare tablets comprising ketoprofen pellets or microcapsules. Preliminary experiments were conducted on uncoated pellets to determine the optimum compression force required to prepare tablets of satisfactory mechanical properties and release profiles. Coated pellets containing ketoprofen were used to investigate the influence of excipients levels. In an attempt to minimize problems associated with blending and segregation of microcapsules and excipients, placebo spheres of Avicel PH101 and lactose DT were produced by the method of extrusion-spheronization. The use of placebo spheres produced tablets with improved drug content uniformity and disintegration time. The tensile strength of such compacts was enhanced by excluding magnesium stearate from the mixes without significant problems of sticking or picking. The use of placebo pellets resulted in significant damage to drug microcapsules, which was attributed to the higher hardness and density of the excipients pellets. The role of membrane coating in protecting the drug core during compression was also evaluated.     

Formulation of ranitidine pellets by extrusion-spheronization with little or no microcrystalline cellulose

The present study was concerned with the feasibility of formulating ranitidine into pellets with a range of alternative excipients in place of microcrystalline cellulose (MCC). Eight ranitidine formulations employing two or more of the excipients lactose, barium sulfate, glyceryl monostearate, and MCC were processed by extrusion-spheronization, and characterized according to a series of physico-mechanical and dissolution criteria. Formulations containing lactose produced unsatisfactory pellets of wide size distribution and irregular shape, whereas formulations incorporating barium sulfate and glyceryl monostearate with or without MCC resulted in relatively spherical pellets of narrow size distribution and good mechanical properties. Ranitidine release was found to be rapid and virtually complete within 15 min, regardless of the pellet formulation. A direct relationship was observed between the concentration of MCC in the formulation and the properties of the pellets. In general, the higher the concentration of MCC, the rounder, stronger, and less friable the pellets. However, even pellets without MCC were also successfully prepared with a superior size distribution and shape over those with MCC. Overall, these results confirm that ranitidine can be formulated into pellet dosage forms with little or no MCC by the extrusion-spheronization process.     

Tableting of coated ketoprofen pellets

Ketoprofen pellets were prepared by the method of extrusion-spheronization, and a film coating of guar gum and Eudragit NE was applied to drug cores using pan technology. In an attempt to design a tablet which, on peroral administration, disintegrates rapidly, releasing intact coated pellets which maintain the integrity of both the cores and their release retarding membrane, Avicel PH101, lactose DT and magnesium stearate were used as excipients to prepare tablets comprising ketoprofen pellets or microcapsules. Preliminary experiments were conducted on uncoated pellets to determine the optimum compression force required to prepare tablets of satisfactory mechanical properties and release profiles. Coated pellets containing ketoprofen were used to investigate the influence of excipients levels. In an attempt to minimize problems associated with blending and segregation of microcapsules and excipients, placebo spheres of Avicel PH101 and lactose DT were produced by the method of extrusionspheronization. The use of placebo spheres produced tablets with improved drug content uniformity and disintegration time. The tensile strength of such compacts was enhanced by excluding magnesium stearate from the mixes without significant problems of sticking or picking. The use of placebo pellets resulted in significant damage to drug microcapsules, which was attributed to the higher hardness and density of the excipients pellets. The role of membrane coating in protecting the drug core during compression was also evaluated.     

白术黄连微丸结肠靶向胶囊的制备及体外释放研究

目的 将中药"白术黄连方"制备成以胃溶微丸和肠溶微丸为基础的结肠靶向胶囊,优化其处方组成和制备工艺,考察其体外释放特性.方法 采用单因素实验和正交实验法优化微丸的处方组成和工艺参数.用挤出-滚圆技术制备素丸,流化床底喷方式进行包衣,考察隔离衣增重、肠溶衣中聚合物比例、增塑剂用量和包衣增重对肠溶微丸释放行为的影响,并对其...     

Controlled drug release from Gelucire-based matrix pellets: experiment and theory

The aim of this work was to elucidate the underlying drug release mechanisms from lipidic matrix pellets, using theophylline and Gelucire 50/02 as model drug and carrier material, respectively. Pellets were prepared by two different techniques: melt-solidification and extrusion-spheronization. The effects of different formulations and processing parameters on the resulting drug release kinetics in 0.1N HCl and phosphate buffer pH 7.4 were studied and the obtained results analyzed using adequate mathematical models in order to get further insight into the underlying mass transport mechanisms. The type of preparation technique was found to strongly affect the underlying drug release mechanisms. Drug release from pellets prepared by the melt-solidification method was primarily controlled by pure diffusion, whereas drug release from pellets prepared by the extrusion-spheronization method was purely diffusion-controlled only at early time points. After approximately 2h, the pellets started to disintegrate, resulting in decreased diffusion pathway lengths and, thus, increased drug release rates. Furthermore, the curing conditions significantly affected the theophylline release kinetics, whereas varying the initial drug loading from 20 to 50% (w/w) resulted only in a slight increase in the relative drug release rate. Interestingly, the effects of the size of pellets prepared by the melt-solidification method on the resulting drug release kinetics could be quantitatively predicted using an analytical solution of Fick's second law of diffusion. These predictions could be verified by independent experiments.     

