吡喹酮聚乳酸纳米粒制备工艺研究

目的探讨改良的自乳化溶剂扩散法制备吡喹酮聚乳酸纳米粒的最佳工艺。方法以包封率为指标，采用正交设计，考察聚乳酸和吡喹酮原料药药物的投料比、PVA浓度、有机相与水相体积比和搅拌速度等影响因素，筛选出比较理想的制备工艺。结果最佳工作条件为：聚乳酸与吡喹酮药物的投料比10：1，水相和有机相比为10：1，PVA浓度选择0．5％，搅拌速度600r·min^-1。所得纳米粒包封率为（46．74％±0．47％），收率为（49．30％±1．85％）。结论改良的自乳化溶剂扩散法可用于吡喹酮纳米粒的制备。     

复乳法制备胰岛素PLGA纳米粒影响包封率因素考察

以Poloxamer188为乳化剂，乙酸乙酯为有机溶剂，采用复乳法制备了胰岛素乳酸／羟基乙酸共聚物（PLGA）纳米粒，考察了乳化剂和PLGA的浓度。内水相中胰岛素的浓度为pH，溶剂挥发方法和内水相中加入聚乙烯醇（PVA）等实验各因素对胰岛素PLGA纳米粒包封率的影响。结果表明，乳化剂的浓度较高，PLGA的浓度较小，内水相的pH接近胰岛素的pI(5．3），胰岛素的浓度较低，缩短有机溶剂挥发时间及内水相中加入PVA有利于提高胰岛素的包封率，经实验条件优化后制备的胰岛素PLGA纳米纳平均粒径为149．6nm，多分散性系数小于0．1，包封率提高到42．8％。     

糠酸莫米松固体脂质纳米粒的制备

目的：研究糠酸莫米松固体脂质纳米粒的处方和制备工艺，并对其质量进行评价。方法：用乳化-溶剂挥发法制备糠酸莫米松固体脂质纳米粒，以包封率为指标采用正交设计法优选处方，用透射电镜和激光粒径测定仪测定纳米粒的形态和粒径，用低速离心法测定药物的包封率。结果：制得的糠酸莫米松固体脂质纳米粒形态规整，几呈球形，体积均粒径为73．8nm，包封率为（92．8±0．89）。结论：本研究所得的处方和工艺可制备性能优良的糠酸莫米松固体脂质纳米粒。     

红霉素白蛋白纳米粒的制备及体内药动学研究

摘要：目的:制备红霉素白蛋白纳米粒,以提高红霉素的生物利用度。方法:采用去溶剂化高压均质法制备红霉素白蛋白纳米粒,以载药量、包封率、粒径及多分散系数为评价指标。通过单因素考察及正交试验进行最佳处方工艺的筛选,并对最佳处方工艺进行表征。SD大鼠随机分成2组,分别尾静脉注射红霉素混悬液与红霉素白蛋白纳米粒,比较药动学参数。结果:当药物与白蛋白比例为1∶3、有机相体积为4 ml、高压均质10次、有机相加入方式为注射器注入、搅拌时间为5 h、搅拌速度为700 r·min-1时,所制备的白蛋白纳米粒性质最优,最佳工艺下包封率为（65.61±1.02）%,载药量为（36.49±1.33）%,平均粒径为（280.71±5.82） nm,多分散系数（PDI）为0.20±0.04,电位为-（11.91±2.29） mV。与原料药相比,白蛋白纳米粒的最大血药浓度(Cmax)提高了5.8倍,血药浓度-时间曲线下面积(AUC0→12)提高了5.15倍（P<0.01）。结论:以去溶剂化高压均质法制备的红霉素白蛋白纳米粒制备方法简单,制剂稳定性良好,能显著提高红霉素的体内生物利用度。     

褪黑素固体脂质纳米粒的制备及理化性质

考察不同的处方对褪黑素固体脂质纳米粒粒径和包封率等理化性质的影响，并进行其体外释放实验。结果表明，以单硬脂酸甘油酯为脂质材料，乳化超声法制备固体脂质纳米粒，平均粒径为（62．4±1．5）nm，ζ电位为（-7．0±0．2）mV，平均包封率为（64．6±3．8）％；药物的体外释放符合Weibull模型。     

