尼莫地平聚乳酸缓释微球的制备及其药剂学性质

目的制备尼莫地平聚乳酸缓释微球,并对其药剂学性质进行研究.方法采用溶剂蒸发萃取法制备微球,正交实验设计考察影响制备工艺的因素,用扫描电镜观察微球表面形态,红外光谱分析验证舍药微球的形成,对制备的尼莫地平微球的粒径、栽药量、包封率等性质及体外释放特性进行了研究.结果尼莫地平聚乳酸微球的最佳制备工艺稳定,微球形态圆整,粒径分布适宜,药物确已被包裹于微球中.优化工艺制得的微球平均粒径为(61.7±0.46)μm,载药量为(53.2±0.8)%,包封率为(86.2±0.6)%,体外释放符合Higuchi方程,Q=17.708t1/2-0.975 8(r=0.995 4),t1/2=8.29 d.结论本实验获得了较理想的尼莫地平聚乳酸微球,其体外释药特性符合长效制剂特征.     

替莫唑胺壳聚糖缓释微球的制备及体外释药特性

目的:制备替莫唑胺壳聚糖缓释微球,并对其体外释药模式进行研究.方法:以替莫唑胺为模型药物,采用乳化交联法制备壳聚糖微球,两步优化法优化处方和制备工艺.通过测定微球的粒径及其分布、载药量、包封率和体外释放速度对微球进行质量评价.结果:优化工艺制得的微球平均粒径为(3.9±1.6)μm,载药量为(7.1±0.5)%(n=3),包封率为(25.0±0.8)%(n=3),体外释药特性研究具有良好的缓释特性,在0～8 h符合Higuchi方程,Q=11.717 26.951t1/2(r=0.980),8～24 h符合一级释放曲线,lnQ=4.37 0.007 5t(r=0.983).结论:通过优化处方和制备工艺,采用乳化交联法可制备出以壳聚糖为载体、替莫唑胺为模型药物的缓释微球,其体外释药具有明显的缓释作用.     

尼莫地平壳聚糖微球的制备及其体外释药特性的研究

目的以壳聚糖为载体材料制备尼莫地平微球,并考察其体外释药特性。方法以壳聚糖为载体,液体石蜡为油相,戊二醛为交联剂,span80为乳化剂,采用正交设计优化壳聚糖微球的制备工艺,用乳化交联法制备尼莫地平壳聚糖微球。模拟人体肠液的环境进行体外释药研究。结果通过单因素考察和正交实验,筛选出尼莫地平壳聚糖微球的优化制备工艺和处方,所得微球形态圆整,大小均匀,表面光滑,平均粒径为9.56μm,载药量为17.82%,包封率为52%。体外释药结果表明,一级动力学方程能较好的对其进行拟合。结论尼莫地平壳聚糖微球的制备工艺稳定可行,所得壳聚糖微球有良好的缓释效果。     

尼莫地平壳聚糖微球的制备及其体外释药特性的研究

目的 以壳聚糖为载体材料制备尼莫地平微球,并考察其体外释药特性。方法 以壳聚糖为载体,液体石蜡为油相,戊二醛为交联剂,span80为乳化剂,采用正交设计优化壳聚糖微球的制备工艺,用乳化交联法制备尼莫地平壳聚糖微球。模拟人体肠液的环境进行体外释药研究。结果 通过单因素考察和正交实验,筛选出尼莫地平壳聚糖微球的优化制备工艺和处方,所得微球形态圆整,大小均匀,表面光滑,平均粒径为9.56 μm,载药量为17.82%,包封率为52%。体外释药结果表明,一级动力学方程能较好的对其进行拟合。结论 尼莫地平壳聚糖微球的制备工艺稳定可行,所得壳聚糖微球有良好的缓释效果。     

布洛芬缓释颗粒的制备及溶出度研究

使用疏水性材料蜂蜡和硬脂酸制备的布洛芬缓释颗粒,能明显延缓药物释放,体外药物溶出符合零级动力学模型,释药速率与缓释颗粒的粒径有关。扫描电镜照相证明颗粒具有骨架结构。X 射线衍射分析表明,布洛芬在缓释颗粒中仍以结晶形式存在。     

