顺铂白及胶微球的制备及栓塞特性

目的:顺铂白及胶微球的制备及栓塞特性的考察.方法:采用乳化-冷凝-化学交联技术制备顺铂白及胶微球,利用正交试验设计法优选顺铂白及胶微球的制备条件和工艺;对微球的载药量、大小及分布、形态及表面状态、体外释放以及栓塞特性等进行了研究.结果:微球平均粒径为(108.3±35.2)μm,顺铂含量为(20.7±6.2)%;电镜扫描显示,微球球形圆整,表面粗糙;微球经60Co辐射灭菌要求;其体外释药实验表明顺铂白及胶微球有明显的缓释性能;动物栓塞试验以及对肿瘤患者的栓塞治疗均显示良好的栓塞效果.结论:该微球制备工艺可行,制得的顺铂白及胶微球可达到介入栓塞和化疗的双重目的,适用于肝癌患者的介入栓塞治疗.     

顺铂壳聚糖微球犬肝动脉栓塞的研究

研究了顺铂壳聚糖微球经犬肝动脉栓塞后体内药动学过程、靶向特征及栓塞效果,并初步应用于临床。经肝动脉给药材24h,栓塞组肝组织顺铂浓度为顺铂溶液组的2.92倍,而其血浓峰值及药时曲线下面积(AUC)均低于溶液组。血管造影显示,微球栓塞后肝脏外周血管明显减少,病理切片可见栓塞部位组织坏死。微球栓塞后GPT,GOT及ALP有一过性升高,3周后基本恢复正常;微球临床初步应用效果较好。结果表明,以壳聚糖为载体材料制备的微球是一种良好的癌症化疗栓塞剂。     

顺铂明胶微球的研制及相关生物学特性

目的 研制包裹有顺铂的颗粒型可降解性栓塞剂。方法 采用改良的双相乳化冷凝聚合法制备顺铂明胶微球，以原子吸收光谱分析为基础，测定顺铂明胶微球的包裹率、载药率及体外释药特性。结果 顺铂明胶微球颗粒直径均匀，药物包裹率91％。载药率17.4%，体外4b内缓释96％。结论 本法制得的顺铂明胶微球性质稳定，微球降解速率及药物释放速度基本符合临床要求。     

顺铂聚乳酸微球的药物释放特性及肝动脉栓塞研究

对顺铂聚乳酸微球进行了体外药物释放和家犬肝动脉栓塞研究。该微球粒径范围为50～200μm,平均粒径为115.76±35.94μm,顺铂含量为37.16%(W/W);体外药物释放机制符合Higuchi方程;肝动脉栓塞后8h,肝组织顺铂浓度高达21.55±12.18μg/g,明显高于肝动脉灌注顺铂组:3.16±0.09μg/g(P<0.05);肝动脉栓塞组的顺铂血浓峰值、各取血点浓度及曲线下面积AUC皆低于肝动脉灌注顺铂组。可望达到提高栓塞部位的药物疗效,降低全身毒副反应的作用。     

栓塞制剂—顺铂微球的研究

本文用非生物降解材料乙基纤维素制备了顺铂微球,用于肿瘤的栓塞治疗。进行的体外制剂学研究、动物体内外毒性考察、栓塞实验及人体临床应用结果显示:顺铂微球具有显著的栓塞肿瘤血管之效果,且可缓解,降低全身毒性,实现靶向给药之目的。     

靶向给药系统—顺铂肝动脉栓塞微球的研究

用改良的油/油(o/o)溶媒蒸发法制备的顺铂-乙基纤维素非生物降解微球作为肝动脉栓塞化疗的新剂型。试用 TLC 和 UV 比值(A_(301nm)/A_(247nm)结合,301nm 处的吸光度进行了药物含量及体外稳定性的检测。兔肝动脉灌注顺铂微球后血清铂浓度的上升与下降速度均较灌注顺铂溶液缓慢,兔灌注顺铂微球后,组织铂含量较低,衰减速度也较慢。对原发性肝癌病人用顺铂微球和临床常规栓塞治疗的比较表明,疗效有显著差异。     

顺铂泛影葡胺微球的制备及其体外释药特性考察

<正>顺氯氨铂简称顺铂[1],是金属配合物抗肿瘤药物,主要用于肺癌、甲状腺癌、食管癌、膀胱癌等治疗。但其肾毒性、骨髓抑制等不良反应较大,影响了治疗效果。本文通过制备含显影剂的顺铂泛影葡胺微球,研究微球的体外释放,并考察其释放机制,同时也为其他药物制备微球提供借鉴作用。1试药与仪器顺铂原料药(锦州九泰药业有限责任公司);顺铂泛影葡胺微球(自制);Visking透析袋(美国);LA-10A型高效液相     

