Search results for "Drying"

Jet-vortex spray freeze drying for the production of inhalable lyophilisate powders

2016

Abstract Spray-freeze-dried powders were suggested for nasal, epidermal (needle-free injection) or pulmonary application of proteins, peptides or nucleic acids. In spray-freeze-drying processes an aqueous solution is atomized into a refrigerant medium and subsequently dried by sublimation. Droplet-stream generators produce a fast stream of monodisperse droplets, where droplets are subject to collisions and therefore the initial monodispersity is lost and droplets increase in diameter, which reduces their suitability for pulmonary application. In jet-vortex-freezing, a droplet-stream is injected into a vortex of cold process gas to prevent droplet collisions. Both the injection position of t…

Spray-Drying, Solvent-Casting and Freeze-Drying Techniques: a Comparative Study on their Suitability for the Enhancement of Drug Dissolution Rates.

2019

Purpose Solid dispersions (SDs) represent the most common formulation technique used to increase the dissolution rate of a drug. In this work, the three most common methods used to prepare SDs, namely spray-drying, solvent-casting and freezedrying, have been compared in order to investigate their effect on increasing drug dissolution rate. Methods Three formulation strategies were used to prepare a polymer mixture of polyvinyl-alcohol (PVA) and maltodextrin (MDX) as SDs loaded with the following three model drugs, all of which possess a poor solubility: Olanzapine, Dexamethasone, and Triamcinolone acetonide. The SDs obtained were analysed and compared in terms of drug particle size, drug-lo…

2019

TEMPO-oxidized cellulose nanofibrils (TCNFs) have unique properties, which can be utilised in many application fields from printed electronics to packaging. Visual characterisation of TCNFs has been commonly performed using Scanning Electron Microscopy (SEM). However, a novel imaging technique, Helium Ion Microscopy (HIM), offers benefits over SEM, including higher resolution and the possibility of imaging non-conductive samples uncoated. HIM has not been widely utilized so far, and in this study the capability of HIM for imaging of TCNFs was evaluated. Freeze drying and critical point drying (CPD) techniques were applied to preserve the open fibril structure of the gel-like TCNFs. Both dry…

Influence of mode stirrer and air renewal on controlled microwave drying of sliced zucchini

2017

An on-line temperature-controlled microwave (MW) system, based on infrared thermography, was developed for drying zucchini slices. Moreover, the effects of different configurations, including turntable rotation, mode stirrer and air renewal, alone or in combination, on drying kinetics and quality of dried product were evaluated. The combination of stirrer and air renewal reduced the drying time of zucchini slices by about 48% with respect to the basic configuration and by 22% with respect to air renewal only. The lowest oscillation of temperatures about the fixed level (65 °C) was found when operating with the stirrer mode, because of the improved uniformity of the MW distribution. The sa…

Ceramic/metal nanocomposites by lyophilization: Processing and HRTEM study

2012

5 páginas, 8 figuras, 1 tabla.-- El pdf del artículo es el manuscrito de autor.

Ceramic/metal nanocomposites by lyophilization: Spark plasma sintering and hardness

2014

The present study is focused on the procedure of spray-drying and lyophilization techniques for the preparation of ceramic/metal nanocomposites. The results of the study at all stages are compared with those corresponding to powders conventionally dried by heating in furnace. Starting from aqueous solutions of metal salts and ceramic powders, the procedure follows with spray-drying, lyophilization, calcination of the resulting powders and subsequent Spark Plasma Sintering (SPS). X-ray diffraction analysis of the powders at different stages of the processing routes was used for phase indexing; further characterization was performed by Transmission Electron Microscopy and Energy Dispersive X-…

Applications of spray-drying in microencapsulation of food ingredients: An overview

2007

International audience; Spray-drying process has been used for decades to encapsulate food ingredients such as flavors, lipids, and carotenoids. During this drying process, the evaporation of solvent, that is most often water, is rapid and the entrapment of the interest compound occurs quasi-instantaneously. This required property imposes a strict screening of the encapsulating materials to be used in addition to an optimization of the operating conditions. Likewise, if the encapsulated compound is of hydrophobic nature, the stability of the feed emulsion before drying should also be considered. Thus, spray-drying microencapsulation process must rather be considered as an art than a science…

Spherical silica agglomerates possessing hierarchical porosity prepared by spray drying of MCM-41 and MCM-48 nanospheres

2003

Hierarchically ordered porous materials possessing both meso- and macropores can be obtained by agglomeration of spherical primary particles of mesoporous MCM-41 and MCM-48 materials using the spray drying technique. A highly interconnected bimodal pore network is obtained due to the intra- and inter-particle pore systems within the micron-sized spherical agglomerates. Further packing of the agglomerates will result in a three-modal hierarchical pore system, where the first level of porosity originates from the ordered mesopores inside the primary particles, the second level is a result of the particle internal porosity, and the third level is due to the voids between the agglomerates. The …

Drying rate control in microwave assisted processing of sliced apples

2018

The most enhanced microwave systems for the preparation of quality-dehydrated fruits continuously adjust the power level in order to maintain the product temperature above a target value. As a result, typical drying curves that exhibit high drying rates in the middle stage are obtained. This can often lead to quality damage or undesirable changes on food colour and texture. In response to these issues, a microwave system is proposed that can realise drying processes keeping drying rates constant. This approach required a continuous temperature adjustment of the apple slices under test, whose temperature was detected by a computer-aided infrared thermography system. Since temperature correct…

On the theoretical–numerical study of the ITER Upper Port Plug structure hydraulic behaviour under steady state and draining and drying transient con…

2011

Abstract The ITER diagnostic Upper Port Plug (UPP) is a water-cooled stainless steel structure aimed to integrate within vacuum vessel the plasma diagnostic systems, shielding them from neutron and photon irradiation. Due to the very intense heat loads expected, a proper cooling circuit has been designed to ensure an adequate UPP cooling with an acceptable thermal rise and an unduly high pumping power and to perform its draining and drying procedure by injection of pressurized nitrogen. A theoretical research activity has been launched at the Department of Nuclear Engineering of the University of Palermo aiming to investigate the hydraulic behaviour of the UPP Trapezoid Section cooling circ…