黄豆苷元固体脂质纳米粒的制备及其性质考察

目的制备黄豆苷元固体脂质纳米粒并考察其性质。方法采用正交实验法优化黄豆苷元固体脂质纳米粒的最佳处方,并测定黄豆苷元固体脂质纳米粒的粒径、ζ电位、包封率、稳定性和累积释放百分率。结果黄豆苷元固体脂质纳米粒的最佳处方组合为：单硬脂酸甘油酯用量为2.0%,黄豆苷元用量为2.0 mg.mL-1,豆磷脂的用量为0.4%,Pluronic F68的用量为1.2%。所制得的纳米粒包封率为84.7%、平均粒径为170 nm、ζ电位为-35.8 mV、72 h累积释放百分率为90.3%。结论新制黄豆苷元固体脂质纳米粒的粒度分布范围窄,包封率较高,稳定性良好。     

黄豆苷元固体脂质纳米粒的制备及其性质考察

目的 制备黄豆苷元固体脂质纳米粒并考察其性质。方法 采用正交实验法优化黄豆苷元固体脂质纳米粒的最佳处方,并测定黄豆苷元固体脂质纳米粒的粒径、ζ电位、包封率、稳定性和累积释放百分率。结果 黄豆苷元固体脂质纳米粒的最佳处方组合为：单硬脂酸甘油酯用量为2.0%,黄豆苷元用量为2.0 mg·mL^-1,豆磷脂的用量为0.4%, Pluronic F68的用量为1.2 %。所制得的纳米粒包封率为84.7%、平均粒径为170 nm、ζ电位为-35.8 mV、72 h累积释放百分率为90.3%。结论 新制黄豆苷元固体脂质纳米粒的粒度分布范围窄,包封率较高,稳定性良好。     

不同工艺制备的固体脂质纳米粒系统性能比较研究

目的：比较不同工艺制备的固体脂质纳米粒系统性能。方法：分别采用长时间高剪切法、长时间探头超声法、单次高剪切超声法和改进的高剪切超声法制备固体脂质纳米粒混悬液，应用激光粒度仪分析仪测定纳米粒粒径及其分布特征，据此评价4种方法制备的固体脂质纳米粒系统性能。结果：与其他3种制备方法比较，改进的高剪切超声法制备的固体脂质纳米粒混悬液粒径分布窄，且呈单模分布，平均粒径约100nm，具良好的贮存稳定性，4℃下可稳定放置达半年。结论：改进的高剪切超声法可制备出性能优良的稳定的固体脂质纳米粒系统。     

氟尿苷二醋酸酯固体脂质纳米粒的研制及质量评价

目的：对氟尿苷二醋酸酯固体脂质纳米粒的制备工艺和含量测定方法进行研究，并对其质量进行评价。方法：采用薄膜超声分散法制备氟尿苷二醋酸酯固体脂质纳米粒，并对其包封率、形态等性质进行研究。结果：制得氟尿苷二醋酸酯固体脂质纳米粒形态均匀圆整、粒径范围为（215．3±83．1）nm，包封率为98．27％，裁药量为8．20％。结论：选择薄膜超声分散法制备氟尿苷二醋酸酯固体脂质纳米粒方法可行，为开发氟尿苷新型注射制剂提供了实验依据。     

莪术油固体脂质纳米粒的制备

目的研究影响莪术油固体脂质纳米粒制备的主要因素。方法采用高压均质法制备莪术油固体脂质纳米粒混悬液,以单因素考察和正交设计法筛选出比较理想的处方和工艺,并考察其形态、粒径、载药量及包封率。结果所制得的固体脂质纳米粒为圆整的类球形实体粒子,表面光滑,平均粒径为80.3nm,载药量为11.82%,包封率为81.75%。结论高压均质法可用于莪术油类液体药物固体脂质纳米粒的制备。     

