(W0930-09-60) Mitigation of Tribocharging in Pharmaceutical Powders Using Surface Modified V-Blenders

Purpose: The pharmaceutical industry involves handling of powders on a large scale for manufacturing of solid dosage forms such as tablets and capsules constituting about 85% of the dosage forms. During this manufacturing process, powders get electrostatically charged due to numerous particle-particle and particle-equipment wall collisions. In this study, a surface-modified blender has been designed to mitigate tribocharging in pharmaceutical powders. The blender has been fabricated using two types of materials, an insulator, and a conductor. The conductor or the metal arm induces a charge of opposite polarity to that of the charge induced by the insulator arm and the overall charge on the powder decreases during the tumbling motion of the blender. In addition to that, a DEM numerical model has been developed using Altair EDEM to provide a mechanistic understanding of tribocharging in pharmaceutical powders using different types of V blenders.

Methods: Ibuprofen was used as the model drug and processed in aluminum, polyvinyl chloride (PVC), stainless steel, surface modified aluminum-PVC (Al-PVC) and surface modified stainless steel- PVC (SS-PVC) blender at 20% RH for different times such as 2, 10, 20, 30 and 40 mins till charge saturation is achieved. The blending was performed at 13 rpm as it was previously established (Mukherjee et. al., 2019) by our group as an optimum speed for uniform mixing [1]. The V blender was designed using SolidWorks and the DEM model was developed using commercial software Altair EDEM.

Results: 50g of ibuprofen was loaded into the V blender which was then rotated at 13 rpm for different time intervals such as 2, 10, 20, 30 and 40 mins at 13 rpm. The charge saturation was observed at 30 minutes and no significant variation in charge was noted after that and therefore considered as the charge saturation point. In addition to that, it was observed that using blender made of metal, negative polarity charge (Fig 1) was observed whereas positive polarity charge was observed using insulator blender (Fig 2). The lowest charge magnitude was observed using surface modified blender and the polarity of charge was negative (Fig 3). Similar observations were made from DEM simulations.

Conclusion: We have demonstrated that tribocharging could be significantly decreased by using surface modified blenders in comparison to insulator or metal only blenders. Moreover, it was established that careful selection of equipment materials could significantly reduce the electrostatic charging of powders.

References: 1) Mukherjee R, Sen K, Fontana L, Mao C, Chaudhuri B. Quantification of Moisture-Induced Cohesion in Pharmaceutical Mixtures. J Pharm Sci. 2019;