普罗布考微囊的制备与性质考察

目的:研究普罗布考微囊的制备工艺,考察其体外释药特性.方法:用复凝聚法制备普罗布考微囊,以包封率为指标,用正交试验设计法对微囊的制备工艺进行研究,对其形态、体外释药特点等进行研究.结果:当囊心与囊材比为1:3、搅拌速率为200r/min、成囊温度为60℃时,制得的普罗布考微囊囊形圆整光滑,囊壁清晰,粒径均匀,平均包封率可高达74.57%,载药量平均为17.93%,囊径为35~95μm,24h累积释药量93.61%.结论:制备的普罗布考微囊工艺简单、可靠,具有缓释效果.     

盐酸小檗碱微囊的制备及其体外释放研究

目的:为改善口感、减小对胃黏膜的刺激,制备盐酸小檗碱微囊,并考察其体外释药特性。方法:以阿拉伯胶、明胶为囊材,采用复凝聚法制备盐酸小檗碱微囊,以包封率、载药量、外形为指标,采用正交设计试验对囊心(盐酸小檗碱)-囊材质量比、囊材质量分数、搅拌速度进行优化,并进行验证。考察所制制剂的粒径分布及在人工肠液中5 h内的体外释药率。结果:最优处方为囊心-囊材质量比为1∶3,阿拉伯胶和明胶的质量分数均为2.50%,搅拌速度为200 r/min,成囊温度为53℃。所制盐酸小檗碱微囊的包封率为38%,载药量为41.71%;微囊圆整光滑,无粘连,粒径均匀,外形评分50.6;80%以上分布在3~9μm;3 h的累积释药率即达90%。结论:成功制得盐酸小檗碱微囊。     

蛇床子素非离子囊泡的制备和质量评价

采用薄膜分散-超声法制备蛇床子素非离子表面活性剂囊泡,以包封率为指标通过正交设计优化处方和工艺.并考察了所得优化囊泡的形态、平均粒径和分布、包封率及体外释药行为.结果表明,制品外观呈球形或椭圆形,平均粒径为(246.1±12.3)nm,多分散系数为0.171,包封率为87.4%,体外释药行为符合Higuchi方程(r=0.998 2).     

克拉霉素微囊的制备及其质量评价

目的:制备克拉霉素微囊并对其质量进行评价。方法:以乙基纤维素为囊材,采用乳化-溶剂挥发法制备克拉霉素微囊,并对微囊粒径、包封率和载药量、体外释药性进行考察。结果:所制微囊粒径分布均匀,粒径33.0～38.0μm,包封率在87%以上,载药量大于45%,6h时累积释药量达75%。结论:该制剂制备方法简便易行,质量评价合格。     

大蒜素肠溶微囊的制备及其性质研究

目的 以肠溶材料聚丙烯酸树脂Ⅱ为囊材制备大蒜素微囊.方法 采用单凝聚法制备大蒜素肠溶微囊并研究其粒径、载药量、包封率、体外释药等性质.结果 经优化制得的大蒜素肠溶微囊为类圆球形颗粒,平均粒径为52.2μm,平均载药量28.97%,包封率80.74%,体外释放符合肠溶制剂的标准,对大鼠的胃黏膜几乎无刺激.在4.5×103 lx照射,60°C高温及相对湿度90%条件下放置10 d,微囊的粒径分布和剩余药量无显著变化.结论 制备工艺简单,所制得的大蒜素微囊具有肠溶特性.     

紫草素钠脂质体的制备及性能研究

目的 研究紫草素钠脂质体的制备工艺并考察其性质,旨在开发一种安全高效的紫草新型制剂。方法 利用碱溶酸提法纯化紫草提取物,并采用乙醇注入法制备紫草素钠脂质体,测定其形貌、粒径和Zeta电位。利用高效液相建立左旋紫草素含量测定方法,并考察了脂质体包封率和体外释放性能。结果 紫草素钠脂质体平均粒径为104.2 nm左右,且大小均一,成正态分布;Zeta电位为-14.8 mV;左旋紫草素在5~50 mg/L范围与峰面积呈良好的线性关系,相关系数为0.999 9;紫草素钠脂质体的包封率为43.67%,药物累积释放量为65.82%。结论 成功制备了紫草素钠脂质体,具有较高的包封率和体外释放率。     

