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Low-voltage electrohydrodynamic (EHD) spray drying of respirable particles

Lastow, Orest; Andersson, Jenny LU ; Nilsson, Alexander and Balachandran, Wamadeva (2007) In Pharmaceutical Development and Technology 12(2). p.175-181
Abstract
Spray drying is a widely used process to produce pharmaceutical powders. In traditional spray drying, the particle size distribution is wide and not well controlled. Using EHD atomization for spray drying offers a possibility to tailor the particle size and morphology. In conventional EHD spray drying, the generated particles are charged and need to be discharged to avoid Rayleigh breakup. Discharging adds complexity to the process and eliminates the possibility to collect the powder using an electric field. The present work describes a novel EHD spray drying setup based on a low-voltage nozzle. The low-voltage nozzle imparts moderate charge to the droplets, which makes discharging unnecessary. The charged particles can be controlled and... (More)
Spray drying is a widely used process to produce pharmaceutical powders. In traditional spray drying, the particle size distribution is wide and not well controlled. Using EHD atomization for spray drying offers a possibility to tailor the particle size and morphology. In conventional EHD spray drying, the generated particles are charged and need to be discharged to avoid Rayleigh breakup. Discharging adds complexity to the process and eliminates the possibility to collect the powder using an electric field. The present work describes a novel EHD spray drying setup based on a low-voltage nozzle. The low-voltage nozzle imparts moderate charge to the droplets, which makes discharging unnecessary. The charged particles can be controlled and collected by using an auxiliary electric field. The EHD spray dryer has been characterized in terms of particle size, particle morphology, process output, and yield. The size distribution of the generated particles is very narrow. Both porous and completely spherical particles can be produced. The yield of small-scale bench-top equipment was 20%, which is similar to the yield of a small-scale conventional spray dryer. The effective output with five nozzles was 75 mg/hr of dry powder. Because of the repelling forces associated with the unipolarly charged droplets, the number of nozzles can be increased without risking coalescence. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
aerosol, powder, monodisperse, EHD atomization, spray drying, inhalable drug, discharging
in
Pharmaceutical Development and Technology
volume
12
issue
2
pages
175 - 181
publisher
Taylor & Francis
external identifiers
  • wos:000246833200008
  • scopus:34248995936
ISSN
1083-7450
DOI
10.1080/10837450701212594
language
English
LU publication?
yes
id
0ee75567-6ef1-4317-af0c-62cfd062a4a1 (old id 662489)
date added to LUP
2007-12-14 13:19:06
date last changed
2017-11-05 04:26:32
@article{0ee75567-6ef1-4317-af0c-62cfd062a4a1,
  abstract     = {Spray drying is a widely used process to produce pharmaceutical powders. In traditional spray drying, the particle size distribution is wide and not well controlled. Using EHD atomization for spray drying offers a possibility to tailor the particle size and morphology. In conventional EHD spray drying, the generated particles are charged and need to be discharged to avoid Rayleigh breakup. Discharging adds complexity to the process and eliminates the possibility to collect the powder using an electric field. The present work describes a novel EHD spray drying setup based on a low-voltage nozzle. The low-voltage nozzle imparts moderate charge to the droplets, which makes discharging unnecessary. The charged particles can be controlled and collected by using an auxiliary electric field. The EHD spray dryer has been characterized in terms of particle size, particle morphology, process output, and yield. The size distribution of the generated particles is very narrow. Both porous and completely spherical particles can be produced. The yield of small-scale bench-top equipment was 20%, which is similar to the yield of a small-scale conventional spray dryer. The effective output with five nozzles was 75 mg/hr of dry powder. Because of the repelling forces associated with the unipolarly charged droplets, the number of nozzles can be increased without risking coalescence.},
  author       = {Lastow, Orest and Andersson, Jenny and Nilsson, Alexander and Balachandran, Wamadeva},
  issn         = {1083-7450},
  keyword      = {aerosol,powder,monodisperse,EHD atomization,spray drying,inhalable drug,discharging},
  language     = {eng},
  number       = {2},
  pages        = {175--181},
  publisher    = {Taylor & Francis},
  series       = {Pharmaceutical Development and Technology},
  title        = {Low-voltage electrohydrodynamic (EHD) spray drying of respirable particles},
  url          = {http://dx.doi.org/10.1080/10837450701212594},
  volume       = {12},
  year         = {2007},
}