羟基喜树碱半固体脂质纳米粒的制备和体外释药特性

目的：制备羟基喜树碱的半固体脂质纳米粒（HCPT-SSLN），初步考察其体外释药规律。方法：采用乳化蒸发-低温固化法制备HCPT-SSLN；用激光粒度仪测定其粒径和ξ电位；考察其混悬液和冻千粉的物理稳定性；用透析法考察其体外释药性质。结果：HCPT-SSLN纳米粒平均粒径为130．5nm，裁药量为2．51％，包封率为79．19％，ξ电位为-33．1mV;室温（25℃）和4℃下放置6个月，纳米粒冻干粉和混悬液外观、粒径及包封率无明显变化；体外释药规律符合Weibull方程lnln[1／（1-Q）]=0．26331nt＋0．0509（R^2=0．9485）。结论：制备的HCPT-SSLN包封率高，稳定性好，大小均匀，体外释药具有缓释特点。     

包载尼莫地平的聚乳酸-聚乙二醇嵌段共聚物纳米粒的制备和质量评价

目的制备尼莫地平纳米粒的粉针剂，以期改善尼莫地平难溶于水而导致易析出晶体的问题以及其制剂中乙醇引起血管刺激的毒副作用。方法以聚乳酸、聚乙二醇嵌段共聚物作为载体，用溶剂挥发法制备载药纳米粒水分散体系及其冻干粉针．并评价其粒径、Zeta电位、包封率、载药量、形态和冻干粉针的再分散性等性能。结果制备了136nm载药纳米粒的冻干粉针，Zeta电位为-29．90mV，包封率为67．9％，载药量为6．17％，冻干再分散情况良好。结论所制备的尼莫地平纳米粒基本解决了原有制剂药物溶解性差，易析出晶体的问题，避免使用有机溶剂和有副作用表面活性剂的应用。     

大黄素-聚乳酸-羟基乙酸共聚物纳米粒的制备

目的 制备大黄素-聚乳酸-羟基乙酸( emodin-polylactic-co-glycolic acid,EMD-PLGA NPs)共聚物纳米粒,观察其电镜形态、稳定性,测定粒径、包封率、载药量.方法 采用乳化-溶剂挥发法( emulsion solvent evaporation method)按照正交设计制备EMD-PLGA NPs并优化处方,透射电镜下观察纳米粒的外观形态,激光粒度仪检测纳米粒的大小、分布及zeta电位,沉降法观察稳定性,用紫外分光光度计测定大黄素纳米粒的吸光度以计算包封率、载药量.结果 得到最佳优化处方工艺条件,在最佳条件下制得大黄素纳米粒呈圆球状或椭圆状;粒径约( 100±50 )nm;分散体系的颗粒由上而下呈逐渐变淡的弥散分布,无明显的沉积物;包封率为(24.5±1.9)％,载药量为(18.5±3.7)％.结论 采用乳化-溶剂挥发法制备大黄素-PLGA纳米粒,该方法材料简单,便于操作,优于以往的固体脂质纳米粒法;制备的大黄素纳米粒粒径小、分布均匀、载药率较高,药物吸光度及稳定性等均符合要求,为进一步制备组织靶向药物的研究奠定了基础.     

改良自乳化-溶剂扩散法制备甲基莲心碱纳米粒的研究

目的制备甲基莲心碱纳米粒(NEF-NP),并采用正交试验设计对甲基莲心碱纳米粒制备工艺进行优化。方法以包封率和载药量为评价指标,采用聚乳酸-羟基乙酸共聚物(PLGA)为载体,丙酮-无水乙醇为有机溶剂,通过正交设计优化改良自乳化-溶剂扩散法制备载NEF的PLGA载药纳米粒的处方工艺。结果优化的最佳处方工艺为:PLGA的浓度为20 mg.mL-1,NEF的投药量为3.3 mg,PVA浓度为1.0%,水相与有机相的体积比为8∶1。最佳条件下制得的纳米粒平均包封率达(70.35±1.16)%,载药量(2.33±1.08)%,平均粒径为(213.5±2.7)nm。结论最佳处方工艺制备的NEF-PLGA纳米粒具有较高的包封率、载药量和较小的粒径。     

