Modification of electrostatic charge on inhaled carrier lactose particles by addition of fine particles

Triboelectrification affects particle adhesion and agglomeration and hence the formulation, manufacture, and use of dry powder inhaler (DPI) devices. Electrostatic charge measurement of two component mixes of spray-dried or c rystalline lactose fine particles (<10 mu m) 0, 5, 10, 15, 20 and 30% w/w w ith spray-dried or crystalline lactose 63-90 mu m, respectively has been un dertaken using a system incorporating pneumatic transport of the mixed powd ers to a stainless steel cyclone charging device. The magnitude of charge o n the mixes was shown to decrease with increased fine particle content, and there was no significant difference in charge for each concentration betwe en spray-dried and crystalline lactose. Both the variation of charge and po wder adhesion to the cyclone surface increased with increase in fine partic le content. The proportion of fine particles in carrier systems in DPIs may thus have an important role where triboelectrification is involved.