The Easyhaler® provides accurate and consistent dosing across varying patient inhalation flow rates

Technical review:

Easyhaler^® provides accurate and consistent dosing across varying patient inhalation flow rates.

In addition to medication and dosage, the technical characteristics of a dry powder inhaler (DPI) are of importance when choosing the most suitable treatment for a patient.^1,2 Importantly, the internal resistance of an inhaler plays a crucial role in dose delivery.

In the case of the Easyhaler (Figure 1) during an inhalation air enters the inhaler around the actuator and encounters high resistance due to the small size of the air vent. This high resistance generates turbulent air flow to the dosing cup. The turbulent air flow empties the dosing cup, and subsequently ensures the de-aggregation of drug particles and accurate dose delivery. This occurs even with low patient inhalation flows.

Figure 1. High-resistance DPI in action. High internal resistance and the generation of turbulent air flow inside a high-resistance dry powder inhaler (Easyhaler). *Easyhaler monotherapy is a high-resistance inhaler³ and Easyhaler combination therapy is a medium-to-high resistance inhaler⁴.

Figure 2. Easyhaler inhalers enable optimal turbulent air flow across all patient groups.^1,5 Mean (SD) maximum pressure change, as a measure of turbulent air flow, generated through dry powder inhalers.¹ *Data provided for the Easyhaler monotherapy.

DPIs with high internal resistance generally provide greater formulation de-aggregation and lung deposition than devices with low internal resistance.¹ Inhalation against high resistance further opens the upper airways, which assists the delivery of medication into the lungs.⁶ Furthermore, highly turbulent air flow is associated with more efficient de-aggregation of the drug formulation and the likelihood of greater lung deposition.²

Clinical experience and recent studies further support the suitability of high-resistance DPIs, even for patients with low inhalation flow. Patients with COPD, and asthmatic children with exacerbations, were able to use high-resistance DPIs effectively.⁶ Among COPD patients, the vast majority (98%) were able to achieve a sufficient inhalation flow through the high-resistance DPI (Easyhaler) for optimal drug delivery.³ High internal resistance is therefore an important technical feature of a DPI.⁷

Figure 3. With Easyhaler optimal drug delivery can be achieved even with low patient inhalation flow. Inspiratory resistance⁸, and optimal peak inspiratory flow (PIF) for adequate drug delivery⁹ of marketed dry powder inhalers.

Learn more about the effect of internal resistance on inhalation flow and pulmonary dose delivery:

High-resistance dry powder inhaler in action. Watch the animation.

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