肝动脉栓塞用顺铂白蛋白微球的研究

按正交设计筛选乳化热固化法制备顺铂白蛋白微球的最佳工艺,并对影响微球粒径大小和体外释药速率的诸多因素进行了研究。该微球粒径范围为50.8～256μm。平均粒径为148.46μm,药物含量为51.16%(W/W)。兔肝动脉栓塞后,与对照组相比铂的分布半衰期延长336%,消除半衰期延长123%,体内最高血浓仅为对照组的30%。肝组织顺铂量显著增加(P<0.01),肾组织药物量明显降低(P<0.05),体内外相关性研究表明顺铂白蛋白微球体外累积溶出百分率与兔体内药物吸收分数呈显著相关(P<0.01)。     

去甲斑蝥酸钠白蛋白微球的研究

选择去甲斑蝥酸钠为模型药物,对含药白蛋白微球的制备、载药性能、形态、表面状态、大小及分布、体外释药、冷冻干燥、⁶⁰Co辐照灭菌和稳定性等进行了研究。结果表明,去甲斑蝥酸钠微球的平均大小为0.43±0.12μm,药物含量为20.34～26.75μg/ml,包入率21.9～26.4%,体外释药符合Higuchi方程,冷冻干燥和⁶⁰Co辐照对微球无影响且能达到无菌要求,放置3个月后微球的稳定性良好。     

卡铂碳包铁纳米壳聚糖微球的制备和特征

目的制备卡铂碳包铁纳米壳聚糖微球,检测其性能,并与卡铂纯铁纳米壳聚糖微球进行比较。方法以吸附药物的碳包铁纳米磁粉为磁性内核,壳聚糖为基质,卡铂为负载药物,采用反相微乳法制备卡铂碳包铁纳米壳聚糖微球。卡铂纯铁纳米壳聚糖微球的制备方法相似,不同的是以无吸附药物能力的纯铁纳米磁粉为磁性内核。检测和比较两种纳米药物微球的形态、粒径、磁响应性、载药量、包封率和体外释药。结果两种药物微球的球形圆整,平均粒径(210±26)nm,粒径分布150~300nm,磁响应性强。碳包铁纳米微球的载药量(11.15±1.03)%,纯铁纳米微球载药量(9.21±1.10)%。碳包铁纳米微球1,2,3,4d的体外释药量分别为60%、74%、84%、92%;纯铁纳米微球1,2d的释药量分别为81%,91%。结论通过活性碳吸附和物理基质包裹双重物理机制载药载药的卡铂碳包铁纳米壳聚糖微球不但载药量高,而且释药速度平稳。多重机制的有机结合是优化纳米微球性能的有效方法。     

Preparation,characterization and performance evaluation of neomycin-HSA microspheres

Abstract

Human serum albumin microspheres containing neomycin sulphate were prepared using emulsion polymerization and polymer dispersion techniques. The many variables which may affect the shape, size, stability, release of the drug from the microspheres such as internal phase to external phase volume ratio, human serum albumin content, stirring rate, polymer content and stabilizing agent concentration, were studied. Unlike the microspheres prepared by the emulsion polymerization technique, polymer dispersion stabilised microspheres were uniform in size and shape with a narrow range of size distribution. In vitro release of neomycin sulphate from albumin microspheres was studied using the dialysis cell method. The drug release from microspheres followed Q versus (t)^?1/2 linear relationship. The in vivo distribution studies on prepared microspheres revealed that the localization takes place preferably in lung tissues, liver, spleen and kidney and is found to be dependent on the microsphere size. On administration of microspheres of 3-6 μm size, approximately 55 per cent of administered drug could be localized in the lungs.     

Formation and Characterization of Cisplatin-Loaded Poly(benzyl 1-glutamate) Microspheres for Chemoembolization

Chemoembolization using microspheres of 100- to 200-µm is a useful way to treat primary and secondary hepatic tumors. In a search for a better embolic material, we described in detail the preparation and characterization of a poly(benzyl 1-glutamate) (PBLG) microspheres containing cisplatin (CDDP). We determined the optimal experimental conditions to produce spherical free-flowing microspheres that were able to release drug content (44% [w/w] CDDP) in a sustained manner. We found that solvent viscosity played a key role in determining the resulting microsphere characteristics. Microscopic studies showed that increasing the polymer concentration (to 10% [w/v]) and the viscosity of the organic phase produced microspheres with uniform drug distribution. Increasing polymer concentration also markedly improved drug incorporation efficiency. In vitro release studies revealed that the release of CDDP was a function of drug loading; microspheres with a higher amount of entrapped CDDP had a slower release rate. This observation and the fact that CDDP/ PBLG microspheres did not show burst effect at higher loading is ascribed to the formation of uniformly distributed drug crystal networks within the polymer matrix. The favorable properties of the CDDP/PBLG system warrants its further evaluation on experimental animal models for the treatment of hepatic tumors.     

