TY - JOUR
T1 - Evaluation of the Physico-mechanical Properties and Electrostatic Charging Behavior of Different Capsule Types for Inhalation Under Distinct Environmental Conditions
AU - Pinto, Joana T.
AU - Wutscher, Thomas
AU - Stankovic-Brandl, Milica
AU - Zellnitz, Sarah
AU - Biserni, Stefano
AU - Mercandelli, Alberto
AU - Kobler, Mirjam
AU - Buttini, Francesca
AU - Andrade, Laura
AU - Daza, Veronica
AU - Ecenarro, Susana
AU - Canalejas, Laura
AU - Paudel, Amrit
PY - 2020/5/1
Y1 - 2020/5/1
N2 - Capsule-based dry powder inhaler (DPI) products can be influenced by a multitude of interacting factors, including electrostatic charging. Tribo-charging is a process of charge transfer impacted by various factors, i.e., material surface characteristics, mechanical properties, processing parameters and environmental conditions. Consequently, this work aimed to assess how the charging behavior of capsules intended for inhalation might be influenced by environmental conditions. Capsules having different chemical compositions (gelatin and hydroxypropyl methylcellulose (HPMC)) and distinct inherent characteristics from manufacturing (thermally and cold-gelled) were exposed to various environmental conditions (11%, 22% and 51% RH). Their resulting properties were characterized and tribo-charging behavior was measured against stainless steel and PVC. It was observed that all capsule materials tended to charge to a higher extent when in contact with PVC. The tribo-charging of the thermally gelled HPMC capsules (Vcaps® Plus) was more similar to the gelatin capsules (Quali-G™-I) than to their HPMC cold-gelled counterparts (Quali-V®-I). The sorption of water by the capsules at different relative humidities notably impacted their properties and tribo-charging behavior. Different interactions between the tested materials and water molecules were identified and are proposed to be the driver of distinct charging behaviors. Finally, we showed that depending on the capsule types, distinct environmental conditions are necessary to mitigate charging and assure optimal behavior of the capsules.
AB - Capsule-based dry powder inhaler (DPI) products can be influenced by a multitude of interacting factors, including electrostatic charging. Tribo-charging is a process of charge transfer impacted by various factors, i.e., material surface characteristics, mechanical properties, processing parameters and environmental conditions. Consequently, this work aimed to assess how the charging behavior of capsules intended for inhalation might be influenced by environmental conditions. Capsules having different chemical compositions (gelatin and hydroxypropyl methylcellulose (HPMC)) and distinct inherent characteristics from manufacturing (thermally and cold-gelled) were exposed to various environmental conditions (11%, 22% and 51% RH). Their resulting properties were characterized and tribo-charging behavior was measured against stainless steel and PVC. It was observed that all capsule materials tended to charge to a higher extent when in contact with PVC. The tribo-charging of the thermally gelled HPMC capsules (Vcaps® Plus) was more similar to the gelatin capsules (Quali-G™-I) than to their HPMC cold-gelled counterparts (Quali-V®-I). The sorption of water by the capsules at different relative humidities notably impacted their properties and tribo-charging behavior. Different interactions between the tested materials and water molecules were identified and are proposed to be the driver of distinct charging behaviors. Finally, we showed that depending on the capsule types, distinct environmental conditions are necessary to mitigate charging and assure optimal behavior of the capsules.
KW - dry powder inhaler (DPI)
KW - gelatin
KW - hydroxypropyl methylcellulose (HPMC)
KW - tribo-charging
KW - water
UR - http://www.scopus.com/inward/record.url?scp=85084585063&partnerID=8YFLogxK
U2 - 10.1208/s12249-020-01676-2
DO - 10.1208/s12249-020-01676-2
M3 - Article
C2 - 32399597
AN - SCOPUS:85084585063
SN - 1530-9932
VL - 21
JO - AAPS PharmSciTech
JF - AAPS PharmSciTech
IS - 4
M1 - 128
ER -