Preparation and evaluation of tamsulosin hydrochloride sustained-release pellets modified by two-layered membrane techniques

The aim of the present study was to develop tamsulosin hydrochloride sustained-release pellets using two-layered membrane techniques.Centrifugal granulator and fluidizedbed coater were employed to prepare drug-loaded pellets and to employ two-layered membrane coating respectively.The prepared pellets were evaluated for physicochemical characterization,subjected to differential scanning calorimetry(DSC)and in vitro release of different pH.Different release models and scanning electron microscopy(SEM)were utilized to analyze the release mechanism of Harnual■ and home-made pellets.By comparing the dissolution profiles,the ratio and coating weight gain of Eudragit■ NE30D and Eudragit■ L30D55 which constitute the inside membrane were identified as 18:1 and 10%-11%.The coating amount of outside membrane containing Eudragit■ L30D55 was determined to be 0.8%.The similarity factors(f_(2))of home-made capsule and commercially available product(Harnual■)were above 50 in different dissolution media.DSC studies confirmed that drug and excipients had good compatibility and SEM photographs showed the similarities and differences of coating surface between Harnual■ and self-made pellets before and after dissolution.According to Ritger-Peppas model,the two dosage form had different release mechanism.

Formulation Optimization Utilizing D-Optimal Experimental Design of Oral Capsules Containing Enteric-Coated Pellets of Lansoprazole and<i>in vivo </i>Bioequivalence

An optimized formulation of capsules containing Lansoprazole enteric-coated pellets using D-Optimal design with a polynomial statistical model were prepared by using Eudragit?L100 as an enteric coated polymer to provide resistance to simulated gastric acid dissolution in buffer media. D-Optimal experimental design was used to determine the optimal level for three coating layers that were applied to formulate the enteric-coated pellets including a drug loading layer, a sub-coating, and an outer enteric coating. Dissolution studies were performed on the prepared Lansoprazole capsules. Less than 5 percent of Lansoprazole was released in 60 minutes in an acidic dissolution medium (pH 1.2) and greater than 90 percent of active ingredient was released in the next 60 minutes in a buffer dissolution medium (pH 6.8). The Lansoprazole capsules were stable with no observable change in physico-chemical properties in accelerated and normal storage conditions for 6 and 18 months, respectively. The pharmacokinetic parameters Cmax, Tmax, AUC0-t, and AUC0-∞ were determined after administration of the D-Optimal design optimized capsules of LPZ to healthy beagle dogs and were statistically compared to Gastevin? capsules as a reference (KRKA, Slovenia) using the non-compartmental method with the aid of WinNonlin 5.2 software. The analysis of variance showed that the two formulations did not demonstrate bioequivalence using a 90% confidence interval range (80% - 120%) of Cmax, AUC0-t, and AUC0-∞. No significant difference in Tmax was found at the 0.95 significance level using the Wilcoxon signed-rank test. D-Optimal Experimental Design provided definitive direction for an optimal formulation of capsules containing enteric-coated pellets of lansoprazole loaded within the coating of pellets that provided similar bioequivalence to Gastevin.

Sticking of iron ore pellets in direct reduction with hydrogen and carbon monoxide:Behavior and prevention

A series of reduction experiments of iron ore pellets with hydrogen,carbon monoxide and their mixture were carried out in a laboratory scale shaft furnace.The sticking behavior accompanying reduction of iron ore pellets was investigated.And morphology of the sticking interface forming during reduction was analyzed by SEM equipped with EDS.In order to evaluate the effects of the temperature and gas composition on sticking properties,reduction of iron ore pellets were conducted at 800-1000 ℃.The results show that the sticking strength of the pellets increases with temperature,however,decreases with hydrogen content in reducing gas.For an efficient shaft furnace operation in direct reduction(DR),relative prevention of sticking such as coating of pellets was also developed to solve sticking problem.The results show that CaO is a suitable material for the coating method.

Preparation of gastro-resistant pellets containing chitosan microspheres for improvement of oral didanosine bioavailability

The purpose of this work was to introduce a new concept of coated pellets containing chitosan microspheres loaded with didadosine for oral administration,aiming at reducing the frequency of administration and improving the bioavailability by a suitable release profile.Chitosan microspheres were produced under fiuidized bed,followed by extrusion and spheronization to obtain pellets with a mean diameter of about 1 mm.The pellets were then coated with Kollidon VA64 and Kollicoat MAE100P in water dispersion to depict a sustained release profile.Conventional hard gelatine capsules were loaded with these pellets and tested in vitro for their release profile of didadosine.Dissolution testing confirmed that chitosan microsphere pellets provides appropriate sustained release up to 2 h behavior for didanosine.