Preparation and evaluation of 188Re sulfide colloidal nanoparticles loaded biodegradable poly (L‐lactic acid) microspheres for radioembolization therapy

Radioembolization with radioactive microspheres has been an effective method for the treatment of liver lesions. The aim of this study was to prepare carrier‐free ¹⁸⁸Re loaded poly (L‐lactic acid) (PLLA) microspheres through ¹⁸⁸Re sulfide colloidal nanoparticles (¹⁸⁸Re‐SC nanoparticles). The formation of ¹⁸⁸Re‐SC nanoparticles was confirmed by ultraviolet‐visible spectrophotometry. The labeling yield of ¹⁸⁸Re‐SC nanoparticles was verified using the RTLC method. Effects of synthesis parameters on morphology and size of prepared ¹⁸⁸Re‐sulfide colloidal‐PLLA microspheres (¹⁸⁸Re‐SC‐PLLA microspheres) were studied by scanning electron microscopy. In vitro stability of ¹⁸⁸Re‐SC‐PLLA microspheres was investigated in normal saline at room temperature and in human serum at 37°C. In vivo distribution studies and gamma camera imaging were performed in healthy BALB / c mice. The microspheres could be prepared with sizes between 13 and 48 μm (modal value 29 μm) and radiolabeling efficiency >99%. After incubation, the microspheres were found stable in vitro up to 72 hours. The biodistribution after intravenous injection in healthy BALB / c mice showed high accumulation in lung as a first capture pathway organ for microsphere followed by great retention over 48 hours for these microspheres. These data show that ¹⁸⁸Re‐SC‐PLLA microspheres are suitable candidate for clinical studies.     

肝动脉栓塞微球的研究

本文用乳化聚合法制备了明胶和聚乙烯醇两种微球,通过正交试验,确定了制备特定粒径微球的最佳工艺条件。以氟脲嘧啶和甲氨喋呤为模型药物,对明胶微球的体外溶出特性进行了探讨,结果表明,经复合交联能延缓药物的体外溶出。实验狗灌注微球前后的肝动脉造影表明术后肝动脉分枝有不同程度的减少;病理检查表明微球沉积于肝血窦前的肌性小动脉;γ-射线扫描也证实锝标记微球在肝内的特异性分布。     

Formulation and evaluation of stomach-specific amoxicillin-loaded carbopol-934P mucoadhesive microspheres for anti-Helicobacter pylori therapy

The purpose of this research was to formulate and systemically evaluate in vitro and in vivo performances of mucoadhesive amoxicillin microspheres for the potential use in the treatment of gastric and duodenal ulcers, which were associated with Helicobacter pylori. Amoxicillin mucoadhesive microspheres containing carbopol-934P as mucoadhesive polymer and ethyl cellulose as carrier polymer were prepared by an emulsion-solvent evaporation technique. Results of preliminary trials indicate that quantity of emulsifying agent, time for stirring, drug-to-polymers ratio and speed of rotation affected the characteristics of microspheres. Microspheres were discrete, spherical, free flowing and showed a good percentage of drug entrapment efficiency. An in vitro mucoadhesive test showed that amoxicillin mucoadhesive microspheres adhered more strongly to the gastric mucous layer and could retain in the gastrointestinal tract for an extended period of time. A 3² full factorial design was employed to study the effect of independent variables, drug-to-polymer-to-polymer ratio (amoxicillin-ethyl cellulose-carbopol-934P) (X₁) and stirring speed (X₂) on dependent variables, i.e. percentage mucoadhesion, drug entrapment efficiency, particle size and t₈₀. The best batch exhibited a high drug entrapment efficiency of 56%; mucoadhesion percentage after 1 h was 80% and the particle size was 109 µm. A sustained drug release was obtained for more than 12 h. The drug-to-polymer-to-polymer ratio had a more significant effect on the dependent variables. The morphological characteristics of the mucoadhesive microspheres were studied under a scanning electron microscope. In vitro release test showed that amoxicillin released slightly faster in pH 1.2 hydrochloric acid than in pH 7.8 phosphate buffer. In vivo H. pylori clearance tests were also carried out by administering amoxicillin powder and mucoadhesive microspheres to H. pylori infectious Wistar rats under fed conditions at single dose or multiple dose(s) in oral administration. The results showed that amoxicillin mucoadhesive microspheres had a better clearance effect than amoxicillin powder. In conclusion, the prolonged gastrointestinal residence time and enhanced amoxicillin stability resulting from the mucoadhesive microspheres of amoxicillin might make a contribution to H. pylori complete eradication.     

