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。     

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。     

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。     

Box-Behnken效应面法优化避蚊胺微囊的制备工艺研究

摘要：目的:优选避蚊胺（DEET）微囊的制备工艺。方法:以明胶作为囊材,采用复凝聚法制备微囊。以包封率为指标,在单因素试验的基础上,选取芯壁比、扩容体积、搅拌转速3个影响因素,采用Box-Behnken效应面法优化DEET微囊的制备工艺。应用Design-Expert 10软件分析试验结果。结果:DEET微囊的最佳制备工艺条件是芯壁比为1.15∶1,壁材在溶液中含量为3.1%,搅拌转速135 r·min-1。采用优选后的制备工艺制备的DEET微囊包封率可达52.65%,接近模型预测值52.71%。DEET微囊粒径为（36.17±3.42）μm,大小相对均匀,可观察到具有一定厚度的透明囊壁。结论:运用单因素考察法和Box-Behnken效应面法优化DEET微囊的制备工艺,结果准确、有效、可行。     

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。     

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.     

京尼平苷微囊的制备及体外评价

目的:优选制备京尼平苷微囊的工艺条件.方法:明胶为材料,采用单凝聚法,以包封率为评价指标,利用均匀设计法优选最佳的微囊制备条件.结果:囊心囊材比为1∶12,温度45℃,转速为500 r·min-1.结论:微囊制备工艺稳定、粒径分布及溶出符合要求.     

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.     

双嘧达莫缓释微囊的制备与体外评价

目的:研究以明胶和阿拉伯胶为囊材,将双嘧达莫微囊化的制备工艺。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:囊材与囊心物的质量比2∶1,搅拌转速140r·min-1,固化时间3h、成囊pH4.0、成囊温度为50℃为最佳工艺条件。结论:以最佳制备工艺条件制备含药微囊,重复性好,工艺稳定,同时体外溶出实验表明,该微囊具有较好的缓释作用。     

萘普生微囊的制备及其质量考察

目的:制备萘普生微囊并考察其制剂质量。方法:以明胶和阿拉伯胶为囊材,采用复凝聚法将萘普生制成微囊;以阿拉伯胶浓度(A)、萘普生与阿拉伯胶的质量比例(B)和成囊温度(C)为考察因素,包封率为指标设计正交试验优化成囊的最佳制备工艺,并对优化工艺所制得微囊的粒径、包封率、载药量、体外释放性进行考察。结果:最佳工艺条件为A2%、B1:1、C50℃;所制微囊的平均囊径48.92μm,包封率(77.03±1.43)%,载药量(35.31±1.02)%,微囊在48h时体外累积溶出百分率达到91.32%。结论:所制萘普生微囊工艺重现性好、稳定,并具有良好的缓释作用。     

Microencapsulation of thyme oil by coacervation

The objective of this work is to develop a novel coacervation process to produce microcapsules of polylactide (PLA) to encapsulate thyme oil that will be used in cosmetics. The novelty of this approach consists of dissolving PLA in dimethylformamide (DMF) which is a good solvent for PLA but in addition has high solubility in water. Upon contact with water, the homogeneous solution of PLA in DMF promotes the precipitation of PLA around the thyme oil core. The produced microcapsules have bimodal particle size distributions in volume with a mean particle size of 40 µm. Microcapsules analysis by microscopy have confirmed the spherical shape, the rough surface and allowed the estimation of the wall thickness around 5 µm. Quantification of the encapsulated thyme oil was performed by gas chromatography and allowed to evaluate the quality of the encapsulated oil and pointed out for a preferential encapsulation of thyme oil apolar compounds.     

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.     

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     

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.     

Solid lipid nanoparticles produced through a coacervation method

Solid lipid nanoparticles (SLN) of fatty acids (FAs) were prepared with a new, solvent-free technique based on FAs precipitation from their sodium salt micelles in the presence of polymeric non-ionic surfactants: this technique was called ‘coacervation’. Myristic, palmitic, stearic, arachidic and behenic acid were employed as lipid matrixes. Spherical shaped nanoparticles with mean diameters ranging from 250 to ～500 nm were obtained. Different aqueous acidifying solutions were used to precipitate various FAs from their sodium salt micellar solution. Good encapsulation efficiency of Nile Red, a lipophilic model dye, in stearic acid nanoparticles was obtained. The coacervation method seems to be a potentially suitable technique to prepare close to monodisperse nanoparticles for drug delivery purposes.     

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.     

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.     

Effect of the cross-linking agent and drying method on encapsulation efficiency of orange essential oil by complex coacervation using whey protein isolate with different polysaccharides

Orange essential oil was microencapsulated by complex coacervation with whey protein isolate (WPI): carboxymethylcellulose (CMC), WPI:sodium alginate (SA) and WPI:chitosan (CH). Effect of pH, protein:polysaccharide ratio and solid concentration on coacervation efficiency were selected for the best coacervation conditions. Tannic acid (TA), sodium tripolyphosphate, oxidised tannic acid and transglutaminase enzyme (TG) were used as cross-linking agents. Highest encapsulation efficiency (EE) for wet coacervated microcapsules ranged from 88% to 94%. Microcapsules were freeze and spray dried to evaluate their effect on its integrity. EE was higher than 80% in freeze dried coacervated microcapsules with and without cross-linking agent, but they formed a solid cake. Spray-dried samples formed a free fluid solid (10–20?µm), where the systems WPI:CMC and WPI:CH cross-linked with TA and TG, respectively showed the highest EE (47% and 50% respectively), representing 400% improvement compared to the samples without cross-linking.