Protein spray freeze drying. 2. Effect of formulation variables on particle size and stability

2002 ◽  
Vol 91 (2) ◽  
pp. 388-395 ◽  
Author(s):  
Henry R. Costantino ◽  
Laleh Firouzabadian ◽  
Chichih Wu ◽  
Karen G. Carrasquillo ◽  
Kai Griebenow ◽  
...  
Keyword(s):  
Particle Size ◽  
Freeze Drying ◽  
Spray Freeze Drying ◽  
Formulation Variables

Binder Jetting Additive Manufacturing of Ceramics: Feedstock Powder Preparation by Spray Freeze Granulation

2019 ◽  
Author(s):  
Wenchao Du ◽  
Guanxiong Miao ◽  
Lianlian Liu ◽  
Zhijian Pei ◽  
Chao Ma
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Feed Rate ◽  
Freeze Drying ◽  
Granule Size ◽  
Feedstock Powder ◽  
Powder Preparation ◽  
Promising Technology ◽  
Spray Freeze Drying ◽  
Binder Jetting

Abstract Objective of this study is to prepare the binder jetting feedstock powder by spray freeze drying and study the effects of its parameters on the powder properties. Binder jetting additive manufacturing is a promising technology for fabricating ceramic parts with complex or customized geometries. However, this process is limited by the relatively low density of the fabricated parts even after sintering. The main cause comes from the contradicting requirements of the particle size of the feedstock powder: a large particle size (> 5 μm) is required for a high flowability while a small particle size (< 1 μm) for a high sinterability. For the first time, a novel technology for the feedstock material preparation, called spray freeze drying, is investigated to address this contradiction. Using raw alumina nanopowder (100 nm), a full factorial design at two levels for two factors (spraying pressure and slurry feed rate) was formed to study their effects on the properties (i.e., granule size, flowability, and sinterability) of the obtained granulated powder. Results show that high pressure and small feed rate lead to small granule size. Compared with the raw powder, the flowability of the granulated powders was significantly increased, and the high sinterability was also maintained. This study proves that spray freeze granulation is a promising technology for the feedstock powder preparation of binder jetting additive manufacturing.

Spray Freeze-Drying for inhalation application: Process and Formulation Variables

2021 ◽  
pp. 1-29
Author(s):  
Mostafa Rostamnezhad ◽  
Hossein Jafari ◽  
Farzad Moradikhah ◽  
Sara Bahrainian ◽  
Homa Faghihi ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Application Process ◽  
Spray Freeze Drying ◽  
Formulation Variables

Comparison of Flowability and Sinterability Among Different Binder Jetting Feedstock Powders: Nanopowder, Micropowder, and Granulated Powder

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Wenchao Du ◽  
Guanxiong Miao ◽  
Zhijian Pei ◽  
Chao Ma
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
Freeze Drying ◽  
Volumetric Flow Rate ◽  
Granule Size ◽  
Hausner Ratio ◽  
Tap Density ◽  
Spray Freeze Drying ◽  
Binder Jetting ◽  
High Flowability

Abstract Feedstock powders used in binder jetting additive manufacturing include nanopowder, micropowder, and granulated powder. Two important characteristics of the feedstock powders are flowability and sinterability. This paper aims to compare the flowability and sinterability of different feedstock powders. Three powders were compared: nanopowder (with a particle size of ∼100 nm), micropowder (with a particle size of 70 μm), and granulated powder (with a granule size of ∼70 μm) made from the nanopowder by spray freeze drying. Flowability metrics employed included apparent density (AD), tap density (TD), volumetric flow rate (VFR), mass flow rate (MFR), Hausner ratio (HR), Carr index (CI), and repose angle (RA). Sinterability metrics employed included sintered bulk density (SBD), volumetric shrinkage (VS), and densification ratio (DR). Results show that the granulated powder has a higher flowability than the nanopowder and a higher sinterability than the micropowder. Moreover, different flowability metric values of the granulated powder are close to those of the micropowder, indicating that these two powers have a comparably high flowability. Similarly, different sinterability metric values of the granulated powder are close to those of the nanopowder, indicating that these two powders have a comparably high sinterability.

scholarly journals Intratracheal inoculation of AHc vaccine induces protection against aerosolized botulinum neurotoxin A challenge in mice

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Changjiao Gan ◽  
Wenbo Luo ◽  
Yunzhou Yu ◽  
Zhouguang Jiao ◽  
Sha Li ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage ◽  
Clostridium Botulinum ◽  
Freeze Drying ◽  
Botulinum Neurotoxin ◽  
Secretory Iga ◽  
Immune Protection ◽  
Dry Powder ◽  
Botulinum Neurotoxin A ◽  
Spray Freeze Drying

AbstractBotulinum neurotoxin (BoNT), produced by Clostridium botulinum, is generally known to be the most poisonous of all biological toxins. In this study, we evaluate the protection conferred by intratracheal (i.t.) inoculation immunization with recombinant Hc subunit (AHc) vaccines against aerosolized BoNT/A intoxication. Three AHc vaccine formulations, i.e., conventional liquid, dry powder produced by spray freeze drying, and AHc dry powder reconstituted in water are prepared, and mice are immunized via i.t. inoculation or subcutaneous (s.c.) injection. Compared with s.c.-AHc-immunized mice, i.t.-AHc-immunized mice exhibit a slightly stronger protection against a challenge with 30,000× LD50 aerosolized BoNT/A. Of note, only i.t.-AHc induces a significantly higher level of toxin-neutralizing mucosal secretory IgA (SIgA) production in the bronchoalveolar lavage of mice. In conclusion, our study demonstrates that the immune protection conferred by the three formulations of AHc is comparable, while i.t. immunization of AHc is superior to s.c. immunization against aerosolized BoNT/A intoxication.

scholarly journals Post-Processing Techniques for the Improvement of Liposome Stability

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1023
Author(s):  
Ji Young Yu ◽  
Piyanan Chuesiang ◽  
Gye Hwa Shin ◽  
Hyun Jin Park
Keyword(s):  
Freeze Drying ◽  
Protective Agent ◽  
Post Processing ◽  
Additional Process ◽  
Spray Freeze Drying ◽  
The Stability ◽  
Processing Techniques ◽  
The Impact ◽  
Self Aggregation ◽  
Liposome Stability

Liposomes have been utilized as a drug delivery system to increase the bioavailability of drugs and to control the rate of drug release at the target site of action. However, the occurrence of self-aggregation, coalescence, flocculation and the precipitation of aqueous liposomes during formulation or storage can cause degradation of the vesicle structure, leading to the decomposition of liposomes. To increase the stability of liposomes, post-processing techniques have been applied as an additional process to liposomes after formulation to remove water and generate dry liposome particles with a higher stability and greater accessibility for drug administration in comparison with aqueous liposomes. This review covers the effect of these techniques including freeze drying, spray drying and spray freeze drying on the stability, physicochemical properties and drug encapsulation efficiency of dry liposomes. The parameters affecting the properties of liposomes during the drying process are also highlighted in this review. In addition, the impact of using a protective agent to overcome such limitations of each process is thoroughly discussed through various studies.

Atomizing into a Chilled Extraction Solvent Eliminates Liquid Gas from a Spray-Freeze Drying Microencapsulation Process

2008 ◽  
Vol 97 (10) ◽  
pp. 4459-4472 ◽  
Author(s):  
Michael T. Kennedy ◽  
Alana Ali-Reynolds ◽  
Christina Farrier ◽  
Paul A. Burke
Keyword(s):  
Freeze Drying ◽  
Extraction Solvent ◽  
Spray Freeze Drying
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