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Article: Effect of moisture on the electrostatic charge properties of metered dose inhaler aerosols

TitleEffect of moisture on the electrostatic charge properties of metered dose inhaler aerosols
Authors
KeywordsElectrostatic Charge
Elpi
Hfa
Mdi
Moisture Content
Issue Date2008
PublisherPergamon. The Journal's web site is located at http://www.elsevier.com/locate/jaerosci
Citation
Journal Of Aerosol Science, 2008, v. 39 n. 3, p. 211-226 How to Cite?
AbstractThe electrostatic charge properties of drug-free metered dose inhaler (MDI) aerosols containing the propellants HFA-134a and 227ea were studied using a modified electrical low pressure impactor (ELPI) with aerodynamic cutoff diameters ranging from 0.028 to 10.07 μ m. The MDIs were spiked with various amounts of water and crimped with Hostaform and PBT (polyester) valves. Polypropylene actuators were dried or wetted by storage in a desiccator or a box saturated with water vapour, respectively. The air humidity was controlled at 5%, 50%, and 92% RH to maintain the actuator surface dryness or moisture during the experiments. The droplet size distributions in the ELPI were determined by chemical assays of another set of inhalers containing crystal violet as a marker. The charge profiles measured were highly variable but on average both HFA-134a and 227ea charged negatively, which was ascribed to the electronegative fluorine atoms in the HFA molecules withdrawing anions from the MDI components. The drug-free MDIs produced lower charges than the commercial medicated ones. The charges of both HFAs shifted towards neutrality or positive polarity as the water content increased. The spiked water would increase the electrical conductivity and/or decreased the electronegativity of the liquid propellant surface. The mean number of elementary charges per droplet decreased with decreasing droplet size. © 2007 Elsevier Ltd. All rights reserved.
Persistent Identifierhttp://hdl.handle.net/10722/171363
ISSN
2015 Impact Factor: 2.278
2015 SCImago Journal Rankings: 1.702
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorChi Lip Kwok, PCLen_US
dc.contributor.authorNoakes, Ten_US
dc.contributor.authorChan, HKen_US
dc.date.accessioned2012-10-30T06:13:37Z-
dc.date.available2012-10-30T06:13:37Z-
dc.date.issued2008en_US
dc.identifier.citationJournal Of Aerosol Science, 2008, v. 39 n. 3, p. 211-226en_US
dc.identifier.issn0021-8502en_US
dc.identifier.urihttp://hdl.handle.net/10722/171363-
dc.description.abstractThe electrostatic charge properties of drug-free metered dose inhaler (MDI) aerosols containing the propellants HFA-134a and 227ea were studied using a modified electrical low pressure impactor (ELPI) with aerodynamic cutoff diameters ranging from 0.028 to 10.07 μ m. The MDIs were spiked with various amounts of water and crimped with Hostaform and PBT (polyester) valves. Polypropylene actuators were dried or wetted by storage in a desiccator or a box saturated with water vapour, respectively. The air humidity was controlled at 5%, 50%, and 92% RH to maintain the actuator surface dryness or moisture during the experiments. The droplet size distributions in the ELPI were determined by chemical assays of another set of inhalers containing crystal violet as a marker. The charge profiles measured were highly variable but on average both HFA-134a and 227ea charged negatively, which was ascribed to the electronegative fluorine atoms in the HFA molecules withdrawing anions from the MDI components. The drug-free MDIs produced lower charges than the commercial medicated ones. The charges of both HFAs shifted towards neutrality or positive polarity as the water content increased. The spiked water would increase the electrical conductivity and/or decreased the electronegativity of the liquid propellant surface. The mean number of elementary charges per droplet decreased with decreasing droplet size. © 2007 Elsevier Ltd. All rights reserved.en_US
dc.languageengen_US
dc.publisherPergamon. The Journal's web site is located at http://www.elsevier.com/locate/jaeroscien_US
dc.relation.ispartofJournal of Aerosol Scienceen_US
dc.subjectElectrostatic Chargeen_US
dc.subjectElpien_US
dc.subjectHfaen_US
dc.subjectMdien_US
dc.subjectMoisture Contenten_US
dc.titleEffect of moisture on the electrostatic charge properties of metered dose inhaler aerosolsen_US
dc.typeArticleen_US
dc.identifier.emailChi Lip Kwok, PCL:pclkwok@hku.hken_US
dc.identifier.authorityChi Lip Kwok, PCL=rp01540en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1016/j.jaerosci.2007.11.004en_US
dc.identifier.scopuseid_2-s2.0-39649118002en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-39649118002&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume39en_US
dc.identifier.issue3en_US
dc.identifier.spage211en_US
dc.identifier.epage226en_US
dc.identifier.eissn1879-1964-
dc.identifier.isiWOS:000254367300002-
dc.publisher.placeUnited Kingdomen_US
dc.identifier.scopusauthoridChi Lip Kwok, PCL=12646007800en_US
dc.identifier.scopusauthoridNoakes, T=25642939400en_US
dc.identifier.scopusauthoridChan, HK=7403402677en_US

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