Low density,good flowability cyclodextrin-raffinose binary carrier for dry powder inhaler: anti-hygroscopicity and aerosolization performance enhancement

Background: The hygroscopicity of raffinose carrier for dry powder inhaler (DPI) was the main obstacle for its further application. Hygroscopicity-induced agglomeration would cause deterioration of aerosolization performance of raffinose, undermining the delivery efficiency.

Methods: Cyclodextrin-raffinose binary carriers (CRBCs) were produced by spray-drying so as to surmount the above issue. Physicochemical attributes and formation mechanism of CRBCs were explored in detail. The flow property of CRBCs was examined by FT4 Powder Rheometer. Hygroscopicity of CRBCs was elucidated by dynamic vapor sorption study. Aerosolization performance was evaluated by in vitro deposition profile and in vivo pharmacokinetic profile of CRBC based DPI formulations.

Results: The optimal formulation of CRBC (R₄) was proven to possess anti-hygroscopicity and aerosolization performance enhancement properties. Concisely, the moisture uptake of R₄ was c.a. 5% which was far lower than spray-dried raffinose (R₀, c.a. 65%). R₄ exhibited a high fine particle fraction value of 70.56 ± 0.61% and it was 3.75-fold against R₀. The pulmonary and plasmatic bioavailability of R₄ were significantly higher than R₀ (p < 0.05).

Conclusion: CRBC with anti-hygroscopicity and aerosolization performance enhancement properties was a promising approach for pulmonary drug delivery, which could provide new possibilities to the application of hygroscopic carriers for DPI.     

The Role of Supplementary Cementitious Materials (SCMs) in Ultra High Performance Concrete (UHPC): A Review

Although ultra high-performance concrete (UHPC) has great performance in strength and durability, it has a disadvantage in the environmental aspect; it contains a large amount of cement that is responsible for a high amount of CO₂ emissions from UHPC. Supplementary cementitious materials (SCMs), industrial by-products or naturally occurring materials can help relieve the environmental burden by reducing the amount of cement in UHPC. This paper reviews the effect of SCMs on the properties of UHPC in the aspects of material properties and environmental impacts. It was found that various kinds of SCMs have been used in UHPC in the literature and they can be classified as slag, fly ash, limestone powder, metakaolin, and others. The effects of each SCM are discussed mainly on the early age compressive strength, the late age compressive strength, the workability, and the shrinkage of UHPC. It can be concluded that various forms of SCMs were successfully applied to UHPC possessing the material requirement of UHPC such as compressive strength. Finally, the analysis on the environmental impact of the UHPC mix designs with the SCMs is provided using embodied CO₂ generated during the material production.     

Waste Foundry Sand in Concrete Production Instead of Natural River Sand: A Review

The by-product of the foundry industry is waste foundry sand (WFS). The use of WFS in building materials will safeguard the ecosystem and environmental assets while also durable construction. The use of industrial waste in concrete offsets a shortage of environmental sources, solves the waste dumping trouble and provides another method of protecting the environment. Several researchers have investigated the suitability of WFS in concrete production instead of natural river sand in the last few decades to discover a way out of the trouble of WFS in the foundry region and accomplish its recycling in concrete production. However, a lack of knowledge about the progress of WFS in concrete production is observed and compressive review is required. The current paper examines several properties, such as the physical and chemical composition of WFS, fresh properties, mechanical and durability performance of concrete with partially substituting WFS. The findings from various studies show that replacing WFS up to 30% enhanced the durability and mechanical strength of concrete to some extent, but at the same time reduced the workability of fresh concrete as the replacement level of WFS increased. In addition, this review recommended pozzolanic material or fibre reinforcement in combination with WFS for future research.     

