A sampling and dilution system for droplet aerosols from medical nebulisers developed for use with an optical particle counter

Kuhli, Maren; Weiß, M.; Steckel, Hartwig

doi:10.1016/j.jaerosci.2009.02.007

Cited by 12 publications

(9 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A minimum of 4 replicas were performed of each sizing experiment. Evaporation is known to affect the size of nebulized aerosol after formation (Abdelrahim and Chrystyn 2009; Kuhli et al, 2009). To determine the initial size distributions, aerosols from the commercial and lab nebulizers were evaluated using inlet air at 21 °C and 99% RH drawn from an environmental cabinet (Espec, Hudsonville, MI) at 30 LPM.…”

Section: Methodsmentioning

confidence: 99%

“…Current mesh nebulizers typically produce aerosols in the size range of 4-6 μm (Kuhli et al, 2009). It is not likely possible to reduce the size of jet nebulizer droplets to the submicrometer and nanometer ranges by decreasing the aperture sizes of the vibrating plate due to surface interactions with the liquid (Zhang et al, 2007a), and doing so would significantly increase delivery times.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Production of inhalable submicrometer aerosols from conventional mesh nebulizers for improved respiratory drug delivery

Longest

Spence

Holbrook

et al. 2012

Journal of Aerosol Science

View full text Add to dashboard Cite

Submicrometer and nanoparticle aerosols may significantly improve the delivery efficiency, dissolution characteristics, and bioavailability of inhaled pharmaceuticals. The objective of this study was to explore the formation of submicrometer and nanometer aerosols from mesh nebulizers suitable for respiratory drug delivery using experiments and computational fluid dynamics (CFD) modeling. Mesh nebulizers were coupled with add-on devices to promote aerosol drying and the formation of submicrometer particles, as well as to control the inhaled aerosol temperature and relative humidity. Cascade impaction experiments were used to determine the initial mass median aerodynamic diameters of 0.1% albuterol aerosols produced by the AeroNeb commercial (4.69 μm) and lab (3.90 μm) nebulizers and to validate the CFD model in terms of droplet evaporation. Through an appropriate selection of flow rates, nebulizers, and model drug concentrations, submicrometer and nanometer aerosols could be formed with the three devices considered. Based on CFD simulations, a wire heated design was shown to overheat the airstream producing unsafe conditions for inhalation if the aerosol was not uniformly distributed in the tube cross-section or if the nebulizer stopped producing droplets. In comparison, a counter-flow heated design provided sufficient thermal energy to produce submicrometer particles, but also automatically limited the maximum aerosol outlet temperature based on the physics of heat transfer. With the counter-flow design, submicrometer aerosols were produced at flow rates of 5, 15, and 30 LPM, which may be suitable for various forms of oral and nasal aerosol delivery. Thermodynamic conditions of the aerosol stream exiting the counter-flow design were found be in a range of 21-45 °C with relative humidity greater than 40% in some cases, which was considered safe for direct inhalation and advantageous for condensational growth delivery.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Production of inhalable submicrometer aerosols from conventional mesh nebulizers for improved respiratory drug delivery

Longest

Spence

Holbrook

et al. 2012

Journal of Aerosol Science

View full text Add to dashboard Cite

show abstract

“…(47,48) This particle size is considered to be typical for mesh nebulizers and DPIs. (36,46,49,50) It is noted that DPI aerosols are not delivered to NPPV systems in clinical practice due to the absence of a viable delivery device. Therefore, conventional DPI delivery refers to the aerodynamic particle size that would be achieved if a commercial inhaler and powder formulation were integrated into the system with a positive pressure actuation device, as with Tang et al (51) or Everard et al (52) In contrast, EEG dry powder delivery implements a much smaller initial aerosol size that once inhaled increases in the humid airways due to the inclusion of the hygroscopic excipient.…”

Section: Steady-state Simulationsmentioning

confidence: 99%

Aerosol Drug Delivery During Noninvasive Positive Pressure Ventilation: Effects of Intersubject Variability and Excipient Enhanced Growth

Walenga

Longest

Kaviratna

et al. 2017

Journal of Aerosol Medicine and Pulmonary Drug Delivery

View full text Add to dashboard Cite

show abstract

“…The results of these various studies typically provide correlations that can be used to estimate the deposition of aerosols in the nasal cavity. For example, pharmaceutical nebulizers generate droplets in the size range of 3-7 μm (Finlay, 1998; Kuhli et al , 2009). Considering a 5 μm aerosol inhaled through the nose with an airflow of 30 LPM, the in vitro study of Kelly et al (2004b) predicts an average deposition of 40% based on nasal models created from a single subject.…”

Section: Introductionmentioning

confidence: 99%

Variability in nose-to-lung aerosol delivery

Walenga

Tian

Hindle

et al. 2014

Journal of Aerosol Science

View full text Add to dashboard Cite

Nasal delivery of lung targeted pharmaceutical aerosols is ideal for drugs that need to be administered during high flow nasal cannula (HFNC) gas delivery, but based on previous studies losses and variability through both the delivery system and nasal cavity are expected to be high. The objective of this study was to assess the variability in aerosol delivery through the nose to the lungs with a nasal cannula interface for conventional and excipient enhanced growth (EEG) delivery techniques. A database of nasal cavity computed tomography (CT) scans was collected and analyzed, from which four models were selected to represent a wide range of adult anatomies, quantified based on the nasal surface area-to-volume ratio (SA/V). Computational fluid dynamics (CFD) methods were validated with existing in vitro data and used to predict aerosol delivery through a streamlined nasal cannula and the four nasal models at a steady state flow rate of 30 L/min. Aerosols considered were solid particles for EEG delivery (initial 0.9 μm and 1.5 μm aerodynamic diameters) and conventional droplets (5 μm) for a control case. Use of the EEG approach was found to reduce depositional losses in the nasal cavity by an order of magnitude and substantially reduce variability. Specifically, for aerosol deposition efficiency in the four geometries, the 95% confidence intervals (CI) for 0.9 and 5 μm aerosols were 2.3-3.1 and 15.5-66.3%, respectively. Simulations showed that the use of EEG as opposed to conventional methods improved delivered dose of aerosols through the nasopharynx, expressed as penetration fraction (PF), by approximately a factor of four. Variability of PF, expressed by the coefficient of variation (CV), was reduced by a factor of four with EEG delivery compared with the control case. Penetration fraction correlated well with SA/V for larger aerosols, but smaller aerosols showed some dependence on nasopharyngeal exit hydraulic diameter. In conclusion, results indicated that the EEG technique not only improved lung aerosol delivery, but largely eliminated variability in both nasal depositional loss and lung PF in a newly developed set of nasal airway models.

show abstract

A sampling and dilution system for droplet aerosols from medical nebulisers developed for use with an optical particle counter

Cited by 12 publications

References 11 publications

Production of inhalable submicrometer aerosols from conventional mesh nebulizers for improved respiratory drug delivery

Production of inhalable submicrometer aerosols from conventional mesh nebulizers for improved respiratory drug delivery

Aerosol Drug Delivery During Noninvasive Positive Pressure Ventilation: Effects of Intersubject Variability and Excipient Enhanced Growth

Variability in nose-to-lung aerosol delivery

Contact Info

Product

Resources

About