复凝聚法制备槲皮素微囊的工艺

目的:优选以明胶和阿拉伯胶为囊材制备槲皮素微囊的最佳工艺条件。方法:采用复凝聚法,以槲皮素为囊芯物,用明胶和阿拉伯胶作囊材,取pH、囊材浓度及搅拌速度3个为考察因素,用正交试验探讨制备槲皮素微囊的最佳条件。结果:当pH为4.0,囊材为3%,搅拌速度为150 r.min-1时为最佳工艺条件。结论:本法工艺简便、稳定,具有应用前景。     

用复凝聚法制备阿维菌素微囊的工艺初探

以明胶、阿拉伯树胶为囊材，用复凝聚法制各阿维菌素(AVM)微囊，初步建立了制各AVM微囊的工艺。     

复凝聚法制备桃金娘油肠溶微囊

目的采用复凝聚法制备桃金娘油肠溶微囊,并对其体外性质进行评价。方法选用海藻酸钠、氯化钙、壳聚糖为囊材采用复凝聚法制备桃金娘油微囊,用扫描电子显微镜(scanning electron microscope,SEM),Beckman Coulter LS 230激光粒度仪表征了微囊表面形态及粒径,采用顶空进样-GC色谱法测定了载药量和包封率。结果正交设计优化处方和工艺如下:海藻酸钠质量浓度为25g.L-1、壳聚糖质量浓度为3 g.L-1、凝聚速度为5 mL.min-1和凝聚时间为60 min,所得微囊粒径为(14.23±1.45)μm,载药质量分数为(11.3±0.4)%,包封率为(73.6±2.5)%。微囊具有耐酸和肠溶性能,表面褶皱,粒径分布均匀。结论复凝聚法可用于桃金娘油肠溶微囊的制备。     

复凝聚法制备吲哚美辛缓释微囊的研究

目的:通过吲哚美辛微囊的制备研究,为吲哚美辛的缓释制剂提供科学依据。方法:以微囊的药物包封率为制备工艺优化指标,利用复凝聚法,通过正交实验得出微囊的最佳制备工艺条件。结果:该法所制备微囊的粒度分布在2.2~32.3μm之间,收率可达80%以上。结论:实验证明,吲哚美辛微囊比吲哚美辛片剂具有明显的缓释作用。     

单凝聚法制备姜黄素微囊的工艺研究

摘 要 目的：优化姜黄素微囊的制备工艺。 方法: 采用单凝聚法制备姜黄素微囊,以包封率、载药量和产率为指标,采用正交试验对明胶浓度、芯壁比、成囊温度、搅拌速度等因素进行考察,并对其形态与粒径进行表征。 结果: 单凝聚法制备姜黄素微囊的最优处方为：明胶浓度5%,芯壁比1∶2,成囊温度50℃,搅拌速度500 r·min-1。制备的姜黄素微囊外观圆整,大小均匀且无粘连。 结论: 单凝聚法制备姜黄素微囊工艺简单,包封率高,载药量大。     

鱼油微囊的制备

应用复凝聚法制备得到了无腥臭味的鱼油粉末化产品一鱼油微囊，并用气相色谱法测得鱼油微囊中廿碳五烯酸和廿二碳六烯酸的包裹率分别为１４．３４％和１４．０６％，收得率分别为６７．９０％和６６．５６％。     

恩诺沙星微囊的制备

目的:制备恩诺沙星微囊及工艺优化。方法:本实验采用单凝聚法制备恩诺沙星微囊,应用显微镜观察产品的形态,采用紫外分光光度法测定微囊中恩诺沙星的包封率。结果:恩诺沙星微囊在显微镜下观察为圆球形微囊,紫外分光光度法测得产品包封率为48.15%。结论:单凝聚法可成功制备恩诺沙星微囊,方法简单,包封率较高,可操作性强。     

鱼油微囊的制备

应用复凝聚法制备得到了无腥臭味的鱼池粉末化产品—色油微囊,并用气相色谱法测得鱼油微囊中廿碳五烯酸(eicosapentaenoicacid,EPA)和廿二碳六烯酸(docosahexaenoicadid,DHA)的包裹率分别为14.34%和14.06%,收得率分别为67.90%和66.56%。     

鱼油微囊的制备

应用复凝聚法制备得到了无腥臭味的鱼池粉末化产品—色油微囊,并用气相色谱法测得鱼油微囊中廿碳五烯酸(eicosapentaenoicacid,EPA)和廿二碳六烯酸(docosahexaenoicadid,DHA)的包裹率分别为14.34%和14.06%,收得率分别为67.90%和66.56%。     

