Prediction of particle size distribution of dronedarone hydrochloride in spiral jet mill using design of experiments

In pharmaceutical industry, micronization is used to achieve solubility enhancement through the increase in specific surface area, and finally improving the dissolution rate of the drug. Industrial application of micronization is mostly based on experience and trial and error method. This research deals with the micronization of dronedarone hydrochloride and the path for evaluation of characteristics of micronized drug. Micronization was performed in laboratory spiral jet mill and the samples were analyzed to determine particle size distribution, span of distribution, sphericity, shape, and specific surface area. Results were analyzed using analysis of variance and in terms of specific energy consumption. Paths for evaluation of particle size and span of distribution were proposed and good correlation between experimental and model results was achieved.     

Production of microparticles from milk fat products using the Supercritical Melt Micronization (ScMM) process

The ScMM (Supercritical Melt Micronization) process was applied for the production of microparticles from anhydrous milk fat (AMF) and a diacylglycerol-based modified milk fat (D-AMF). Both fats were able to dissolve ca. 30 wt% CO₂ in the studied pressure and temperature ranges, being the CO₂ amount slightly higher for AMF. A melting point depression was observed in both systems in the presence of CO₂. Two powder morphologies were obtained (spherical hollow particles and a mass sponge-like broken particles) depending on the ScMM process conditions. The concentration of CO₂ in the fat melt was the main process variable affecting the particle morphology, followed by the temperature of the melt. The small broken particles originated from the breakage of spherical fat particles that solidified before all CO₂ could escape from the atomized droplets. While the hollow spheres had a tendency to agglomerate, the broken microparticles constituted a free-flowing powder as long as they were stored at low temperatures (up to −18 °C). Both types of particles have a potential for being incorporated in refrigerated or frozen food products as a structuring agent.     

用含夹带剂丙酮的超临界CO2快速膨胀法制备灰黄霉素的微细颗粒

Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).     

聚乙烯微粉蜡在精细化工行业中的应用

本文介绍了聚乙烯微粉蜡乳液在涂料度水性油墨中的应用，阐述了微粉蜡的应用机理和在加工中所使用的工艺，列举了聚乙烯微粉蜡乳液在使用过程中应注意的问题以度其行业发展前景。     

Micronization of Dihydroartemisinin by Rapid Expansion of Supercritical Solutions

The purpose of this study was to prepare fine particles of antimalarial drug dihydroartemisinin (DHA) by rapid expansion of supercritical solutions (RESS) using carbon dioxide as supercritical fluid. The mechanical grinding by jet mill and additional vibration rod mill also was performed as a comparative method. In the RESS process, drug particles were prepared by varying processing conditions, including extraction condition, pre-expansion condition, nozzle diameter, nozzle temperature, and collecting distance. Particle size and morphology and physicochemical characteristics of the drug particles were investigated. The RESS process could produce the smaller drug particles (about 1–2 μm) when compared to mechanical grinding method (about 7 μm). All RESS processing parameters had an effect on size and morphology of drug particles. The particle size of drug was related to the solubility of drug in supercritical CO₂ at each processing condition. The fine particles of DHA (about 1 μm) with narrow size distribution could be obtained at extraction pressure of 18 MPa and extraction temperature of 32°C, which was closed to the critical temperature of supercritical CO₂ whereas broad size distribution was obtained at extraction temperature of 60°C. Powder X-ray diffraction study indicated that the RESS-processed particles were in crystalline form. The results revealed that RESS process is applicable for micronization of DHA.     

