title: Effects of Temperature and Humidity on Laser Diffraction Measurements to Jet Nebulizer and Comparison with NGI.
abstract: Laser diffraction (LD) and next generation impactor (NGI) are commonly used for the evaluation of inhaled drug formulations. In this study, the effect of temperature and humidity on the assessment of the nebulizer particle size distribution (PSD) by LD was investigated, and the consistency between NGI and LD measurements was evaluated. There was an increase in particle size with higher temperature or lower humidity. The particle population with a diameter less than 1 μm was significant at a temperature of 5°C or at relative humidity >90%; however, the same particle population became undetectable when temperature increased to 39°C or at relative humidity of 30-45%. The results of the NGI and LD measurements of aerosol generated from three types of jet nebulizers were compared. A poor correlation between the NGI and LD measurements was observed for PARI LC (2.2 μm) (R (2) = 0.893) and PARI LC (2.9 μm) (R (2) = 0.878), while a relatively good correlation (R (2) = 0.977) was observed for the largest particle size nebulizer (PARI TIA (8.6 μm)). We conclude that the ambient environment and the nebulizer have significant impacts on the performance and consistency between these instruments. These factors should be controlled in the evaluation of inhaled aerosol drug formulations when these instruments are used individually or in combination.
authors.affiliation: Pre-incubater for Innovative Drugs and Medicine, South China University of Technology, Guangzhou, Guangdong, China.|School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, Guangdong, China.
authors.forename: Xinghan
authors.initials: X
authors.lastname: Song
authors.affiliation: Pre-incubater for Innovative Drugs and Medicine, South China University of Technology, Guangzhou, Guangdong, China.|School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, Guangdong, China.
authors.forename: Junhua
authors.initials: J
authors.lastname: Hu
authors.affiliation: Pre-incubater for Innovative Drugs and Medicine, South China University of Technology, Guangzhou, Guangdong, China.|School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, Guangdong, China.
authors.forename: Shuyao
authors.initials: S
authors.lastname: Zhan
authors.affiliation: Pre-incubater for Innovative Drugs and Medicine, South China University of Technology, Guangzhou, Guangdong, China.|School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, Guangdong, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Pre-incubater for Innovative Drugs and Medicine, South China University of Technology, Guangzhou, Guangdong, China. hujunhua19900404@163.com.|Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, Guangdong, China. hujunhua19900404@163.com.|School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, Guangdong, China. hujunhua19900404@163.com.
authors.forename: Wen
authors.identifier: http://orcid.org/0000-0003-2272-0861
authors.initials: W
authors.lastname: Tan
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D006813:Humidity; D007834:Lasers; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D013696:Temperature
chemical_list: D000336:Aerosols
keywords: impactor; jet nebulizer; laser diffraction; particle size distribution