In vitro performance characterization of the new sidestream plus breath-enhanced jet nebulizer

In vitro Performance Characterization of the New Sidestream® Plus Breath-Enhanced Jet
Nebulizer
J.P. Young, T.J. Hurren, R.K. Harrington, R.H.M. Hatley, T. Dyche Respironics Respiratory Drug Delivery (UK) Ltd, Chichester Business Park, Chichester, West We compared in vitro the performance of a new breath-enhanced Sidestream Plus® (SP)
nebulizer (NEB) in terms of particle size, respirable fraction and dose with that of an available
breath-enhanced NEB (Pari LC Plus; LCP). Two drugs were used: 2mg/mL salbutamol sulphate
(SALB), and 250mg/mL ipratropium bromide (IB). Particle size - mass median aerodynamic
diameters (MMAD) - and respirable fractions (% particles <5m) - were measured with a Marple
cascade impactor. For simulated treatment tests each NEB was connected via an inhalation filter
to a Harvard pump and run until 60s after onset of sputter. Inhalation valve aerosol leakage was
tested using a fume hood with extraction filter. Respirable dose was calculated from respirable
fraction × inhalation filter dose. Tests were run in triplicate/drug and drug analyses performed with
IB with LCP 3.98µm. Respirable fractions: SALB with SP 63%, SALB with LCP 58%, IB with SP 68%, IB with LCP 60%. Respirable dose: SALB with SP 959 µg, SALB with LCP 1121 µg, IB with SP 64 µg, IB with LCP 81 µg. Extraction filter: SALB with SP <1 µg, SALB with LCP 11 µg, IB with SP 0µg, IB with LCP 0 µg. The new SP NEB compared favorably with the LCP, delivering an aerosol with a higher respirable fraction. Introduction
Figure 1. The new Sidestream Plus jet nebulizer Sidestream® Plus is a new breath-enhanced jet nebulizer (Respironics Respiratory Drug Delivery
(UK) Ltd) designed to deliver an aerosol with a high respirable fraction in a short nebulization
time. For the introduction of a new jet nebulizer, it is of clinical value to compare the performance
in terms of particle size, respirable fraction, respirable dose, and nebulization time with an
available jet nebulizer within the same design category. We have therefore compared the
performance of Sidestream Plus in terms of particle size and simulated treatment with that of an
available breath-enhanced jet nebulizer (Pari LC Plus; Pari GmbH, Germany).
Material and Methods

One nebulizer of each brand was tested in triplicate for each of two drugs: 2mg/mL salbutamol
sulphate, and 250g/mL ipratropium bromide. The particle sizes - mass median aerodynamic
diameters (MMAD) – and the respirable fractions (percent particles <5 m) were measured with a
Marple cascade impactor with nebulizer fills of 2.5mL salbutamol sulfate, and 4mL ipratropium
bromide. For simulated treatment tests each nebulizer was filled with 3mL albuterol, and 2mL
ipratropium bromide, connected via an inhalation filter to a Harvard pump set to generate the
CEN simulated breathing pattern (Vt = 500 mL, f = 15 breaths / min, I:E ratio = 1:1) and run until
60s after onset of sputter. Exhaled drug was caught on exhalation filters. Inhalation valve aerosol
leakage was tested using a fume hood with extraction filter. The respirable dose was calculated
from the respirable fraction × the inhalation filter dose. The tests were run in triplicate per drug
and drug analyses were performed with HPLC.
Results

Table 1. Mean results of the performance characterization

There was a difference of 10-15% between the nebulizers for most of the performance
parameters, apart from exhaled drug, which was approximately 45% less for Sidestream Plus
compared with LC Plus.
Aerosol leakage caught by the extraction hood filter
Figure 2. Amount of drug caught on the extraction hood filter for the Sidestream Plus and LC Plus
nebulizers.
No aerosol leakage was detected when nebulizing ipratropium bromide, the largest amount of
aerosol leakage was detected when nebulizing salbutamol sulphate through the LC Plus
nebulizer.

Discussion

These tests conducted with one device of each brand suggest that the performance of the new
Sidestream Plus jet nebulizer will compare favorably with the performance of the LC Plus jet
nebulizer. The results showed an aerosol mass median aerodynamic diameter from the
Sidestream Plus approximately 10% smaller than the LC Plus, and a respirable fraction
approximately 10% greater than the LC Plus. The amount of aerosol wasted to the atmosphere
was approximately 45% less from the Sidestream Plus compared to the LC Plus, this could be of
importance for those in the vicinity of patients nebulizing drug formulations with unwanted side
effect profiles. The time to sputter was also approximately 15% shorter for the Sidestream Plus,
which could be advantageous for patients taking multiple daily nebulizer treatments. The
inhalation valve of the Sidestream Plus seemed to operate more efficiently than the inhalation
valve on the LC Plus in these tests. These results need to be confirmed in a larger sample of
nebulizers.

Conclusions
It is of clinical importance to compare the characteristics of a new breath-enhanced nebulizer with those of existing nebulizers. The new Sidestream Plus nebulizer compared favorably with the LC Plus, it had a higher respirable fraction, lower exhaled dose, and shorter time to sputter.

Source: http://www.aerosol-soc.org.uk/files2/DDL17-2006/63.Young.pdf