超微粉碎对藕节膳食纤维理化性质的影响

目的研究超微粉碎对藕节理化性质的影响,增强其膳食纤维的生理功能,提高可溶性膳食纤维含量。方法在不同研磨条件下,采用激光粒度法测定其粒度,采用化学法测定持水性、持油性、溶胀性,酶重法测定可溶性膳食纤维含量。结果超微粉碎可显著减小物料粒径。随着粒度的减小,持油性、持水性、溶胀性及可溶性膳食纤维含量呈上升趋势。当研磨条件为研磨时间12 h、介质物料比8%、转速300 r/min时,粒度显著减小至15.3μm(P0.05)。在此条件下,藕节膳食纤维持油性、持水性、溶胀性分别为2.23 g/g、3.62 g/g、5.97 mL/g。可溶性膳食纤维含量从3.55%显著提高至11.20%(P0.05),比未超微粉碎提高了2.16倍。结论超微粉碎能有效降低藕节膳食纤维粒度,显著增加可溶性膳食纤维含量,并赋予其优良的理化性质,为藕节渣综合利用提供相关依据。     

高压射流流道结构对纤维素微细化的影响

采用计算流体动力学方法研究相同操作压力下不同阀体结构内的压降和速度分布差异,并结合不同阀体结构微细化膳食纤维单一组分纤维素的粒径变化,研究流道结构对纤维素微细化处理的影响。结果表明,纤维素水分散液质量浓度越小,单阀的微细化效果越好;而纤维素水分散液质量浓度(≤2%)对组阀处理的微细化效果无明显影响;阀体结构对微细化效果的影响取决于流道内是否形成大区域和大幅度的流速变化。     

微粉化对天麻（Gastrodia elata Bl.）粉理化性质和吸收的影响

研究了微粉化处理对天麻(Gastrodia elata Bl.)粉的理化性质及在大鼠体内吸收的影响。对天麻普通粉和超微粉进行粒径大小、分布、微观形貌、休止角、滑角、膨胀力、松密度、水溶性和主要成分等理化指标的测定,以及天麻活性成分天麻素的生物利用度研究。结果表明:微粉化处理使天麻粉平均粒径由121.50μm减小到34.09μm,粒径分布范围变窄,粉体更加均匀;天麻微粉膨胀力、松密度和水溶性较之细粉均有不同程度的提高,粉体的流动性降低;红外光谱显示天麻经超微粉碎后其主要成分未发生变化。普通粉和微粉的天麻素绝对生物利用度分别是34.18%和45.49%。研究结果表明微粉化处理对天麻粉物理特性的改善有助于营养成分溶出,显著提高天麻有效成分的吸收率,为指导天麻微粉的应用生产提供理论依据。     

预成膜雾化超临界流体强制分散溶液过程及应用

设计了预成膜二流式喷嘴用于超临界流体强制分散溶液(SEDS)过程以获得良好的雾化与传质效果。采用预成膜雾化的SEDS(SEDS-PA)过程对胡萝卜素、麻黄素及黄芩甙进行了超细和聚合物包覆实验以考察该法制备药物微粒和载药聚合物微粒的有效性。通过SEM及光学显微镜照片分析微粒形态,用分光光度法检测药物在聚合物微粒中的含量。实验表明,通过SEDS-PA过程可成功地对天然药物超细化,并用聚合物对其包覆,从而制备药物微粒及载药聚合物微粒。     

Micronization of curcumin with biodegradable polymer by supercritical anti-solvent using micro swirl mixer

Curcumin is a hydrophobic polyphenol compound exhibiting a wide range of biological activities such as anti-inflammatory, anti-bacterial, anti-fungal, anti-carcinogenic, anti-human immunodeficiency virus, and anti-microbial activity. In this work, a swirl mixer was employed to produce the micronized curcumin with polyvinylpyrrolidone (PVP) by the supercritical anti-solvent process to improve the bioavailability of curcumin. The effects of operating parameters such as curcumin/PVP ratio, feed concentration, temperature, pressure, and CO₂ flow rate were investigated. The characterization and solubility of particles were determined by using scanning electron microscopy, Fourier Transform Infrared spectroscopy, and ultra-violet-visible spectroscopy. The result shows that the optimal condition for the production of curcumin/PVP particles is at curcumin/PVP ratio of 1:30, feed concentration of 5 mg·mL⁻¹, temperature of 40 °C, pressure of 15 MPa, and CO₂ flow rate of 15 mL·min⁻¹. Moreover, the dissolution of curcumin/PVP particles is faster than that of raw curcumin.