Evaluation of Disposable and Traditional Accessory Devices for Use With a Pressurized Metered-Dose Inhaler

BACKGROUND

The use of accessory devices with pressurized metered-dose inhalers (pMDIs) enhances aerosol delivery and helps overcome any lack of patient coordination when using the pMDI. The use of accessory devices could be influenced by the efficacy, availability, and cost of these devices. The aim of this study was to compare drug delivery with the pMDI alone and with non-antistatic and antistatic accessory devices.

METHODS

The total emitted dose and aerodynamic characterization of salbutamol particles were measured for the pMDI alone and for the pMDI combined with 4 different accessory devices: a homemade spacer, the Dolphin spacer, the DispozABLE paper spacer, and the AeroChamber Plus valved holding chamber. Aerodynamic characterization was analyzed with an Andersen cascade impactor at an inhalation flow of 28.3 L/min, and drug deposition was measured with high-performance liquid chromatography.

RESULTS

The mean ± SD total emitted dose from the pMDI alone, 155.2 ± 20.5 μg, was the greatest of all modalities, and the difference was significant (P < .001). The homemade and Dolphin spacers had the highest mean ± SD deposited amounts of salbutamol remaining on their walls (ie, 124.1 ± 11.1 μg and 131.5 ± 11.8 μg, respectively). The mean ± SD total emitted doses with the AeroChamber Plus valved holding chamber (61.9 ± 8.9 μg) and the DispozABLE paper spacer (76.4 ± 8.6 μg) were significantly higher than the emitted doses with the other devices. The mean ± SD fine-particle doses emitted with the AeroChamber plus valved holding chamber (51.4 ± 4.7 μg) and the DispozABLE paper spacer (39.7 ± 5.6 μg) were significantly higher than those with the other devices. The AeroChamber Plus valved holding chamber had the lowest mass median aerodynamic diameter (MMAD) values, but there were no statistically significant differences in MMAD between any of the combinations of pMDI and accessory device.

CONCLUSIONS

The valved holding chamber and the paper spacer had better aerodynamic characteristics than the other devices tested. We consider the antistatic devices to be the optimum devices for aerosol delivery due to their high efficacy compared to non-antistatic devices.

Impact of Advanced Patient Counseling Using a Training Device and Smartphone Application on Asthma Control

BACKGROUND

Pressurized metered-dose inhalers (pMDIs) are among the most commonly used aerosol delivery devices. Poor lung deposition from a pMDI is often a result of incorrect inhalation technique. The aim of this study was to compare the impact of combining a newly released training device with a smartphone application (advanced counseling) in asthma control to the impact of traditional verbal training.

METHODS

A total of 371 subjects with asthma were divided into 2 groups: advanced counseling (n = 187) and verbal counseling (n = 184). Both groups had 3 visits, each meeting being a month apart. At each visit, lung function (ie, FEV₁, ratio of FEV₁ to forced vital capacity [FEV₁/FVC], and peak expiratory flow) were measured, an asthma control test was given, and subjects were trained in the correct inhalation technique. Inhalation flow through the pMDI was also recorded at each visit because the correct pMDI technique requires an inspiratory flow of < 60 L/min.

RESULTS

In the advanced counseling group, lung function significantly improved after both the first and the second visit (P < .001), whereas in the verbal group, lung function improved significantly only after the second visit (P < .001). Although the inspiratory flow through the pMDI improved significantly in both groups, it was closest to the target range in the advanced counseling group. In addition, more subjects in the advanced counseling group had monthly increases of ≥ 3 points in their asthma control test scores compared to the verbal counseling group.

CONCLUSIONS

The use of a training device with a smartphone application in conjunction with traditional verbal counseling in pMDI technique resulted in significant improvements in asthma control compared to traditional verbal counseling in pMDI technique alone.

Total emitted dose of salbutamol sulphate at different inhalation flows and inhalation volumes through different types of dry powder inhalers

The aim of the present study was to compare the performance of two different dry powder inhalers (DPIs) at different inhalations volumes and inhalation flows. Ventolin Diskus contain blisters of 200µg salbutamol. To test the TED from Aerolizer, salbutamol in Diskus blister was emptied and placed in size 3 capsules suitable for use with Aerolizer. Total emitted dose (TED) delivered by Diskus and Aerolizer was determined using DPI sampling apparatus after one and two inhalations from the same dose. 10-60L/min inhalation flows at 2 and 4L inhalation volume were used in the determination. At inhalation flow ≤30L/min, two inhalations resulted in higher TED than one inhalation (p < 0.05) and Diskus resulted in higher TED than Aerolizer (p < 0.05). The highest TED was at inhalation flow 40L/min above which the effect of the second inhalation and formula device relation were negligible. Device formula relation is present at low inhalation flow but at flow >30L/min Diskus drug formula can be delivered by Aerolizer with no significant difference in TED produced. For the best TED patients are required to inhale as fast as possible (a minimum of 40L/min). At lower inhalation flow two inhalations results in better emitted dose than one inhalation for both DPIs. So, we recommend patients with poor inspiratory efforts to inhale twice and as hard and deep as possible from each dose as they may not receive much benefit from one inhalation even when using DPI with low resistance (Aerolizer) or medium resistance (Diskus). However, further in-vivo study are required to validate this recommendtation.