亮丙瑞林硬脂酸纳米粒的制备及其理化性质研究

目的制备亮丙瑞林硬脂酸纳米粒,并对其理化性质进行研究。方法分别采用溶剂扩散法和乳化溶剂蒸发法制备硬脂酸固体脂质纳豢粒．并潮定纳束粒形态、粒径、药物包封率和体外释放等理化性质。结果溶剂扩散法和乳化溶剂蒸发法制备得到的硬脂酸纳米粒平均粒径均在400nm左右,形态呈椭圆形。与溶剂扩散法相比．以乳化溶剂蒸发法制备的纳米粒,亮丙瑞林的药物包封率从28．0％提高到53．1％。体外释放2h的药物突释量显著下降。药物释放总维持时闻在24h左右。结论以乳化溶剂扩散法制备亮丙瑞林硬脂酸SLN。药物包封率高。药物突释量小。具有一定的亮丙瑞林口服给药开发前景。     

阿柔比星A聚乳酸毫微粒主要性质研究

目的：对载药毫微粒主要质量指标载药量、包封率及其关系,粒径及其分布进行研究,方法：以阿柔比星Ａ聚乳酸微粒为研究对象,以分光光度测定载药量与包封率,以激光粒度分析仪测定粒径及其分布。结果：阿柔比星Ａ聚乳酸毫微粒平均载药量为１８．５％。平均包封率为８６．７％,平均数目径为８０ｎｍ,平均体积径为２３０ｎｍ。结论：载药量与包封率之间具有一定关系。体积径分布是载药毫微粒粒径分布评价不可忽视的内容。     

Preparation of poly(DL-lactide-co-glycolide) nanoparticles by modified spontaneous emulsification solvent diffusion method.

PURPOSE: The objectives of this study were to establish a new preparation method for poly(DL-lactide-co-glycolide) (PLGA) nanoparticles by modifying the spontaneous emulsification solvent diffusion (SESD) method and to elucidate the mechanism of nanoparticle formation on the basis of the phase separation principle of PLGA and poly(vinyl alcohol) (PVA) in the preparation system. METHODS: PLGA nanoparticles were prepared by the modified-SESD method using various solvent systems consisting of two water-miscible organic solvents, in which one solvent has more affinity to PLGA than to PVA and the other has more affinity to PVA than to PLGA. The yield, particle size, size distribution and PVA content of the PLGA nanoparticles were evaluated, and the phase separation behaviors of the polymers were elucidated. RESULTS: The modified-SESD method provided a good yield of PLGA nanoparticles over a wide range of composition ratios in the binary mixture of organic solvents. Several process parameters, including the fed amount of PLGA, PLGA concentration and PVA concentration were examined to achieve the optimum preparation conditions. The discrete powder of PLGA nanoparticles was obtained by freeze-drying. No change in the PVA content of PLGA nanoparticles was observed even after several times of washing treatment by ultrafiltration, suggesting a strong surface adsorption. It was found that the appropriate selections of binary solvent mixtures and polymeric concentrations in both organic and aqueous phases could provide excellent yield and favorable physical properties of PLGA nanoparticles. CONCLUSION: The proposed modified-SESD method can be used to provide PLGA nanoparticles of satisfactory quality at an acceptable yield for industrial purposes.     

A novel formulation design about water-insoluble oily drug: preparation of zedoary turmeric oil microspheres with self-emulsifying ability and evaluation in rabbits

To enhance in vivo absorption of zedoary turmeric oil (ZTO) and develop new formulations of a water-insoluble oily drug, novel ZTO microspheres with self-emulsifying ability, called self-emulsifying microspheres here, were prepared in a liquid system by the quasi-emulsion solvent diffusion method. The microspheres containing hydroxypropyl methylcellulose acetate succinate (HPMCAS-LG), Talc and Aerosil 200 formed the stable surfactant-free emulsion when exposed to the pH 6.8 phosphate buffer, and were significantly different from the conventional self-emulsifying systems (SES), defined as isotropic mixtures of oil, surfactant and drug. Micromeritic properties, the efficiency of emulsification and the drug-release rate of the resultant microspheres were investigated. The bioavailability of the microspheres to the conventional self-emulsifying formulation for oral administration was evaluated in 12 healthy rabbits. A HPLC method was employed to determine the plasma concentration of Germacrone, an indexical component found in ZTO. The release rates of ZTO and Germacrone from the microspheres were enhanced significantly with increasing amounts of dispersing agents, and the efficiency of self-emulsification greatly depended on the HPMCAS-LG/Aerosil 200 ratio. The emulsion droplets released from the microspheres were much smaller than that of the conventional SES. The microsphere bioavailability (F) to the conventional SES for oral administration was 157.7%. Our method greatly improved the bioavailability of the water-insoluble oily drug from the self-emulsifying microspheres over the conventional SES and it is useful for the oily drug to form solid preparations.     

