 Dry powder inhalers, or DPIs, are among the most widely used inhalers currently available for treating patients with asthma and COPD. To be effective, DPIs must reliably deliver a predictable drug dose and generate drug particles of a specified size. They must also be simple and easy for patients to use. A recent study assessed the robustness of Easyhaler by assessing the delivered dose and fine particle dose over the inhaler's lifespan and under stress conditions, mimicking everyday use by patients. Currently available in several European countries, Easyhaler combines two drugs for the treatment of asthma and COPD, salmeterol, a long-acting beta-agonist, and fluticosone propionate, an inhaled corticosteroid. The Easyhaler's unique internal design uses patient inhalation to de-agglomerate and dispense the two drug formulations at specified doses. In a non-comparative in vitro study, researchers evaluated the performance of the Easyhaler using two batches of inhalers at two different dose levels. They found that both the delivered dose and the fine particle dose remained constant throughout the inhaler's lifespan or through 60 delivered doses. The fine particle dose of the delivered drugs also demonstrated as aerodynamic particle size distribution via impactor stage-by-stage analysis was not affected by dropping onto a hard wooden surface. The size distribution also remained unaffected by vibrational stress. Similarly, the fine particle and delivered dose achieved by the Easyhaler was not affected by moisture, as measured by storing at 75% relative humidity for 48 hours. The fine particle and delivered dose remained constant after submitting Easyhaler to three cycles of freeze-thawing during a two-week time period. Unfortunately, these stress tests can account for all scenarios encountered by patients in everyday life, including more realistic testing methods such as those that mimic lung deposition more accurately could offer valuable insight. Still, the findings are promising. They suggest that the Easyhaler is able to deliver consistent and reliable dosing even under simulated stress and or suboptimal handling. For patients with asthma and COPD, the Easyhaler represents a safe and effective treatment option.