降香挥发油固体脂质纳米粒的制备工艺研究

目的研究降香挥发油固体脂质纳米粒制备中的主要影响因素。方法分别采用高压乳匀法和熔融 超声法制备了降香挥发油固体脂质纳米粒混悬液。以单因素考察和正交设计法研究制备工艺中影响降香挥发油固体脂质纳米粒质量的主要因素 ,筛选出较理想的处方和工艺。结果所得纳米粒为圆整的类球形实体粒子 ,表面光滑 ,平均粒径为 4 0 0nm和 34 5nm ,含药量为 72 11%和71 5 4 % ,包封率为 91 2 7%和 92 36 %。结论采用熔融 超声法制备降香挥发油固体脂质纳米粒实用性更强。     

全反式维甲酸固体脂质纳米粒的制备及体内外评价

目的以山嵛酸甘油酯(Compritol 888 ATO)为脂质材料，采用超声分散法制备维甲酸固体脂质纳米粒，并考察其体内外性质。方法选用脂溶性较高的维甲酸作为模型药物，采用超声分散法制备固体脂质纳米粒，并对其各种理化性质进行研究。考察了纳米粒的体外释放，以维甲酸溶液剂为对照，测定了两种纳米粒在大鼠体内的药代动力学参数。结果采用超声分散法可以简便、快速制备得到两种维甲酸固体脂质纳米粒，透射电镜测得纳米粒为圆球状，大小均匀。动态光散射法测得平均粒径分别为(158±9) nm和(89±11) nm。于4 ℃放置1年粒径无明显变化，载药量为3.3%，包封率大于95%。药物体外释放符合Weibull方程。与对照组相比，两种维甲酸固体脂质纳米粒静脉注射后药物在血液中的滞留时间显著延长。结论超声分散法适用于固体脂质纳米粒的制备。     

壳聚糖修饰的托氟啶固体脂质纳米粒的制备

摘 要 目的： 研究托氟啶固体脂质纳米粒及壳聚糖修饰的托氟啶固体脂质纳米粒的制备方法。方法: 采用薄膜 超声分散法制备托氟啶固体纳米脂质粒（TFu-SLNs）及壳聚糖修饰的TFu-SLNs,并对纳米粒的形态、粒径和表面电位进行测定,通过单因素考察及正交设计优化制备方法,同时考察处方稳定性。结果: 薄膜 超声分散法制备的TFu-SLNs平均粒径为160.2 nm,Zeta电位为－33.12 mV,壳聚糖修饰TFu-SLNs平均粒径为400.3 nm,Zeta电位为+12.87 mV。经壳聚糖修饰后,随着壳聚糖浓度的增加,电位逐渐增大。优化后的处方重复性、稳定性良好。结论:通过采用正交设计法对TFu固体脂质纳米粒处方进行优化,得到TFu固体脂质纳米粒及壳聚糖修饰的TFu固体脂质纳米粒的优化处方。     

乳化蒸发法制备固体脂质纳米粒

目的：采用乳化蒸发法制备固体脂质纳米粒,并考察其载药性能。方法：对影响固体脂质纳米粒质量的工艺因素和处方因素进行考察和优化设计,得到最优处方。选用模型药物酮洛芬制备载药固体脂质纳米粒,考察其包封率和体外释放行为。结果：所得固体脂质纳米粒平均粒径为（228.2±18.1）nm,多分散系数为（0.217±0.022）,ξ电位为-（21.4±0.6）mV。载药固体脂质纳米粒最佳包封率为（64.1±3.3）%,体外释放行为符合Weibull模型。结论：采用乳化蒸发法制备固体脂质纳米粒是可行的。     

酮洛芬固体脂质纳米粒的制备

目的：微乳法制备固体脂质纳米粒,以酮洛芬作为模型药物,考查其载药性能。方法：通过对空白微乳粒径和稳定性考查,确定优化处方,将其保温分散于冷水中制备固体脂质纳米粒。对影响其质量的工艺因素和处方因素进行考查和优化设计,筛选最优处方。结果：制备固体脂质纳米粒的直接影响因素包括脂质用量、药物的用量、冷水相温度和微乳保温温度等,所得固体脂质纳米粒的平均粒径（143.9±1.2）nm,多分散系数为0.443。载药固体脂质纳米粒包封率为81.47%,载药量为8.16%。结论：该法稳定可靠,可用于酮洛芬固体脂质纳米粒的制备。     

