体外研究聚合物P(DLLA-co-TMC)的降解性能与释药行为

目的 研究P(DLLA-co-TMC)聚合物的体外降解性能与释药行为,且探讨该聚合物作为长效避孕释放载体的可行性.方法 以PBS溶液为溶媒研究P(DLLA-co-TMC)的降解性能;以P(DLLA-co-TMC)聚合物为载体制备含孕二烯酮的载药片,并通过蒸馏水浸泡载药片研究载药体系的体外释药行为.结果 P(DLLA-co-TMC)聚合物前期降解较慢,第30天和第90天失重率分别为10.0%和12.3%,后期降解速率较快,第120天的失重率为59.3%;P(DLLA-co-TMC)的载药片前期释药速率较大,出现"暴释现象",后期释药速率减缓并逐渐趋于平稳,第100天时累计释放率为5.64%.结论 P(DLLA-co-TMC)聚合物降解性能良好、释药效果明显,有望通过体内研究使含孕二烯酮的P(DLLA-co-TMC)聚合物载药系统应用于长效埋植避孕.     

体外研究聚合物P（DLLA—co—TMC）的降解性能与释药行为

目的 研究P（DLLA—CO-TMC）聚合物的体外降解性能与释药行为,且探讨该聚合物作为长效避孕释放载体的可行性。方法以PBS溶液为溶媒研究P（DLLA-CO-TMC）的降解性能;以P（DLLA—CO—TMC）聚合物为载体制备含孕二烯酮的载药片,并通过蒸馏水浸泡载药片研究载药体系的体外释药行为。结果P（DLLA-CO-TMc）聚合物前期降解较慢,第30天和第90天失重率分别为10．0％和12．3％,后期降解速率较快,第120天的失重率为59．3％;P（DLLA-CO-TMC）的载药片前期释药速率较大,出现“暴释现象”,后期释药速率减缓并逐渐趋于平稳,第100天时累计释放率为5．64％。结论P（DLLA-co-TMC）聚合物降解性能良好、释药效果明显,有望通过体内研究使含孕二烯酮的P（DLLA—CO—TMC）聚合物载药系统应用于长效埋植避孕。     

米非司酮对皮下埋植后子宫内膜雌、孕激素受体含量的影响

皮下埋置避孕剂是置于皮下硅胶管中左炔诺孕酮通过低剂量恒定释放至血液，发挥长效避孕作用的埋植剂。因其应用方便、长效、安全、可逆和无雌激素副作用，而具有良好的应用前景。由于其干扰正常月经周期，引起不规则子宫出血，成为终止使用的主要原因。米非司酮防治皮下埋植避孕后异常出血具有明显的疗效，能够减少出血／滴血天数，我们研究米非司酮对皮下埋植避孕者子宫内膜形态学与雌、孕激素受体的影响，探讨米非司酮的作用机理。     

青蒿琥酯硅橡胶埋植剂的制备与体外释放量的测试

制备青蒿琥酯硅橡胶棒埋植剂,进行体外释放量的测试,为动物(小鼠)试验提供样品及参考依据。用青蒿琥酯原料药与硅橡胶基质混炼均匀,分别加入交联剂和催化剂混匀,于手工挤出机上挤出一定直径的药棒,加热硫化,裁成一定长度的药棒。首先,测定含量,然后测定体外释放量。结果表明青蒿琥酯硅橡胶棒埋植剂平均含量为24.025mg/cm,体外(含药24mg/支)释放量:第一天达860ug,第20天为539ug,第30天仍有305ug的药释放。青蒿琥酯硅橡胶棒埋植剂制剂稳定,体外释放较缓慢稳定。     

左炔诺孕酮长效缓释埋植剂Ⅰ.结构特征的研究和体内外药物释放的长期观察

用生物降解性聚己内酯（ＰＣＬ）为载体制备女性抗生育药物左炔诺孕酮（ＬＮＧ）的长效皮下埋植胶囊。除可降解外,该胶囊具有微孔结构,重要技术特征是在ＰＣＬ中加入固体水溶性大分子ＰｌｕｒｏｎｉｃＦ６８（Ｆ６８）作为致孔剂,研究了加入致孔剂的工艺和微孔形成的原理,用核磁共振和扫描电镜等方法证明在亲水介质中Ｆ６８很快溶出,形成多微孔结构。体外和动物体内药物释放的研究证明该埋植剂具有零级释放动力学,可在体内长期维持稳定的药物释放量,每根３ｃｍ长的埋植剂在体内每天释放约２１微克ＬＮＧ,预期一次植入两根可有效地避孕两年     