Transdermal delivery of zidovudine: effect of vehicles on permeation across rat skin and their mechanism of action.

The purpose of this study was to investigate the effects of various solvent systems containing water, ethanol, propylene glycol (PG), and their binary combinations on the ex vivo permeation of zidovudine (AZT) across Sprague-Dawley rat skin using Franz diffusion cells at 37 degrees C. Further, saturation solubility and epidermis/vehicle partition coefficient of AZT in the solvent systems, and their effect on percentage hydration of epidermis using thermogravimetric analysis were determined to understand the mechanisms by which these solvent systems change drug permeability properties. All binary combinations of PG, ethanol and water significantly increased saturation solubility of AZT. Maximum AZT flux was observed with 66.6% ethanol among ethanol-water solvents, with 33.3% PG in PG-water solvents and with 100% ethanol among PG-ethanol combinations. PG-water and PG-ethanol solvents neither reduced the lag time nor increased AZT flux across rat skin. In addition, high concentrations of PG in both water and ethanol reduced steady state flux of AZT. Further, thermogravimetric studies revealed that solvents containing high PG concentrations dehydrate epidermis. Among all the solvent combinations, highest flux and short lag time were achieved with ethanol at 66.6% in water and hence is a suitable vehicle for transdermal delivery of AZT.     

Preparation and stabilization of nifedipine lipid nanoparticles

Design methods of nanoparticle formulations are divided into a break-down method and a build-up method. Furthermore, the former is further divided into dry and wet processes. For drug nanoparticle preparations, the wet process is generally employed, and organic solvents are used in most formulations. In this study, we investigated the preparation of nifedipine (NI) nanoparticles without using any organic solvent. NI nanoparticles with a mean particle size of approximately 50 nm could be prepared without organic solvent by a combination of roll mixing and high-pressure homogenization. The X-ray diffraction peak of the sample prepared by roll mixing was present at an identical position (2theta) to that of NI crystals, showing that no peak shift was induced by interaction with lipid. These findings clarified that most NI remained as crystals in lipid. To maintain the particle size of the nanoparticles in suspension for a long time, a method of adding gelatin powder to the NI-lipid nanoparticle suspension, dissolving the mixture by heating, and then solidifying by cooling was investigated. The mean particle size of the sample was about 55 nm, and that after heat-liquefaction of the NI-lipid nanoparticle suspension gelated at 5 degrees C for 24h was also about 55 nm, showing that the nanoparticle condition was retained.     

Biodegradable poly(epsilon -caprolactone) nanoparticles for tumor-targeted delivery of tamoxifen

To increase the local concentration of tamoxifen in estrogen receptor (ER) positive breast cancer, we have developed and characterized nanoparticle formulation using poly(epsilon -caprolactone) (PCL). The nanoparticles were prepared by solvent displacement method using acetone-water system. Particle size analysis, scanning electron microscopy, zeta potential measurements, and differential scanning calorimetry (DSC) were used for nanoparticle characterization. Biodegradation studies were performed in the presence and absence of Pseudomonas lipase in phosphate-buffered saline (PBS, pH 7.4) at 37 degrees C. Tamoxifen loading over different concentrations was analyzed by high-performance liquid chromatography (HPLC) and the optimum loading concentration was determined. In vitro release studies were performed in 0.5% (w/v) sodium lauryl sulfate (SLS) containing PBS at 37 degrees C. Cellular uptake and distribution of fluorescent-labeled nanoparticles was examined in MCF-7 breast cancer cells. SEM micrographs and Coulter analysis showed nanoparticles with spherical shape and uniform size distribution (250-300 nm), respectively. Zeta potential analysis revealed a positive surface charge of +25 mV on the tamoxifen-loaded formulation. Being hydrophobic crystalline polyester, PCL did not degrade in PBS alone, but the degradation was enhanced by the presence of lipase. The maximum tamoxifen loading efficiency was 64%. Initial burst release of tamoxifen was observed, probably due to significant surface presence of the drug on the nanoparticles. A large fraction of the administered nanoparticle dose was taken up by MCF-7 cells through non-specific endocytosis. The nanoparticles were found in the perinuclear region after 1 h. Results of the study suggest that nanoparticle formulations of selective ER modulators, like tamoxifen, would provide increased therapeutic benefit by delivering the drug in the vicinity of the ER.     