Scale-up and optimization of an evaporative drying process applied to aqueous dispersions of solid lipid nanoparticles

An apparatus to dry aqueous dispersions of solid lipid nanoparticles (SLNs) was designed. Optimal running conditions were evaluated to obtain minimum process time and produce dried SLNs characterized by small size variation. To achieve process optimization, SLN average diameter, SLNs polydispersity index, and drying time were related to three operative variables: process temperature, SLN concentration in the original aqueous dispersions, and nitrogen flow rate as the physical means of the drying process. An experimental design procedure and a multicriteria optimization method, targeting desirability functions, enabled us to obtain the optimal conditions for all responses. Drying time, average diameter, and polydispersity index of dried SLN batches were more favorable than those obtained by freeze-drying identical SLN aqueous dispersions with the same initial nanoparticle concentration.     

Improved dissolution behavior of lipophilic drugs by solid dispersions: the production process as starting point for formulation considerations

INTRODUCTION: Many new drug substances have low aqueous solubility which can cause poor bioavailability after oral administration. The application of solid dispersions is a useful method to increase the dissolution rate of these drugs and thereby improve their bioavailability. So far, several methods have been developed to prepare solid dispersions. To obtain a product with the desired attributes, both the formulation and production processes should be considered. AREAS COVERED: The most currently used methods to produce solid dispersions, such as the fusion method, hot melt extrusion, spray drying, freeze drying and supercritical fluid precipitation, are reviewed in this paper. In addition, the physicochemical characteristics of the obtained solid dispersions are discussed. EXPERT OPINION: Solid dispersions can be successfully prepared by simple fusion, hot melt extrusion, spray drying, freeze drying and supercritical fluid precipitation. Hot melt extrusion, spray drying and freeze drying are processes that can be applied for large scale production. The simple fusion method is not very suitable for large scale production, but is particularly suitable for screening formulations. The most recent method to produce sold dispersions is supercritical fluid precipitation. The process conditions of this method need extensive investigation, in particular in relationship with the selection of the type of carrier and/or solvent. Both processes and formulation aspects strongly affect the characteristics of solid dispersion products. Furthermore, application of crystalline solid dispersions is gaining increasing interest because they are thermodynamically more stable than amorphous solid dispersions.     

Single step bottom-up process to generate solid phospholipid nano-particles

Abstract

Context: The particularity of the Nano Spray Dryer B-90 is the nozzle containing a mesh vibrating at ultrasonic frequency.

Objective: To study process parameters and processability of crude phospholipid dispersions, in particular the effect of concentration and mesh aperture on both particle size of the dry solid phospholipid nano-particles and on the re-dispersed powder.

Materials and methods: Phospholipid dispersions containing trehalose as a stabilizer were spray dried. Particle size distributions of dry powders were evaluated by SEM micrographs and by PCS and cryo-TEM for the re-dispersed particles.

Results: Spray drying of crude liposome dispersions revealed solid phospholipid nano-particles. Aperture of nozzle mesh and concentration of the dispersions, respectively, both increased the size of solid phospholipid nano-particles. For crude dispersions, an upper limit with respect to processability was found close to below 10% (m/m) even if the crude dispersion was passed along the mesh several times; however, more effective dispersing methods such as pre-sonication can push the limit of processability to higher values.

Discussion and conclusion: The nano spray dryer is capable of spray drying crude dispersions of phospholipids in concentrations below 10% (m/m) generating solid phospholipid nano-particles relevant for pulmonary delivery. Re-dispersion of spray dried powder reveals liposomes.     

Improved dissolution behavior of lipophilic drugs by solid dispersions: the production process as starting point for formulation considerations

Introduction: Many new drug substances have low aqueous solubility which can cause poor bioavailability after oral administration. The application of solid dispersions is a useful method to increase the dissolution rate of these drugs and thereby improve their bioavailability. So far, several methods have been developed to prepare solid dispersions. To obtain a product with the desired attributes, both the formulation and production processes should be considered.

Areas covered: The most currently used methods to produce solid dispersions, such as the fusion method, hot melt extrusion, spray drying, freeze drying and supercritical fluid precipitation, are reviewed in this paper. In addition, the physicochemical characteristics of the obtained solid dispersions are discussed.