Fenofibrate solid dispersion pellets prepared by fluid-bed coating:physical characterization,improved dissolution and oral bioavailability in beagle dogs

Solid dispersion of fenofibrate （FNB）, a poorly water-soluble drug, was prepared by a fluid-bed coating technique with PEG 6000 as the carrier. The physical state was characterized by DSC and X-ray powder diffractometry, which indicated the existence of fenofibrate in crystalline form in the solid dispersion. In vitro dissolution was studied in water containing 1% sodium lauryl sulfate, FASSIF and FESSIF. Significant enhancement in dissolution was achieved at PEG/FNB ratio of 4/1 with near complete dissolution within 30 min. Moderate improvement in dissolution rate was observed at smaller PEG/FNB ratios. Oral bioavailability was studied in beagle dogs after oral administration of fenofibrate solid dispersion pellets by monitoring fenofibric acid in plasma. The oral bioavailability of PEG/FNB 3/1 and 4/1 solid dispersion pellets was improved by 3.4 and 4.4-fold as compared to Lipanthyl, a commercial micronized fenotibrate formulation. There was a strong dependence of oral bioavailability on the in vitro dissolution rate. Good correlation was observed between the in vivo absorption fraction and the in vitro dissolution rate in each of the dissolution media, water containing 1% sodium lauryl sulfate, FASSIF and FESSIF. It could be concluded that PEG/FNB solid dispersion pellets were able to improve the dissolution and oral bioavailability of fenofibrate.

琥珀酸美托洛尔缓释微丸保护性衣层对其缓释片形成的影响与初步评价

目的评价羟丙纤维素及羟丙甲纤维素对琥珀酸美托洛尔缓释微丸的机械保护作用及差异。方法用不同分子量等级的羟丙纤维素和羟丙甲纤维素对琥珀酸美托洛尔缓释微丸进行包衣,通过检测微丸负压载荷、微丸完整性、体外溶出曲线,评价两种高分子材料对微丸的保护效果。通过制备了羟丙纤维素和羟丙甲纤维素薄膜并考察两种高分子材料薄膜的抗张强度、延展率、韧性和弹性模量等方面的机械性能差异。结果包被羟丙纤维素和羟丙甲纤维素的琥珀酸美托洛尔微丸,断裂载荷增加,压片后微丸完整性提高,机械性能提升,药物泄漏率降低。结论羟丙纤维素和羟丙甲纤维素保护层包衣对琥珀酸美托洛尔片释放单元有一定的机械保护作用,羟丙纤维素具有相对更高的保护能力,可以为多单元微丸药物释放系统的微丸保护策略提供借鉴。

基于事故容错燃料的高燃耗组件研究进展

针对核电高经济性和高安全性的目标,高燃耗(大于62 GWd/MTU)成为核燃料的发展趋势,然而,燃耗加深势必会导致芯块和包壳性能衰退甚至失效,引发安全隐患。本文首先回顾和梳理高燃耗状态传统UO_(2)芯块-Zr合金包壳核燃料系统所面临的挑战,如芯块边缘高燃耗结构(HBS)形成-迅速扩展、裂变气体释放份额增大、燃料棒内压增大、包壳腐蚀和吸氢量加剧以及失水事故(LOCA)工况芯块碎裂-迁移-重置现象等,并以相关问题为切入点厘清关键对策。然后,归纳总结现阶段核工业界近期型事故容错燃料(ATF)方案研究进展和成果,重点阐述主流Cr涂层锆合金包壳和大晶粒UO_(2)芯块ATF候选材料的关键服役性能,包括裂变气体释放、芯块-包壳接触压力、包壳水侧腐蚀及高温蒸汽氧化-淬火行为等。同时,对比分析Cr涂层锆合金包壳+大晶粒UO_(2)芯块相较于传统核燃料系统服役优势,尤其是高燃耗状态,研究表明近期型ATF方案在高燃耗项目中极具应用潜力。本文概述的内容有助于加深核工业工作者对高燃耗项目的理解,同时为我国自主研发ATF和高燃耗项目相结合提供参考,助力提升核电经济性、安全性与可靠性。

