Numerical investigation of powder dispersion mechanisms in Turbuhaler and the contact electrification effect

Zhu, Qixuan; Gou, Dazhao; Li, Lunjian; Chan, Hak‐Kim; Yang, Runyu

doi:10.1016/j.apt.2022.103839

Cited by 9 publications

(1 citation statement)

References 41 publications

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“…The importance of particle–particle contact charging was also highlighted by Chowdhury et al [ 33 ]. Zhu et al [ 35 ] studied the contact electrification effect of selected API agglomerates in the Turbuhaler ® , finding a reduction in inhaler efficiency due to the triboelectrification of powders. Specific numerical studies on the motion of particles in the capsule of capsule-based DPIs are available in the literature [ 36 , 37 , 38 , 39 ], but the effects of charges generated upon contact on the release of powder from the capsule itself are not taken into account.…”

Section: Introductionmentioning

confidence: 99%

Discrete Element Method Evaluation of Triboelectric Charging Due to Powder Handling in the Capsule of a DPI

2023

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The generation and accumulation of an electrostatic charge from handling pharmaceutical powders is a well-known phenomenon, given the insulating nature of most APIs (Active Pharmaceutical Ingredients) and excipients. In capsule-based DPIs (Dry Powder Inhalers), the formulation is stored in a gelatine capsule placed in the inhaler just before inhalation. The action of capsule filling, as well as tumbling or vibration effects during the capsule life cycle, implies a consistent amount of particle–particle and particle–wall contacts. A significant contact-induced electrostatic charging can then take place, potentially affecting the inhaler’s efficiency. DEM (Discrete Element Method) simulations were performed on a carrier-based DPI formulation (salbutamol–lactose) to evaluate such effects. After performing a comparison with the experimental data on a carrier-only system under similar conditions, a detailed analysis was conducted on two carrier–API configurations with different API loadings per carrier particle. The charge acquired by the two solid phases was tracked in both the initial particle settling and the capsule shaking process. Alternating positive–negative charging was observed. Particle charging was then investigated in relation to the collision statistics, tracking the particle–particle and particle–wall events for the carrier and API. Finally, an analysis of the relative importance of electrostatic, cohesive/adhesive, and inertial forces allowed the importance of each term in determining the trajectory of the powder particles to be estimated.

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