Background: Chiesi’s NEXThaler® is a dry powder inhaler equipped with a breath actuated mechanism (BAM) which controls dose release in response to pressure drop. In this investigation the BAM was modified to vary the release of formulation and subsequently the airflow velocity into which the dose was dispersed. Methods: A 4.7% w/w API:lactose carrier formulation was delivered from 4 modified NEXThaler devices, in vitro dispersion performance was assessed using a fast screening impactor (FSI), asthmatic profiles were generated using a breath simulator; a bespoke LiveShot rig was used to understand evacuation kinetics. Results: Releasing the dose later in the inhalation profile, into higher velocity airflow, results in improved dispersion performance. Conclusion: The velocity of the air has an effect on entrainment and API dispersion performance; this can be controlled using a BAM system, such as that exemplified in the NEXThaler device.