单硝酸异山梨酯脉冲控释微丸的制备及体外释药影响因素的研究

制备单硝酸异山梨酯脉冲控释微丸并对影响释药的因素进行考察.采用挤出滚圆法制备载药丸芯,以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、溶胀层和控释层包衣增重、介质pH值等对药物释放的影响.结果表明,该包衣微丸可脉冲释药,药物释放情况不受pH值的影响,低取代羟丙基纤维素与羟丙基甲基纤维素以一定比例混合作为内包衣层,乙基纤维素水分散体为外包衣层制备的脉冲控释微丸,当内包衣层增重为15%和外包衣层增重为13%时,达到了时滞为5 h、时滞后1.5 h累积释药80%以上的脉冲释药效果.     

美斯地浓聚乳酸载药纳米粒的制备及体外释放

背景：美斯地浓临床常用于治疗重症肌无力,但其水溶性较强,半衰期短,生物利用度低,给药频率高,患者依从性差,因此提高其缓释作用对临床应用有重要意义。 目的：制备美斯地浓聚乳酸纳米粒,并考察其体外释放性能。 方法：以聚乳酸为载药材料,采用复乳液中干燥法制备美斯地浓聚乳酸纳米粒,运用单因素实验设计优化处方,动态透析法进行体外药物释放实验。 结果与结论：确定以二氯甲烷作为油相制备纳米粒,内水相与油相的比例1∶10,聚乳酸浓度6%,外水相聚乙烯醇浓度3%,美斯地浓投药量40 mg为最佳制备工艺,此条件制备的药物纳米粒包封率和载药率分别为(67.59±1.46)%和(4.31±0.17)%。美斯地浓聚乳酸纳米粒的平均粒径为937 nm,圆球形,表面光滑,未观察到粘连现象。与美斯地浓游离药物相比,美斯地浓聚乳酸纳米粒存在突释现象,之后呈现缓慢释放特性,72 h释放量为57.03%,提示成功制备美斯地浓聚乳酸纳米粒,具有缓释效应。     

5-氟尿嘧啶缓释剂制备及体外释药性能比较*

背景：5-氟尿嘧啶-聚乳酸-乙醇酸共聚物缓释微球在青光眼滤过术后抑制滤过泡的瘢痕化具有潜在应用价值,但微球制备程序复杂,微球载药量一般较低,且药物突释现象明显。 目的：比较乳化溶剂挥发法制备的5-氟尿嘧啶-聚乳酸-乙醇酸共聚物微球和喷雾成膜法制备的5-氟尿嘧啶-聚乳酸-乙醇酸共聚物缓释膜两种缓释剂的形态、载药量、体外释放规律,以探讨获得缓释效果较佳的5-氟尿嘧啶缓释剂制备方法。 方法：以聚乳酸-乙醇酸共聚物为载体,采用乳化溶剂挥发法制备5-氟尿嘧啶-聚乳酸-乙醇酸共聚物微球;用喷雾成膜法制备5-氟尿嘧啶-聚乳酸-乙醇酸共聚物缓释膜。 结果与结论：用乳化溶剂挥发法制备的微球外观圆整,粒径为(4 447.4±359.8) nm,载药量(8.67±0.37)%,包封率为(86.68± 1.92)%;用喷雾成膜法制备的缓释膜表面光滑平整,质量为(13.76±0.26) mg ,直径为6 mm ,厚度为(0.24±0.005) mm,载药量(23.76±0.37)%,包封率为(95.04±1.36)%。缓释剂制备过程未影响5-氟尿嘧啶的药物性能。微球体外释放突释明显,缓释膜的体外释放平稳持久,释放曲线符合Higuchi方程。结果表明缓释膜制备方法更简单易行,且能明显提高缓释剂的载药量,降低突释现象,同时延长药物的缓释时间。 关键词：聚乳酸-聚乙醇酸;5-氟尿嘧啶;微球;缓释膜;体外释放 doi:10.3969/j.issn.1673-8225.2012.08.022     

琥珀酸美托洛尔HPMC骨架片释放影响因素研究

以羟丙基甲基纤维素（HPMC）为骨架材料，乙基纤维素（EC）为阻滞剂，采用湿颗粒压片法制备琥珀酸美托洛尔亲水凝胶骨架片，考察HPMC用量、HPMC黏度、EC用量、制备方法、压片压力、释放介质及转速对琥珀酸美托洛尔（MS）骨架片体外释药的影响。结果表明，MS骨架片体外释药符合Higuchi方程，药物释放机制是骨架溶蚀和药物扩散的综合效应；HPMC用量与黏度、阻滞剂用量、制备方法、压片压力对释放速率均有显著性影响；释放介质的pH值及转速对释放速率无显著性影响。     