尼莫地平柱塞型脉冲释药胶囊的制备

目的:制备尼莫地平柱塞型脉冲释药胶囊。方法:采用灌注法制备非渗透性囊体,以HPMC K15M为缓释骨架材料制备柱塞片,以PEG 6000和PEG 4000为基质制备尼莫地平滴丸,用柱塞片将滴丸密封于非渗透性囊体内制备尼莫地平柱塞型脉冲释药胶囊。结果:溶剂为丙酮/二氯甲烷/乙酸乙酯(2:0.7:0.3),醋酸纤维素溶液浓度为10.5%,柱塞片缓释骨架材料HPMC K15M和乳糖比例为1:10,制得的尼莫地平柱塞型脉冲释药胶囊体外呈明显的脉冲释放,释药时滞为4~5 h。结论:通过调节柱塞片中HPMC K15M和乳糖比例可调节脉冲胶囊的释药时滞,将尼莫地平制成滴丸可满足脉冲胶囊时滞后快速释药的要求。     

关节腔注射用氟比洛芬PLGA缓释微球的制备及体外释放特性研究

目的制备关节腔注射用氟比洛芬(FP)缓释微球并研究其体外释药特性。方法以聚乳酸-羟基乙酸共聚物(PLGA)为材料,采用乳化-溶剂挥发法制备微球;正交设计法优化微球的制备工艺;采用透析法研究体外释药特性,UV法测定FP的含量。结果正交试验表明,PLGA的浓度是影响微球包封率的非常显著性因素。微球粒径范围为1.5~24.3μm,平均粒径为10.6μm,载药量为7.1%(W/W),包封率为92.7%,体外释药符合Higuchi方程,释放时间显著延长。结论本法制备的FP微球粒径大小适宜,具有明显的缓释作用,符合关节腔注射给药设计要求。     

眼镜蛇毒细胞毒素缓释微球制备及体外性质研究

目的研究眼镜蛇毒细胞毒素(Cytotoxin,CTX)聚乳酸/羟基乙酸缓释微球的制备方法,考察其一般性质、体外释药特性及生物学活性。方法采用色谱方法纯化眼镜蛇CTX,MTT方法检测细胞毒活性,复乳-溶剂挥发法制备载药微球,考察微球表面形态、粒径、包封率、载药率、体外释药行为及释放眼镜蛇CTX细胞毒活性。结果纯化眼镜蛇CTX具有明显的细胞毒作用,对肝癌HepG2细胞12,24 h的IC50分别为1.43,1.12μg/mL,对L02肝细胞12,24 h的IC50分别为1.37,1.01μg/mL。微球表面光滑圆整,粒径2.1~7.8μm,包封率和载药率分别为(74.10±9.92)%和(0.72±0.09)%,30 d药物累积释放84.3%,释放眼镜蛇CTX保持较好的生物学活性。结论采用复乳-溶剂挥发法可制备具有较高包封率,良好缓释效果,保持完整生物学活性的眼镜蛇CTX缓释微球。     

PLA-PEG-PLA的微波合成及其磁性载药微球的表征、释药性

目的 采用微波法合成PLA-PEG-PLA,并以该嵌段共聚物为基质制备ASA/PLA-PEG-PLA载药微球和ASA-Fe3O4/PLA-PEG-PLA载药微球,考察磁性载药微球和非磁性载药微球的药物缓释性能.方法 通过傅立叶变换红外光谱(FT-IR)、核磁(NMR)对微波法合成的PLA-PEG-PLA的微观结构进行了表征分析.采用乳化-溶剂挥发法制备了ASA/PLA-PEG-PLA载药微球,通过正交设计实验优选载药微球的最佳制备条件,在此基础上利用单微乳法制备的Fe3O4纳米粒子制备了ASA-Fe3O4/PLA-PEG-PLA载药微球.通过透射电子显微镜(TEM)、X-射线衍射(XRD)对Fe3O4纳米粒子进行微观结构表征和性能分析.采用傅立叶变换红外光谱(FT-IR),扫描电子显微镜(SEM)对制备的载药微球进行了微观结构的表征和分析.结果 微波法合成的PLA-PEG-PLA是一种三嵌段共聚物.载药微球呈规则球形,表面光滑,粒径分布较均匀,平均粒径约为20μm.体外模拟释药试验表明ASA/PLA-PEG-PLA载药微球和ASA-Fe3O4/PLA-PEG-PLA载药微球24h释药率分别为69.16％和100％.结论 以微波法合成的PLA-PEG-PLA作为药物载体具有明显的缓释作用.ASA-Fe3O4/PLA-PEG-PLA磁性载药微球比ASA/PLA-PEG-PLA非磁性载药微球具有较快的药物释放速率.     

