Nicholas Mason-Smith1, Daniel J Duke2, Alan L Kastengren3, Peter J Stewart4, Daniela Traini5, Paul M Young5, Yang Chen5, David A Lewis6, Julio Soria7,8, Daniel Edgington-Mitchell7, Damon Honnery7. 1. Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia. nick.masonsmith@gmail.com. 2. Energy Systems Division, Argonne National Laboratory, Lemont, Illinois, USA. 3. X-ray Science Division, Argonne National Laboratory, Lemont, Illinois, USA. 4. Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Melbourne, Australia. 5. Respiratory Technology, Woolcock Institute of Medical Research and the Discipline of Pharmacology, Sydney Medical School, Sydney, Australia. 6. Chiesi Ltd, Chippenham, UK. 7. Laboratory for Turbulence Research in Aerospace and Combustion, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia. 8. Department of Aeronautical Engineering, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia.
Abstract
PURPOSE: Typical methods to study pMDI sprays employ particle sizing or visible light diagnostics, which suffer in regions of high spray density. X-ray techniques can be applied to pharmaceutical sprays to obtain information unattainable by conventional particle sizing and light-based techniques. METHODS: We present a technique for obtaining quantitative measurements of spray density in pMDI sprays. A monochromatic focused X-ray beam was used to perform quantitative radiography measurements in the near-nozzle region and plume of HFA-propelled sprays. RESULTS: Measurements were obtained with a temporal resolution of 0.184 ms and spatial resolution of 5 μm. Steady flow conditions were reached after around 30 ms for the formulations examined with the spray device used. Spray evolution was affected by the inclusion of ethanol in the formulation and unaffected by the inclusion of 0.1% drug by weight. Estimation of the nozzle exit density showed that vapour is likely to dominate the flow leaving the inhaler nozzle during steady flow. CONCLUSIONS: Quantitative measurements in pMDI sprays allow the determination of nozzle exit conditions that are difficult to obtain experimentally by other means. Measurements of these nozzle exit conditions can improve understanding of the atomization mechanisms responsible for pMDI spray droplet and particle formation.
PURPOSE: Typical methods to study pMDI sprays employ particle sizing or visible light diagnostics, which suffer in regions of high spray density. X-ray techniques can be applied to pharmaceutical sprays to obtain information unattainable by conventional particle sizing and light-based techniques. METHODS: We present a technique for obtaining quantitative measurements of spray density in pMDI sprays. A monochromatic focused X-ray beam was used to perform quantitative radiography measurements in the near-nozzle region and plume of HFA-propelled sprays. RESULTS: Measurements were obtained with a temporal resolution of 0.184 ms and spatial resolution of 5 μm. Steady flow conditions were reached after around 30 ms for the formulations examined with the spray device used. Spray evolution was affected by the inclusion of ethanol in the formulation and unaffected by the inclusion of 0.1% drug by weight. Estimation of the nozzle exit density showed that vapour is likely to dominate the flow leaving the inhaler nozzle during steady flow. CONCLUSIONS: Quantitative measurements in pMDI sprays allow the determination of nozzle exit conditions that are difficult to obtain experimentally by other means. Measurements of these nozzle exit conditions can improve understanding of the atomization mechanisms responsible for pMDI spray droplet and particle formation.
Authors: Daniel J Duke; Alan L Kastengren; Nicholas Mason-Smith; Yang Chen; Paul M Young; Daniela Traini; David Lewis; Daniel Edgington-Mitchell; Damon Honnery Journal: Pharm Res Date: 2015-11-12 Impact factor: 4.200
Authors: Nicolas A Buchmann; Daniel J Duke; Sayed A Shakiba; Daniel M Mitchell; Peter J Stewart; Daniela Traini; Paul M Young; David A Lewis; Julio Soria; Damon Honnery Journal: Pharm Res Date: 2014-06-17 Impact factor: 4.200
Authors: Alan Kastengren; Christopher F Powell; Dohn Arms; Eric M Dufresne; Harold Gibson; Jin Wang Journal: J Synchrotron Radiat Date: 2012-05-11 Impact factor: 2.616
Authors: Nicholas Mason-Smith; Daniel J Duke; Alan L Kastengren; Daniela Traini; Paul M Young; Yang Chen; David A Lewis; Daniel Edgington-Mitchell; Damon Honnery Journal: Pharm Res Date: 2017-01-17 Impact factor: 4.200