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。     

强的松龙纳米微球缓释膜制备及缓释特性

背景:近年来将强的松龙应用于促进周围神经损伤后功能恢复取得了良好效果,但因半衰期短、局部应用血药浓度不稳定及较大的不良反应限制了其临床应用。目的:制备强的松龙纳米微球缓释膜并对其药物缓释特性进行检测。方法:采用反胶束乳化溶剂挥发法制备强的松龙纳米微球,对载药纳米微球的形态、粒径、载药量、包封率和体外释药行为等性质进行研究;同时将纳米微球与胶原、壳聚糖、大豆卵磷脂等膜材相结合,制得复合药膜,考察复合药膜的形貌、膜中材料的相互作用及药膜的体外释药行为。结果与结论:强的松龙纳米微球具有良好的微观结构,药物均匀分布于纳米微球中,纳米微球粒径均一,表面光滑,平均粒径500 nm,包封率达90%以上,体外缓释实验药物释放良好,存在一定的药物突释现象。观察球膜结合方法制得的复合膜,可见纳米微球均匀分散于复合膜中,复合膜微观结构良好,体外缓释实验见复合膜药物释放更加稳定,无明显药物突释现象出现,显示了良好的药物释放效果。表明通过反胶束乳化溶剂挥发法和球膜结合方法制备出的强的松龙缓释膜剂具有良好的药物缓释特性。     

国产避孕埋植剂Ⅱ型手术观察

我县于1993年9月开始采用国产避孕埋植剂Ⅱ型(以下简称埋植剂)作为长效避孕措施,共施手术108例,现报告如下: 材料与方法 一、材料:埋植剂系上海达华制药厂生产的18—甲基炔诺酮埋植剂Ⅱ型,由二根硅橡胶管组成,每根长4cm,外径2.4mm,内含孕激素,埋植24小时后即起避孕作用。     

基于各类型材料的宫内节育器、皮下避孕埋植剂及输卵管节育器

背景：明确避孕材料特点、技术手段及对生殖健康的影响,减少非意愿妊娠,降低人工流产率有着重大意义。目的：概述避孕材料的进展、现状及使用情况,综合分析宫内节育器、皮下避孕埋植剂、输卵管避孕材料特点、效果及不良影响,为育龄妇女选择安全可靠的避孕材料提供依据。方法：分别以“宫内节育器、皮下避孕埋植剂、输卵管避孕材料、生殖、健康、避孕方式”为中文关键词,检索中国知网全文数据库1985至2015年有关文献。以“intrauterine contraceptive device,subcutaneous contraceptive implants,oviduct contraceptive,materials,reproductive health,influences”为英文关键词,检索PubMed数据库1985至2015年有关文献,最终选择44篇文章进入结果分析。结果与结论：宫内节育器发展快、受众广,材料可靠、技术成熟,在已育妇女中具有较高的认知度和使用率。皮下埋植剂具有亲和性强,恒释、缓释效果好,操作简单方便等特点。输卵管避孕栓材料生物性、记忆性、耐受性强,具有无创、可复、安全和长效等优点。研究安全、可靠、无不良反应的避孕材料及方法,对保证妇女生殖健康具有积极的现实意义。 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     

长效避孕皮下埋制剂

长效避孕皮下埋制剂长效避孕埋植剂是近２０年来国际上兴起的一种新的避孕方法，它是避孕药物缓释系统，具有长效、高效、安全、简便、可逆的优点，适合大多数育龄妇女选择应用。该剂化学名称为左旋炔诺孕酮硅胶棒，是国家计生委“七五”期间组织研究的科技攻关项目，已由...     

硫酸庆大霉素-壳聚糖纳米粒的制备及性能评价

背景：庆大霉素珠链是较早用于治疗慢性骨髓炎的局部释药系统,但是由于其不能在体内降解吸收,须二次取出,因而限制了其的应用。因此国内外学者一直致力于可吸收材料负载抗生素装置的研究。 目的：制备负载庆大霉素的壳聚糖纳米粒,评价其性能,观察其体外释药行为及体外抗金黄色葡萄球菌的作用。 方法：以壳聚糖为药用载体,硫酸庆大霉素为模型药物,三聚磷酸钠为离子交联剂,采用离子交联法制备庆大霉素-壳聚糖纳米粒,在MH平板上进行抑菌实验,观察及评价其抑制金黄色葡萄球菌的作用。 结果与结论：制备的纳米粒形态为类圆形,粒径为40~70 nm,包封率及载药量分别为31.3%和15.4%,体外释药可持续14 d左右,对金黄色葡萄球菌的体外抑菌效果可持续25 d,在第5天纳米粒的抑菌作用达到最大,随着时间的推移,抑菌圈逐渐缩小。     