盐酸恩丹西酮缓释片的研制及体外释药特性

制备盐酸恩丹西酮缓释片并对影响释药的因素进行考察。以羟丙甲纤维素（HPMC）为骨架材料制备了盐酸恩丹西酮缓释片，通过正交设计试验优选最佳处方和工艺。对影响释药的因素，如HPMC的黏度和用量、填充剂的种类、制片工艺、润湿剂及释放介质pH等进行了考察。盐酸恩丹西酮缓释片体外释药符合Higuchi方程，HPMC的黏度、填充剂的种类及测定释放度的转速对该缓释片的释药几乎无影响，而制片工艺、润湿剂及释放介质pH值对缓释片释药影响较大。盐酸恩丹西酮缓释片在体外12h缓释效果较好。     

利福平/聚乳酸-聚羟基乙酸缓释微球的制备及特性

背景：虽然国内外有很多制备利福平/聚乳酸-聚羟基乙酸共聚物(poly lactic acid-glycolic acid copolymer,PLGA)微球的报道,但这些微球粒径多在10 μm左右,不适合与磷酸钙骨水泥复合制备成具有良好降解性的抗结核修复材料。 目的：制备大粒径利福平/PLGA缓释微球,观察其理化特性和体外缓释特性。 方法：以PLGA为载体,将利福平分散于PLGA的有机溶剂中,采用复乳溶剂挥发法制备利福平/ PLGA缓释微球。光镜和扫描电镜下观察微球的形态特征,测定微球平均直径和跨距,高效液相色谱法测定载药量和包封率,以溶出法和高效液相色谱法观察其体外释药特性,并拟合药物体外释放曲线建立曲线方程。 结果与结论：利福平/PLGA微球电镜观察呈圆球形,分散性好,粘连少,粒径分布集中,平均粒径(80.0±9.4) μm。载药量、包封率分别为(33.18±1.36)%,(54.79±1.13)%。体外缓释试验显示突释期内微球释放度为(14.66±0.18)%,前3 d累计释放度(18.09±0.45)%,到42 d体外累积释放度达到(92.17±1.23)%。提示利福平/PLGA微球具有良好的缓释效果,是一种较为理想的抗结核药物的载体材料和释放系统;PLGA是良好的药物缓释载体,可以用来制备载药缓释微球。     

戊二醛交联对壳聚糖/羟基磷灰石-庆大霉素缓释材料性能的影响

背景：交联是骨组织工程材料改性的一种常用方法,但目前仍缺乏交联剂对载药人工骨材料性能影响的相关研究与报道。 目的：研究戊二醛交联对壳聚糖/羟基磷灰石-庆大霉素载药人工骨材料力学性能、降解性能及体外药物缓释行为的影响。 方法：分别制备壳聚糖质量分数为10%,20%,30%的壳聚糖/羟基磷灰石-庆大霉素载药人工骨材料与戊二醛交联壳聚糖/羟基磷灰石-庆大霉素载药人工骨材料,检测各组材料的机械强度、吸水率、降解率及体外药物释放行为。 结果与结论：壳聚糖含量为10%,20%,30%壳聚糖/羟基磷灰石-庆大霉素的抗压强度分别为(10.16±1.17),(28.40±0.64),(23.28±1.30) MPa,经戊二醛交联后材料的抗压强度分别增大至(36.30±1.20),(51.60±2.08),(36.90±3.22) MPa。壳聚糖含量为10%,20%,30%壳聚糖/羟基磷灰石-庆大霉素交联后的吸水率与降解率均低于交联前。在体外缓释的第1天,30%壳聚糖/羟基磷灰石-庆大霉素的药物释放量为42.2%,材料经戊二醛交联处理后药物释放量降至33.6%,在随后的9 d,交联壳聚糖/羟基磷灰石-庆大霉素的总释放量均低于壳聚糖/羟基磷灰石-庆大霉素。表明戊二醛交联赋予了材料更好的生物稳定性,减缓了材料降解速率,显著改善了药物突释现象。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

壳聚糖复合微胶囊的研制及在维生素D2可控释放中的应用

研究了以壳聚糖为核心壁材，以乙基纤维素为包衣材料的控制释放体系，以．维生素D2为模型药物，采用喷雾干燥方法对其进行有效包覆，并用乙基纤维进行了涂覆。对不同制备方法的微胶囊的形态及释放效果进行了测试。并探讨了制备过程中壳聚糖浓度，壳聚糖分子量，乙酸浓度，维生素D2负载量等因素对药物释放方式的影响。所制备的微胶囊不仅在肠液中具有显著的缓释效果。并且大大降低了维生素D2在胃中的释放，达到肠溶的目的。     

氨酚氯雷伪麻双层片的处方设计

目的 研究亲水凝胶型骨架片氨酚氯雷伪麻双层缓释片的处方工艺,并对缓释片制备过程中的几点影响因素进行了初步探讨.方法 以氯雷他定的含量均匀度为考察指标,通过正交试验筛选出最佳处方工艺,并考察羟丙甲基纤维素(HPMC)用量对氨酚氯雷伪麻缓释片体外释放度的影响.结果 按最佳处方制备的氨酚氯雷伪麻缓释片,对乙酰氨基酚和硫酸伪麻黄碱释放度达到要求,氯雷他定含量均匀度符合要求.结论 按优化处方制备的氨酚氯雷伪麻缓释片符合相关规定.     