Expert opinion: Solid dispersions can be successfully prepared by simple fusion, hot melt extrusion, spray drying, freeze drying and supercritical fluid precipitation. Hot melt extrusion, spray drying and freeze drying are processes that can be applied for large scale production. The simple fusion method is not very suitable for large scale production, but is particularly suitable for screening formulations. The most recent method to produce sold dispersions is supercritical fluid precipitation. The process conditions of this method need extensive investigation, in particular in relationship with the selection of the type of carrier and/or solvent. Both processes and formulation aspects strongly affect the characteristics of solid dispersion products. Furthermore, application of crystalline solid dispersions is gaining increasing interest because they are thermodynamically more stable than amorphous solid dispersions.     

Cyclosporine a loaded solid lipid nanoparticles: optimization of formulation, process variable and characterization

Solid lipid nanoparticles (SLNs) loaded with Cyclosporine A using glyceryl monostearate (GMS) and glyceryl palmitostearate (GPS) as lipid matrices were prepared by melt-homogenization using high-pressure homogenizer. Various process parameters such as homogenization pressure, homogenization cycles and formulation parameters such as ratio of drug: lipid, emulsifier: lipid and emulsifier: co-emulsifier were optimized using particle size and entrapment efficiencies as the dependent variables. The mean particle size of optimized batches of the GMS SLN and GPS SLN were found to be 131 nm and 158 nm and their entrapment efficiencies were 83 +/- 3.08% and 97 +/- 2.59% respectively. To improve the handling processing and stability of the prepared SLNs, the SLN dispersions were spray dried and its effect on size and reconstitution parameters were evaluated. The spray drying of SLNs did not significantly alter the size of SLNs and they exhibited good redispersibility. Solid state studies such as Infra Red Spectroscopy and Differential Scanning Calorimetry indicated absence of any chemical interaction between Cyclosporine A and the lipids. Scanning Electron Microscopy of optimized formulations showed spherical shape with smooth and non porous surface. In vitro release studies revealed that GMS based SLNs released the drug faster (41.12% in 20 hours) than GPS SLNs (7.958% in 20 hours). Release of Cyclosporine A from GMS SLN followed Higuchi equation better than first order while release from GPS SLN followed first order better than Higuchi model.     

Anomalous properties of spray dried solid dispersions

The use of solid dispersions for oral dosage forms can increase the dissolution rate of poorly soluble drugs. Spray drying is one process that can be used to prepare solid dispersions. Spray dried solid dispersions of griseofulvin, poly[N-(2-hydroxypropyl)methacrylate] (PHPMA) and polyvinylpyrrolidone (PVP) were prepared from acetone and water. When methanol was substituted for water, the morphology, stability and dissolution properties of the solid dispersion changed dramatically. The glass transition temperature for the ternary solid dispersion (GF, PHPMA, and PVP) shifted from 83°C (acetone/water) to 103°C for the acetone/methanol system. These differences in the dispersions are thought to derive from conformational variations of the polymers in solution prior to spray drying. Both PHPMA and PVP formed globules in solution of a size range between 16 and 33 nm. The effect of drug and polymer concentration in solution (before spray drying) on the properties of the solid dispersion was studied. It was found that solid dispersions that were prepared using lower concentrations of drug and polymers in solutions resulted in the formation of particles that display a lower relaxation rate. This result supports the hypothesis that the polymer conformation may significantly change the properties of the solid dispersion. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4724–4737, 2009     

Silymarin-solid dispersions: characterization and influence of preparation methods on dissolution

The influence of preparation methodology of silymarin solid dispersions using a hydrophilic polymer on the dissolution performance of silymarin was investigated. Silymarin solid dispersions were prepared using HPMC E 15LV by kneading, spray drying and co-precipitation methods and characterized by FTIR, DSC, XRPD and SEM. Dissolution profiles were compared by statistical and model independent methods. The FTIR and DSC studies revealed weak hydrogen bond formation between the drug and polymer, while XRPD and SEM confirmed the amorphous nature of the drug in co-precipitated solid dispersion. Enhanced dissolution compared to pure drug was found in the following order: co-precipitation > spray drying > kneading methodology (p < 0.05). All preparation methods enhanced silymarin dissolution from solid dispersions of different characteristics. The co-precipitation method proved to be best and provided a stable amorphous solid dispersion with 2.5 improved dissolution compared to the pure drug.     