The influence of HLB on the encapsulation of oils by complex coacervation

Abstract

Microcapsules are used for the formulation of drug controlled release and drug targeting dosage forms. Encapsulated hydrophobic drugs are often applied as their solutions in plant oils. The uptake of the oils in the complex coacervate microcapsules can be improved by the addition of surfactants. In this study, soybean, olive and peanut oils were chosen as the representatives of plant oils. The well characterized complex coacervation of gelatin and acacia has been used to produce the microcapsules. The amount of encapsulated oil has been determined gravimetrically. The encapsulation of the oils was high (75–80%). When the surfactants with HLB values from 1.8 to 6.7 were used, the amount of encapsulated oil was high (65–85%). A significant decrease of the oil content in the microcapsules was found when Tween 61 with HLB = 9.6 had been added into the mixture. No oil was found inside the microcapsules from the coacervate emulsion mixture containing Tween 81 (HLB = 10) and Tween 80 (HLB = 15), respectively. The results of the experiment confirm the dependence of hydrophobic substance encapsulation on the HLB published recently for Squalan     

Preparation of microcapsules with narrow-size distribution by complex coacervation: Effect of sodium dodecyl sulphate concentration and agitation rate

In this paper, microcapsules with narrow-size distribution, in which the core materials are a kind of suspension containing pigment scarlet powders dispersed in dyed tetrachloroethylene with Span-80 as an emulsifier, are prepared by complex coacervation through controlling sodium dodecyl sulphate (SDS) concentration and agitation rate. The microcapsules, formed in optimized process of 0.01 wt% SDS and 800 rpm, are ～40 μm in diameter. The phase diagram for the gelatin/SDS/water system indicates that the concentration of SDS in the experiments is outside of the complex formation zone to form a gelatin–SDS complex. Consequently, SDS preferential adsorbs and enriches on the surface of the core droplets due to its higher surface activity. Then, gelatin deposits with SDS at the core droplet/water interface to form a primary layer of complexation. Subsequently, with the pH lower than the isoelectric point of gelatin, complex coacervate of gelatin and gum arabic grows on the primary layer surface and finally deposits on the droplets to form a secondary layer. On the whole, the research indicates that the existence of SDS not only decreases the droplet diameters and centralizes the droplets size distribution, but also accelerates coacervation of gelatin and gum arabic to reach the core droplet/water interface, forming no aggregating microcapsules.     

Microencapsulation of esterified krill oil,using complex coacervation

The microencapsulation of the esterified krill oil (EKO), obtained from the transesterification of krill oil (KO) with 3,4-dihydroxyphenylacetic acid (DHPA), via complex coacervation and was investigated. The experimental findings showed that the DHPA and phenolic lipids (PLs) in the EKO affected the stability of the gelatine (GE)-EKO emulsion. To improve its stability, the effects of varying the pH of GE and the use of two emulsification devices, including the homogeniser and ultrasonic liquid processor were investigated, where the ultrasonic liquid processor was found to be a relatively more appropriate emulsification device. In addition, the capsules prepared using a pH of GE of 8.0 showed superior storage and had significantly (p?<0.05) lower peroxide value as compared to those prepared with a pH of GE of 6.5. The microencapsulation of the EKO was effective in delaying the development of oxidation products during a period of 25?d of storage, at 25?°C.     

Microencapsulation of eugenol by gelatin-sodium alginate complex coacervation

Present study describes microencapsulation of eugenol using gelatin-sodium alginate complex coacervation. The effects of core to coat ratio and drying method on properties of the eugenol microcapsules were investigated. The eugenol microcapsules were evaluated for surface characteristics, micromeritic properties, oil loading and encapsulation efficiency. Eugenol microcapsules possessed good flow properties, thus improved handling. The scanning electron photomicrographs showed globular surface of microcapsules prepared with core: coat ratio1:1.The treatment with dehydrating agent isopropanol lead to shrinking of microcapsule wall with cracks on it. The percent oil loading and encapsulation efficiency increased with increase in core: coat ratio whereas treatment with dehydrating agent resulted in reduction in loading and percent encapsulation efficiency of eugenol microcapsules.     

Development of vegetable extracts by microencapsulation

Abstract

The microencapsulation of essential oils offers protection against oxidation and evaporation, and allows the concurrent utilization of several vegetable extracts. Complex coacervation methods have been described for essential oils. Even though microencapsulation involves wrapping the essential oils in shells, some difficulties arise in the process of stabilizing the essential oils: oil may be lost by evaporation and partial dissolution in the water-gelatin phase and this will vary with the type of essential oil being encapsulated. In order to investigate the efficacy of the gelatin-polyphosphate methods we analysed their essential oil microcapsules peppermint and rosemary, in particular their granulometric size distribution, oil content (%) and encapsulation yield (%). In addition the essential oils were analysed by GC before and after microencapsulation so as to investigate the loss of their components during the process.     