氨苄青霉素钠-乙基纤维素纳米微球的制备与表征

低分子量的乙基纤维素 (EC)包覆氨苄青霉素钠 ,采用纳米沉淀法制备氨苄青霉素钠 -乙基纤维素纳米微球。乙基纤维素 (EC)被 34% (w/ w)硝酸降解可以得到低分子量的乙基纤维素 ;FTIR,1 3C- NMR,元素分析 ,X-射线衍射分析证实在硝酸降解过程中 ,除了聚合度和结晶度降低之外 ,乙基纤维素的基本特性和基本结构没有变化 ;EC分子量的大小影响纳米微球的粒径大小、粒径分布和对药物的包覆效率。体外试验表明 ,氨苄青霉素钠 -乙基纤维素纳米微球对氨苄青霉素钠的缓慢释放为 3～ 10 h     

全反式维甲酸-聚酸酐长效缓释剂研制及其可行性

背景：如何提高全反式维甲酸疗效、稳定性和降低毒副作用是临床治疗所面临的最大问题。近年来用可生物降解的聚合物为材料,通过乳化包囊等分散技术将药物制备成微粒分散体系,用作缓释、控释注射剂的研究日益增多。 目的：研制全反式维甲酸-聚酸酐长效缓释微球肿瘤治疗剂,观察其体内外全反式维甲酸经时缓释变化规律。 方法：采用乳剂-扩散溶剂挥发法制备全反式维甲酸-聚酸酐长效缓释微球肿瘤治疗剂,扫描电镜检测微球外观及微球粒径,高效液相色谱法检测微球载药量、包封率及体内外释药量。 结果与结论：所制微球治疗剂光滑圆整,大小均一,平均粒径(154.42±26.76) nm,载药率(16.5±1.45)%,包封率(87.84±4.79)%;体外释放实验证明该微球治疗剂可持续释放全反式维甲酸约50 d,将其肌肉注射到大耳白兔体内,可稳定缓释全反式维甲酸近45 d。结果表明该微球治疗剂载药量及包封率均较高,体内外释药平稳并且具有明显的长效缓释作用。     

用于体外循环管材的新型醛基化海藻酸钠-地塞米松缓释涂层研究

研制新型醛基化海藻酸钠-地塞米松缓释涂层,筛选最佳涂层模式和涂层条件,对涂层稳定性、抗凝性能、缓释性能等进行评价。高碘酸钠氧化海藻酸钠得醛基化海藻酸钠（OSA）,酸化预处理聚氯乙烯（PVC）管材表面,聚乙烯亚胺涂抹经酸化预处理的PVC管材。聚乙烯亚胺涂层管材（PP）通过离子键直接交联地塞米松磷酸钠（DSP）制备DSP单涂层管材（PPD组）,PP通过离子键交联（PPI组）、共价键交联（PPC组）两种方式制备醛基化海藻酸钠-地塞米松磷酸钠复合涂层管材,同时设置空白对照（C组）。以正交实验筛选3种涂层模式的最佳涂层条件。对3种涂层管材进行涂层物定性和定量分析,抗凝、抗血小板、抗蛋白粘附、体外释放等性能进行评价研究,从而筛选最佳涂层模式。结果显示,PPD、PPI和PPC等3种涂层模式均能固定DSP,最佳固定密度分别为(333±075)、(163±076) 、(206±068)μg/cm2;复合涂层组（PPI和PPC）血小板粘附量（109/L）分别为（1388±189）和（1913±340）,均较C组（4138±320）显著减少;复合涂层组蛋白粘附量（mg/cm2）（HAS：（2986±1357）和（4667±320）,HPF：（3499±352）和（4567±379））,均较PPD组（HAS：（6873±426）,HPF：（7254±790））显著减少;体外释放方面PPC组明显优于PPI组。醛基化海藻酸钠-地塞米松复合涂层具备良好的血液相容性和生物相容性,通过共价交联的DSP能够达到缓释效果。     