对乙酰氨基酚复合微囊缓释栓的制备及体外释放度研究

目的:采用复凝聚法制备对乙酰氨基酚(AAP)微囊并考察其体外释药行为。制备AAP复合微囊栓剂,具有良好释放效果。方法:考察复凝聚法制备AAP微囊过程的处方和工艺因素,并进行正交试验设计,筛选出最佳条件制备AAP微囊并考察其体外释药行为。同时采用复合缓释技术(速释部分+微囊缓释)制备复合微囊缓释栓剂,考察其释药行为。结果:建立了复凝聚法制备AAP微囊方法,优化后的制备条件为:明胶阿拉伯胶囊材用量各为7 g(溶液浓度7%),药物用量为8 g,搅拌速度为300 r·min^-1,制备温度55℃。此条件制备的微囊形态圆整,粒径均匀,重复性好,包封率为(79.71±0.10)%,载药量为23.11±0.69%。微囊有缓释效果,拟合缓释方程符合一级方程。制备的复合微囊栓与普通栓剂相比,具有更好的释放效果,其中缓释过程药物释放符合Higuchi方程。结论:基于普通栓剂与复合微囊技术制备的新型AAP栓具有更佳的释药特性。     

抗癫疒间肽纳米粒的制备及体外释药性能的研究

目的制备抗癫疒间肽纳米粒,并研究其体外释药性能。方法选用聚乙二醇-聚乳酸-聚乙醇酸嵌段共聚物为载体,采用复乳-溶剂挥发法制备抗癫疒间肽纳米粒,以包封率、载药量等指标优化制备工艺,并研究纳米粒体外释药性能。结果抗癫疒间肽纳米粒外观呈圆形或类圆形,平均粒径为(100.2±2.45)nm,包封率和载药量分别为(64.46±1.34)%和(4.73±0.32)%,体外释药呈现缓释和突释两个阶段,符合Weibull方程。结论建立的制备工艺简便可行,得到的抗癫疒间肽纳米粒包封率和载药量较高,粒径小,体外释药具有明显的缓释特征。     

冬凌草甲素纳米粒制备及其体外抗肿瘤作用

目的制备冬凌草甲素纳米粒(ORI-Nps),考察其体外抗肿瘤作用.方法采用界面沉淀法制备ORFNps,并对其形态、粒径、ξ电位、包封率、载药量、体外释药特征和抗肿瘤作用进行研究.结果制备的ORI-Nps为类球形,粒径分布均匀,平均粒径为101.5 nm;ξ电位为-29.8 mV;载药量和包封率分别为6.84%和92.25%;体外释药缓慢;对Eta-109细胞具有较强的毒性作用.结论制备的ORI-Nps包封率和载药量高,粒径均匀,体外释药具有缓释特点,体外抗肿瘤作用强.     

依托泊苷鼻用壳聚糖微球的制备及体外释放度考察

目的研制依托泊苷鼻黏膜给药壳聚糖微球,对微球的制备方法及体外释放度进行考察.方法以壳聚糖为栽体,甲醛为交联剂,采用乳化交联固化法制备微球,对微球的粒径、形态及体外释药进行研究.结果微球的外观圆整,平均粒径为(46.9±0.7)μm,78.4 %的微球粒径在30～70μm范围内,体外释药符合Higuchi模型.结论依托泊苷壳聚糖微球制备工艺简单、稳定,包封率高,药物释放符合鼻腔给药要求.     

正交实验设计优化岩白菜素微囊的制备工艺

目的优化岩白菜素微囊的制备工艺,并对制备的岩白菜素微囊进行质量评价。方法以明胶为囊材,单凝聚法制备岩白菜素微囊,通过正交实验设计优化其制备工艺,并对包封率、载药量、平均粒径、体外溶出率进行研究。结果明胶制备岩白菜素微囊的最佳工艺条件为:明胶质量分数为6%,囊心囊材质量比为1∶2,搅拌速度为750r·min^-1。此最佳工艺制备的岩白菜素微囊包封率为75.90%,载药量为23.09%,体外溶出度测定30min为28.6%,12h累计释放达到90%以上。结论以最佳工艺条件制备岩白菜素微囊工艺稳定,包封率高,同时体外释放实验表明,该微囊具有较好的缓释作用。     

Synthesis and release studies of shikonin-containing microcapsules prepared by the solvent evaporation method