Formulation of curcumin-loaded solid lipid nanoparticles produced by fatty acids coacervation technique

Curcumin (CU) loaded solid lipid nanoparticles (SLNs) of fatty acids (FA) were prepared with a coacervation technique based on FA precipitation from their sodium salt micelles in the presence of polymeric non-ionic surfactants. Myristic, palmitic, stearic, and behenic acids, and different polymers with various molecular weights and hydrolysis grades were employed as lipid matrixes and stabilisers, respectively. Generally, spherical-shaped nanoparticles with mean diameters below 500?nm were obtained, and using only middle-high hydrolysis, grade-polymer SLNs with diameters lower than 300?nm were produced. CU encapsulation efficiency was in the range 28–81% and highly influenced by both FA and polymer type. Chitosan hydrochloride was added to FA SLN formulations to produce bioadhesive, positively charged nanoparticles. A CU-chitosan complex formation could be hypothesised by DSC analysis, UV–vis spectra and chitosan surface tension determination. A preliminary study on HCT-116 colon cancer cells was developed to evaluate the influence of CU-loaded FA SLNs on cell viability.     

Evaluation of ketorolac tromethamine microspheres by chitosan/gelatin B complex coacervation

Microspheres (MS) of Ketorolac Tromethamine (KT) for oral delivery were prepared by complex coacervation (method-1) and simple coacervation (method-2) methods without the use of chemical crossalinking agent (glutaraldehyde) to avoid the toxic reactions and other undesirable effects of the chemical cross-linking agents. Alternatively, ionotropic gelation was employed by using sodium-tripolyphosphate (Na-TPP) as cross linking agent. Chitosan and gelatin B were used as polymer and copolymer respectively. All the prepared microspheres were subjected to various physico-chemical studies, such as drug-polymer compatibility by Thin Layer Chromatography (TLC) and Fourier Transform Infra Red Spectroscopy (FTIR), surface morphology by Scanning Electron Microscopy (SEM), frequency distribution, encapsulation efficiency, in-vitro drug release characteristics and release kinetics. The physical state of drug in the microspheres was determined by Differential Scanning Calorimetry (DSC) and X-ray powder Diffractometry (XRD). TLC and FTIR studies indicated no drug-polymer incompatibility. All the MS showed release of drug by a fickian diffusion mechanism. DSC and XRD analysis indicated that the KT trapped in the microspheres existed in an amorphous or disordered-crystalline status in the polymer matrix. It is possible to design a controlled drug delivery system for the prolonged release of KT, improving therapy by possible reduction of time intervals between administrations.     

地红霉素微囊制备及体外释放度的考察

目的：制备地红霉素微囊并考察其体外释放度。方法：选用生物降解材料明胶和阿拉伯胶为囊材，采用复凝聚法制备流动性粉末状地红霉素微囊。填充胶囊后与参比制剂比较体外释放行为。结果：与参比制剂比较，微囊释放度明显的提高。结论：地红霉素制成微囊剂型后，减少副作用的同时，体外释放度明显的提高。     

紫草素微囊的固化机制与性能

目的考察单宁酸和氯化钙作为固化剂对微囊的成囊性及体外释药特征的影响,并对其固化机制进行探讨。方法以明胶和海藻酸钠为壁材,单宁酸和氯化钙作为固化剂,采用复凝聚法制备紫草素微囊;用扫描电子显微镜、激光粒径测试仪、红外光谱仪等手段研究微囊微球的形态结构;采用转篮法评价微囊的体外释药特性。结果制备得到了球形良好、缓释效果良好的单宁酸微囊,单宁酸和氯化钙制备的微囊包封率分别为90.34%±1.36%和69.89%±1.28%;平均粒径为241.7±6.94和278.1±4.74 nm,Zeta电位为-27.3±3.6和-24.7±3.2 mV;红外图谱显示单宁酸固化的微囊可以将紫草素包裹得更完全,使紫草素的特征峰完全消失,而氯化钙固化的微囊只能包裹部分紫草素,不能使其特征峰消失。体外释放实验结果表明,单宁酸作固化剂制备的微囊在12 h时释药率达到96.81%;而以氯化钙作固化剂制备的微囊,在6 h时释药率达到97.57%。结论固化剂的选择对微囊的成囊有较大的影响,为微囊固化剂的研究奠定了基础。