不同种衣剂配方对油菜生长的影响

本研究旨在提高油菜种子质量,实现种子标准化,并促进油菜增产。通过对油菜种子进行丸粒化包衣,探讨了不同药种比种衣剂包衣对油菜生长的影响。以甘蓝型油菜‘帆鸣1号’为试材,研究了不同药种比的丸粒化种衣剂NXY-1和瑞士悬浮种衣剂SLS包衣油菜种子对油菜苗期生长的影响。结果表明:在丸粒化种衣剂NXY-1中,最佳药种质量比为1:300,该配比的丸粒化种衣剂能促进种子出苗,冬前和盛花期干鲜重比最高,出苗后21 d氮磷含量,钾含量较对照相比最高,能有效提高叶绿素和赤霉素含量,效果均优于进口种衣剂SLS。

Mixed plastics waste valorization to high-added value products via thermally induced phase separation and spin-casting

Plastic waste is an underutilized resource that has the potential to be transformed into value-added materials.However,its chemical diversity leads to cost-intensive sorting techniques,limiting recycling and upcycling opportunities.Herein,we report an open-loop recycling method to produce graded feedstock from mixed polyolefins waste,which makes up 60%of total plastic waste.The method uses heat flow scanning to quantify the composition of plastic waste and resolves its compatibility through controlled dissolution.The resulting feedstock is then used to synthesize blended pellets,porous sorbents,and superhydrophobic coatings via thermally induced phase separation and spin-casting.The hybrid approach broadens the opportunities for reusing plastic waste,which is a step towards creating a more circular economy and better waste management practices.

基于DEM的3种匀盘结构的玉米种子丸粒化数值模拟

【目的】解决种子丸粒包衣质量不高、种粉间混合均匀度差的问题。【方法】分析3种匀盘结构的丸粒化机制,模拟玉米种子丸粒化过程;基于离散元软件EDEM建立玉米种子丸粒化的仿真模型,将离散系数作为评价指标研究3种匀盘结构的转速、振动频率、振动幅度对种粉间混合均匀度的影响;通过Design-Expert软件建立玉米种子离散系数的二阶回归方程进行方差分析。【结果】3种匀盘结构的最优工艺参数组合分别为:匀盘Ⅰ的转速为50 r/min,振动频率为10 Hz,振动幅度为6 mm;匀盘Ⅱ的转速为60 r/min、振动频率为15 Hz,振动幅度为6 mm;匀盘Ⅲ的转速为70 r/min,振动频率为20 Hz,振动幅度为8 mm。【结论】当匀盘Ⅰ的转速为56.3 r/min、振动频率为11.5 Hz,振动幅度为5.8 mm时,玉米种子丸粒化效果最优,为玉米种子包衣技术提供理论依据自我评价。

我国种子丸粒化加工技术现状(综述)

介绍了当今种子加工领域丸粒化种子加工技术的研究概况 :丸粒化包衣的类型、丸粒化包衣的作用 ,同时比较详细地说明丸粒化包衣一般使用的包衣材料、包衣用粘合剂、一些包衣材料的功能、几种丸粒化加工方法以及种子丸粒化加工工艺流程等。同时分析了国内外在种子丸粒化加工技术上的差异 ,提出该研究所今后的研究发展方向。

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。

水性包衣工艺制备红霉素肠溶微丸的研究

目的 采用丙烯酸树脂水性包衣工艺制备红霉素肠溶微丸。方法 采用切线喷型流化床包衣设备和肠溶丙烯酸树脂水性包衣材料对红霉素微丸进行包衣 ,考察药物体外释放度和稳定性 ,并进行人体生物利用度研究。结果 包衣微丸具有良好的肠溶效果 ,pH1.2盐酸溶液中释放量小于 10 % ,pH6 .8磷酸盐缓冲液中药物迅速释放完全。微丸体外稳定 ,工艺重现性好。 2 0例健康志愿者体内药动学证明 ,自制肠溶胶囊与进口对照品生物等效 ,相对生物利用度 (10 0 .5 9± 19.47) %。结论 水性包衣方法制备红霉素肠溶微丸工艺可行 ,制剂质量稳定。