尼莫地平由溶胀性亲水性骨架中释放的动力学

本研究选用尼莫地平PVP－K30固体分散体为原料,以羟丙基甲基纤维素（HPMC）为缓释材料,进行了尼莫地平缓释片剂处方的设计,考查其体外释药动力学,并对几种辅及及不同的制备方法对片剂释药情况的影响进行了研究。体外溶出度实验结果表明,在本实验范围内,尼莫地平由HPMC亲水性凝胶骨架片中的溶出过程更符合零级动力学。微晶纤维素的加入可使片剂释药速度加快,低粘度的羟乙基纤维素可使药物的溶出速率常数增加。将HPMC制成40目颗粒后,再行压片,可使药物溶出度减慢。本研究筛选出的缓释片剂,可在12小时内平稳释药。     

他克莫司纳米微球的制备及其体外释药性能

目的采用甲氧基聚乙二醇-聚乳酸聚合物（PEG—PLA）制备他克莫司微球（PPT），研究其体外释药特性。方法考察PPT的载药量、包封率、粒径大小、粒径分布和药物体外释放实验。结果PPT的制备工艺稳定、重复性好，微球外形圆整，表面光滑，分布均匀，平均粒径为（545．1±0．9）nm，平均载药量为（18．90±3．22）％，平均包封率为（25．0±1．6）％，35d的药物累积释放率为67．21％。结论他克莫司微球缓释时间长达35d，能够满足临床治疗的要求。     

阿苯达唑-聚乙二醇6000固体分散体壳聚糖微球的制备与药剂学性质研究

目的:制备阿苯达唑-聚乙二醇6000(PEG)固体分散体壳聚糖微球并评价其性质。方法:以阿苯达唑-PEG固体分散体(ASD)为主体,壳聚糖为载体,采用乳化交联法制备ASD壳聚糖微球;采用电镜、红外光谱、X衍射分析法等对微球进行表征并考察其药剂学性质;动态透析法研究微球的体外释放特性。结果:所制得微球形态圆整,粒径分布均匀,平均粒径约(210±3.8)μm,载药量(6.42±0.32)%,包封率(57.86±0.74)%;红外光谱、X衍射分析法证明药物成功包载于微球中;微球在醋酸盐溶液(pH3.5)介质中的释放情况遵循Higuchi方程,可持续释放400h以上。结论:本法制备微球工艺稳定,所制微球具有显著的缓释效果。     

Ionotropic cross-linked chitosan microspheres for controlled release of ampicillin

The solubility of non cross-linked chitosan in weak acid solutions restricts its utility in microspheres for drug delivery. The primary aim of this study was to produce pentasodium tripolyphosphate cross-linked chitosan microspheres with higher acid resistance for controlled release of ampicillin. The microspheres were prepared by two different microencapsulation procedures (by emulsification and by spray-drying) and characterized by their particle size, surface morphology, stability, drug entrapment efficiency and drug release. The size of the microspheres was <10 microm with a narrow size distribution. The entrapment of ampicillin in the microspheres was more than 80%. Stability of uncross-linked and cross-linked microspheres was affected by the pH of simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.5). The inclusion of the enzymes pepsin and pancreatin did not affect the stability of the microspheres. The inclusion of lysozyme in phosphate buffer saline resulted in increased solubilization. The release of the drug was affected by cross-linking of microspheres with tripolyphosphate (TPP). The cross-linked microspheres were more stable in simulated gastric fluid and showed slower but sustained release of ampicillin. The antimicrobial activity of the released ampicillin was confirmed by Staphylococcus aureus bioassay.     

胰岛素-壳聚糖缓释微球释药机制的研究

目的：研制具有良好缓释效果的胰岛素微球，并研究胰岛素-壳聚糖微球的释药机制。方法：用乳化交联技术制备了胰岛素微球，并对胰岛素-壳聚糖缓释微球缓释机制进行了初步探讨。结果：该微球具有良好缓释效果。结论：胰岛素-壳聚糖微球的释药机制为药物的突释效应、亚胺键的水解、壳聚糖的吸水膨胀以及药物通过胶状黏稠层向外扩散等几个相互衔接的步骤。     

β-榄香烯海藻酸钙-壳聚糖微囊的制备

采用乳化-内部凝胶化技术制得载β-榄香烯的海藻酸钙凝胶微球,然后与壳聚糖反应制得β-榄香烯海藻酸钙-壳聚糖微囊.利用激光共聚焦扫描显微镜和激光粒度仪观测所得微囊的形态、粒径及分布,通过气相色谱法考察体外释放性能.结果表明制品球形度好、膜层均匀,粒径呈正态分布,体外释放曲线符合Higuchi方程.     