Solid Lipid Nanoparticles of a Water Soluble Drug,Ciprofloxacin Hydrochloride

The aim of this study was to understand and investigate the relationship between experimental factors and their responses in the preparation of ciprofloxacin hydrochloride based solid lipid nanoparticles. A quadratic relationship was studied by developing central composite rotatable design. Amount of lipid and drug, stirring speed and stirring time were selected as experimental factors while particle size, zeta potential and drug entrapment were used as responses. Prior to the experimental design, a qualitative prescreening study was performed to check the effect of various solid lipids and their combinations. Results showed that changing the amount of lipid, stirring speed and stirring time had a noticeable influence on the entrapment efficiencies and particle size of the prepared solid lipid nanoparticles. The particle size of a solid lipid nanoparticle was in the range of 159-246 nm and drug encapsulation efficiencies were marginally improved by choosing a binary mixture of physically incompatible solid lipids. Release of ciprofloxacin hydrochloride from solid lipid nanoparticle was considerably slow, and it shows Higuchi matrix model as the best fitted model. Study of solid lipid nanoparticle suggested that the lipid based carrier system could potentially be exploited as a delivery system with improved drug entrapment efficiency and controlled drug release for water soluble actives.     

Preparation of an enteric-soluble solid-state emulsion using oily drugs

To improve the patient's compliance and enhance the stability of oily drugs in the gastric fluid, an enteric-soluble solid-state emulsion (ESE), was developed. The ESE was prepared by spreading liquid o/w-emulsions on a flat glass and drying at the oven maintained at 40 degrees C. Aerosil 200 was applied as solid carrier and emulsifier. And Eudragit L30D-55 was used as enteric coating material. The influence of various preparation parameters on the residual volatile oil and the release behavior was investigated. Droplet size distribution of the primary emulsions and the emulsion after reconstitution of zedoary turmeric oil (ZTO) ESE in the phosphate buffer were also measured. When ZTO ESE was immersed into phosphate buffer (pH 6.8), the stable emulsion was formed in 20min, but the release was obviously suppressed when it was exposed to the gastric fluid. It was concluded that preparation of enteric-soluble solid-state emulsion by the present method for oral oily drug was feasible.     

Effect of conditions of preparation on the size and encapsulation properties of PLGA-mPEG nanoparticles of cisplatin

The effect of conditions of preparation on the size and encapsulation properties of PLGA-mPEG nanoparticles of cisplatin was investigated. A modified double emulsion method was applied for the preparation of PLGAmPEG nanoparticles of cisplatin, based on the partial or complete replacement of the water of the inner aqueous phase of the emulsion by dimethyl formamide(dmf) or the addition of cisplatin in the form of a complex with poly(glutamic acid). These modifications resulted in significant improvement of cisplatin loading in the PLGA-mPEG nanoparticles. Increased cisplatin loading and encapsulation efficiency were obtained when a relatively low dmf/water ratio, low dmf volume (when pure dmf formed the inner polar phase), or a high drug/polymer ratio were applied. A reduction of average size of nanoparticles was observed with decreasing the amount of PLGA-mPEG added in the formulation or increasing sonication time. The only factor that had a significant effect on size distribution was the sonication time, with the size P.I. being decreased with increasing sonication time. Prolonged sonication, however, decreased cisplatin loading and encapsulation efficiency. From the four lyoprotectant sugars tested (glucose, lactose, mannitol, and trehalose), only mannitol could prevent nanoparticle aggregation upon lyophilization. When appropriate amounts of an effective lyoprotectant were added in nanoparticles before lyophilization, drug loading of the nanoparticles was not affected by nanoparticle lyophilization.