PMID- 17763140
OWN - NLM
STAT- MEDLINE
DCOM- 20071105
LR  - 20191110
IS  - 1083-7450 (Print)
IS  - 1083-7450 (Linking)
VI  - 12
IP  - 4
DP  - 2007
TI  - Influence of impactor operating flow rate on particle size distribution of four 
      jet nebulizers.
PG  - 353-9
AB  - When a nebulizer is evaluated by the Andersen Cascade Impactor (ACI), the flow 
      rate is generally maintained at 28.3 L/min, as recommended by the manufacturer. 
      However, the nebulizer flow rate that a patient inhales is only around 18 L/min. 
      Because the drive flow of a nebulizer is approximately 6-8 L/min, the nebulized 
      drug is mixed with outside air when delivered. Evaluating impactor performance at 
      the 28.3 L/min flow rate is less than ideal because an additional 10 L/min of 
      outside air is mixed with the drug, thereby affecting the drug size distribution 
      and dose before inhalation and deposition in the human lung. In this study we 
      operated the ACI at an 18.0 L/min flow rate to test whether the effect of the 
      changing ambient humidity was being exaggerated by the 28.3 L/min flow rate. The 
      study was carried out at three different relative humidity levels and two 
      different impactor flow rates with four commercially available nebulizers. The 
      mass median aerodynamic diameter (MMAD) and the geometric standard deviation 
      (GSD) of the droplets were found to increase when the impactor was operated at a 
      flow rate of 18 L/min compared to that of 28.3 L/min. The higher MMAD and GSD 
      could cause the patient to inhale less of the drug than expected if the nebulizer 
      was evaluated by the ACI at the operating flow rate of 28.3 L/min.
FAU - Zhou, Yue
AU  - Zhou Y
AD  - Lovelace Respiratory Research Institute, Albuquerque, NM, USA. yzhou@lrri.org
FAU - Brasel, Trevor L
AU  - Brasel TL
FAU - Kracko, Dean
AU  - Kracko D
FAU - Cheng, Yung-Sung
AU  - Cheng YS
FAU - Ahuja, Amitkumar
AU  - Ahuja A
FAU - Norenberg, Jeffrey P
AU  - Norenberg JP
FAU - Kelly, H William
AU  - Kelly HW
LA  - eng
PT  - Journal Article
PL  - England
TA  - Pharm Dev Technol
JT  - Pharmaceutical development and technology
JID - 9610932
RN  - 0 (Aerosols)
RN  - 0 (Bronchodilator Agents)
RN  - 51333-22-3 (Budesonide)
RN  - QF8SVZ843E (Albuterol)
SB  - IM
MH  - Aerosols/administration & dosage/*chemistry
MH  - Albuterol/administration & dosage/*chemistry
MH  - Bronchodilator Agents/administration & dosage/*chemistry
MH  - Budesonide/administration & dosage/*chemistry
MH  - Chemistry, Pharmaceutical
MH  - Equipment Design
MH  - Humidity
MH  - Nebulizers and Vaporizers
MH  - Particle Size
MH  - Technology, Pharmaceutical/methods
EDAT- 2007/09/01 09:00
MHDA- 2007/11/06 09:00
CRDT- 2007/09/01 09:00
PHST- 2007/09/01 09:00 [pubmed]
PHST- 2007/11/06 09:00 [medline]
PHST- 2007/09/01 09:00 [entrez]
AID - 781510367 [pii]
AID - 10.1080/10837450701366937 [doi]
PST - ppublish
SO  - Pharm Dev Technol. 2007;12(4):353-9. doi: 10.1080/10837450701366937.