聚己内酯埋植剂的制备及药物通透性研究

目的制备聚己内酯（PCL）长效药物缓释制剂,优化药物缓释效果,并研究PCL埋植剂的药物通透性.方法 合成分子质量为（8～16）×104 u含有普朗尼克F68的PCL,用挤出法制备不同壁厚的PCL长效缓释埋植剂.将左炔诺孕酮（LNG）装入PCL管封装,制成LNG药囊.通过高效液相色谱法测定LNG的释放效果,考察PCL的分子质量及PCL管壁厚度对LNG通透性的影响.结果 当PCL分子质量为（8～16）×104u时,对LNG通透性无显著影响.PCL管壁厚在0.20～0.40 mm时,对LNG通透性亦无显著影响;当壁厚小于0.15 mm时,LNG通透性显著提高.结论 PCL埋植剂对LNG具有通透性,可通过改变PCL管壁厚度增加药物通透性.     

Poly(2-hydroxyethyl methacrylate) film as a drug delivery system for pilocarpine

This work investigates pilocarpine trapped in a matrix diffusion-controlled drug delivery system using hydrophilic inserts of Poly(2-hydroxyethyl methacrylate) (pHEMA) to ensure an increased bioavailability of pilocarpine and prolong the length of time in which the medication remains in the eyes of the test subjects. The physical and chemical properties of pilocarpine were investigated to elucidate the mechanism of drug-polymer interaction and the effect on drug release behavior of controlled release polymeric devices. In vitro release studies indicated that pilocarpine continued to be released from the inserts for a 24 h period. The results of intraocular pressure tests performed on albino rabbits were consistent with the observed in vitro behavior. The pressure decrease was significant for a period longer than 48 h. It confirms that the inserts, as sustainable releasing devices, are promising carriers for ophthalmic drug delivery systems.     

载表柔比星的壳聚糖纳米粒的制备及其特性研究

目的 制备经聚乙二醇修饰的壳聚糖纳米粒(PEG/CS NP),并负载表柔比星(EPI),研究载表柔比星的壳聚糖纳米粒(PEG/CS-EPI NP)体外释药性能.方法 应用阴离子凝聚法制备PEG/CS-EPI NP,透射电镜观察纳米粒的形态特征,激光粒度分析仪测定粒径大小,紫外分光光度法测定纳米粒的载EPI量,动态透析法考察载EPI纳米粒的体外释放特性.结果 当壳聚糖与三聚磷酸钠质量比为6∶1,壳聚糖与EPI质量比为8∶1时,制备的PEG/CS-EPI NP呈圆形或椭圆形,分散性良好,平均粒径(322.1±14.4)nm,载EPI量为(13.9±1.1)%,包封率(74.2±1.8)%,72 h累积释药率达(82.0±2.1)%.结论 采用阴离子凝聚法制备的PEG/CS-EPI NP形状规则、粒度分布均匀,具有较高包封率和较好缓释性能.     

Dexamethasone incorporating liposomes: an in vitro study of their applicability as a slow releasing delivery system of dexamethasone from covered metallic stents

Aim: To investigate the possibility of covering PET-covered commercially available metallic stents, with liposomal dexamethasone that will act as a slow releasing drug-depot at the site of interest. Methods: Large multilamellar (MLV), sonicated (SUV) and dried reconstituted (DRV) liposomes entrapping dexamethasone were prepared by thin film hydration, sonication and the DRV method, respectively, and applied on stents using a simple evaporation technique. Drug encapsulation and retention in liposomes were measured by HPLC. The presence of liposomes on the stent surface was confirmed by scanning electron microscopy, while the release of dexamethasone and lipid from the liposome-covered stent was evaluated under different conditions (flow rate, presence of plasma proteins), in an in vitro assembly that was developed to simulate in vivo conditions. Results: The release of dexamethasone from liposome-covered stents ranged from 25% to 50% after 48 h of incubation in buffer, depending on the type of liposome. The release was highest from stents covered with DRV liposomes. When increasing the flow rate from 2 to 6 ml/min a slight increase in release of drug was observed, while a higher release was measured when stents were incubated in plasma proteins. Liposome size does not affect liposome placement on stents. Conclusion: The basic characteristics that should be considered when preparing liposomes to cover stents should be their drug loading capacity and their stability under the conditions prevailing at the site of interest. By preparing the appropriate formulation, it is possible that liposomal drugs may be used to cover stents and serve as drug releasing depots at the site of interest. Further in vitro and in vivo studies are needed in order to exploit the possible applications of this methodology.     