Preparation, characterization and in vitro dissolution of aceclofenac-loaded PVP solid dispersions prepared by spray drying or rotary evaporation method

This study was conducted to enhance dissolution rate of aceclofenac (ACF) with extremely low solubility and high permeability (BCS class II) in water using poly vinyl pyrrolidone (PVP) and sodium lauryl sulfate as carriers. Solid dispersions were prepared by spray drying method and rotary evaporation method using different ratios of ACF and polymers. The characterization of solid dispersions was evaluated by scanning electron microscopy, Fourier transformation infrared spectroscopy, differential scanning calorimetry and powder X-ray diffractometer. The dissolution behavior of solid dispersions was compared with pure ACF (API) and Airtal^® (Deawoong, Co, Korea) as control groups in simulated phosphate buffer at pH 6.8. The dissolution rate of the drug was affected by nature and amount of polymer used. The prepared solid dispersion of ACF/PVP (1:5) appeared to have the highest dissolution rate. Therefore, solid dispersion techniques of spray drying and rotary evaporation method can be successfully used for the enhancement of the dissolution rate of ACF.     

Flocculated Amorphous Nanoparticles for Highly Supersaturated Solutions

Purpose  To recover polymer-stabilized amorphous nanoparticles from aqueous dispersions efficiently by salt flocculation and to show that the particles redisperse and dissolve rapidly to produce highly supersaturated solutions. Methods  Nanoparticle dispersions of itraconazole stabilized by nonionic polymers were formed by antisolvent precipitation and immediately flocculated with sodium sulfate, filtered and dried. The size after redispersion in water, crystallinity, and morphology were compared with those for particles produced by spray drying and rapid freezing. Results  Particle drug loading increased to ∼90% after salt flocculation and removal of excess polymer with the filtrate. The formation of the flocs at constant particle volume fraction led to low fractal dimensions (open flocs), which facilitated redispersion in water to the original primary particle size of ∼300 nm. Amorphous particles, which were preserved throughout the flocculation–filtration–drying process, dissolved to supersaturation levels of up to 14 in pH 6.8 media. In contrast, both spray dried and rapidly frozen nanoparticle dispersions crystallized and did not produce submicron particle dispersions upon addition to water, nor high supersaturation values. Conclusions  Salt flocculation produces large yields of high surface area amorphous nanoparticle powders that de-aggregate and dissolve rapidly upon redispersion in pH 6.8 media, for supersaturation levels up to 14.     

Preparation and characterisation of novel spray-dried nano-structured para-aminosalicylic acid particulates for pulmonary delivery: impact of ammonium carbonate on morphology, chemical composition and solid state

Objectives The objective of this work was to spray dry p‐aminosalicylic acid (PAS) and its ammonium salt and to investigate the impact of the pore‐forming agent, ammonium carbonate (AC), on the morphological, aerodynamic and physicochemical properties of the resulting powders. Methods Microparticles were prepared by spray drying from ethanol/water solvent systems. Their solid‐state properties were evaluated by scanning electron microscopy, powder X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis and in‐vitro deposition, using the twin impinger. Key Findings The physicochemical properties of PAS were altered on spray drying with AC and a new solid state was produced. The solution composition impacted on the morphology of the resulting powders, which ranged from irregular crystal agglomerates to spherical crystal clusters and porous microparticles. The chemical composition, structure and morphology were dependent on process inlet temperature, low inlet temperatures resulting in a novel solid of stoichiometry; PAS : ammonia : water, 2 : 1 : 0.5. At higher temperatures pure PAS was obtained. In‐vitro deposition studies showed an increase in emitted dose from spray dried drug, relative to the micronised PAS. Conclusions Under appropriate process conditions AC interacts with the acidic PAS, resulting in the formation of a novel solid‐state drug phase. Spray‐dried PAS powders have potential for pulmonary delivery.