蓝萼甲素固体脂质纳米粒的制备及理化性质研究

目的:制备蓝萼甲素固体脂质纳米粒,并对其理化性质进行研究。方法:用乳化-溶剂挥发法制得蓝萼甲素固体脂质纳米粒,并对其粒径、形态、表面电位、包封率、体外释药性质等进行研究。结果:所得蓝萼甲素固体脂质纳米粒的粒径分布均匀,平均粒径为(190±10·3)nm,Zeta电位为—31·2mV,平均包封率为(50·45±0·804)%;药物体外释放符合Higuchi线性方程,具有显著缓释作用。结论:固体脂质纳米粒可作为蓝萼甲素新型缓释给药系统。     

Controlled release calcium silicate based floating granular delivery system of ranitidine hydrochloride

The objective of the present investigation was to prepare and evaluate floating granular delivery system consisting of (i) calcium silicate (CS) as porous carrier; (ii) ranitidine hydrochloride (RH), an anti-ulcer agent; and (iii) hydroxypropyl methylcellulose K4M (HPMC) and ethylcellulose (EC) as matrix forming polymers. The effect of various formulation and process variables on the particle morphology, particle size, micromeritic properties, percent drug content, in vitro floating behavior, and in vitro drug release from the floating granules was studied. The scanning electron microscopy (SEM) of granules revealed that that more pores of CS in secondary coated granules (SCG) were covered by the polymer film than those in primary coated granules (PCG). The formulation demonstrated favorable in vitro floating and drug release characteristics. The in vivo evaluation for the determination of pharmacokinetic parameters was performed in albino rats. Higher plasma concentration was maintained throughout the study period from the floating granules of RH. The enhanced bioavailability and elimination half-life observed in the present study may be due to the floating nature of the dosage form. The results suggested that CS is a useful carrier for the development of floating and sustained release preparations.     

沙美特罗白蛋白微球的制备与体外释放度考察

目的:制备沙美特罗白蛋白微球,并考察其体外释放性能。方法:以白蛋白为载体,采用乳化交联法制备沙美特罗白蛋白微球。在单因素考察的基础上,利用正交设计优化沙美特罗白蛋白微球制备工艺,并对微球的粒径,形态,体外释放特性进行研究。结果:制得的微球形态圆整,平均粒径为（16.82±1.25）μm,平均载药量为（52.08±3.26）%,平均包封率为（60.54±3.17）%,体外释放符合Higuchi方程,Q=11.5846t_1/2-1.207（r=0.9985）。结论:沙美特罗白蛋白微球体外释放特性符合长效制剂特征。     

Controlled release of vancomycin from freeze-dried chitosan salts coated with different fatty acids by spray-drying

The aim of this study was to describe a controlled drug release system based on chitosan salts for vancomycin hydrochloride delivery. Chitosan aspartate (CH-Asp), chitosan glutamate (CH-Glu) and chitosan hydrochloride (CH-HCl) were prepared by freeze-drying and coated with stearic, palmitic, myristic and lauric acids by spray-drying technique. Vancomycin hydrochloride was used as a peptidic model drug whose sustained release should minimize its inactivation in the upper part of the gastrointestinal tract. This study evaluated, in vitro, the influence of chitosan salts on the release behaviour of vancomycin hydrochloride from the freeze-dried and spray-dried systems at pH 2.0 and 7.4.     

Chitosan and poly(methyl vinyl ether-co-maleic anhydride) microparticles as nasal sustained delivery systems.

An original dosage form for nasal delivery based on the encapsulation of hydrophilic drug in chitosan-poly(methyl vinyl ether-co-maleic anhydride) (CH-PVM/MA) microparticles prepared by spray-drying technique was developed. Microparticles were characterized in terms of morphology, size, swelling properties, encapsulation efficiency and drug release. The physical state of the drug and the polymer was determined by scanning electron microscopy (SEM) and infrared spectroscopy (IR). Propranolol hydrochloride (PH) was a beta-blocker, used for the treatment of hypertension and was chosen as a model of hydrophilic drug. SEM studies showed spherical particles with smooth surfaces for chitosan hydrochloride (CH-HCl), whereas rather gross surface defects resulted from the incorporation of poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA). In vitro release studies revealed a sustained release of propranolol HCl from microparticles and in particular chitosan hydrochloride provided the lowest release of drug.