Microcapsules, containing the pharmaceutical substance shikonin, were prepared by the solvent evaporation method in order to enhance shikonin stability (reduce photo-oxidation, polymerization), decrease its hydrophobicity and control its release rate. The effect of various parameters, such as type of polymer, type and concentration of surfactant, solvent volume and mastic gum (Pistacia lentiscus resin) content/concentration as core additive, on the characteristics of the produced microcapsules and the release rate of shikonin, were experimentally investigated. Among the polymers tested for matrix, ethylcellulose (EC) of viscosity 10 cp was the most successful; EC 100 cp and mastic gum result in larger/compact particles with no pores and much slower release. Sodium dodecyl sulphate (SDS) results in microcapsules with desirable morphological and physicochemical characteristics, while polyethylene glycol (PEG) and polyvinyl alcohol (PVA) are not indicated as surfactants in shikonin microencapsulation. Decreasing the solvent volume (dichloromethane) results in increased mean particle size and, thus, in slower release rate of shikonin, while the incorporation of mastic gum in the capsule core results in better control of shikonin release. Finally, the combination of EC 10 cp as matrix, mastic gum as core additive, low dichloromethane (DCM) volume and low SDS concentration results in microcapsules with the best characteristics in terms of efficiency, loading, release and particle size distribution.     

Synthesis and release studies of shikonin-containing microcapsules prepared by the solvent evaporation method

Microcapsules, containing the pharmaceutical substance shikonin, were prepared by the solvent evaporation method in order to enhance shikonin stability (reduce photo-oxidation, polymerization), decrease its hydrophobicity and control its release rate. The effect of various parameters, such as type of polymer, type and concentration of surfactant, solvent volume and mastic gum (Pistacia lentiscus resin) content/concentration as core additive, on the characteristics of the produced microcapsules and the release rate of shikonin, were experimentally investigated. Among the polymers tested for matrix, ethylcellulose (EC) of viscosity 10 cp was the most successful; EC 100 cp and mastic gum result in larger/compact particles with no pores and much slower release. Sodium dodecyl sulphate (SDS) results in microcapsules with desirable morphological and physicochemical characteristics, while polyethylene glycol (PEG) and polyvinyl alcohol (PVA) are not indicated as surfactants in shikonin microencapsulation. Decreasing the solvent volume (dichloromethane) results in increased mean particle size and, thus, in slower release rate of shikonin, while the incorporation of mastic gum in the capsule core results in better control of shikonin release. Finally, the combination of EC 10 cp as matrix, mastic gum as core additive, low dichloromethane (DCM) volume and low SDS concentration results in microcapsules with the best characteristics in terms of efficiency, loading, release and particle size distribution.     

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.     

Effect of alginate-pectin composition on drug release characteristics of microcapsules

Microencapsulation of model drug, acetylsalicylic acid into bio-based polymer, alginate-pectin matrix has been undertaken in this work to characterize the microcapsules based on their composition. Different proportions of the alginate-pectin solutions prepared with drug were homogenized and atomized using nitrogen gas into 1.0 M calcium chloride solution to form sol-gel microcapsules. Drug loaded microcapsules were dried using microwave energy under vacuum at low temperature. Average particle size of the microcapsules was found to be 90 micron. Scanning electron microscopy graphs and Fourier Transform Infrared Spectroscopy analysis on the microcapsules confirm the presence of drug in the polymer matrix. X-ray diffraction pattern showed that the microstructure was more like an amorphous pattern. Drug release of the microcapsules was tested in three different pH levels of 1.2, 7.4 and 8.2. Slow and controlled release of drug was observed at all the pH levels. Increase in pectin increased the drug release and also the release was more in acidic pH (1.2) as 75.6% for alginate: pectin-20:80.     

Patent Briefing

Polyurea microcapsules containing 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide as the active agent were prepared by the method of interfacial polycondensation with methylene bis(phenyl isocyanate) as the multifunctional isocyanate, hexamethylene diamine as the diamine, and anionic sodium lignin sulphonate (SLS) as the emulsifying agent. The internal structure and morphology of the microcapsules were examined with transmission electron microscopy. The microcapsules had a micro-reservoir structure in which the wall extended well into the core and the active agent was accommodated by the micro-reservoirs, distributed uniformly throughout the entire volume of a microcapsule. Based on the observed morphology, permeability of the water soluble monomer in the polyurea film and its solubility in the oil phase have a significant effect on the morphology and microstructure of the microcapsules. The multivalent salt, calcium chloride, plays a significant role in stabilizing the microcapsule structure, by interacting with the anionic surfactant SLS, and physically crosslinks the SLS chains, by interacting with the negatively charged carboxylic and phenolic groups, with subsequent phase separation of the physically crosslinked chains to form a concentrated gel phase. This gel phase encompasses the microcapsule, increases the stability, and modifies its release behaviour.     