Formation of alginate microspheres produced using emulsification technique

This study investigated the formative process of alginate microspheres produced using an emulsification technique. The alginate microspheres were produced by cross-linking alginate globules dispersed in a continuous organic phase using various calcium salts: calcium chloride, calcium acetate, calcium lactate and calcium gluconate. The size, shape, drug content and Ca²⁺ content of the microspheres were evaluated. The tack, viscosity and pH of the calcium salt solution and percentage of Ca²⁺ partitioned into the organic phase were determined. Microscopic examination of the test emulsion at various stages of the emulsification process was also carried out. The propensity of cross-linking reaction was found to be dependent on successful collision between alginate and calcium salt globules. Examination of the characteristics of microspheres indicated that the formed microsphere was a resultant product of alginate globule clustering. The growth propensity of microspheres was promoted by the higher rate and extent of cross-linkage which was governed by the pH, tack and/or Ca²⁺ content of the cross-linking solution, as well as the dissociation constant and diffusivity of the calcium salt. Overall, the amount of free Ca²⁺ cross-linked with alginate in the formed microspheres was in the following order: calcium acetate > calcium chloride + calcium acetate > calcium chloride + calcium gluconate; calcium chloride + calcium lactate > calcium chloride. In microencapsulation by emulsification, the mean size of the microspheres produced can be modified by varying the tack, pH and Ca²⁺ content of the cross-linking solution and through the use of a combination of calcium salts. The shape of the microspheres produced was, nonetheless, unaffected by the physicochemical properties of the cross-linking solution.     

A Heterogeneously Structured Composite Based on Poly(lactic-co-glycolic acid) Microspheres and Poly(vinyl alcohol) Hydrogel Nanoparticles for Long-Term Protein Drug Delivery

Purpose. To prepare a heterogeneously structured composite based on poly (lactic-co-glycolic acid) (PLGA) microspheres and poly(vinyl alcohol) (PVA) hydrogel nanoparticles for long-term protein drug delivery. Methods. A heterogeneously structured composite in the form of PLGA microspheres containing PVA nanoparticles was prepared and named as PLGA-PVA composite microspheres. A model protein drug, bovine serum albumin (BSA), was encapsulated in the PVA nanoparticles first. The BSA-containing PVA nanoparticles was then loaded in the PLGA microspheres by using a phase separation method. The protein-containing PLGA-PVA composite microspheres were characterized with regard to morphology, size and size distribution, BSA loading efficiency, in vitroBSA release, and BSA stability. Results. The protein-containing PLGA-PVA composite microspheres possessed spherical shape and nonporous surface. The PLGA-PVA composite microspheres had normal or Gaussian size distribution. The particle size ranged from 71.5 m to 282.7 m. The average diameter of the composite microspheres was 180 m. The PLGA-PVA composite microspheres could release the protein (BSA) for two months. The protein stability study showed that BSA was protected during the composite microsphere preparation and stabilized inside the PLGA-PVA composite microspheres. Conclusions. The protein-containing PLGA-PVA composite may be suitable for long-term protein drug delivery.     

Cisplatin-loaded polymer-metal complex micelle with time-modulated decaying property as a novel drug delivery system

Purpose. The pharmacological activity and pharmacokinetics of cisplatin (CDDP)-loaded polymeric micelles were examined to reveal their usefulness as a novel tumor-directed drug carrier system of CDDP. Methods. In biodistribution assay, free CDDP or CDDP-loaded micelles were administered intravenously to Lewis lung carcinoma-bearing mice. Antitumor activity and nephrotoxicity were respectively evaluated by the measurement of tumor size and plasma blood urea nitrogen (BUN) after single bolus i.v. administration of each drug. Results. The time profile of the plasma Pt level after the injection of the micelles exhibited a time-modulated disappearance as observed in saline in vitro. The micelles exhibited 5.2- and 4.6-fold higher AUC of Pt in the plasma and tumor, respectively, with minimal change in the kidney, in comparison with free CDDP, suggesting that prolonged circulation of Pt in circulation and specific accumulation in the tumor were achieved utilizing the micellar drug carrier system. Administration of the micelles at the dose exhibiting antitumor activity similar to free CDDP did not increase the plasma BUN, whereas free CDDP induced its remarkable increase. Conclusion. CDDP-loaded micelles restrained nephrotoxicity, which is the dose-limiting factor of CDDP, while exhibiting tumor-specific accumulation. Thus, CDDP-loaded micelles are expected to be a novel formulation of CDDP for clinical use.