Improving functional properties of pea protein isolate for microencapsulation of flaxseed oil

Unhydrolysed pea protein (UN) forms very viscous emulsions when used at higher concentrations. To overcome this, UN was hydrolysed using enzymes alcalase, flavourzyme, neutrase, alcalase–flavourzyme, and neutrase–flavourzyme at 50?°C for 0?min, 30?min, 60?min, and 120?min to form hydrolysed proteins A, F, N, AF, and NF, respectively. All hydrolysed proteins had lower apparent viscosity and higher solubility than UN. Foaming capacity of A was the highest, followed by NF, N, and AF. Hydrolysed proteins N60, A60, NF60, and AF60 were prepared by hydrolysing UN for 60?min and used further for microencapsulation. At 20% oil loading (on a total solid basis), the encapsulated powder N60 had the highest microencapsulation efficiency (ME?=?56.2). A decrease in ME occurred as oil loading increased to 40%. To improve the ME of N60, >90%, UN and maltodextrin were added. Flowability and particle size distribution of microencapsulated powders with >90% microencapsulation efficiency and morphology of all powders were investigated. This study identified a new way to improve pea protein functionality in emulsions, as well as a new application of hydrolysed pea protein as wall material for microencapsulation.     

粉煤气化工业装置煤粉黏附力表征及其流动性评价

气流床粉煤加压气化工艺中,煤粉颗粒粒径小、比表面积大,受颗粒间黏附力影响,煤粉在锁斗下料单元经常出现结拱架桥现象。本文以SE （Sinopec-ECUST）-东方炉气流床粉煤加压气化工艺为工业应用背景,以典型粒径特征的煤粉样品为研究对象,采用连续介质模型与颗粒间作用力分析相结合的方法,建模求解煤粉颗粒间的黏附力。通过对比不同样品的流动参数、颗粒间作用力及其与重力的相互关系,揭示了平均粒径及细颗粒含量对煤粉流动性和下料过程的影响,并在实验室可视化下料平台和工业装置下料单元对上述结果进行了验证。研究结果表明,随着平均粒径降低、细颗粒含量增加,煤粉流动性减弱,下料逐渐从结拱架桥过渡至无拱自由流。本文为改善入炉煤粉流动性、提高煤粉供料系统运行稳定性提供了有效的参考。     

Effect of Geometric Structure of Flow Promoting Agents on the Flow Properties of Pharmaceutical Powder Mixture

Purpose. The object of this work was to investigate the mechanism of how the surface geometric structure of flow agents affects on the flowability of pharmaceutical powder mixtures. Methods. Nonporous and porous silicas were mixed with directly compressible fillers as flow promoting agents. The geometric structure of flow agents was investigated by gas adsorption and laser diffraction analysis. Flowability was evaluated with Carr's index measurement. Adhesion force between fillers and flow agents was determined using atomic force microscopy. Results. Flowability was improved with the addition of both nonporous and porous flow agents. In the case of nonporous flow agents, effect to promote flowability decreased with the increase of particle diameter, whereas porous flow agents highly improved flowability independent of particle diameter. Atomic force microscopy measurement found that the adhesion force between a porous agent and filler was smaller than that between a nonporous agent and filler. Conclusions. Enhancement of flowability varies depending on the geometric structure of flow agents. Porous flow agents improve flow properties more than nonporous agents, because porosity is highly contributed to reduction of adhesion force between particles.     

直接压片辅料-Cellactose80的粉体学性能评价

 目的考察Cellactose80的直接压片性能。方法测定Cellactose80的休止角、卡氏指数、屈张压力、润滑敏感率、稀释潜力等粉体学基本性质,并将Cellactose80应用于4种模型药物的粉末直接压片工艺中。结果和喷雾干燥单水乳糖以及微晶纤维素相比,复合型辅料Cellactose80的休止角最小,Heckel曲线显示了典型的塑性变型特征。该辅料对硬脂酸镁是敏感的,对可压性差的药物具有很大的稀释作用。结论Cellactose80改变了单水乳糖的物理压缩性质,由脆性变型转换成塑性变型,显著增强了流动性和可压性,更加适合于粉末直接压片工艺。     

超分散剂对炭黑体系分散性能的研究

以流动度，粘度，触变环面积为定量指标，研究了超分散剂对炭黑的分散性，实验结果表明，超分散剂的加入，明显地改善了体系的分散性能，在选取的最佳分散剂含量下，体系具有高流动度，低粘度，小触变性等性质，并且触变环面积出现一平台区域。