TY - JOUR
T1 - Investigation into powder tribo–charging of pharmaceuticals. Part II
T2 - Sensitivity to relative humidity
AU - Beretta, M.
AU - Hörmann, T. R.
AU - Hainz, P.
AU - Hsiao, W. K.
AU - Paudel, A.
PY - 2020/12/15
Y1 - 2020/12/15
N2 - Environmental conditions can have a profound impact on the bulk behaviour of pharmaceutical powders, including their tribo–charging tendency. Typically, high relative humidity (RH) has been associated to a reduction in the electrostatic charge of the material. However, the occurrence of charge mitigation seems to be related to the quantity of water molecules at the powder surface, which depends on intrinsic material attributes (i.e., water sorption propensity), and external factors (i.e., RH level). In the present study, pharmaceutical powders (i.e., microcrystalline cellulose, D–mannitol, paracetamol and magnesium stearate) were conditioned at three levels of RH, relevant for pharmaceutical operations, and their bulk behaviour, including charging propensity, was analyzed. Depending on the material type, powders sorbed water from the humid atmosphere to different extents, resulting in different charging behaviours. Overall, the charge density of the materials was found to decrease after a certain RH or monotonically decrease with an increase of RH, except for D–mannitol. For this material, a contrasting trend of increase in charging was observed with an increase in RH. Moreover, the powders showed a distinct tribo–charging sensitivity to RH, with paracetamol being the most affected. These findings suggest that a careful consideration on solid material–moisture interactions is needed when using RH as strategy to minimize electrostatic effects in powder processing.
AB - Environmental conditions can have a profound impact on the bulk behaviour of pharmaceutical powders, including their tribo–charging tendency. Typically, high relative humidity (RH) has been associated to a reduction in the electrostatic charge of the material. However, the occurrence of charge mitigation seems to be related to the quantity of water molecules at the powder surface, which depends on intrinsic material attributes (i.e., water sorption propensity), and external factors (i.e., RH level). In the present study, pharmaceutical powders (i.e., microcrystalline cellulose, D–mannitol, paracetamol and magnesium stearate) were conditioned at three levels of RH, relevant for pharmaceutical operations, and their bulk behaviour, including charging propensity, was analyzed. Depending on the material type, powders sorbed water from the humid atmosphere to different extents, resulting in different charging behaviours. Overall, the charge density of the materials was found to decrease after a certain RH or monotonically decrease with an increase of RH, except for D–mannitol. For this material, a contrasting trend of increase in charging was observed with an increase in RH. Moreover, the powders showed a distinct tribo–charging sensitivity to RH, with paracetamol being the most affected. These findings suggest that a careful consideration on solid material–moisture interactions is needed when using RH as strategy to minimize electrostatic effects in powder processing.
KW - Environmental conditions
KW - Pharmaceutical powders
KW - Powder characterization
KW - Powder tribo–charging
UR - http://www.scopus.com/inward/record.url?scp=85094828134&partnerID=8YFLogxK
U2 - 10.1016/j.ijpharm.2020.120015
DO - 10.1016/j.ijpharm.2020.120015
M3 - Article
C2 - 33148521
AN - SCOPUS:85094828134
SN - 0378-5173
VL - 591
JO - International Journal of Pharmaceutics
JF - International Journal of Pharmaceutics
M1 - 120015
ER -