西罗莫司自乳化给药系统及其固体化研究

目的 筛选西罗莫司自微乳给药系统处方,并制备微丸。方法 通过溶解度试验确定助乳化剂、油相和乳化剂的选择范围;采用三元相图法、星点设计和效应面法对该体系优化制备工艺及处方。采用挤出-滚圆法制备不同处方的西罗莫司自微乳化微丸。结果 西罗莫司自微乳微丸的最终处方为:西罗莫司0.4%、油酸聚乙二醇甘油酯9.3%、聚氧乙烯-35-蓖麻油15.9%、二乙二醇单乙基醚8.0%、微晶纤维素49.8%、乳糖13.3%、羧甲基淀粉钠3.3%。溶出度试验显示,西罗莫司固体自微乳微丸在水中的溶出度远大于市售西罗莫司片,在0.4%SDS溶液中,两制剂的溶出度相当。结论 自微乳化给药系统可用于提高西罗莫司的体外溶出度。     

Preparation and evaluation of pellets using acacia and tragacanth by extrusion-spheronization

Background and the purpose of the study

Extrusion-spheronization is an established technique for the production of pellets for pharmaceutical applications. In this study, the feasibility and influence of the incorporation of acacia, by itself and in combination with tragacanth, on the ability of formulations containing 2 model of drugs (ibuprofen and theophylline) to form spherical pellets by extrusion-spheronization was investigated.

Material and Methods

Formulations containing different ratios of acacia and tragacanth (8:2, 9:1, and 10:0) and different drug concentrations (20%, 40%, and 60%) were prepared, on the basis of a 3² full factorial design. Pellet properties, such as aspect ratio, sphericity (image analysis), crushing strength and elastic modulus (mechanical tests), mean dissolution time, and dissolution profiles were evaluated. The effect of particular factors on responses was determined by linear regression analysis.

Results

The sphericity, drug release rate, and the mechanical properties of the pellets were affected by the amounts and types of the drugs, and the ratio of the gums. Acacia, relative to tragacanth, produced pellets with higher mechanical strength and a faster drug release rate. Addition of small amounts of tragacanth to ibuprofen formulations resulted in matrix pellets with slow drug release.

Conclusion

The results showed that acacia and tragacanth can be used successfully as 2 natural binders in the pellet formulations.     

Evaluating tamsulosin hydrochloride-released microparticles prepared using single-step matrix coating

The purpose of the present study was to prepare matrix extended release pellets of diclofenac potassium using low amount of release-modifying agents and, to compare its performance in vivo with coated pellets and matrix tablets. Coated pellets were prepared by extrusion-spheronization, followed by double layer coating using different polymers separately. Matrix pellets with different release rate in vitro were prepared by extrusion-spheronization with different kinds of retarding materials. Bioavailability study of different coated pellets revealed that the drug concentration in plasma of beagle dogs was too low to be detected and, implied that the drug was nearly not released from the preparations before reaching colon due to the appearance of lag time in the dissolution process. The phenomenon indicated that slow-release pellets of diclofenac potassium perhaps should not be developed as double membrane-controlled type. The AUC((0 → 24)) of the immediate release pellets, the two matrix pellets and the reference were 304.4, 87.7, 204.1 and 179.1 μg h/ml, respectively. The C(max) of the formulations mentioned above were 46.3, 13.0, 33.6 and 32.1 μg/ml, respectively. All the matrix formulations, including the reference, exhibited incomplete absorption due to the short small intestine transit time and termination of the drug release in the colon because of its limited solubility. The matrix pellets were bioequivalent with the commercially available tablet (Voltaren(?)) although the drug release in vitro of the former was much faster, while the bioavailability of the matrix pellets with similar in vitro drug release to the reference (Voltaren(?)) was much lower than the latter. The results perhaps was caused by lacking of physical robustness in the waxy tablet formulation, resulted in low wet strength and easily destroyed by the mechanical destructive forces and finally introduced faster drug release rate in vivo. It is apparent that preparations with similar performance in vitro may differ a lot in vivo because of the differences in drug release rate in vivo owing to various wet strengths of excipients contained, especially for sustained release products.