Morphology and structure of microcapsules prepared by interfacial polycondensation of methylene bis(phenyl isocyanate) with hexamethylene diamine.

Polyurea microcapsules containing 2- chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide as the active agent were prepared by the method of interfacial polycondensation with methylene bis(phenyl isocyanate) the multifunctional isocyanatae, hexamethylene diamine as the diamine, and anionic (SLS) as the emulsifying sodium lignin liinin the agent. The internal structure and morphology of the microcapsules were examined with transmission electron microscopy. The microcapsules had a micro-reservoir structure in which the wall extended well into the core and the active agent was accomodated by the micro-reservoirs, distributed uniformly throughout the entire volume of a microcapsule. Based on the observed morphology, permeability of the water soluble monomer in the polyurea film and its solubility in the oil phase have a significant effect on the morphology and microstructure of the microcapsules. The multivalent salt, calcium chloride, plays a significant role in stabilizing the microcapsule structure, by interacting with the anionic surfactant SLS, and physically crosslinks the SLS chains, by interacting with the negatively charged carboxylic and phenolic groups, with subsequent phase separation of the physically crosslinked chains to form a concentrated gel phase. This gel phase encompasses the microcapsule, increases the stability, and modifies its release behaviour.     

Preparation and in vitro dissolution of salbutamol sulphate microcapsules and tabletted microcapsules

Abstract

Salbutamol sulphate is a sympathomimetic amine having a rather short plasma half-life. Aiming to achieve sustained release of this drug through microencapsu-lation, the coacervation method with a 1:1 core-shell ratio was used. In vitro release rate experiments were performed on the microcapsules prepared using ethyl cellulose as the coating agent and compared to the results of intact drug, the tabletted microcapsules and a commercial tablet. The release rate of salbutamol sulphate could be controlled through microencapsulation. The time for the 50% release of the drug was 15 and 90 min for the tabletted microcapsules and microcapsules respectively. The specific surface area of the intact drug was 0.35m²/cc while it reduced to 0.06m²/cc after encapsulation.     

Effect of surface active agents on drug release from polylactic acid-hydrocortisone microcapsules

Polylactic acid microcapsules containing randomly distributed hydrocortisone particles were prepared. The rate of release of hydrocortisone from the microcapsules in pH 7.4 phosphate buffer was found to be largely increased by the presence of polysorbate 80, cetylpyridinium chloride, or aerosol OT in the dissolution medium. The surfactant effect was attributed to the ability of the surface active agent to improve solvent penetration into the microcapsules by lowering the surface tension at the solid-liquid interface. The effect of the cationic surfactant, cetylpyridinium chloride on the rate of drug release is similar in magnitude to that of the nonionic surfactant, polysorbate 80. In these systems, the rate of drug release from the microcapsules was found to be linearly related to the surface tension of the dissolution medium in the range of 40-60 dyn/cm (x 10(-3) N/m). In the same surface tension range, the effect of aerosol OT on rate increase was found to be much less than those of the cationic and nonionic surfactants. This suggests that the anionic surfactant is not well adsorbed at the interface due to the negative charge characteristics of the surface of the polylactic acid microcapsules. However, at nearly the critical micelle concentration of aerosol OT, where the corresponding surface tension is much lower than those of the cationic and nonionic surfactants, the microcapsules exhibited the highest rate of drug release.     

The effect of various polymeric coating systems on the dissolution and tableting properties of potassium chloride microcapsules

Two solvent-based coating systems and four aqueous film-forming dispersions were evaluated for their ability to encapsulate potassium chloride crystals and to regulate drug release by fluid-bed technology. Coated potassium chloride crystals were compressed into dispersible tablets as an alternative to capsule filling. Solvent-based coatings generated films with high flexibility and mechanical stability, so that very few coated crystals were damaged. The effect of mixed latex coatings on potassium chloride release rate from microcapsules was also studied.