地塞米松复合聚己内酯胶原支架材料的构建及性能评价

BACKGROUND: Tissue engineering scaffold materials have been widely used in all kinds of tissue and nerve repair, but there are many limitations and the effect is not good. OBJECTIVE: To construct a kind of tissue engineering scaffold material for the regeneration and repair of spinal cord injury. METHODS: The dexamethasonemicrospheres were prepared by emulsification-solvent evaporation. The comprehensive scores of encapsulation efficiency, drug-loading rate and yield were taken as the indexes. The effect of dosage of dexamethasone and polylactic acid-glycolic acid copolymer and mass fraction of polyvinyl alcohol on formulation process of dexamethasone sustained-release microsphere was inspected by orthogonal experiment. The characterization of microspheres was observed by scanning electron microscope. The nanofiber scaffold of compound dexamethasone microspheres was prepared by taking collagen protein and polycaprolactone as raw materials using electrospinning technology. The mouse bone marrow mesenchymal stem cells were co-cultured with the scaffold for 3 days. Cell morphology was observed by scanning electron microscope. Composite material was implanted into the defect of spinal cord in rats. RESULTS AND CONCLUSION: The optimal preparation process of dexamethasone sustained-release microspheres: dosage of dexamethasone was 10 mg, dosage of poly lactic acid-glycolic acid copolymer was 80%, mass fraction of polyvinyl alcohol was 0.5%. Appearance of dexamethasone microspheres was smooth, with a round surface. The encapsulation efficiency, drug-loading rate and yield of microspheres were (2.26±0.03)%, (83.62±0.21)% and (90.87±2.45)% respectively. The growth of mouse bone marrow mesenchymal stem cells was good on the surface of compound dexamethasone microspheres. There was no immunological reaction between the implant material and host, and the material was degraded gradually with time. These results demonstrate that the compound dexamethasone microsphere scaffold has good biocompatibility, which is a favorable kind of biological scaffold material.        

红外色谱分析二期高温高压处理Ceramage瓷聚体的单体转化率

背景：采用适当的方法提高材料的聚合程度,有利于改善其相应的理化性能。 目的：观察二期高温、高压处理对Ceramage瓷聚体单体转化率的影响。 方法：应用傅里叶变换红外色谱仪,分别测试经Solidilite聚合器固化的Ceramage体部材料和经过自控多用途树脂聚合仪在温度120 ℃,压力0.6 MPa,时间7 min条件下二次处理后的材料,在标准基线方法下得到各自的单体转化率并进行比较。 结果与结论：常规处理时Ceramage体部材料的单体转化率为(72.7±2.2)%,经二期热压处理后单体转化率为(75.4±1.5)%,提高幅度为2.7%。提示二期热压处理可以显著提高Ceramage体部材料的单体转化率,从而有可能改善材料的各项性能。     

Physical characterization of controlled release of paclitaxel from the TAXUS Express2 drug-eluting stent

The polymer carrier technology in the TAXUS drug-eluting stent consists of a thermoplastic elastomer poly(styrene-b-isobutylene-b-styrene) (SIBS) with microphase-separated morphology resulting in optimal properties for a drug-delivery stent coating. Comprehensive physical characterization of the stent coatings and cast film formulations showed that paclitaxel (PTx) exists primarily as discrete nanoparticles embedded in the SIBS matrix. Thermal and chemical analysis did not show any evidence of solubility of PTx in SIBS or of any molecular miscibility between PTx and SIBS. Atomic force microscope data images revealed for the first time three-dimensional stent coating surfaces at high spatial resolutions in air and in situ under phosphate-buffered saline as drug was released. PTx release involves the initial dissolution of drug particles from the PTx/SIBS coating surface. Morphological examination of the stent coatings in vitro supported an early burst release in most formulations because of surface PTx followed by a sustained slower release of PTx from the bulk coating. The in vitro PTx release kinetics were dependent on the formulation and correlated to the drug-to-polymer ratio. Atomic force microscopy analysis confirmed this correlation and further supported the concept of a matrix-based drug-release coating.     

Controlled release of swine semen encapsulated in calcium alginate beads

A quick and successful encapsulation method of swine spermatozoa is described: hydroxypropylmethylcellulose and calcium chloride were added to the sampled ejaculate swine sperm (sperm-rich fraction: creamy white) and then this suspension was dropped into an aqueous solution of sodium alginate. In order to obtain different capsule thicknesses, different calcium chloride concentrations were used. The influence of different formulations on in vitro spermatozoa release behavior and on the mechanical properties has been studied. In vitro sperm kinetics (motility and average velocity) have been determined. The results obtained from motility and average velocity tests of treated seminal material are promising, especially if the difficulty of preservation of swine spermatozoa compared to bovine sperm is considered. The different membranes obtained from the different calcium concentrations have had an influence on mechanical properties and on the release profile of spermatozoa from the capsules, and therefore, it is possible to modulate the release rate of the cells.