Endothelial cells lining polyester fabric express pro-coagulant phenotypein vitro

The paper deals with the in vitro assessment of endothelial cell (EC) phenotype covering an albumin- and chitosan-coated polyester fabric and shows that resting ECs express a pro-coagulant phenotype by releasing a high von Willebrand factor level and expressing low thrombomodulin surface activity, despite maintaining an adequate response to stimulating agents.     

载基因壳聚糖纳米粒的研究

RNA干扰技术已被广泛应用于心血管领域,壳聚糖纳米粒以其良好的生物特性而作为基因递送载体成为现在研究的热点.就BNA干扰技术与纳米技术在心血管领域的应用及目前常采用的制备壳聚糖纳米粒的方法、影响质粒与壳聚糖纳米粒结合效率的因素、质粒壳聚糖复合物纳米粒转染的影响因素及体外释药行为作一简单的回顾.     

Molecular release from a polymeric microreservoir device: Influence of chemistry, polymer swelling, and loading on device performance

A polymeric microreservoir device for controlled-release drug delivery relies on the degradation of thin poly(lactic-co-glycolic acid) membranes that seal each reservoir to achieve pulsatile drug delivery. In vitro release studies in which the swelling of the reservoir membranes was measured indicate a correlation between the release times of various radiolabeled molecules from the devices and the time at which the maximum membrane swelling was observed. Varying the chemistry (lipophilicity/hydrophilicity) or molecular weight of the molecules loaded into the devices did not appear to affect the degree of membrane swelling that was observed, or the time at which the molecules were released from the devices. The amount of drug that was loaded into the reservoirs also did not appear to affect the observed release time of the drug from the device, a significant departure from the behavior of many matrix-type polymeric drug delivery systems.     

Endometrial safety with a low-dose intrauterine levonorgestrel-releasing system after 3 years of estrogen substitution therapy

OBJECTIVE: To evaluate the pharmacodynamic effects of a novel intrauterine drug delivery system, FibroPlant-levonorgestrel (LNG), on the endometrium in 24 postmenopausal women using estrogen substitution therapy (EST) to suppress climacteric symptoms. DESIGN: A 3-year non-comparative prospective clinical trial. SUBJECTS: The treatment with the FibroPlant-LNG intrauterine system (IUS), releasing 14 microg of LNG per day, was part of a regimen for estrogen substitution therapy in symptomatic postmenopausal women to prevent endometrial proliferation and bleeding. The majority of women received percutaneous 17 beta estradiol, 1.5 mg daily, or an equivalent dose by patch or orally, on a continuous basis. OUTCOME MEASURES: Menstrual pattern, endometrial histology and ultrasonographic evidence of endometrial suppression, after 3 years of use. RESULTS: The endometrial histology specimen showed profound endometrial suppression with glandular atrophy and stroma decidualization in all women. On transvaginal ultrasound, this corresponds with a thin endometrium (<5 mm) and clinically with a "bleed-free" menstrual pattern or amenorrhoea. CONCLUSION: The results of this 3-year study in 24 postmenopausal women using EST suggest that the FibroPlant-LNG IUS is effective in causing strong suppression of the endometrium during the entire period of EST. Target delivery in the uterine cavity could be the preferred route of administering a progestin to oppose estrogen stimulation of the endometrium.     

Management of patients with non-atypical and atypical endometrial hyperplasia with a levonorgestrel-releasing intrauterine system: long-term follow-up

OBJECTIVES: Levonorgestrel (LNG), delivered locally into the uterine cavity has a profound effect on the endometrium. The aim of the study was to use a LNG intrauterine system to treat non-atypical and atypical endometrial hyperplasia in women and to evaluate the long-term cure (remission) rate. METHODS: Each of the 20 women in the study, of whom eight were diagnosed with atypical hyperplasia, received a LNG-IUS, releasing 20 microg LNG/day. The study is a non-comparative study with long-term follow-up (range 14-90 months). RESULTS: All women developed a normal endometrium, except one asymptomatic woman with atypical hyperplasia who still had focal residual non-atypical hyperplasia at 3 years follow-up in the presence of a thin (< 4 mm) endometrium. CONCLUSION: Continuous intrauterine delivery of LNG appears to be a promising alternative to hysterectomy for the treatment of endometrial hyperplasia and could enhance the success rate when compared with other routes of progestagen administration as well as intrauterine progesterone delivery. The significant reduction of the PR expression observed during treatment with the LNG-IUS appears to be a marker for the strong antiproliferative effect of the hormone at a cellular level resulting in an inhibition of estrogen bioactivity and endometrial suppression.