新型丙烯酸树脂肠溶包衣材料的合成与应用

用自由基溶液共聚合的方法合成了３种有不同羧基含量的ｐＨ敏感性甲基丙烯酸甲酯（ＭＭＡ）和甲基丙烯酸（ＭＡＡ）二元共聚物以及ＭＭＡ，ＭＡＡ与丙烯酸丁酯（ＢＡ）三元共聚物；将合成物用作萘普生微丸的包衣材料进行包衣，测定萘普生包衣微丸在不同ｐＨ缓冲溶液中的溶出度。结果表明：通过改变反应单体中ＭＡＡ的含量，可制备有不同酸值的丙烯酸树脂；包衣微丸的萘普生溶出度与溶出介质的ｐＨ值和包衣材料的酸值密切相关，萘普生在其用作包衣材料制备的微丸中只有在较高ｐＨ值的缓冲介质中才有较高的溶出度和溶出速率；ＭＭＡ，ＭＡＡ和ＢＡ的三元共聚物本身具有可塑性。

吲哚美辛肠溶包衣微丸的制备及其释放度的研究

目的：制备吲哚美辛肠溶包衣微丸，考察其释放特性。方法：采用正交试验设计筛选微丸的处方、工艺参数，用滚动凝聚法制备素丸，用沸腾包衣技术制备微丸，通过溶出试验考察其释放特性。结果：以优选处方、工艺制备的微丸在规定的酸性介质中几乎不释放，而在磷酸盐缓冲液中则释放８０％以上。结论：本品处方合理，制备工艺简单，能达到肠溶目的。

离心造粒法制备盐酸二甲双胍缓释微丸

在盐酸二甲双胍微丸外依次包滑石粉隔离层和Eudragit缓释层,并考察两者对体外释放度的影响。采用EudragitNE30D-L30D55(20∶1)包衣所得微丸表现出缓释特征,在体内与参比制剂生物等效。

奥美拉唑肠溶微丸胶囊的制备

目的制备奥美拉唑肠溶微丸胶囊。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,制备成奥美拉唑肠溶微丸,并对其处方和工艺进行优化,将肠溶微丸装入普通胶囊制成奥美拉唑肠溶微丸胶囊。结果将奥美拉唑、羟丙基甲基纤维素(5 mPa.s)、无水碳酸钠、聚山梨酯-80、二甲基硅油和水混合制成主药层包衣溶液,以无水碳酸钠作为隔离层的碱性调节剂,EUDRAGITL30D-55作为肠溶包衣材料,自制的3批奥美拉唑肠溶微丸胶囊在人工肠液中45 min的释放度分别为(98.0±1.2)%、(95.3±4.0)%和(94.3±1.8)%。结论以肠溶微丸技术制备奥美拉唑肠溶胶囊,工艺可行,重复性良好,质量稳定可靠。

不同包衣条件下银杏缓释微丸体外释放考察

目的考察不同包衣条件下银杏缓释微丸的体外释放。方法采用单因素考察及正交设计法。结果以丙烯酸树脂EudragitRL30D和EudragitRS30D为包衣材料,质量比为4∶1,包衣增重10 % (w) ,增塑剂的用量为2 0 % (w ) ,无需熟化,可满足2 4h缓释的要求。结论包衣量。

盐酸青藤碱缓释组合微丸系统的研究

目的:建立线性叠加组合微丸释药模型,以盐酸青藤碱为模型药,进行模型验证和预测。方法:采用挤出滚圆法制备速释丸,流化床底喷包衣制备肠溶和缓释微丸。根据各种微丸的释药机制选择适宜的释放模型,利用Matlab的曲线拟合工具箱进行拟合,根据相关统计参数选择最佳拟合方程,将各种微丸释药方程进行线性叠加,得到组合微丸理论释药方程。根据预期的24h释放要求,利用Matlab解析线性不等式或线性方程组,预测各种微丸所需用量并实际组合,将释放试验结果与预测值进行对比验证。结果:对组合系统释药行为的数学解析结果显示,预测值(组合微丸理论释药方程)与实测值较接近,说明组合系统的释药行为是可控的,能较好地预测组合各种微丸所需的用量以满足不同释放行为的需要。结论:有预见性地组合不同的微丸或为不同组合比例提供了一种设计缓释系统的新方法。

丸化型水稻种衣剂对直播稻生长及产量的影响

用丸化型种衣剂包衣水稻种子,通过大田直播试验,研究了丸化型水稻种衣剂对水稻生长及产量的影响,并与进口种衣剂进行了比较.结果表明,丸化型种衣剂具有促进直播水稻萌发与生长、提高秧苗综合素质、成秧率及抗逆境能力,有效防治病虫害,增产等作用.与对照相比,包衣处理成秧率、根系活力和脯氨酸含量分别提高17.4%、23.3%和34.8%;对主要病虫害防效达79.1%～97.6%;增产11.4%.其综合效果优于对比试验所用的进口种衣剂.